Reference : HD 148937: A multiwavelength study of the third galactic member of the Of?p class
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Earth sciences & physical geography
http://hdl.handle.net/2268/2778
HD 148937: A multiwavelength study of the third galactic member of the Of?p class
English
Nazé, Yaël mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Sciences spatiales >]
Walborn, Nolan R. [Space Telescope Science Institute (Baltimore, USA)]
Rauw, Grégor mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE) - Sciences spatiales >]
Martins, Fabrice [> > > >]
Pollock, A. M. T. [> > > >]
Bond, Howard E. [> > > >]
2008
Astronomical Journal (The)
Univ Chicago Press
135
5
1946-1957
Yes (verified by ORBi)
International
0004-6256
Chicago
IL
[en] stars : individual (HD 148937) ; X-rays : individual ( HD 148937) ; X-rays : stars ; stars : early-type
[en] Three Galactic O-type stars belong to the rare class of Of? p objects: HD 108, HD 191612, and HD 148937. The first two stars show a wealth of phenomena, including strong X-ray emission, light variability, and dramatic periodic spectral variability. We present here the first detailed optical and X-ray study of the third Galactic Of? p star, HD 148937. Spectroscopic monitoring has revealed low-level variability in the Balmer and He II lambda 4686 lines, but constancy at He I and C III lambda 4650. The H alpha line exhibits profile variations at a possible periodicity of similar to 7 days. Model atmosphere fits yield T-eff = 41000 +/- 2000 K, log(g) = 4.0 +/- 0.1, M-sph less than or similar to 10(-7) M-circle dot yr(-1), and an overabundance of nitrogen by a factor of 4. At X-ray wavelengths, HD 148937 resembles HD 108 and HD 191612 in having a thermal spectrum dominated by a relatively cool component (kT = 0.2 keV), broad lines (>= 1700 km s(-1)), and an order-of-magnitude overluminosity compared to normal O stars (log[L-X(unabs) / L-BOL]similar to -6).
Professionals
http://hdl.handle.net/2268/2778
10.1088/0004-6256/135/5/1946
http://arxiv.org/abs/0803.0605

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