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相关论文: A CNO Dichotomy among O2 Giant Spectra in the Mage…

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[Abridged] We have studied the optical spectra of 28 O- and early B-type stars in the Large Magellanic Cloud, 22 of which are associated with the young star-forming region N11. Stellar parameters are determined using an automated fitting…

We study the evolutionary and physical properties of evolved O stars in the Small Magellanic Cloud (SMC), with a special focus on their surface abundances to investigate the efficiency of rotational mixing as a function of age, rotation and…

This is the second paper in a series aiming at the analysis of nitrogen abundances in O-type stars, to enable further constraints on the early evolution of massive stars. We investigate the NIV lambda4058 emission line formation, provide…

太阳与恒星天体物理 · 物理学 2015-05-30 J. G. Rivero Gonzalez , J. Puls , F. Najarro , I. Brott

We study the evolution, rotation, and surface abundances of O-type dwarfs in the Small Magellanic Cloud. We analyzed the UV and optical spectra of twenty-three objects and derived photospheric and wind properties. The observed binary…

太阳与恒星天体物理 · 物理学 2015-06-15 Jean-Claude Bouret , Thierry Lanz , Fabrice Martins , Wagner L. F. Marcolino , D. John Hillier , Eric Depagne , Ivan Hubeny

We analyze the optical and UV spectra of an additional sample of 20 Magellanic Cloud O stars, and draw conclusions from the complete sample of 40 stars. We find (1) The SMC O3-7 dwarfs are about 4000 K cooler than their Galactic…

In this paper, we present high-resolution HST/COS observations of the extreme magnetic O star NGC 1624-2. These represent the first ultraviolet spectra of this archetypal object. We examine the variability of its wind-sensitive resonance…

The nitrogen to carbon (N/C) and nitrogen to oxygen (N/O) ratios are the most sensitive quantities to mixing in stellar interiors of intermediate and massive stars. We further investigate the theoretical properties of these ratios as well…

Our goal is to determine the stellar and wind properties of seven O stars in the cluster NGC2244 and three O stars in the OB association MonOB2. These properties give us insight into the mass loss rates of O stars, allow us to check the…

太阳与恒星天体物理 · 物理学 2015-05-30 F. Martins , L. Mahy , G. Rauw , D. J. Hillier

We present quantitative studies of 8 late O and early B-type supergiants in the Magellanic Clouds using far-ultraviolet FUSE, ultraviolet IUE/HST and optical VLT-UVES spectroscopy. Temperatures, mass-loss rates and CNO abundances are…

天体物理学 · 物理学 2009-11-10 C. J. Evans , P. A. Crowther , A. W. Fullerton , D. J. Hillier

We have undertaken quantitative analysis of four LMC and SMC O4--9.7 extreme supergiants using far-ultraviolet FUSE, ultraviolet IUE/HSTand optical VLT UVES spectroscopy. Extended, non-LTE model atmospheres that allow for the consistent…

天体物理学 · 物理学 2009-11-07 P. A. Crowther , D. J. Hillier , C. J. Evans , A. W. Fullerton , O. De Marco , A. J. Willis

In this paper we review the observational data for OB stars in the SMC concentrating on those aspects of their spectra which provide information on processes which may strongly influence their evolution, namely mass-loss, rotational mixing…

天体物理学 · 物理学 2007-05-23 D. J. Lennon , C. J. Evans , C. Trundle

We present spectral classifications from optical spectroscopy of 263 massive stars in the north-eastern region of the Large Magellanic Cloud. The observed two-degree field includes the massive 30 Doradus star-forming region, the environs of…

太阳与恒星天体物理 · 物理学 2015-11-18 C. J. Evans , J. Th. van Loon , R. Hainich , M. Bailey

Two new ON supergiant spectra (bringing the total known to seven) and one new ONn giant (total of this class now eight) are presented; they have been discovered by the Galactic O-Star Spectroscopic Survey. These rare objects represent…

太阳与恒星天体物理 · 物理学 2016-03-23 Nolan R. Walborn , Nidia I. Morrell , Rodolfo H. Barba , Alfredo Sota

Massive stars likely played an important role in the reionization of the Universe, and the formation of the first black holes. Massive stars in low-metallicity environments in the local Universe are reminiscent of their high redshift…

太阳与恒星天体物理 · 物理学 2014-11-26 F. Tramper , H. Sana , A. de Koter , L. Kaper , O. H. Ramirez-Agudelo

Stars which start their lives with spectral types O and early-B are the progenitors of core-collapse supernovae, long gamma-ray bursts, neutron stars, and black holes. These massive stars are the primary sources of stellar feedback in…

太阳与恒星天体物理 · 物理学 2019-05-22 Varsha Ramachandran , W. -R. Hamann , L. M. Oskinova , J. S. Gallagher , R. Hainich , T. Shenar , A. A. C. Sander , H. Todt , L. Fulmer

Massive, hot OB-stars show clear evidence of strong macroscopic broadening (in addition to rotation) in their photospheric spectral lines. This paper examines the occurrence of such "macro-turbulence" in slowly rotating O-stars with strong,…

太阳与恒星天体物理 · 物理学 2015-06-16 J. O. Sundqvist , V. Petit , S. P. Owocki , G. A. Wade , J. Puls , the MiMeS Collaboration

Magnetic massive stars comprise approximately 10% of the total OB star population. Modern spectropolarimetry shows these stars host strong, stable, large-scale, often nearly dipolar surface magnetic fields of 1 kG or more. These global…

太阳与恒星天体物理 · 物理学 2017-11-15 Christiana Erba , Alexandre David-Uraz , Veronique Petit , Stanley P. Owocki

Complete samples of 2MASS stars in 3 fields of differing metallicities (and possibly differing age distributions) have been extracted and cross-correlated with MACHO and ISO data to determine their variability and mass-loss properties. In…

天体物理学 · 物理学 2009-11-10 M. Schultheis , I. S. Glass , M. -R. Cioni

Massive stars play a key role in the evolution of the Universe. Our goal is to compare observed and predicted properties of single Galactic O stars to identify and constrain uncertain physical parameters and processes in stellar evolution…

太阳与恒星天体物理 · 物理学 2018-05-16 Nevena Markova , Joachim Puls , Norbert Langer

Based on an analysis of the interstellar highly ionised species C IV, Si IV, N V, and O VI observed in the FUSE and HST/STIS E140M spectra of four hot stars in the Large Magellanic Cloud (LMC), we find evidence for a hot LMC halo fed by…

天体物理学 · 物理学 2010-05-12 N. Lehner , J. C. Howk
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