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Full-Text Articles in Stars, Interstellar Medium and the Galaxy

X-Ray Properties Of Early-Type Stars In The Tarantula Nebula From T-Rex, Paul A. Crowther, Patrick S. Broos, Leisa K. Townsley, Andy M. T. Pollock, Katie A. Tehrani, Marc Gagné Aug 2022

X-Ray Properties Of Early-Type Stars In The Tarantula Nebula From T-Rex, Paul A. Crowther, Patrick S. Broos, Leisa K. Townsley, Andy M. T. Pollock, Katie A. Tehrani, Marc Gagné

Earth & Space Sciences Faculty Publications

We reassess the historical L-X/L-Bol relation for early-type stars from a comparison between T-ReX, the Chandra ACIS X-ray survey of the Tarantula Nebula in the Large Magellanic Cloud (LMC), and contemporary spectroscopic analysis of massive stars obtained primarily from VLT/FLAMES, VLT/MUSE, and HST/STIS surveys. For 107 sources in common (some host to multiple stars), the majority of which are bolometrically luminous (40 per cent exceed 10(6)L(circle dot)), we find an average log L-X/L-Bol = -6.90 +/- 0.65. Excluding extreme systems Mk 34 (WN5h+WN5h), R140a (WC4+WN6+), and VFTS 399 (O9 IIIn+?), plus four WR sources with anomalously hard X-ray components (R130, …


Helium-Like X-Ray Line Complexes Show That The Hottest Plasma On The Zeta Supergiant Puppis Is In Its Wind, David H. Cohen, Ariel M. Overdorff, Maurice A. Leutenegger, Marc Gagné, Veronique Petit, Alexandre David-Uraz May 2022

Helium-Like X-Ray Line Complexes Show That The Hottest Plasma On The Zeta Supergiant Puppis Is In Its Wind, David H. Cohen, Ariel M. Overdorff, Maurice A. Leutenegger, Marc Gagné, Veronique Petit, Alexandre David-Uraz

Earth & Space Sciences Faculty Publications

We present an analysis of Chandra grating spectra of key helium-like line complexes to put constraints on the location with respect to the photosphere of the hottest (T greater than or similar to 6 x 10(6) K) plasma in the wind of the O supergiant zeta Pup and to explore changes in the 18 yr between two sets of observations of this star. We fit two models - one empirical and one wind-shock-based - to the S XV, Si XIII, and Mg XI line complexes and show that an origin in the wind flow, above r approximate to 1.5 R*, …


Erratum: Chandra Grating Spectroscopy Of Embedded Wind Shock X-Ray Emission From O Stars Shows Low Plasma Temperatures And Significant Wind Absorption, David H. Cohen, Winter Parts, Graham M. Doskoch, Jiaming Wang, Veronique Petit, Maurice A. Leutenegger, Marc Gagné Feb 2022

Erratum: Chandra Grating Spectroscopy Of Embedded Wind Shock X-Ray Emission From O Stars Shows Low Plasma Temperatures And Significant Wind Absorption, David H. Cohen, Winter Parts, Graham M. Doskoch, Jiaming Wang, Veronique Petit, Maurice A. Leutenegger, Marc Gagné

Earth & Space Sciences Faculty Publications

This is an erratum to the paper ‘ Chandra grating spectroscopy of embedded wind shock X-ray emission from O stars shows low plasma temperatures and significant wind absorption’ (2021, MNRAS, 503, 715). We present here a modest correction to the o v erall scaling of the differential emission measures (DEMs) of six O stars originally presented in Cohen et al. ( 2021 ). While working on a follow-up paper, we realized that we had incorrectly converted the bvapec spectral emission model’s normalization parameters (proportional to the emission measure per temperature bin size) to the emission measure per decade Kelvin shown …


Chandra Revisits Wr 48a: Testing Colliding Wind Models In Massive Binaries, Svetozar A. Zhekov, Marc Gagné, Stephen L. Skinner Feb 2022

Chandra Revisits Wr 48a: Testing Colliding Wind Models In Massive Binaries, Svetozar A. Zhekov, Marc Gagné, Stephen L. Skinner

Earth & Space Sciences Faculty Publications

We present results of new Chandra High-Energy Transmission Grating (HETG) observations (2019 November-December) of the massive Wolf-Rayet binary WR 48a. Analysis of these high-quality data showed that the spectral lines in this massive binary are broadened (full width at half-maximum, FWHM = 1400 km s(-1)) and marginally blueshifted (similar to-100 km s(-1)). A direct modelling of these high-resolution spectra in the framework of the standard colliding stellar wind (CSW) picture provided a very good correspondence between the shape of the theoretical and observed spectra. Also, the theoretical line profiles are in most cases an acceptable representation of the observed ones. …