X-ray emission from single magnetic early-type stars

1992 ◽  
Vol 395 ◽  
pp. 575 ◽  
Author(s):  
V. V. Usov ◽  
D. B. Melrose
Keyword(s):  
Early Type ◽  
X Ray ◽  
Early Type Stars

scholarly journals Chemical Abundances of Early Type Stars

1998 ◽  
Vol 188 ◽  
pp. 224-225
Author(s):  
S. Tanaka ◽  
S. Kitamoto ◽  
T. Suzuki ◽  
K. Torii ◽  
M.F. Corcoran ◽  
...  
Keyword(s):  
Surface Layer ◽  
Stellar Wind ◽  
Nuclear Reactions ◽  
X Rays ◽  
Early Type ◽  
Chemical Abundances ◽  
X Ray ◽  
Low Metallicity ◽  
Early Type Stars

X-rays from early-type stars are emitted by the corona or the stellar wind. The materials in the surface layer of early-type stars are not contaminated by nuclear reactions in the stellar inside. Therefore, abundance study of the early-type stars provides us an information of the abundances of the original gas. However, the X-ray observations indicate low-metallicity, which is about 0.3 times of cosmic abundances. This fact raises the problem on the cosmic abundances.

X‐Ray Emission from Early‐Type Stars in the Orion Nebula Cluster

2005 ◽  
Vol 160 (2) ◽  
pp. 557-581 ◽  
Author(s):  
B. Stelzer ◽  
E. Flaccomio ◽  
T. Montmerle ◽  
G. Micela ◽  
S. Sciortino ◽  
...  
Keyword(s):  
Orion Nebula ◽  
Early Type ◽  
X Ray ◽  
Early Type Stars

scholarly journals Radio and X-Ray Emissions from Chemically Peculiar B- and A-Type Stars: Observations and a Model

1993 ◽  
Vol 138 ◽  
pp. 507-516 ◽  
Author(s):  
Jeffrey L. Linsky
Keyword(s):  
Energy Source ◽  
Stellar Wind ◽  
Mechanical Energy ◽  
Early Type ◽  
Late Type ◽  
X Ray ◽  
Nonthermal Radio ◽  
Chemically Peculiar ◽  
Early Type Stars

AbstractConventional wisdom holds that early-type and late-type stars have very different outer atmospheres, because the early-type stars lack deep convective zones. I argue that the magnetic chemically peculiar (CP) stars hotter than about spectral type A2 display many of the activity phenomena seen in the most active late-type stars. In particular, many CP stars are luminous nonthermal radio and coronal x-ray sources like the RS CVn systems. A wind-fed magnetosphere model has been proposed to explain both the nonthermal radio and the x-ray emission. In this model the stellar wind plays the role of a mechanical energy source analogous to the role played by convection in the active late-type stars.

X-ray Properties of Early-Type Stars

1994 ◽  
pp. 200-201 ◽  
Author(s):  
Thomas W. Berghöfer ◽  
Jürgen H. M. M. Schmitt
Keyword(s):  
Early Type ◽  
X Ray ◽  
Early Type Stars

Rosat X-Ray Light Curves of Early-Type Stars

1994 ◽  
pp. 309-320 ◽  
Author(s):  
Thomas W. Berghöfer ◽  
Jürgen H. M. M. Schmitt
Keyword(s):  
Light Curves ◽  
Early Type ◽  
X Ray ◽  
Early Type Stars

scholarly journals X-Ray Emission-Line Profiles of Three Early-Type Stars Observed with Chandra

2007 ◽  
Vol 59 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Norimasa Yamamoto ◽  
Haruko Takano ◽  
Shunji Kitamoto ◽  
Takayoshi Kohmura
Keyword(s):  
Emission Line ◽  
Line Profiles ◽  
Early Type ◽  
X Ray ◽  
Early Type Stars

scholarly journals X-ray diagnostics of massive star winds

2016 ◽  
Vol 12 (S329) ◽  
pp. 151-155
Author(s):  
L. M. Oskinova ◽  
R. Ignace ◽  
D. P. Huenemoerder
Keyword(s):  
High Resolution ◽  
Stellar Wind ◽  
Massive Star ◽  
Massive Stars ◽  
Stellar Winds ◽  
X Rays ◽  
Early Type ◽  
Stellar Rotation ◽  
X Ray ◽  
Early Type Stars

AbstractObservations with powerful X-ray telescopes, such as XMM-Newton and Chandra, significantly advance our understanding of massive stars. Nearly all early-type stars are X-ray sources. Studies of their X-ray emission provide important diagnostics of stellar winds. High-resolution X-ray spectra of O-type stars are well explained when stellar wind clumping is taking into account, providing further support to a modern picture of stellar winds as non-stationary, inhomogeneous outflows. X-ray variability is detected from such winds, on time scales likely associated with stellar rotation. High-resolution X-ray spectroscopy indicates that the winds of late O-type stars are predominantly in a hot phase. Consequently, X-rays provide the best observational window to study these winds. X-ray spectroscopy of evolved, Wolf-Rayet type, stars allows to probe their powerful metal enhanced winds, while the mechanisms responsible for the X-ray emission of these stars are not yet understood.

scholarly journals On the perspectives of using XMM to study fundamental parameters of early-type stars

1999 ◽  
Vol 193 ◽  
pp. 90-91
Author(s):  
Gregor Rauw ◽  
Karel A. van der Hucht ◽  
Rolf Mewe ◽  
Manuel Güdel ◽  
Jean-Marie Vreux ◽  
...  
Keyword(s):  
Effective Area ◽  
Early Type ◽  
X Ray ◽  
Fundamental Parameters ◽  
Medium Resolution ◽  
Wide Range ◽  
Imaging Camera ◽  
Substantial Progress ◽  
Early Type Stars ◽  
Reflection Grating

Although substantial progress has been achieved since the discovery of X-ray emission from early-type stars with the EINSTEIN satellite, several crucial aspects of this phenomenon are still not fully understood. Considerable breakthroughs in this field are expected from observations with the X-ray Multi-Mirror satellite (XMM) due for launch in early 2000. XMM is the second cornerstone mission of the ESA Horizon 2000 science programme (see Lumb et al. 1996 and references therein for an overall description of the satellite). XMM offers a large effective area over a wide range of energies and its instrumentation provides simultaneously non-dispersive spectroscopic imaging (EPIC - European Photon Imaging Camera), medium-resolution dispersive spectroscopy (RGS - Reflection Grating Spectrometer) and optical-UV imaging (OM - Optical Monitor).

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