X-ray Spectroscopy of the O2If* Star HD 93129A
نویسنده
چکیده
The O2If* star, HD 93129A, is among the earliest in the Galaxy and has one of the strongest winds of any O star. In this paper, we show that its hard and strong X-ray emission can be understood in terms of the standard embedded wind shock paradigm for effectively single, hot, massive stars. Wind attenuation of the intrinsically soft X-ray emission is an important effect, which explains the hardness of the observed X-rays. We measure the degree of wind absorption in two different ways in order to derive a mass-loss rate of roughly 6 × 10−6 M⊙ yr −1. This value is consistent with the observed Hα line if a clumping factor of fcl = 12 is assumed.
منابع مشابه
The X-ray View of OB Star Wind Structure and Dynamics
High-resolution X-ray grating spectroscopy enables us to measure the kinematics and spatial distribution of the shock-heated wind plasma in O and early B stars, testing the predictions of the embedded wind shock scenario of massive star Xray production. By fitting models to the resolved, Doppler broadened X-ray emission line profiles measured by the Chandra X-ray Observatory’s grating spectrome...
متن کاملar X iv : a st ro - p h / 04 10 54 7 v 1 2 2 O ct 2 00 4 Radio behavior of four southern non - thermal O - type stars
We have conducted high resolution continuum observations at 1.4 and 2.4 GHz with the Australia Telescope Compact Array, towards the four southern Of stars: CD-47 4551, HD 93129A, HD 124314, and HD 150136. All stars have been detected at the two frequencies. HD 93129A – the only O2 I star catalogued so far, and in a double system –, has also been observed at 17.8 and 24.5 GHz. Its radio spectrum...
متن کاملThe Herbig Ae Star Hd 163296 in X-rays
Chandra X-ray imaging spectroscopy of the nearby Herbig Ae star HD 163296 at 100 AU angular resolution is reported. A point-like, soft (kT∼0.5 keV), emission-line source is detected at the location of the star with an X-ray luminosity of 4 × 10 ergs s (logLX/Lbol = −5.48). In addition, faint emission along the direction of a previously-detected Lyα-emitting jet and Herbig-Haro outflow may be pr...
متن کاملThe Coronal X-ray spectrum of the multiple weak-lined T Tauri star system HD 98800
We present high-resolution X-ray spectra of the multiple (hierarchical quadruple) weak-lined T Tauri star system HD 98800, obtained with the High Energy Transmission Gratings Spectrograph (HETGS) aboard the Chandra X-ray Observatory (CXO). In the zeroth-order CXO/HETGS X-ray image, both principle binary components of HD 98800 (A and B, separation 0.8) are detected; component A was observed to f...
متن کاملASTRONOMY AND ASTROPHYSICS X - ray spectroscopy of the weak - lined T Tauri star HD 283572
We have analyzed the existing X-ray spectroscopic data for the Weak-Line T Tauri star (WTTS) HD 283572, from the ROSAT, ASCA and SAX satellites. All the data sets are well fit with an absorbed two-temperature model based on col-lisional ionization equilibrium. Together with the Einstein data discussed in the literature, these data sets afford a 16.5 years time span, allowing to study the short-...
متن کامل