3 edition of A search for X-ray evidence of a compact companion to the unusual Wolf-Rayet star HD 50896 (EZ CMa) found in the catalog.
A search for X-ray evidence of a compact companion to the unusual Wolf-Rayet star HD 50896 (EZ CMa)
by Elsevier, National Aeronautics and Space Administration, National Technical Information Service, distributor in [Amsterdam, The Netherlands], [Washington, DC, Springfield, Va
Written in English
|Statement||Stephen L. Skinner, Masayuki Itoh, Fumiaki Nagase.|
|Series||NASA contractor report -- NASA CR-208149.|
|Contributions||Itoh, Masayuki., Nagase, F. 1941-, United States. National Aeronautics and Space Administration.|
|The Physical Object|
Eta Car is a colliding wind binary in which strong variations in X-ray emission and in other wavebands are driven by the violent collision of the wind of eta Car-A and the fast, less dense wind of an otherwise hidden companion star. X-ray variations are the simplest diagnostic we have to study the wind-wind collision and allow us to measure the. The physical properties of X-ray novae as close binary systems are analysed. Observational data in X-ray, UV, optical, IR and radio ranges are summarized. Modern theoretical considerations of the problem of X-ray novae, taking into account some new ideas and results, are described. Properties of optical stars in X-ray novae are analysed. Data about the masses of black holes .
For a star with radius, the wind velocity v at radius r is commonly fit by a "beta velocity law", β. The original point-star CAK (Castor, Abbott, & Klein) model for line-driving gives β, corresponding to an outward acceleration proportional to the local inward pull of gravity. Context. Wolf-Rayet (WR) stars have a severe impact on their environments owing to their strong ionizing radiation ﬁelds and powerful stellar winds. Since these winds are considered to be driven by radiation pressure, it is theoretically expected that the degree of the wind mass-loss depends on the initial metallicity of WR stars. by:
Magnetic field generator. DOEpatents. Krienin, Frank. A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current . The ultraviolet spectral energy distribution of the O5f star Zeta Pup and the WN5 star HD are derived from OAO-2 observations with the calibration of Bless, Code, and Fairchild (). An estimate of the interstellar reddening ( magnitude) of the Wolf-Rayet star is determined from the size of the characteristic interstellar extinction.
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We analyze results of a ≈ 25 ksec ASCA X-ray observation of the unusual Wolf-Rayet star HD (= EZ CMa). This WN5 star shows optical and ultraviol Cited by: Get this from a library.
A search for X-ray evidence of a compact companion to the unusual Wolf-Rayet star HD (EZ CMa). [Stephen Lee Skinner; Masayuki Itoh; F Nagase; United States. National Aeronautics and Space Administration.].
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This image shows a giant bubble of material blown by the Wolf-Rayet star HD X-ray data are shown in blue, optical data are in red and green. Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar surface temperatures range f.
Wolf-Rayet stars represent a final burst of activity before a huge star begins to die. These stars, which are at least 20 times more massive than.
Masayuki ITOH of Kobe University, Kobe (Shindai) | Read 82 publications | Contact Masayuki ITOH A search for X-ray evidence of a compact companion to the unusual Wolf-Rayet star HD. Wolf-Rayet stars represent a final burst of activity before a huge star begins to die.
These stars, which are at least 20 times more massive than the Sun. There is no evidence of harder X-rays coming from accretion onto a compact star.
Nevertheless, the presence of a collapsar is not excluded at h v ≲ 5 keV, where absorption in the WR wind would likely reduce the X-ray flux to a level which is masked by Cited by: 4. Using recent determinations of some Wolf-Rayet star parameters, and more detailed physics than previously used, the expected X-ray luminosity of the proposed WR plus compact object system HD Stephen Lee Skinner has written: 'A search for X-ray evidence of a compact companion to the unusual Wolf-Rayet star HD (EZ CMa)' -- subject(s): X.
WR is a triple star system located about 7, light-years (2, pc) from primary star is a Wolf–Rayet star, abbreviated as WR, with a B main sequence star in close orbit and another more distant fainter companion.
The WR star is surrounded by a distinctive spiral Wolf–Rayet nebula, often referred to as a pinwheel rotational axis of the binary Distance: 2, pc. The Einstein Observatory showed that Wolf-Rayet stars have a much larger range in the ratio of X-ray to bolometric luminosity than normal early-type stars.
EXOSAT measurements of HDT93 (WCT+abs) show it to be extremely X-ray bright. This result is probably not connected with the infra-red and radio outburst that the star underwent in Cited by: 3. The exposed hot core is referred to as a Wolf-Rayet (WR) star, while the discarded outer layers that surround it make up what is known as a Wolf-Rayet nebula.
These objects are named after the pair of French astronomers who first discovered them via their unusual spectra, which feature broad emission lines jutting above the continuum. This Wolf-Rayet star in Cygnus is an archetypal colliding wind binary system, the interaction between the powerful winds generated by the WR and O type stars being a subject of interest for astronomers working at wavelengths from radio to X-ray.
Wolf-Rayet stars are very hot, with surface temperatures in the range of 25, K to 50, K. It is believed that the star in the galaxy NGC that exploded into a supernova on January 9, — SN D, the first supernova ever observed in the act of.
The X-ray variability of stars with multiple or long observations has also been investigated. One of the most outstanding cases of X-ray variability is LMC-WR 19 (Brey 16). Chandra observations of this star reveal an increase of its X-ray ﬂux from xto x phot cm-2 s-1 from Dec. to Feb.
We report the discovery of weak yet hard X-ray emission from the Wolf–Rayet (WR) star WR with the XMM-Newton X-ray telescope. Being of spectral subtype WO2, WR is a massive star in a very advanced evolutionary stage shortly before its explosion as a supernova or γ-ray burst.
This is the ﬁrst detection of X-ray emission from a WO. NEAR-INFRARED COUNTERPARTS TO CHANDRA X-RAY SOURCES TOWARD THE GALACTIC CENTER. DISCOVERY OF WOLF–RAYET STARS AND O SUPERGIANTS J. Mauerhan 1,2, M. Morris3, or by accretion onto a compact companion.
However, without direct evidence for companions, the possibility of intrinsic hard X-ray generation from. X-ray survey of Wolf-Rayet stars in the Magellanic Clouds M. Guerrero1 and Y.-H. Chu2 1Instituto de Astrof´ısica de Andaluc´ıa, Consejo Superior de Investigaciones Cient´ıﬁcas (IAA-CSIC), Spain 2Department of Astronomy, University of Illinois at Urbana-Champaign, USA Abstract: Systematic X-ray surveys of Wolf-Rayet (WR) stars in our Galaxy are hampered by the.
that the progenitors could have been a WO type Wolf-Rayet star or a very low metallicity star. Finally we turn our attention to the matter of stellar wind material producing absorption lines in the afterglow spectra.
We discuss the observational signatures of two Wolf-Rayet stellar types, WC and WO, in the afterglow lightcurve and spectra."Line Formation in Winds with Enhanced Equatorial Mass-Loss Rates and its Application to the Wolf-Rayet Star HD " ApJ R Frisch, P.
C. "Precise Positions and Optical Search for the 38 Second X-ray Pulsar near OAO and Upper Limit on X-ray Emission from V Scorpii" "Observations of Compact X-ray Sources.07/ A HABERL, F.;BELLONI, T.; Soft x ray emission from supergiant x ray MAVROMATAKIS, F.
binaries detected on the ROSAT all-sky survey 07/ A BRINKMANN, W.;BOLLER, T.; Extragalactic radio sources in the ROSAT SIEBERT, J. survey.