نتایج جستجو برای: pspc

تعداد نتایج: 575  

2004
J. Greiner

We have performed Chandra observations during the past 3 years of 5 of the M31 supersoft X-ray sources discovered with ROSAT. Surprisingly, only one of these sources has been detected, despite a predicted detection of about 20-80 counts for these sources. This has motivated a thorough check of the ROSAT M31 survey I data, including a relaxation of the hardness ratio requirement used to select s...

2000
Th. Boller A. C. Fabian W. N. Brandt M. J. Freyberg

We report on a ROSAT PSPC observation of the highly-luminous z = 4.72 radio-loud quasar GB 1428+4217 obtained between 1998 December 11 and 17, the final days of the ROSAT satellite. The low-energy sensitivity of the PSPC detector was employed to constrain the intrinsic X-ray absorption of the currently most distant X-ray detected object. Here we present the detection of significant soft X-ray a...

1997
F. Verbunt W. H. Bunk H. Ritter E. Pfeffermann

91 cataclysmic variables from a sample of 162 systems with known or suspected binary periods were detected during the ROSAT XRT-PSPC All Sky Survey. Among the non-magnetic systems, the X-ray to optical/ultraviolet flux ratio decreases along the sequence SU UMa type – U Gem type – Z Cam type – UX UMa type, due mainly to variations in the optical/ultraviolet flux. 8 of the 10 brightest systems in...

2000
Almudena Prieto

ROSAT/HRI observations of the powerful radio-loud galaxy 3C382 reveal extended X-ray emission associated with the source. On the basis of this new spatial component, a previous ROSAT/PSPC spectral analysis of the source is revised. Allowing for the presence of an additional thermal component in the PSPC spectrum, the non-thermal component is found to be compatible with the extrapolation of the ...

Journal: :Astronomy and Astrophysics Supplement Series 1999

2015
S. Guillot V. M. Kaspi R. F. Archibald M. Bachetti C. Flynn F. Jankowski M. Bailes S. Boggs F. E. Christensen W. W. Craig C. A. Hailey F. A. Harrison D. Stern W. W. Zhang

We present a hard X-ray Nuclear Spectroscopic Telescope Array (NuSTAR) observation of PSR J0437−4715, the nearest millisecond pulsar. The known pulsations at the apparent pulse period ∼5.76ms are observed with a significance of 3.7σ , at energies up to 20 keV above which the NuSTAR background dominates. We measure a photon index = 1.50 ± 0.25 (90 per cent confidence) for the power-law fit to th...

2003
R. Mukherjee J. P. Halpern E. V. Gotthelf

We have made a multiwavelength study of the overlapping error boxes of the unidentified γ-ray sources TeV J2032+4130 and 3EG J2033+4118 in the direction of the Cygnus OB2 association (d = 1.7 kpc) in order to search for a pointsource counterpart of the first unidentified TeV source. Optical identifications and spectroscopic classifications for the brighter X-ray sources in ROSAT PSPC and Chandr...

Journal: :Astronomy and Astrophysics Supplement Series 1996

Journal: :Monthly Notices of the Royal Astronomical Society 1994

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