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\centerline{\darkframe{3}{10}{13.8cm}{\centerline{\LARGE\bf \hfill 
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THE \hfill 
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\centerline{\small formely known as {\em the hot star newsletter}
} 
\centerline{$\star $}
\\  \lightframe{0.5}{2}{1cm}
   {No. 81}   2004 January-February 
% \hfill {\small  http://www.astro.ugto.mx/$\sim$eenens/hot/} 
\\   editor: Philippe Eenens  
\\ \mbox{} \hfill {\small http://www.astroscu.unam.mx/massive\_stars} 
% \hfill {\small http://www.star.ucl.ac.uk/$\sim$hsn/index.html}
\\   eenens@astro.ulg.ac.be 
\hfill {\small ftp://ftp.sron.nl/pub/karelh/{\sc uploads/wrbib/}}
 }}

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\centerline{\lightframe{0.7}{5}{6cm}{
\centerline{\Large Contents of this newsletter}}} 
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\begin{quote}
\begin{quote}

% \smallskip Working group matters \dotfill 1 \\
% \smallskip Discussion forum \dotfill 888 \\
% \smallskip Commentary \dotfill 888 \\
\smallskip Abstracts of 26 accepted papers \dotfill 1 \\
\smallskip Abstracts of 2 submitted papers \dotfill 18 \\
\smallskip Abstracts of 1 proceedings paper \dotfill 19 \\
\smallskip Abstract of 2 dissertation theses \dotfill 20 \\
% \smallskip News   \dotfill 888 \\
\smallskip Jobs   \dotfill 22 \\
\smallskip Meetings  \dotfill 23 \\

 
\end{quote}
\end{quote}

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% \centerline{\Large  Working Group Matters}}} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  \vspace*{4mm}

% \begin{quote}
% ...
% \end{quote}

% \vspace*{9mm}


\centerline{\lightframe{0.7}{5}{4cm}{
\centerline{\Large Accepted Papers}}} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 \vspace*{4mm}

 % >>> <sven.VANLOO@oma.be> jan 22 

\begin{center}{\Large\bf   Non-thermal radio emission from single hot stars
}\end{center}
\centerline{\bf   S. Van Loo, M.C. Runacres and R. Blomme
}{\footnotesize
     Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel, Belgium
}\vspace*{4mm}  \\ %  
We present a theoretical model for the non-thermal radio emission from single
hot stars, in terms of synchrotron radiation from electrons accelerated in
wind-embedded shocks.  The model is described by five independent parameters
each with a straightforward physical interpretation. Applying the model to a
high-quality observation of Cyg~OB2~No.~9 (O5 If), we obtain meaningful
constraints on most parameters. The most important result is that the outer
boundary of the synchrotron emission region must lie  between 500 and 2200
stellar radii. This means that shocks must persist up to that distance.
We also find that relatively weak shocks (with a compression ratio
$< 3$) are needed to produce the observed radio spectrum. These results are
compatible with current hydrodynamical predictions. Most of our models
also show a relativistic electron fraction that increases outwards. This
points to an increasing efficiency of the acceleration mechanism, perhaps
due to multiple acceleration, or an increase in the strength of the shocks.
Implications of our results for non-thermal X-ray emission are discussed.
 
{\bf   Accepted by Astronomy \& Astrophysics } \\
{\it Preprints from} {\tt  sven.vanloo@oma.be  } \\
{\it or on the web at} {\tt http://arxiv.org/abs/astro-ph/0401389}




 \vspace*{6mm}

 % >>> <th@astro.ex.ac.uk>  %  Tim Harries


\begin{center}{\Large\bf  Three-dimensional dust radiative-transfer
models: \\The Pinwheel Nebula
  of WR104
}\end{center}
\centerline{\bf Tim J. Harries$^1$, John D. Monnier$^2$, Neil H.
Symington$^1$, and
  Ryuichi Kurosawa$^1$
}{\footnotesize   
     $^1$   School of Physics, University of Exeter, Stocker Road,
Exeter EX4
4QL, England.
 \\  $^2$   University of Michigan, 941 Dennison Building, 500 Church
Street, Ann
Arbor, MI 48109-1090, U.S.A.  
}\vspace*{4mm}  \\ %  
 We present radiative-transfer modelling of the dusty spiral Pinwheel
  Nebula observed around the Wolf-Rayet/OB-star binary WR104. The
  models are based on the three-dimensional radiative-transfer code
  {\sc torus}, modified to include an adaptive mesh
  that allows us to adequately resolve both the inner spiral turns
  (sub-AU scales) and the outer regions of the nebula (distances of
  10$^4$ AU from the central source).  The spiral model provides a
  good fit to both the spectral energy distribution and Keck
  aperture masking interferometry, reproducing both the maximum
  entropy recovered images and the visibility curves. We deduce a dust
  creation rate of $8\pm 1 \times 10^{-7}$ M$_\odot$\,yr$^{-1}$,
  corresponding to approximately 2\% by mass of the carbon produced by
  the Wolf-Rayet star. Simultaneous modelling of the imaging and
  spectral data enables us to constrain both the opening-angle of the
  wind-wind collision interface and the dust grain size.  We conclude
  that the dust grains in the inner part of the Pinwheel nebula are
  small ($\sim100$\AA), in agreement with theoretical
  predictions, although we cannot rule out the presence of larger
  grains ($\sim 1\mu$m) further from the central binary. The
  opening angle of the wind-wind collision interface appears to be
  about $40^\circ$, in broad agreement with the wind parameters
  estimated for the central binary. We discuss the success and
  deficiencies of the model, and the likely benefits of applying
  similar techniques to the more complex nebulae observed
  around other WR/O star binaries.


{\bf   Accepted by  MNRAS} \\
{\it Preprints from} {\tt    th@astro.ex.ac.uk   } 



 \vspace*{6mm}

\def\deg{\hbox{$^\circ$}}
\def\arcsec{$^{\prime\prime}$}
\def\la{\mathrel{\hbox{\rlap{\hbox{\lower4pt\hbox{$\sim$}}}\hbox{$<$}}}}

 % >>> <ccappa@fcaglp.fcaglp.unlp.edu.ar>


\begin{center}{\Large\bf   
A Very Large Array 3.6\,cm continuum survey of Galactic Wolf-Rayet 
stars
}\end{center}
\centerline{\bf   C. Cappa$^1$, W.M. Goss$^2$ and K.A. van der Hucht$^3$
}{\footnotesize  
   $^1$ Instituto Argentino de Radioastronom\'{\i}a, CC 5, 1894 Villa Elisa,
       Argentina, and Facultad de Ciencias Astron\'omicas y Geof\'{\i}sicas,
       Universidad Nacional de La Plata, Paseo del Bosque s/n, 1900 La 
       Plata, Argentina
\\ $^2$ National Radio Astronomy Observatory, P.O. Box 0, Socorro, 
       NM\,87801, USA
\\ $^3$ SRON National Institute for Space Research, Sorbonnelaan 2, 
       Utrecht, NL-3584 CA, the Netherlands
}\vspace*{4mm}  \\
We report the results of a survey of radio continuum emission of Galactic
Wolf-Rayet stars north of $\delta$\,=\,$-$46\deg.  The observations were
obtained at 8.46\,GHz (3.6\,cm) using the Very Large Array (VLA), with an
angular resolution of $\sim$\,6\arcsec $\times$ 9\arcsec\ and typical rms noise
of $\sim$\,0.04\,mJy beam$^{-1}$.  Our survey of 34 WR stars resulted in 15
definite and  5  probable detections, 13 of these for the first time
at radio wavelengths. 
All detections are unresolved ($\theta$\,$\la$\,5\arcsec).
Time variations in flux are confirmed in the cases of WR\,98a, WR\,104, 
WR\,105, and WR\,125. WR\,79a and WR\,89 are also variable in flux and 
we suspect they are also non-thermal emitters. Thus, of our sample 
20\,-\,30\,\% of the detected stars are non-thermal emiters. Average mass 
loss rates determinations obtained excluding definite and suspected 
non-thermal cases give similar values for WN (all subtypes) and WC5-7 stars 
($\dot{M}$(WN)\,=\,[4\,$\pm$\,3]$\times$10$^{-5}$\,M$_\odot$\,yr$^{-1}$ and 
$\dot{M}$(WC5-7)\,=\,[4\,$\pm$\,2]$\times$10$^{-5}$\,M$_\odot$\,yr$^{-1}$), 
while a lower value was obtained for WC8-9 stars
($\dot{M}$(WC8-9)\,=\,[2\,$\pm$\,1]$\times$10$^{-5}$\,M$_\odot$\,yr$^{-1}$).
Uncertainties in stellar distances largely contribute to the observed
scatter in mass loss rates. 
Upper limits to the mass loss rates were obtained in cases of undetected
sources or for sources which probably show additional non-thermal emission. 

{\bf   Accepted by the Astronomical Journal} \\
{\it Preprints from} {\tt ccappa@fcaglp.fcaglp.unlp.edu.ar} \\
{\it or on the web at} {\tt astro-ph/0401571} 

 \vspace*{6mm}

 % >>> 

% etasax2 for The Hot Star Newsletter
% Cari saluti Roberto
%
%                 latex template at the end of this file
%


\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE
BeppoSAX broad X-ray range observations of $\eta$ Car during
high and low spectroscopic states
}\end{center}
\centerline{\bf
R. F. Viotti$^1$, L. A. Antonelli$^2$, C. Rossi$^3$, S. Rebecchi$^4$}
{\footnotesize
   $^1$ Istituto di Astrofisica Spaziale e Fisica Cosmica,
CNR, Area di Ricerca Tor Vergata,
Via Fosso del Cavaliere 100, 00133 Roma, Italy
\\ $^2$
INAF-Osservatorio Astronomico di Roma,
Via Frascati 33, 00040 Monte Porzio Catone (Roma), Italy
\\$^3$
Dipartimento di Fisica, Universit\`a La Sapienza,
Piazzale Aldo Moro 3, 00185 Roma, Italy
\\$^4$
ASI Science Data Center (ASDC), c/o ESA-ESRIN, Via Galileo Galilei,
00044 Frascati (Roma), Italy
}\vspace*{4mm}  \\
We report on the June 2000 long (100 ks)
BeppoSAX exposure that has unveiled above 10 keV
a new very high energy component of the X-ray spectrum
of $\eta$ Car extending to at least 50 keV.
We find that the 2-150 keV spectrum is best reproduced
by a thermal $+$ non-thermal model.
The thermal component dominates the 2-10 keV spectral
range with kT$_h$=5.5$\pm$0.3 keV and log\,NH$_h$=22.68$\pm$0.01.
The spectrum displays a prominent iron emission line centred
at 6.70 keV. Its equivalent width of 0.94 keV,
if produced by the thermal source, gives a slightly
sub-solar iron abundance ([Fe/H]=$-$0.15$\pm$0.02).
The high energy tail above 10 keV is best fitted by a power law
with a photon index of 2.42$\pm$0.04.
The integrated 13-150 keV luminosity of $\sim$12 $L_{\odot}$ is
comparable to that of the 2-10 keV thermal component (19 $L_{\odot}$).
The present result can be explained,
in the $\eta$ Car binary star scenario,
by Comptonisation of low frequency radiation by high energy
electrons, probably generated in the colliding wind shock front,
or in instabilities in the wind of the S Dor primary star.
It is possible that the high energy tail had
largely weakened near the minimum of the 5.53 yr cycle.
With respect to the thermal component,
it probably has a longer recovering time like
that of the highest excitation optical emission lines.
Both features can be associated with the large absorption
measured by BeppoSAX at phase 0.05. \\
{\bf   Accepted by  A\&A} \\
{\it Preprints from} {\tt uvspace@rm.iasf.cnr.it} \\
{\it or by anonymous ftp to} 
  {\tt ftp.rm.iasf.cnr.it/uvspace/etasax2.ps.gz } \\
{\it or on the web at} 
  {\tt ftp://ftp.ias.rm.cnr.it/uvspace/BEPPOSAX/etasax2.ps.gz} 


 \vspace*{6mm}

 % >>> <nathans@ozma.colorado.edu>

\begin{center}{\Large\bf
Nitrogen and Oxygen Abundance Variations in the Outer Ejecta of Eta
Carinae: Evidence for Recent Chemical Enrichment
}\end{center}
\centerline{\bf Nathan Smith$^1$ and Jon A.\ Morse$^{1,2}$
}{\footnotesize
 $^1$ Center for Astrophysics and Space Astronomy, University of
 Colorado, 389 UCB, Boulder, CO 80309 \\ $^2$ Department of Physics \&
 Astronomy, Arizona State University, Box 871504, Tempe, AZ 85287-1504
}\vspace*{4mm}  \\
% 
We present optical spectra of the ionized `Outer Ejecta' of $\eta$
Carinae that reveal differences in chemical composition at various
positions.  In particular, young condensations just outside the dusty
Homunculus Nebula show strong nitrogen lines and little or no oxygen
--- but farther away, nitrogen lines weaken and oxygen lines become
stronger.  The observed variations in the apparent N/O ratio may
signify either that the various blobs were ejected with different
abundances, or more likely, that the more distant condensations are
interacting with normal-composition material.  The second hypothesis
is supported by various other clues involving kinematics and X-ray
emission, and would suggest that $\eta$ Car is enveloped in a
``cocoon'' deposited by previous stellar-wind mass loss.  In
particular, all emission features where we detect strong oxygen lines
are coincident with or outside the soft X-ray shell.  In either case,
the observed abundance variations suggest that $\eta$ Car's ejection
of nitrogen-rich material is a {\it recent} phenomenon --- taking
place in just the last few thousand years.  Thus, $\eta$ Carinae may
be at a critical stage of evolution when ashes of the CNO cycle have
just appeared at its surface.  Finally, these spectra reveal some
extremely fast nitrogen-rich material, with Doppler velocities up to
3200 km s$^{-1}$, and actual space velocities that may be much higher.
This is the fastest material yet seen in $\eta$ Car's nebula, but with
unknown projection angles its age is uncertain.

{\bf   Accepted by  ApJ, to appear April 20 2004} \\
{\it Preprints from} {\tt   nathans@casa.colorado.edu} \\
{\it or on the web at} {\tt http://arxiv.org/abs/astro-ph/0402476 } 

 \vspace*{6mm}


\def\farcs{\hbox{$.\!\!^{\prime\prime}$}}

 % >>> 



\begin{center}{\Large\bf
Kinematics and UV-to-IR Morphology of the Inner Homunculus of Eta Carinae
}\end{center}
\centerline{\bf
Nathan Smith$^1$, Jon A.\ Morse$^{1,2}$, Theodore R.\ Gull$^3$,
 D.\ John Hillier$^4$, 
}\centerline{\bf
Robert D. Gehrz$^5$, Nolan R.\
 Walborn$^6$, Manuel Bautista$^7$, 
Nicholas R.\ Collins$^3$,
}\centerline{\bf
 Michael F.\ Corcoran$^8$, 
Augusto Damineli$^9$, Fred
 Hamann$^{10}$, 
Henrik Hartman$^{11}$, 
}\centerline{\bf
Sveneric Johansson$^{11}$,
 Otmar Stahl$^{12}$, and Kerstin Weis$^{5,13}$
}{\footnotesize

$^1$ Center for Astrophysics and Space Astronomy, University of
Colorado, 389 UCB, Boulder, CO 80309 \\ $^2$ Department of Physics and
Astronomy, Arizona State University, Box 871504, Tempe, AZ 85287-1504
\\ $^3$ Laboratory of Astronomy and Space Science, NASA/Goddard Space
Flight Center, Code 681, Greenbelt, MD 20771 \\ $^4$ Department of
Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street,
Pittsburgh, PA 15260 \\ $^5$ Astronomy Department, University of
Minnesota, 116 Church St. SE, Minneapolis, MN 55455 \\ $^6$ Space
Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD
21218 \\ $^7$ Centro de F\'{\i}sica, Instituto Venezolano de
Investigaciones Cient\'{\i}ficas, PO Box 21827, Caracas 1020A,
Venezuela \\ $^8$ Laboratory for High Energy Astrophysics,
NASA/Goddard Space Flight Center, Greenbelt, MD 20771 \\ $^9$
Instituto de Astronomia, Geofisica e Ciencias Atmosfericas R. do Matao
1226, Sao Paulo, Brazil \\ $^{10}$ Department of Astronomy, University
of Florida, Gainesville, FL 32611 \\ $^{11}$ Atomic Astrophysics, Lund
Observatory, Lund University, P.O. Box 43, SE-22100 Lund, Sweden \\
$^{12}$ Landessternwarte K\"{o}nigstuhl, D-69117 Heidelberg, Germany
\\ $^{13}$ Institute of Astronomy, Ruhr-University Bochum,
Universit\"{a}tsstrasse 150 44780 Bochum, Germany
}\vspace*{4mm}  \\
% 
We present the first ultraviolet and optical images of $\eta$ Carinae
and its circumstellar Homunculus Nebula obtained with the Advanced
Camera for Surveys/High Resolution Camera (ACS/HRC) onboard the {\it
Hubble Space Telescope} ({\it HST}).  Compared to visual wavelengths,
UV images reveal excess emission 0$\farcs$1 to 0$\farcs$6 from the
central source along the minor axis that may emanate from the outer
parts of $\eta$ Car's non-spherical stellar wind, which dominates the
UV flux from $\eta$ Car.  The UV emission fills the cavity inside a
dust torus measured from infrared data; within 0$\farcs$2 of the star
it projects a morphology reminiscent of the IR torus, but it is a
factor of 10 smaller. This `little torus' seen in the UV may be
related to the `Little Homunculus' discovered recently, signifying
recurrent mass ejections with the same geometry.  Finally, we
re-examine the kinematics of nebular condensations near the star
(Weigelt objects C and D) in {\it HST} images and spectra obtained
over the past decade.  We measure heliocentric velocities slower than
previous estimates, and from proper motions we derive an ejection date
of 1908 $\pm$12 yr, assuming linear motion.  However, because of
radiative acceleration, they may have been ejected earlier --- perhaps
during the 1890 outburst of $\eta$ Carinae.

{\bf   Accepted by ApJ, to appear April 2004} \\
{\it Preprints from} {\tt  nathans@casa.colorado.edu} 


 \vspace*{6mm}

 % >>> 


\begin{center}{\Large\bf
Spatially extended K~I~$\lambda$7699 emission in the nebula of VY~CMa:
Kinematics and geometry
}\end{center}
\centerline{\bf   Nathan Smith$^1$
}{\footnotesize
$^1$ Center for Astrophysics and Space Astronomy, University of
Colorado, 389 UCB, Boulder, CO 80309
}\vspace*{4mm}  \\
% 
Long-slit echelle spectra reveal bright extended emission from the K~I
$\lambda$7699 resonance line in the reflection nebula surrounding the
extreme red supergiant VY Canis Majoris.  The central star has long
been known for its unusually-bright K~I emission lines, but this is
the first report of intrinsic emission from K~I in the nebula.  The
extended emission is not just a reflected spectrum of the star, but is
due to resonant scattering by K atoms in the outer nebula itself, and
is therefore a valuable probe of the kinematics and geometry of
VY~CMa's circumstellar environment.  Dramatic velocity structure is
seen in the long-slit spectra, and most lines of sight through the
nebula intersect multiple distinct velocity components.  A faint
``halo'' at large distances from the star does appear to show a
reflected spectrum, however, and suggests a systemic velocity of +40
km/s with respect to the Sun.  The most striking feature is
blueshifted emission from the filled interior of a large shell seen in
images; the kinematic structure is reminiscent of a Hubble flow, and
provides strong evidence for asymmetric and episodic mass loss due to
localized eruptions on the star's surface.

{\bf Accepted by MNRAS Letters} \\
{\it Preprints from} {\tt nathans@casa.colorado.edu} \\
{\it or on the web at} {\tt http://arxiv.org/abs/astro-ph/0401012} 


 \vspace*{6mm}

 % >>> <sana@astro.ulg.ac.be>


\begin{center}{\Large\bf A  Phase-Resolved XMM-Newton Campaign \\ on the 
Colliding Wind Binary HD 152248
} \end{center}
\centerline{\bf H. Sana$^1$, I.R. Stevens$^2$, E. Gosset$^1$, G. Rauw$^1$ and 
J.-M. Vreux$^1$
}{\footnotesize   
        $^1$ Institut d'Astrophysique et de G\'eophysique,
	Universit\'e de Li\`ege,
	All\'ee du 6 Ao\^ut 17, Bat. B5c,
	B-4000 Li\`ege,
	Belgium \\
$^{2}$School of Physics \& Astronomy,
 University of Birmingham,
 Edgbaston, Birmingham B15 2TT,
 United Kingdom
}\vspace*{4mm}  \\ %  
We report the first results of an XMM-Newton monitoring campaign of the 
NGC 6231 open cluster in the Sco OB1 association. This first paper focuses 
on the massive colliding wind binary HD 152248, which is the brightest 
X-ray source of the cluster. The campaign, with a total duration of 180\,ksec, 
was split into six separate observations, following the orbital motion of 
HD 152248. The X-ray flux from this system presents a clear, asymmetric modulation 
with the phase and ranges from $0.73$ to $1.18\,10^{-12}$ erg\ s$^{-1}$\ 
cm$^{-2}$ in the [0.5-10.0\,keV] energy band. The maximum of the emission 
is reached slightly after apastron. The EPIC spectra are quite soft and peak 
around 0.8-0.9\,keV. We characterize their shape using several combinations 
of {\sc mekal}\ models and power-law spectra and we detect significant spectral 
variability in the [0.5-2.5\,keV] energy band. 

We also perform 2-D hydrodynamical simulations using different sets of parameters 
that closely reproduce the physical and orbital configuration of the HD 152248 
system at the time of the six XMM-Newton pointings. This allows a direct 
confrontation of the model predictions with the constraints deduced from the 
X-ray observations of the system. We show that the observed variation of the 
flux can be explained by a variation of the X-ray emission from the colliding 
wind zone, diluted by the softer X-ray contribution of the two O-type stars of 
the system. Our simulations also reveal that the interaction region of HD 152248 
should be highly unstable, giving rise to shells of dense gas that are separated 
by low density regions. 

Finally, we perform a search for short-term variability in the light curves of 
the system and we show that trends are present within several of the 30\,ksec 
exposures of our campaign. Further, most of these trends are in good agreement 
with the orbital motion and provide a direct constraint on the first order 
derivative of the flux. In the same context, we also search for long-range 
correlations in the X-ray data of the system, but we only marginally detect 
them in the high energy tail of the signal.

{\bf   Accepted by  MNRAS    } \\
{\it Preprints from} {\tt  sana@astro.ulg.ac.be } \\
{\it or on the web at} {\tt http://vela.astro.ulg.ac.be/Preprints/P87/index.html }  



 \vspace*{6mm}

 % >>> 


\begin{center}{\Large\bf   %WRITE THE TITLE BELOW THIS LINE 
The Physical Properties and Effective Temperature Scale
of O-type Stars as a Function of Metallicity. I. A Sample of 20
Stars in the Magellanic Clouds
}\end{center}
\centerline{\bf        Philip Massey$^1$, Fabio Bresolin$^2$, 
}\centerline{\bf
Rolf P. Kudritzki$^2$, Joachim Puls$^3$ and
A. W. A. Pauldrach$^3$
}{\footnotesize $^1$   Lowell Observatory, 1400 W. Mars Hill Rd., Flagstaff, AZ 86001
           \\   $^2$   Instiute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822
           \\   $^3$   Universit\"{a}ts-Sternwarte M\"{u}nchen,
Scheinerstrasse 1, 81679, Munich, Germany
}\vspace*{4mm}\\      
We have obtained {\it HST} and ground-based observations of a sample of
20 O-type stars in the LMC and SMC, including six of the hottest
massive stars known (subtypes O2-3) in the R136 cluster.  In general,
these data include (a) the {\it HST} UV spectra in order to measure the
terminal velocities of the stellar winds, (b) high signal-to-noise,
blue-optical data where the primary temperature- and gravity-sensitive
photospheric lines are found, and (c) nebular-free H$\alpha$ profiles,
which provide the mass-loss rates.  We find that the older (FOS) {\it
HST} data of the R136 stars (which were obtained without the benefits
of sky measurements) suffered from significant nebular emission, which
would increase the derived mass-loss rates by factors of $\sim 3$, all
other factors being equal.  We also find several stars in the SMC
for which the N~III
$\lambda\lambda 4634,42$ and He~II$\lambda 4686$ emission ``f"
characteristics do not appear to follow the same pattern as in Galactic
stars. Since He~II emission is due to the stellar wind (which will be
weaker in SMC for stars of the same luminosity), while N~III emission
is a complex NLTE effect affected mostly by temperature, it would not
be surprising to find that these features do not correlate with each
other or with luminosity in SMC stars in the same was as they do
in Galactic stars,
but theory does not provide a clean answer, and analysis of more stars
(both SMC and Galactic) are needed to resolve this issue.  The
line-blanketed non-LTE atmosphere code FASTWIND was then used to
determine the physical parameters of this sample of stars. We find good
agreement between the synthetic line profiles for the hydrogen, He~I,
and He~II lines in the majority of the stars we analyzed; the three
exceptions show evidence of being incipiently resolved spectroscopic
binaries or otherwise spectral composites.  One such system is
apparently an O3~V+O3~V eclipsing binary, and a follow-up radial
velocity study is planned to obtain Keplerian masses.  Although we did
not use them to constrain the fits, good agreement is also found for
the He~I $\lambda 3187$ and He~II $\lambda 3203$ lines in the near-UV,
which we plan to exploit in future studies.  Our effective temperatures
are compared to those recently obtained by Repolust, Puls \& Herrero
for a sample of Galactic stars using the same techniques.  We find that
the Magellanic Cloud sample is 3,000-4,000$^\circ$K hotter than their
Galactic counterparts for the early through mid-O's.  These higher
temperatures are the consequence of a decreased importance of wind
emission, wind blanketing, and metal-line blanketing at lower
metallicities.


{\bf       Accepted by  the Astrophysical Journal } \\ 
Preprints available from ftp://ftp.lowell.edu/pub/massey/haw.ps.gz

 \vspace*{6mm}

 % >>> 

\begin{center}{\Large\bf  {\it XMM-Newton} observations of the giant HII 
region N\,11 in the LMC 
}\end{center}
\centerline{\bf Y. Naz\'e$^1$, I.I. Antokhin$^{1,2}$, G. Rauw$^1$, Y.-H. Chu$^3$, 
E. Gosset$^1$,  and J.-M. Vreux$^1$ 
}{\footnotesize   
        $^1$ Institut d'Astrophysique et de G\'eophysique;
	Universit\'e de Li\`ege;
	All\'ee du 6 Ao\^ut 17, Bat. B5c;
	B 4000 - Li\`ege;
	Belgium 
 \\  $^2$   Astronomy and Astrophysics Group;
	Department of Physics and Astronomy;
	Kelvin Building, University of Glasgow;
	Glasgow G12 8QQ;
	United Kingdom
 \\  $^3$   Astronomy Department;
University of Illinois at Urbana-Champaign;
	1002 West Green Street;
	 Urbana, IL 61801;
	USA
}\vspace*{4mm}  \\ %  
Using the sensitive {\it XMM-Newton} observatory, we have observed 
the giant HII region N\,11 in the LMC for $\sim$30~ks. We have 
detected several large areas of soft diffuse X-ray emission along with 37 
point sources. One of the most interesting results is the possible
association of a faint 
X-ray source with BSDL 188, a small extended object of uncertain nature. 

The OB associations in the field-of-view (LH9, LH10 and LH13) are all detected
with {\it XMM-Newton}, but they appear very different from one another. 
The diffuse soft X-ray emission associated with LH9 peaks near 
HD 32228, a dense cluster of massive stars. The combined emission of 
all individual massive stars of LH9 and of the superbubble they have 
created is not sufficient to explain the high level of emission observed: 
hidden SNRs, colliding-wind binaries and the numerous pre-main sequence 
stars of the cluster are most likely the cause of this discrepancy. 
The superbubble may also be leaking some hot gas in the ISM since faint, 
soft emission can be observed to the south of the cluster. 
The X-ray emission from LH10 consists of three pointlike sources and a 
soft extended emission of low intensity. The two brightest point
sources are clearly associated with the fastest expanding bubbles 
blown by hot stars in the SW part of the cluster. The total X-ray emission 
from LH10 is rather soft, although it presents a higher temperature than the 
other soft emissions of the field. The discrepancy between
the combined emission of the stars and the observed luminosity 
is here less severe than for LH9 and could be explained in terms of hot 
gas filling the wind-blown bubbles. 
On the other hand, the case of LH13 is different: it does not harbour any 
extended emission and its X-ray emission could most probably be explained by 
the Sk $-66^{\circ}$41 cluster alone. 

Finally, our {\it XMM-Newton} observation included simultaneous observations with 
the OM camera that provide us with unique UV photometry of more than 6000 
sources and enable the discovery of the UV emission from the SNR N11L.  

{\bf   Accepted by  A\&A    } \\
{\it Preprints from} {\tt  naze@astro.ulg.ac.be } \\
{\it or on the web at} {\tt 
  http://vela.astro.ulg.ac.be/Preprints/P88/index.html or astro-ph/0402623}  

 \vspace*{6mm}

 % >>> 

\begin{center}{\Large\bf  An X-ray investigation of the NGC\,346 
field in the SMC (3): {\it XMM-Newton} data 
}\end{center}
\centerline{\bf Ya\"el Naz\'e$^1$, Jean Manfroid$^{1}$, Ian R. Stevens$^2$, 
Michael F. Corcoran$^3$, and Aaron Flores$^4$
}{\footnotesize   
        $^1$ Institut d'Astrophysique et de G\'eophysique;
	Universit\'e de Li\`ege;
	All\'ee du 6 Ao\^ut 17, Bat. B5c;
	B 4000 - Li\`ege;
	Belgium 
 \\  $^2$   School of Physics \& Astronomy;
        University of Birmingham;
        Edgbaston, Birmingham B15 2TT;
	United Kingdom
 \\  $^3$  Universities Space Research Association;
        7501 Forbes Blvd, Ste 206;
        Seabrook, MD 20706;
        and Laboratory for High Energy Astrophysics;
        Goddard Space Flight Center;
        Greenbelt, MD 20771;
        USA
 \\  $^4$  Universidad Autonoma del Carmen;
        Facultad de Ingenieria;
        Calle 56 No 4;
        Cd del Carmen, Campeche;
        Mexico
}\vspace*{4mm}  \\ %  
We present new {\it XMM-Newton} results on the field around the NGC\,346 star cluster
in the SMC. This continues and extends previously published work on {\it
Chandra} observations of the same field. The two {\it XMM-Newton} observations were
obtained, respectively, six months before and six months after the
previously published  {\it Chandra} data.
Of the 51 X-ray sources detected with {\it XMM-Newton}, 29 were already detected with
{\it Chandra}. Comparing the properties of these X-ray sources in each
of our three datasets has enabled us to investigate their variability on
times scales of a year. Changes in the flux levels and/or spectral
properties were observed for 21 of these sources. In addition, we
discovered long-term variations in the X-ray properties of the peculiar
system HD\,5980, a luminous blue variable star, that is likely to be a
colliding wind binary system, which displayed the largest luminosity
during the first {\it XMM-Newton} observation.

{\bf   Accepted by  ApJ   } \\
{\it Preprints from} {\tt  naze@astro.ulg.ac.be } \\
{\it or on the web at} 
  {\tt http://vela.astro.ulg.ac.be/Preprints/P89/index.html or astro-ph/0402629}  


 \vspace*{6mm}

 % >>> <debecker@astro.ulg.ac.be> % Michaël

\begin{center}{\Large\bf Quasi-simultaneous {\it XMM-Newton} and VLA
observation of the non-thermal radio emitter HD\,168112 (O5.5III(f$^+$))

}\end{center}
\centerline{\bf   M. De Becker$^1$, G. Rauw$^1$, R. Blomme$^2$, W.L.
Waldron$^3$, H. Sana$^1$, J.M. Pittard$^4$,
}
\centerline{\bf   P. Eenens$^{1,5}$, I.R. Stevens$^6$, M.C.
Runacres$^2$, S. Van Loo$^2$ and A.M.T. Pollock$^7$
}
{\footnotesize
     $^1$   Institut d'Astrophysique, Universit\'e de Li\`ege, All\'ee
du 6
Ao\^ut, B\^at B5c, B-4000 Li\`ege (Sart Tilman), Belgium\\
     $^2$   Royal Observatory of Belgium, Avenue Circulaire 3, 1180
Brussels, Belgium\\
     $^3$   L-3 Communications Government Services, Inc., 1801 McCormick
Drive, Suite 170, Largo, MD 20774, USA\\
     $^4$   Department of Physics \& Astronomy, University of Leeds,
Leeds LS2 9JT, UK\\
     $^5$   Departamento de Astronomia, Universidad de Guanajuato,
Apartado 144, 36000 Guanajuato, GTO, Mexico\\
     $^6$   School of Physics \& Astronomy, University of Birmingham,
Edgbaston
Birmingham B15 2TT, UK\\
     $^7$   ESA/Vilspa, Apartado 50727, 28080 Madrid, Spain
 }\vspace*{4mm} \\
We report the results of a multiwavelength study of the non-thermal
radio emitter HD\,168112 (O5.5III(f$^+$)). The detailed analysis of two
quasi-simultaneous {\it XMM-Newton} and VLA observations reveals strong
variability of this star both in the X-ray and radio ranges. The X-ray
observations separated by five months reveal a {\em decrease} of the
X-ray flux of $\sim$\,30\,\%. The radio emission on the other hand {\em
increases} by a factor 5--7 between the two observations obtained
roughly simultaneously with the {\it XMM-Newton} pointings. The X-ray
data reveal a hard emission that is most likely produced by a thermal
plasma at kT\,$\sim$\,2--3 keV while the VLA data confirm the
non-thermal status of this star in the radio waveband. Comparison with
archive X-ray and radio data confirms the variability of this source in
both wavelength ranges over a yet ill defined time scale. The properties
of HD\,168112 in the X-ray and radio domain point towards a binary
system with a significant eccentricity and an orbital period of a few
years. However, our optical spectra reveal no significant changes of the
star's radial velocity suggesting that if HD\,168112 is indeed a binary,
it must be seen under a fairly low inclination.\\

{\bf   Accepted by A\&A} \\
{\it Preprints from} {\tt    debecker@astro.ulg.ac.be   } \\
{\it or by anonymous ftp to} {\tt
http://vela.astro.ulg.ac.be/Preprints/P90/index.html}




 \vspace*{6mm}

 % >>> <fabrice.martins@obs.unige.ch>

\begin{center}{\Large\bf   
  Puzzling wind properties of young massive stars in SMC-N81
}\end{center}
\centerline{\bf        F. Martins$^1,^2$, D. Schaerer$^2,^1$,
  D.J. Hillier$^3$, M. Heydari-Malayeri$^4$ 
}{\footnotesize $^1$   LA2T-OMP, 14 Avenue Edouard Belin, F-31400
Toulouse, France 
           \\   $^2$   Observatoire de Gen\`eve, 51 Chemin des
           Maillettes, CH-1290, Sayverny
           \\   $^3$   Department of Physics and Astronomy, University
           of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260,
           USA
           \\   $^4$   LERMA, Observatoire de Paris, 61 Avenue de
           l'Observatoire, F-75014 Paris, France
}\vspace*{4mm}\\      
We present a quantitative study of massive stars in the High
Excitation Blob N81, a compact star forming region in the SMC.
The stellar content
was resolved by HST and STIS was used to obtain medium
resolution spectra.
The qualitative analysis of the stellar properties presented in
Heydari-Malayeri et al.\ (2002) is 
extended using 
non-LTE spherically extended atmosphere models including
line-blanketing computed with the code CMFGEN (Hillier \& Miller
1998), and the wind properties are investigated. The main results
are the following: 

1) The SMC-N81 components are young ($\sim$ 0--4
Myrs) O stars with effective temperatures compatible with
medium to late 
subtypes and with luminosities lower than average 
Galactic O dwarfs, rendering them possible ZAMS candidates. 

2) The winds are extremely weak: with values of the order
 10$^{-8}$/10$^{-9}$ M$_{\odot}$ yr$^{-1}$, the mass loss rates are 
lower than observed so 
 far for Galactic dwarfs. Only the recent study of SMC stars by Bouret
 et al.\ (2003) show the same trend. The modified wind momenta
 ($\dot{M}$ v$_{\infty}$ $\sqrt{R}$) are also 1 to 2 orders of
 magnitude lower than observed for Galactic stars. Both the mass loss
 rates and the modified wind momenta are lower than the predictions of 
 the most recent hydrodynamical models.

The accuracy of the UV based mass loss rate determination, relying  
in particular on the predicted ionisation fractions, are carefully
examined. We find that $\dot{M}$ could be underestimated by a factor
of up to 10. Even in this unlikely case, the above conclusions
remain valid  \textit{qualitatively}. 

The reasons for such weak winds are
investigated with special emphasis on the modified wind momenta:

1) There may be a break-down of the wind momentum - luminosity
relation (WLR) for dwarf stars at low luminosity (log L/L$_{\odot}$
< 5.5). However, reasons for such a
breakdown remain unknown. 

2) The slope of the WLR may be steeper at low metallicity. This is
predicted by the radiation driven wind theory, but the current
hydrodynamical simulations do not show any change of the slope at SMC
metallicity. Moreover, there are indications that some Galactic objects
have wind momenta similar to those of the SMC stars.

3) Decoupling may take place in the atmosphere of the SMC-N81
stars, leading to multicomponent winds. However, various tests
indicate that this is not likely to be the case.


  The origin of the weakness of the wind observed in the SMC-N81
  stars remains unknown. 
  We suggest that this weakness may be linked with the youth of 
  these stars and represents possibly the onset of stellar winds in 
  recently formed massive stars.

{\bf Accepted by A\&A  } \\
{\it For preprints, contact} {\tt fabrice.martins@obs.unige.ch }\\ 
Astro-ph: http://fr.arxiv.org/abs/astro-ph/0403415 \\
Preprints also available from 
http://obswww.unige.ch/$\sim$martins/publications.html


 \vspace*{6mm}

 % >>>   csterken@vub.ac.be 

\begin{center}{\Large\bf  Light variations of massive stars ($\alpha$~Cyg
variables): 
The late-type supergiants R\,59, HDE\,268822, HDE\,269355, HDE\,269612 and
HDE\,270025 in the LMC
}\end{center}
\centerline{\bf   A.M. van Genderen$^1$,  C. Sterken$^2$ and A.F. Jones$^3$ 
}{\footnotesize
     $^1$   Leiden Observatory, Postbus 9513, NL-2300RA Leiden, The
Netherlands  
 \\  $^2$   Vrije Universiteit   Brussel, Pleinlaan 2, B-1050 Brussels,
Belgium
\\ $^3$    31 Ranui Road, Stoke, Nelson, New Zealand
}\vspace*{4mm}  \\ We present and discuss $VBLUW$ photometry (Walraven system)
of five supergiants in the LMC. 
For one well-known variable, the hypergiant R\,59 = HDE\,268757 (G7\,Ia$^{+}$)
also Hipparcos photometry 
and numerous visual observations are available. The second variable is
HDE\,269612 (F0\,Ia), and a third 
one is  HDE\,268822 (F6\,Ia). Two F6\,Ia supergiants turned out to be
constant: HDE\,269355 and HDE\,270025.


{\bf   Accepted by  A\&A   } \\
{\it Preprints from} {\tt   csterken@vub.ac.be  }  


 \vspace*{6mm}


 % >>>  <w.varricatt@jach.hawaii.edu>

\begin{center}{\Large\bf 
Near IR Spectroscopic monitoring of WR 140 during the 2001 periastron passage
}\end{center}
\centerline{\bf Watson P. Varricatt$^1$, P. M. Williams$^2$ \& N. M. Ashok$^3$
}{\footnotesize $^1$  Joint Astronomy Centre, 660 N. Aohoku Place, Hilo,  Hawaii 96720, USA
           \\   $^2$  Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ, UK
	   \\   $^3$  Physical Research Laboratory, Navrangpura, Ahmedabad, India 380009
}\vspace*{4mm}\\       
We present new spectra of WR 140 (HD 193793) in the $JHK$ bands with some
covering the 1.083-$\mu$m He\,{\sc i} emission line at higher resolution,
observed between 2000 October and 2003 May to cover its 2001 periastron
passage and maximum colliding-wind activity.  The WC7 + O4-5 spectroscopic
binary WR 140 is the prototype of colliding-wind, episodic dust-making
Wolf-Rayet systems which also show strong variations in radio and X-ray emission.
The $JHK$ spectra showed changes in continuum and in the equivalent widths of
the WC emission lines, consistent with formation of dust starting between
2001 January 3 and March 26 (orbital phases 0.989 and 0.017) and its
subsequent fading and cooling.  The 1.083-$\mu$m He\,{\sc i} line has a
P-Cygni profile which showed variations in both absorption and emission
components as WR 140 went through periastron passage. The variation of the
absorption component of the profile yielded tight constraints on the geometry
of the wind-collision region, giving $\theta = 50^{\circ}\pm8^{\circ}$
for the opening semi-angle of the interaction region `cone', indicating
a wind-momentum ratio
$(\dot{M} v_{\infty})_{\rm O} / (\dot{M} v_{\infty})_{\rm WR} = 0.10$,
about three times larger than previously believed.
As the system approached periastron, the normally flat-topped emission
component of 1.083-$\mu$m line profile showed the appearance of a
significant sub-peak. The movement of the sub-peak across the profile was
seen to be consistent with its formation in wind material flowing along
the contact discontinuity between the WC7 and O4-5 stellar winds and the
changing orientation of the colliding wind region as the stars moved in
their orbits. The flux carried in the sub-peak was significant, exceeding
the X-ray fluxes measured at previous periastron passages. This additional
source of radiative cooling of the shock-heated gas probably causes it to depart
from being adiabatic around periastron passage, thereby accounting for the
departure of the X-ray flux from its previously expected $1/d$-dependency.


{\bf  Accepted by  MNRAS} \\
{\it For preprints, contact} {\tt w.varricatt@jach.hawaii.edu } \\
{\it or on the web at} {\tt http://arxiv.org/abs/astro-ph/0403639 } 
% (If applicable)




 \vspace*{6mm}

 % >>> 


\begin{center}{\Large\bf  
An exceptional population of late-type WC stars
in the metal-rich spiral galaxy M~83}\end{center}
\centerline{\bf   
Paul A. Crowther$^{1}$,
          L. J. Hadfield$^{1}$, 
          H. Schild$^{2}$, W. Schmutz$^{3}$}
{\footnotesize   
     $^1$   Department of Physics and
Astronomy, University of Sheffield, Hicks Building, Hounsfield Rd,
Shefffield, S3 7RH
 \\  $^2$                Institut f\"ur Astronomie, ETH-Zentrum, CH 8092 Z\"urich, 
                Switzerland
  \\ $^3$   Physikalisch-Meteorologisches Observatorium, CH-7260 Davos,
           Switzerland
}\vspace*{4mm}  \\ %  
We have surveyed the metal-rich spiral galaxy M~83 (NGC~5236) for
its Wolf-Rayet population using VLT-FORS2 narrow-band imaging and follow-up 
spectroscopy. From a total of 280 candidates identified using He\,{\sc ii}
$\lambda$4686 imaging, Multi Object Spectroscopy of 
198 sources was carried out, revealing 132 objects containing 
bona-fide Wolf-Rayet features. From this sample, an exceptional W-R content
of $\sim$1030 is inferred, with  N(WC)/N(WN)$\sim$1.3, continuing the 
trend to larger values at higher metallicity amongst Local Group galaxies. 
More dramatic is the dominance of late-type  WC stars
in M~83 with N(WC8--9)/N(WC4--7)=9 which we attribute to
the sensitivity of the 
classification line  C\,{\sc iii} $\lambda$5696 to mass-loss, providing 
the strength of WC winds scale with metallicity. 
One young massive compact cluster, \#74 in our catalogue, hosts 20\% of 
the entire galactic  population, namely $\sim$180 late WC stars  and 
$\sim$50  late WN stars. 


{\bf   Accepted by  Astronomy \& Astrophysics (Letters) } \\
{\it Preprints from} {\tt  Paul.Crowther@sheffield.ac.uk   } \\
{\it or on the web at} {\tt http://xxx.lanl.gov/abs/astro-ph/0403636 }  



 \vspace*{6mm}

 % >>> <IGNACE@mail.etsu.edu>


\begin{center}{\Large\bf   Free-Free Spectral Energy Distributions of Hierarchically 
Clumped HII Regions
}\end{center}
\centerline{\bf     Richard Ignace$^1$ and Edward B.~Churchwell$^2$
}{\footnotesize   
     $^1$   East Tennessee State University
 \\  $^2$   University of Wisconsin
}\vspace*{4mm}  \\ %  
In an effort to understand unusual power-law spectral slopes observed in some
hypercompact HII regions, we consider the radio continuum energy distribution
from an ensemble of spherical clumps.  An analytic expression for the free-free
emission from a single spherical clump is derived.  The radio continuum slope
(with $F_\nu \propto \nu^\alpha$) is governed by the population of clump optical
depths $N(\tau)$, such that (a) at frequencies where all clumps are thick,
a continuum slope of $+2$ is found, (b) at frequencies where all clumps are
optically thin, a flattened slope of $-0.11$ is found, and (c) at intermediate
frequencies, a power-law segment of significant bandwidth with slopes between
these two limiting values can result.  For the ensemble distribution, we
adopt a power-law distribution $N(\tau) \propto \tau^{-\gamma}$, and find that
significant power-law segments in the SED with slopes from $+2$ to $-0.11$ result
only for a relatively restricted range of $\gamma$ values of 1 to 2.  Further,
a greater range of clump optical depths for this distribution leads to a wider
bandwidth over which the intermediate power-law segment exists.  The model is
applied to the source W49N-B2 with an observed slope of $\alpha\approx +0.9$,
but that may be turning over to become optically thin around 2 mm. An adequate
fit is found in which most clumps are optically thin and there is little
``shadowing'' of rearward clumps by foreground clumps (i.e., the geometrical
covering factor $C \ll 1$).  The primary insight gained from our study is that
in the Rayleigh-Jeans limit for the Planck function that applies for the radio
band, it is the distribution in optical depth of the clump population that is
solely responsible for setting the continuum shape, with variations in the size
and temperature of clumps serving to modulate the level of free-free emission.

{\bf   Accepted by  ApJ  } \\
{\it Preprints from} {\tt    ignace@etsu.edu  } \\
{\it or on the web at} {\tt www.etsu.edu/physics/ignace/pubs.html }  



 \vspace*{6mm}

\def\lesssim{\mathrel{\hbox{\rlap{\hbox{\lower4pt\hbox{$\sim$}}}\hbox{$<$}}}}


 % >>> nelan@stsci.edu 


\begin{center}{\Large\bf  Resolving OB Systems in the Carina Nebula with 
Hubble Space Telescope's Fine Guidance Sensor}
\end{center}
\centerline{\bf  E.P. Nelan$^1$, N.R. Walborn$^1$, D.J. Wallace$^2$, A.F.J. Moffat$^3$}
  \centerline{\bf   R.B. Makidon$^1$, D.R. Gies$^4$, N. Panagia$^1$}
{\footnotesize $^1$   Space Telescope Science Institute, Baltimore, Md. 
           \\  $^2$  Goddard Space Flight Center, Greenbelt, Md.
           \\  $^3$ Universite de Montreal, Montreal, Quebec, Ca.
           \\  $^4$  Georgia State University, Atlanta, Ga.}
\\
\\
We observed 23 OB stars in the Carina Nebula (NGC~3372) with the {\it Hubble 
Space Telescope's } Fine Guidance Sensor 1r (FGS1r) in its high angular resolution 
mode. Five of these OB stars are newly resolved binaries with projected separations 
ranging from 0\farcs015 to 0\farcs352 (37 to 880~AU at a distance of 2.5~kpc), and 
V-band magnitude differences ranging from 0.9 to 2.8. The most important astrophysical 
result is the unexpected resolution of the prototype O2~If* star HD~93129A as a 
55~milliarcsec double with a $\Delta m_{V}$ of 0.9. This object has served as a 
spectroscopic benchmark for the analysis of the most massive hot stars and their 
winds on the prior assumption that it is a single star. This discovery  supports 
the interpretation of recent radio and X-ray observations as evidence of colliding 
wind phenomena in HD~93129A. Another interesting result is the determination of an 
upper limit of about 35~AU for the projected separation of the binary pairs in the 
hierarchical double spectroscopic binary HD~93206. The high incidence of resolved 
binaries provides motivation for a more thorough, statistically meaningful study of 
multiplicity among the most massive stars in the young ionizing clusters of the nebula 
to obtain a complete sample of the long-period systems that have evaded spectroscopic 
detection. However, considering that the 9 spectroscopic binaries with accurate orbits 
in the Carina Nebula have orbital dimensions $\lesssim$1~AU, which at a distance 
of 2.5~kpc subtends an angle of only 0.4~mas, well below the $\simeq10$ mas angular 
resolution of FGS1r, there remains a significant range of orbital periods \& 
separations over which it is very difficult to detect multiplicity in the nebula 
with currently available instruments.

{\bf Accepted by The Astronomical Journal} \\
Preprints available on the web at: {\tt www.stsci.edu/$\sim$nelan} 
(file: carina-nebula-paper.ps ; 502K) 
 
\newpage


% \vspace*{6mm}



 % >>> <morel@oapa23.astropa.unipa.it>

\begin{center}{\Large\bf  Large-scale wind structures in OB supergiants: 
a search for rotationally modulated H$\alpha$ variability
}\end{center}
\centerline{\bf T. Morel,$^{1,2}$ S. V. Marchenko,$^{3}$ A. K. Pati,$^{4}$ 
K. Kuppuswamy,$^{5}$ 
}\centerline{\bf
M. T. Carini,$^{3}$ E. Wood,$^{3}$ and R. Zimmerman$^{3}$  
}{\footnotesize   
     $^1$ Istituto Nazionale di Astrofisica, Osservatorio Astronomico di 
Palermo G. S. Vaina, Piazza del Parlamento 1, I-90134 Palermo, Italy 
 \\  $^2$ Inter-University Centre for Astronomy and Astrophysics (IUCAA), 
Post Bag 4, Ganeshkhind, Pune, 411 007, India
 \\  $^3$ Department of Physics and Astronomy, Western Kentucky University, 
1 Big Red Way, Bowling Green, KY 42101--3576, USA
 \\  $^4$ Indian Institute of Astrophysics (IIAP), III block, Koramangala, 
Bangalore, India
 \\  $^5$ Vainu Bappu Observatory, Indian Institute of Astrophysics (IIAP), 
Kavalur, Alangayam 635 701 India
}\vspace*{4mm}  \\  
We present the results of a long-term monitoring campaign of the H$\alpha$ line 
in a sample of bright
OB-supergiants (O7.5--B9) that aims at detecting rotationally modulated changes 
potentially related to
the existence of large-scale wind structures. A total of 22 objects were monitored 
during 36 nights spread
over 6 months in 2001--2002. Coordinated broad-band photometric observations were 
also obtained for
some targets. Conspicuous evidence for variability in H$\alpha$ is found for the 
stars displaying a feature contaminated by wind emission.  Most changes take place 
on a daily time-scale, although hourly variations are also occasionally detected. 
Convincing evidence for a cyclical pattern of variability in H$\alpha$ has been 
found in 2 stars: HD 14134 and HD 42087 (periodic signals are also detected in other 
stars, but independent confirmation
is required). Rotational modulation is suggested from the similarity between the 
observed recurrence time-scales (in the range
13--25 days) and estimated periods of stellar rotation. We call attention to the 
atypical case of HD 14134 which exhibits a clear 12.8-d periodicity both in
the photometric and in the spectroscopic data sets. This places this object among a
handful of early-type stars where one may observe a clear link
between extended wind structures and photospheric disturbances. Further
modelling may test the hypothesis that azimuthally-extended wind streams are 
responsible for the patterns
of spectral variability in our target stars.

{\bf Accepted by MNRAS} \\
{\it Preprints from} {\tt  morel@astropa.unipa.it} \\
{\it or on the web at} {\tt http://www.astropa.unipa.it/Library/preprint.html} 
\\ or {\tt http://www.astropa.unipa.it/$\sim$morel/research.html} 


 \vspace*{6mm}

 % >>> 


\begin{center}{\Large\bf Wolf-Rayet Stars in M\,33. I: 
Optical Spectroscopy using CFHT-MOS}\end{center}
\centerline{\bf   
Jay B. Abbott$^{1}$, Paul A. Crowther$^{1,2}$,
Laurent Drissen$^{3}$, 
}\centerline{\bf   
Luc
Dessart$^{4}$, Pierre Martin$^{5}$ and Guillaume Boivin$^{3}$ }
{\footnotesize   
$^{1}$Department of Physics and
Astronomy, University College London, Gower Street, London, WC1E 6BT; \\
$^{2}$Department of Physics and Astronomy, University of Sheffield,
Hicks Building, Hounsfield Road, Sheffield S3 7RH;\\ 
$^{3}$D\'epartement de Physique, Universit\'e Laval, Qu\'ebec, G1K
7P4, Canada;\\
$^{4}$Max-Planck-Institut f\"{u}r Astrophysik, Karl-Schwarzschild-Str
1, 85748 Garching, Germany;\\
$^{5}$Canada France Hawaii Telescope, 65-1238 Mamalahoa Hwy, HI 96743, USA.}
\vspace*{4mm}  \\ %  
We have obtained spectroscopy of a large sample of Wolf-Rayet stars in
M\,33 with CFHT-{\small MOS}, including 26 WC stars, 15 WN stars plus a 
WN/C star. In general, spectral types are merely refined, although the
spectral type of X9 from Massey \& Johnson is revised from WNL?+abs to
WC4+abs, whilst their G1 and C21 candidates are not confirmed as
Wolf-Rayet stars.  We also re-examine the metallicity gradient of M\,33 from 
H\,{\sc ii} regions and identify the present sample, lying in the inner disk, 
with  8.6$\leq \log$(O/H)$\leq$8.9. Spectral types are in accord with
similar regions in the Milky Way.
Our large sample has allowed us to examine the claimed anti-correlation 
between WC line widths and galactocentric distance by Schild et al.  
We find a  much larger scatter, though there remains an absence of broad-line 
WC  stars in the  inner disk  and narrow-line WC stars in the outer galaxy.

{\bf   Accepted by                       MNRAS     } \\
{\it Preprints from} {\tt   Paul.Crowther@sheffield.ac.uk}\\
{\it or on the web at} 
{\tt http://www.shef.ac.uk/physics/people/pacrowther/m33.pdf}



 \vspace*{6mm}

 % >>> <mokiem@science.uva.nl> %  Rohied Mokiem


\begin{center}
  {\Large\bf Metallicity and the spectral energy distribution and
    spectral types of dwarf O-stars}
\end{center}
\centerline{\bf M.\,R. Mokiem$^1$, N.\,L. Mart\'{\i}n-Hern\'{a}ndez$^2$,
}\centerline{\bf       A. Lenorzer$^1$, A. de Koter$^1$ and A.\,G.\,G.\,M.
Tielens$^{2,3}$}
{\footnotesize
     $^1$ Astronomical Institute Anton Pannekoek, University of  Amsterdam
\\
     $^2$ Kapteyn Institute \\
     $^3$ SRON, National Institute for Space Reasearch
}\vspace*{4mm}  \\ %  
We present a systematic study of the effect of metallicity on the
stellar spectral energy distribution (SED) of O main sequence (dwarf)
stars, focussing on the hydrogen and helium ionizing continua, and on
the optical and near-IR lines used for spectral classification.  The
spectra are based on non-LTE line blanketed atmosphere models with
stellar winds calculated using the {\sc cmfgen} code of Hillier \&
Miller (1998). We draw the following conclusions. First, we find that
the total number of Lyman photons emitted is almost independent of
line blanketing effects and metallicity for a given effective
temperature. This is because the flux that is blocked by the forest of
metal lines at $\lambda < 600$ \AA\ is redistributed mainly within the
Lyman continuum. Second, the spectral type, as defined by the ratio of
the equivalent widths of He\,{\sc i}~$\lambda$4471 and He\,{\sc
ii}~$\lambda$4542, is shown to depend noticeably on the microturbulent
velocity in the atmosphere, on metallicity and, within the luminosity
class of dwarfs, on gravity. Third, we confirm the decrease in
$T_{\mathrm eff}$ for a given spectral type due to the inclusion of
line blanketing recently found by e.g. Martins et al.\ 2002. Finally,
we find that the SED below $\sim 450$ \AA\ is highly dependent on
metallicity. This is reflected in the behaviour of nebular
fine-structure line ratios such as [Ne\,{\sc iii}]/[Ne\,{\sc ii}]
15.5/12.8 and [Ar\,{\sc iii}]/[Ar\,{\sc ii}] 9.0/7.0 $\mu$m. This
dependence complicates the use of these nebular ratios as diagnostic
tools for the effective temperature determination of the ionizing
stars in H\,{\sc ii} regions and for age dating of starburst regions
in galaxies.

{\bf Accepted by A\&A} \\
{\it Preprints from} {\tt http://xxx.lanl.gov/abs/astro-ph/0402496} 

 \vspace*{6mm}

 % >>>  <rkp@star.ucl.ac.uk>

\begin{center}{\Large\bf   Photospheric and stellar wind variability in
$\epsilon$ Ori (B0 Ia) 
}\end{center}
\centerline{\bf   R.K. Prinja$^1$, Th. Rivinius$^2$, O. Stahl$^2$,
A. Kaufer$^3$,
}\centerline{\bf 
B.H. Foing$^4$,J. Cami$^5$, and S. Orlando$^6$  
}{\footnotesize   
     $^1$   Department of Physics {\&} Astronomy, University
College London, Gower Street, London WC1E 6BT, U.K.
 \\  $^2$   Landessternwarte Heidelberg, K\"onigstuhl 12,
  69117 Heidelberg, Germany
 \\  $^3$   European Southern Observatory,
  Alonso de Cordova 3107,
  Casilla 19001,
  Santiago 19, Chile
  \\ $^4$   Research Support Division, ESA RSSD, ESTEC/SCI-SR postbus 299,
2200 AG Noordwijk, The Netherlands
  \\ $^5$   NASA Ames Research Center, Mail Stop 245-6, Moffett Field, CA 
94035-1000,
USA
  \\ $^6$ INAF - Osservatorio Astronomico di Palermo,
Piazza del Parlamento 1, Palermo, Italy
}\vspace*{4mm}  \\ %  
   We provide direct observational evidence for a link between
photospheric activity and perturbations in the dense inner-most
stellar wind regions of the B supergiant star $\epsilon$ Ori. The
results, which are relevant to our understanding of the origin
of wind structure, are based on a multi-spectral line analysis of
optical time-series data secured in 1998 using the HEROS spectrograph
on the ESO Dutch 0.9-m telescope in La Silla. A period of $\sim$ 1.9-days
is
consistently identified in Balmer, He\,{\sc i} absorption, and weak
metal lines such as Si\,{\sc iii} and C\,{\sc ii}. The primary 
characteristic
is a large-amplitude swaying of the central absorption trough of the
line, with differential velocities in lines formed at varying depths
in the atmosphere. The variance resulting from the `S-wave'
velocity behaviour of the lines is constrained within $\pm$ the projected
rotation velocity ($\sim$ 80 km s$^{-1}$)
in the weakest absorption lines, but extends blue-ward to over
$-$200 km s$^{-1}$ in H$\alpha$. A second (superimposed) 1.9-day
signal is present at more extended blue-ward velocities (to $\sim$ $-$300
km s$^{-1}$) in lines containing stronger circumstellar components.
Inspection of archival optical data from 1996 provides evidence that this
modulation signal has persisted for at least 2.5 years.
Non-radial pulsational modelling is carried out in an attempt to
reproduce the key observational characteristics of the line profile
variability. Only limited success is obtained with prograde (m=$-$1)
modes. The principal S-wave pattern cannot be matched by these
models and remains enigmatic.

{\bf   Accepted by A{\&}A   } \\
{\it Preprints from} {\tt   rkp@star.ucl.ac.uk   } 



 \vspace*{6mm}

 % >>>  <j.drew@imperial.ac.uk>



\begin{center}{\Large\bf  Discovery of a WO star in the Scutum-Crux arm of the 
inner Galaxy}\end{center}
\centerline{\bf  
Janet E. Drew$^1$, M. J. Barlow$^2$, Y. C. Unruh$^1$, Q. A. Parker$^{3,4}$,
}\centerline{\bf  
R. Wesson$^2$, M. J. Pierce$^5$, M. R. W. Masheder$^5$ \& S. Phillipps$^5$  
}{\footnotesize   
     $^1$  Imperial College of Science, Technology and Medicine,
Blackett Laboratory, Exhibition Road, London,  SW7 2AZ, U.K. \\
     $^2$  University College London, Department of Physics \& Astronomy,
Gower Street, London WC1E 6BT, U.K. \\
     $^3$  Department of Physics, Macquarie University, NSW 2109, Australia \\
     $^4$   Anglo-Australian Observatory, PO Box 296, Epping NSW 1710, 
Australia \\
     $^5$  Astrophysics Group, Department of Physics, Bristol University,
Tyndall Avenue, Bristol, BS8 1TL, U.K.
}\vspace*{4mm}  \\ %  
We report the discovery of only the fourth massive WO star to be found in the
Milky Way, and only the seventh identified within the Local Group.  This has
resulted from the
first observations made in a programme of follow-up spectroscopy of candidate
emission line stars from the AAO/UK Schmidt Southern Galactic Plane H$\alpha$
Survey.  The optical spectrum of this star, to become WR~93b in the Catalogue
of Galactic Wolf-Rayet stars, is presented and described.  WR~93b is
classified as WO3 and is shown to be highly reddened ($E_{B-V} = 2.1\pm0.1$).
A recombination line analysis of the emission lines yields the
abundance ratios C/He = 0.95 and O/He = 0.13 (by number).
Comparisons at near infrared wavelengths of reddening corrected photometry
between WR~93b and both of Sand~2 (WO3, $D = 49$~kpc) and Sand~5 (WO2, $D =
1.75$~kpc) yields a consistent distance to WR~93b of 3.4~kpc.  Positioned at
Galactic co-ordinates $\ell = 353.27^{\rm o}$, $b = -0.85^{\rm o}$, the star
is most
likely located in the Scutum-Crux Arm of the inner Milky Way. We note
that none of the four Galactic WO stars lies significantly beyond the Solar
Circle (with two well inside).
 
Estimation of the wind terminal velocity in WR~93b at 5750~km~s$^{-1}$ makes
this star the current wind speed record holder among all non-degenerate
stars.


{\bf   Accepted by MNRAS   } \\
{\it Preprints from} {\tt j.drew@imperial.ac.uk} \\
{\it or on the web at} {\tt astro-ph/0403482 }  


 \vspace*{6mm}



 % >>> <conny@ster.kuleuven.ac.be>


\begin{center}{\Large\bf  Maximum mass-loss rates of line-driven winds of 
massive stars: the effect
of rotation and an application to $\eta\,$Carinae
}\end{center}
\centerline{\bf   
C.\ Aerts$^1$, H.J.G.L.M.\ Lamers$^{2,3}$ and G. Molenberghs$^4$
}{\footnotesize   
     $^1$ Institute of Astronomy, Catholic University of Leuven,
    Celestijnenlaan 200 B, B-3001 Leuven, Belgium\\  
$^2$   Astronomical Institute,
    Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands\\
$^3$ SRON Laboratory, for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The
    Netherlands\\
$^4$ Center for Statistics, Limburgs Universitair Centrum,
    Universitaire Campus, Building D, B-3590 Diepenbeek, Belgium
}\vspace*{4mm}  \\ %  
We investigate the effect of rotation on the maximum mass-loss rate
due to an optically-thin radiatively-driven wind according to a formalism which
takes into account the possible presence of any instability at the base of the
wind that might increase the mass-loss rate.  We include the Von Zeipel effect
and the oblateness of the star in our calculations. We determine the maximum
surface-integrated mass that can be lost from a star by line driving as a
function of rotation for a number of relevant stellar models of massive OB stars
with luminosities in the range of $5.0< \log(L/L_{\odot})<6.0$. We also
determine the corresponding maximum loss of angular momentum.  We find that
rotation increases the maximum mass-loss rate by a moderate factor for stars far
from the Eddington limit as long as the ratio of equatorial to critical velocity
remains below 0.7. For higher ratios, however, the temperature, flux and
Eddington factor distributions change considerably over the stellar surface such
that extreme mass loss is induced. Stars close to the Eddington-Gamma limit
suffer extreme mass loss already for a low equatorial rotation velocity.  We
compare the maximum mass-loss rates as a function of rotation velocity with
other predicted relations available in the literature which do not take into
account possible instabilities at the stellar surface and we find that the
inclusion thereof leads to extreme mass loss at much lower rotation rates. We
present a scaling law to predict maximum mass-loss rates. Finally, we provide a
mass-loss model for the LBV $\eta\,$Carinae that is able to explain the large
observed current mass-loss rate of $\sim 10^{-3}\,M_\odot\,$yr$^{-1}$ but that
leads to too low wind velocities compared to those derived from observations.

{\bf   Accepted by  Astronomy \& Astrophysics   } \\
{\it Preprints from} {\tt    conny@ster.kuleuven.ac.be   } 


 \vspace*{6mm}

 % >>> <Frederic.Meynadier@obspm.fr>

\begin{center}{\Large\bf Stellar populations associated with 
the LMC Papillon Nebula
}\end{center}
\centerline{\bf   
F. Meynadier,$^1$ 
 M. Heydari-Malayeri,$^1$
 L. Deharveng,$^2$
 V. Charmandaris,$^{3,1}$ 
}\centerline{\bf   
 Th. Le Bertre,$^1$ 
 M.R. Rosa,$^4$
 D. Schaerer$^{5,6}$
and H. Zinnecker$^7$
}{\footnotesize   
     $^1$ {\sc lerma}, Observatoire de Paris, 61 Avenue de l'Observatoire,
F-75014 Paris, France
 \\  $^2$  Observatoire de Marseille, 2 Place Le Verrier, F-13248 Marseille 
Cedex 4, France
 \\  $^3$  Cornell University, Astronomy Department,
106 Space Sciences Bldg., Ithaca, NY 14853, U.S.A.
 \\  $^4$ Space Telescope European Coordinating Facility, European Southern
Observatory, Karl-Schwarzschild-Strasse-2, D-85748 Garching bei
M\"unchen, Germany 
 \\  $^5$  Observatoire de Gen\`eve, 51, Ch. des Maillettes,
 CH-1290 Sauverny,  Switzerland
 \\  $^6$  Laboratoire d'Astrophysique, UMR 5572, Observatoire Midi-Pyr\'en\'ees, 
14,  Avenue E. Belin, F-31400 Toulouse, France
 \\ $^7$ Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, 
Germany
}\vspace*{4mm}  \\ %  
We study the Large Magellanic Cloud Papillon Nebula (N\,159-5), a
conspicuous High Excitation Blob (HEB) lying in the star forming
complex N\,159. Using {\it JHK} near-infrared photometry obtained at
the ESO VLT with the ISAAC camera, we examine the stellar populations
associated with the Papillon, tracing their history using stellar
evolution models. Two populations are revealed: one composed of young,
massive stars with an age $\sim$\, 3 Myr, and a second consisting of
older lower mass stars of age spreading between 1 and 10 Gyr.  We
analyze the properties of those populations and discuss their
significance in the context of N\,159.  We also estimate that if the
star at the center of the Papillon is single its initial mass is
$\sim$\,50\,$M_\odot$\, and it is affected by an 
extinction $A_{V}$\,$\sim$\,7 mag. 

{\bf   Accepted by  A\&A   } \\
{\it Preprints from} {\tt    Frederic.Meynadier@obspm.fr   } \\
{\it or on arXiv} {\tt astro-ph/0403626 }  


 \vspace*{3mm}

 % >>> <sewilo@astro.wisc.edu> % Marta Sewilo 


\begin{center}{\Large\bf  Broad Radio Recombination Lines from 
Hypercompact H II Regions}
\end{center}
\centerline{\bf   M. Sewilo$^1$, E. Churchwell$^1$, S. Kurtz$ ^2$, W. M. 
Goss$^3$, and P. Hofner$^3,4$  
}{\footnotesize   
     $^1$   University of Wisconsin - Madison, Department of Astronomy, 
475
N. Charter St., Madison, WI 53706 \\
$^2$  Centro de Radioastronom\'\i a y Astrof\'\i sica,
UNAM, Apdo. Postal 3-72, 58089, Morelia, Mich. Mexico \\
$^3$   National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 
87801\\
$^4$  New Mexico Tech, Physics Department, 801 Leroy Place, Socorro, NM 
87801 
}\vspace*{4mm}  \\ 
The H92$\alpha$ recombination line was observed toward six massive star 
formation regions (MSFRs) and the H76$\alpha$ line was observed toward one 
MSFR. All seven MSFRs were suspected of harboring hypercompact (HC) H 
{\small II} regions. The goal was to detect broad-line sources and to 
investigate their properties.  The sources were selected according to 
their small sizes, high brightness temperatures, and rising continuum 
spectra (typical spectral index $\alpha \sim +1$, S$_{\nu} \propto 
\nu^{\alpha}$) at centimeter wavelengths.  Two of the HC H {\small II} 
candidates, G25.5+0.2 and NGC 7538 (IRS 1), were previously known to have 
extremely broad lines (line widths of 160 and 180 km s$^{-1}$, 
respectively). 

Sixteen separate, compact, radio continuum components were detected, 
fourteen of which were detected in either the H92$\alpha$ or H76$\alpha$ 
line. Eight sources have line widths (FWHMs) greater than 40 km s$^{-1}$; 
typical ultracompact (UC) H {\small II} region line widths are 25-30 km 
s$^{-1}$. These broad lines may be produced by a combination of thermal, 
turbulent, electron impact broadening, and large scale motions (rotation, 
expansion, jets, shocks, inflow, disk, etc.). On the basis of one line and 
a relatively low spatial resolution, we are unable to determine the 
relative contributions from each mechanism. 

All the MSFRs in the current sample are composed of two or more continuum 
components. The large projected separations between the continuum 
components within a given MSFR indicate that they are unlikely to be 
gravitationally bound massive protostars. 

Possible origins of the observed intermediate sloped power-law spectral 
energy distributions (SEDs) are discussed. It is suggested that hierarchal 
clumping in HC H {\small II} regions (Ignace and Churchwell 2004) may 
produce the observed power-law SEDs.


{\bf   Accepted by The Astrophysical Journal   } \\
{\it Preprints from} {\tt    sewilo@astro.wisc.edu   } 



\newpage

% \vspace*{6mm}

\centerline{\lightframe{0.7}{5}{4cm}{
\centerline{\Large Submitted Papers}}} %%%%%%%%%%%%%%%%%%%%%%%%%%%

\vspace*{4mm}

 % >>>  <IGNACE@mail.etsu.edu>

\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE
The Hanle Effect as a Diagnostic of Magnetic Fields in Stellar
Envelopes IV.  Application to Polarized P~Cygni Wind Lines
}\end{center}
\centerline{\bf
 R. Ignace$^1$, K. Nordsieck$^2$, and J. Cassinelli$^2$
}{\footnotesize
   $^1$ Department of Physics, Astronomy, and Geology, East Tennessee State University
\\ $^2$ Department of Astronomy, University of Wisconsin
}\vspace*{4mm}  \\
The Hanle effect has been proposed as a new diagnostic of circumstellar
magnetic fields for early-type stars, for which it is sensitive
to field strengths in the 1-300~G range. In this paper we compute
the polarized P-Cygni line profiles that result from the Hanle
effect. For modeling the polarization, we employ a variant of the
``last scattering approximation''.  For cases in which the Sobolev
optical depths are greater than unity, the emergent line intensity
is assumed to be unpolarized; while for smaller optical depths, the
Stokes source functions for the Hanle effect with optically thin line
scattering are used. For a typical P~Cygni line, the polarized emission
forms in the outer wind, because the Sobolev optical depth is large at
the inner wind.  For low surface field strengths, weak P~Cygni lines
are needed to measure the circumstellar field.  For high values of the
surface fields, both the Zeeman and Hanle diagnostics can be used, with
the Zeeman effect probing the photospheric magnetic fields, and the Hanle
effect measuring the magnetic field in the wind flow.  Polarized line
profiles are calculated for a self-consistent structure of the flow and
the magnetic geometry based on the WCFields model, which is applicable
to slowly rotating stellar winds with magnetic fields drawn out by the
gas flow. For surface fields of a few hundred Gauss, we find that the
Hanle effect can produce line polarizations at the level of a few tenths
of a percent up to a 1--2\%.


{\bf   Submitted to the Astrophysical Journal} \\
{\it Preprints from} {\tt    ignace@mail.etsu.edu} \\
{\it or on the web at} {\tt http://www.etsu.edu/physics/ignace/pubs.html} 



\vspace*{6mm}

 % >>> <lida@astro.physik.uni-potsdam.de>


\begin{center}{\Large\bf   
X-ray emission lines from inhomogeneous stellar winds
}\end{center}


\centerline{\bf  L.M. Oskinova, A. Feldmeier and W.-R. Hamann 
}{\footnotesize   
Astrophysik, Universit{\"a}t Potsdam, Am Neuen Palais 10, D-14469
Potsdam, Germany 
}\vspace*{4mm}  \\ %  
It is commonly adopted that X-rays from O stars are produced
deep inside the stellar wind, and transported outwards through the bulk
of the expanding matter which attenuates the radiation and affects the
shape of emission line profiles. The ability of the X-ray observatories
Chandra and XMM-Newton to resolve these lines spectroscopically provided
a stringent test for the theory of the X-ray production. It turned out
that none of the existing models was able to fit the observations
consistently. The possible caveat of these models was the underlying
assumption of a smooth stellar wind. Motivated by the various evidences
that the stellar winds are in fact structured, we present a 2-D
numerical model of a stochastic, inhomogeneous wind. Small parcels of
hot, X-ray emitting gas are permeated with cool, absorbing wind material
which is compressed into thin shell fragments. Wind fragmentation alters
the radiative transfer drastically, compared to homogeneous models of
the same mass-loss rate. X-rays produced deep inside the wind, which
would be totally absorbed in a homogeneous flow, can effectively escape
from a fragmented wind. The wind absorption becomes wavelength
independent if the individual fragments are optically thick. The X-ray
line profiles are flat-topped in the blue part and decline steeply in
the red part for the winds with short acceleration zone. For the winds
where the acceleration extends over significant distances, the lines can
appear nearly symmetric and only slightly blueshifted, in contrast to
the skewed, triangular line profiles typically obtained from homogeneous
wind models of high optical depth. We show that profiles from a
fragmented wind model can reproduce the observed line profiles from 
$\zeta$\,Orionis. The present numerical modeling confirms the results
from a previous study, where we derived analytical formulae from a
statistical treatment.

{\bf Submitted to  A\&A   } \\
{\it Preprints from} {\tt  lida@astro.physik.uni-potsdam.de   } \\
{\it or by anonymous ftp to} {\tt
ftp.astro.physik.uni-potsdam.de/pub/oskinova/fragment\_abs.ps.gz       }
\\ {\it or on the web at} {\tt astro-ph/0403707 }  



\vspace*{6mm}

 % >>> (sub) 

 \vspace*{6mm}


\centerline{\lightframe{0.7}{5}{3.8cm}{
\centerline{\Large In Proceedings}}} %%%%%%%%%%%%%%%%%%%%%%%%%%%

\vspace*{4mm} 

 % >>>  <Sally.Oey@lowell.edu>

\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE 
The Local Group as an Astrophysical Laboratory for \\ 
Massive Star Feedback
}\end{center}
\centerline{\bf M. S. Oey$^1$
}{\footnotesize  
   $^1$  Lowell Observatory, 1400 W. Mars Hill Rd., Flagstaff, AZ\ \ \ 86001
}\vspace*{4mm}  \\
\def\hii{{\sc H\thinspace ii}}
The feedback effects of massive stars on their galactic and
intergalactic environments can dominate evolutionary processes in
galaxies and affect cosmic structure in the Universe.  Only the Local
Group offers the spatial resolution to quantitatively study feedback
processes on a variety of scales.  Lyman continuum
radiation from hot, luminous stars ionizes \hii\ regions and is
believed to dominate production of the warm component of the
interstellar medium (ISM).  Some of this radiation apparently escapes from
galaxies into the intergalactic environment.  Supernovae and strong
stellar winds generate shell structures such as supernova remnants,
stellar wind bubbles, and superbubbles around OB associations.  Hot
($10^6$ K) gas is generated within these shells, and is believed to be
the origin of the hot component of the ISM.  Superbubble activity thus
is likely to dominate the ISM structure, kinematics, and phase balance
in star-forming galaxies.  Galactic superwinds in starburst galaxies
enable the escape of mass, ionizing radiation, and heavy elements.
Although many important issues remain to be resolved, there is little
doubt that feedback processes plays a fundamental role in energy cycles on
scales ranging from individual stars to cosmic structure.  This
contribution reviews studies of radiative and mechanical feedback in
the Local Group. 

{\bf  
Invited review to appear in: 
{\sl The Local Group as an Astrophysical Laboratory,} 2003 STScI May
Symposium, eds. M. Livio et al., (Cambridge:  Cambridge U. Press)
} \\
{\it Preprints from} {\tt Sally.Oey@Lowell.edu} \\
{\it or on the web at} {\tt http://www.lowell.edu/\~{}oey} and
{\tt \ astro-ph/0307131} 


\newpage

% \vspace*{6mm} 



\centerline{\lightframe{0.7}{5}{2cm}{
\centerline{\Large Theses}}} %%%%%%%%%%%%%%%%%%%%%%%%%%%
\vspace*{4mm}

 % >>>  <ndelmott@eso.org>

\begin{center}{\Large\bf   %WRITE THE TITLE BELOW THIS LINE 
Multiwavelength Cross-Identifications of Stars. Application 
to \\
 Stellar Populations 
in the Magellanic Clouds and to Young Stars \\[2mm]
of our Galaxy.
}\end{center}
\centerline{\bf        N. Delmotte$^1$ 
}{\footnotesize $^1$   European Southern Observatory, Garching bei M\"unchen, Germany
           \\   
}\vspace*{4mm}\\   My thesis benefits from the recently released infrared and 
visible large surveys and takes place within the framework of the ongoing Virtual 
Observatory.
~\\~\\
I built a Master Catalogue of stars towards the Magellanic Clouds (MC2) based on 
multiwavelength cross-identifications of the DENIS, 2MASS, GSC-II and UCAC point 
source catalogues. I derived important results on the astro-photometric accuracy 
and calibration of the cross-identified catalogues. The MC2 can be queried on-line 
through a dedicated web interface I designed to handle its composite nature. 
See http://vizier.u-strasbg.fr/MC2/. 
I produced multispectral views of the LMC where its various populations discriminate 
remarkably well in colour-colour and colour-magnitude diagrams based on both infrared 
and visible wavelengths. The MC2 provides an unprecedented basis for the study of 
stellar populations in the Magellanic Clouds and for further cross-identifications 
with catalogues at other wavelengths.
~\\~\\
I calibrated the absolute magnitudes of the B-type stars in the near-infrared, as a 
function of their spectral types. I combined high quality Hipparcos-based distance 
measurements with homogeneous photometry from the near-infrared 2MASS point sources. 
I corrected the data from extinction effect and assessed by means of simulations the 
contribution of various measurement errors and physical effects (binarity, rotation) 
to the scatter observed in the calibration. It is a mandatory step towards the 
determination of the structure of the young Galactic disk and of the distances and 
properties of young open clusters revealed by large area infrared surveys such as 2MASS.
~\\~\\
I started a morphological and multiwavelength analysis of ionized regions and their 
stars in the LMC, observed in narrow-band imaging. Massive stars and their reciprocal 
interaction with the surrounding interstellar medium enable to gain insight into the 
local star formation history and stellar contents of these regions and to obtain a 
sketch of their dynamical evolution.    
~\\~\\
{\bf European Ph.D. Thesis - 07th November 2003 \\ Conducted both at CDS, Strasbourg, 
France and ESO, Germany \\ Advisor: D. Egret, Director of Paris Observatory\\ 
Co-Advisor: F. Comer\'on, ESO\\}
{\it For preprints, contact} {\tt ndelmott@eso.org
}
\\ 
Also available from http://www.eso.org/$\sim$ndelmott/PhD/ \\
and from http://tel.ccsd.cnrs.fr/documents/archives0/00/00/42/38/index.html
% (If applicable)

\newpage

% \vspace*{6mm}

 % >>> 

\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE 
Probing the interactions of early-type stars with their
\\[2mm]
surroundings through X-ray and optical observations
}\\ [7mm]

{\Large\bf 
 Ya\"el Naz\'e }
\\ [3mm]

naze@astro.ulg.ac.be
\\

\end{center}

This work is devoted to the study of the interactions of massive stars
with
their environment, either through their intense radiation fields or
through
their powerful stellar winds.

First, we have studied the close neighbourhood of the peculiar Of?p star
HD108, i.e. its stellar wind and associated emissions. We have notably
uncovered the important variations of the emission lines seen in the
visible domain. At the same time, in contrast, the X-ray emission
remained
stable. To better understand the X-rays emitted by the star, we have
developed a program for modelling the ionisation of the stellar wind,
that enabled us to determine the absorption of this ionised wind in the
X-ray domain. Our X-ray observations have then permitted us to discard
several
models proposed to explain the nature of the system, and we have
discussed
the remaining possibilities in the light of the behaviour of the two
other Of?p stars, the possible ``twins" of HD108.
The wind modelling program was also used to study the properties,
in the X-ray range, of the Wolf-Rayet star WR40: combined to the
observations taken by XMM-Newton, we have shown that the non-detection
of X-rays
from this star can be explained by the very large opacity of its wind.
The study of the ionisation of the surrounding gas by Wolf-Rayet stars
was extended through the analysis of HeII nebulae. For the first time,
high quality images of the highly excited regions surrounding Wolf-Rayet
stars were taken and analysed, enabling to derive the extreme UV flux of
these stars, and thus their temperature, from ground-based observations.

In addition to the ionisation by massive stars, the impact of their
stellar winds was also considered in this work, especially the
wind-blown
structures called ``bubbles''. These bubbles arise from the action of
the winds of massive stars, in isolation or in clusters, onto the
interstellar medium. We first focused on the bubbles blown by isolated
stars, and we started by the study of the high energy properties of the
bubble
blown by WR40. Thanks to XMM-Newton data, we showed that even the most
recent
theoretical models cannot account for the lack of X-ray emission of this
bubble.
To better understand the discrepancies between the theory and the
observations of wind-blown bubbles, we then turned to the most simple
structures, the ones blown by single main sequence massive stars.
Several
bubbles have been discovered in N11B, N180B, and N44, and their
properties
agree better with theoretical expectations than in the case of WR
bubbles and superbubbles. Before our study, only a few interstellar
bubbles were known: we showed that a simple morphological search was
insufficient, and that kinematic studies were essential. In fact, the
low-velocity expansion of these bubbles implies a weak compression of
the gas, that can inhibit the morphological detection.
Finally, we investigated the properties of the interaction of massive
star clusters with their surroundings in the high-energy range. The
clusters of N11 were observed in X-rays and UV thanks to the XMM-Newton
satellite:
their differences or similarities appear clearly at these energies,
and we note that the diffuse X-ray emission always exceeded the expected
level. Moreover, a unique dataset composed of Chandra and XMM-Newton
observations
enabled us to study the largest star formation region of the Small
Magellanic
Cloud, NGC346. Notably, the X-ray emissions from the NGC346 cluster
itself and from the peculiar WR binary system HD5980 were discovered
and analysed in details.

Our work underlines the complementarity between the visible, UV and
X-ray
domains, and the necessity to have observatories on the ground as well
as
in space. It also illustrates the important contribution of
multiwavelength
datasets to the study of massive stars. These observations indeed play
a crucial role in the determination of the properties of early-type
stars
but they also provide critical tests for theoretical models (present
or future).
\\

 17 March 2004 
\\
Advisor : Dr Gregor Rauw
\\
University : Institut d'Astrophysique et de G\'eophysique, Universit\'e
de Li\`ege (Belgium)



 \vspace*{6mm}


\vspace*{4mm}  


\centerline{\lightframe{0.7}{5}{1.5cm}{
\centerline{\Large  Jobs }}} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\vspace*{4mm}


\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE 
Postdoctoral position on: \\[2mm]
Starbursts from the local Universe to high redshift
}
\end{center}

\vspace*{4mm}  



The Geneva Observatory in Geneva, Switzerland, announces the availability of
a research position at the postdoctoral level, open to applicants of all 
nationalities.

The succesfull candidate will work on a project aimed at studying 
starbursts nearby, at intermediate redshift (z$\sim$2-3), or in the early
Universe (z$>$7), involving multi-wavelength observations and/or 
theoretical modeling.The successfull applicant will in particular 
have access to ground-based observational data covering the optical 
to near-IR (including ESO/VLT data), and state-of-the-art modeling tools.
He/she will mostly work in collaboration with Prof. Daniel Schaerer in Geneva.

The Geneva Observatory and the associated Laboratory of Astrophysics
of the Swiss Federal Institute of Technology in Lausanne carry 
out observational, interpretative and theoretical research in the 
fields of extra-solar planets, stellar evolution, stellar physics, 
high energy astrophysics, galaxy evolution and dynamics, and
observational cosmology.

The appointment will be for one to two years starting around October
1, 2004 (negotiable).

Qualified candidates are encouraged to send their application including
a CV and publication list, description of research experience and 
interests, and contact information of three references preferably 
via email to the above address. All applications received by 1 May, 2004
will receive full consideration. Informal enquiries with Daniel Schaerer 
(daniel.schaerer@obs.unige.ch) are welcome.


{\it Contact\, }       {\tt   daniel.schaerer@obs.unige.ch}\\
{\it Related information also available from the URL\, }  

\centerline
        {\tt   http://obswww.unige.ch/sfr }

 \vspace*{6mm}


 % >>> <jdrake@cfa.harvard.edu>

\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE 
SAO Predoctoral Fellowships 2004
}\end{center}

The Smithsonian Astrophysical Observatory announces the availability
of predoctoral fellowships beginning in July 2004, designed to allow
students from other institutions throughout the world to do all or
part of their thesis research at SAO.  A wide variety of research
projects may be proposed, with about 200 SAO scientific staff
available as research advisors.  Facilities at SAO include the MMT,
Magellan, and other optical and infrared telescopes; radio telescopes,
including the Submillimeter Array being constructed on Mauna Kea,
Hawaii; a large network of workstations; a number of specialized
laboratories; an outstanding library system; and access to data from a
wide range of space missions.

 Further information on the program can be found at

\centerline{
http://cfa-www.harvard.edu/predoc/}

 Applicants can contact directly Smithsonian scientists in their areas
of interest, or the Program Scientist at predoc@cfa.harvard.edu, to
discuss possible research topics.

 Applicants must be ready to begin dissertation research at the time of
the award.  Fellowships are awarded for one year at a time with
possible renewal for up to three years, contingent upon funding.
Stipends will be \$24,600 for the coming year.  Applications are due by
15 April 2004. Application forms can be found at the web address
above, and should be completed and mailed to SAO.  Electronic or fax
submissions will not be accepted.
 
 The CfA is an Equal Opportunity/Affirmative Action Employer where all
qualified applicants receive consideration for employment without
regard to race, creed, sex or national origin.

% {\it or on the web at} {\tt http://cfa-www.harvard.edu/predoc/ } 





 \vspace*{6mm}



% \centerline{\lightframe{0.7}{5}{1.5cm}{
% \centerline{\Large  News }}} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% \vspace*{4mm}

 \vspace*{6mm}

\centerline{\lightframe{0.7}{5}{2.1cm}{
\centerline{\Large   Meetings }}} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\vspace*{4mm}

 % >>>  <IGNACE@mail.etsu.edu>



\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE
Announcement for the Workshop on The Nature and Evolution of Disks around
Hot Stars
}\end{center}


To be held 2004 July 7, 8, and 9 in Johnson City, TN, at the Carnegie
Hotel.  \\

A reminder that the deadline for submission of abstracts is April 1st.
The deadline for registration is May 1st (beyond which, a late fee will
be assessed). \\

The website for the workshop has moved to: 

\centerline{www.etsu.edu/physics/astronomy/ } 


 where one can find information about the workshop (the Second
Announcement), a registration form, a macro for submission of abstracts,
and links for the Carnegie Hotel and surrounding area. 
\\

Please direct questions to the SOC/LOC via email to:

\centerline{
 hotstars@etsu.edu}



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% WHEN SUBMITTING AN ABSTRACT, PLEASE USE THE FOLLOWING TEMPLATE IF POSSIBLE: 


\begin{center}{\Large\bf    % WRITE THE Title BELOW THIS LINE 

}\end{center}
\centerline{\bf   A. Author$^1$ and B. Author$^2$  
}{\footnotesize  
   $^1$ Institute One and Address 
\\ $^2$ Institute Two and Address 
}\vspace*{4mm}  \\
    % WRITE TEXT OF ABSTRACT HERE 


{\bf   Accepted by  /or/  Submitted to   JOURNAL} \\
{\it Preprints from} {\tt    YOUR ELECTRONIC ADDRESS} \\
{\it or by anonymous ftp to} {\tt    ... } \\
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