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Related papers: The ASCA Hard Serendipitous Survey

200 papers

We present results from a radio survey for variable and transient sources on 15-min timescales, using the Australian SKA Pathfinder (ASKAP) pilot surveys. The pilot surveys consist of 505 h of observations conducted at around 1 GHz…

We present the results of the deepest optically identified X-ray survey yet made. The X-ray survey was made with the ROSAT PSPC and reaches a flux limit of 1.6x10^-15 erg cm^-2 s^-1 (0.5--2.0 keV). Above a flux limit of 2x10^-15 erg cm^-2…

We present the preliminary findings of our XMM-Newton Survey performed in the hard band [7-11] keV. The survey covers nearly 30 squares degrees for a total of 112 fields observed. We detected in the [7-11] keV band, down to a limit flux of…

Astrophysics · Physics 2017-03-29 N. Carangelo , S. Molendi , the Hellas2XMM collaboration

We present radio observations of 19 candidate compact steep-spectrum (CSS) objects selected from a well-defined, complete sample of 52 B2 radio sources of intermediate strength. These observations were made with the VLA A-array at 4.835…

Astrophysics · Physics 2009-11-07 D. J. Saikia , P. Thomasson , R. E. Spencer , F. Mantovani , C. J. Salter , S. Jeyakumar

Observations of Galactic black hole sources are traditionally done in the classical X-ray range (2 -- 10 keV) due to sensitivity constraints. Most of the accretion power, however, is radiated above 10 keV and the study of these sources in…

High Energy Astrophysical Phenomena · Physics 2013-10-02 A. R. Rao

We report on highlight results on celestial sources observed in the high energy band (>20 keV) with BeppoSAX. In particular we review the spectral properties of sources that belong to different classes of objects, i.e. stellar coronae…

The bright persistent X-ray source and type I X-ray burster 1E1724-3045 located in the globular cluster Terzan 2 was observed by ASCA for about 10 ksec on September 24-25th, 1995 while it was in its hard state, with a luminosity of…

Astrophysics · Physics 2007-05-23 D. Barret , J. E. Grindlay , I. M. Harrus , J. F. Olive

Optical spectroscopy has enabled us to identify the optical counterparts to over 200 faint X-ray sources to a flux limit of S_(0.5-2keV)=4x10^-15 erg s^-1 cm^-2 on 5 deep ROSAT fields. Here we present a spectral analysis of all the X-ray…

We present detailed broadband timing and spectral analysis of the persistent, low luminosity and slowly spinning pulsar X Persei using a deep Suzaku observation of the source. The spectrum is unusually hard with a cyclotron resonance…

High Energy Astrophysical Phenomena · Physics 2017-06-28 Chandreyee Maitra , Harsha Raichur , Pragati Pradhan , Biswajit Paul

We have observed an area of approximatley 27 deg^2 to an rms noise level of less than 0.2 mJy at 15.7 GHz, using the Arcminute Microkelvin Imager Large Array. These observations constitute the most sensitive radio-source survey of any…

We study the clustering properties of X-ray sources detected in the wide area ($\sim 2 $deg$^{2}$) bright, contiguous XMM-{\em Newton}/2dF survey. We detect 432 objects to a flux limit of $5\times 10^{-15}$ ergcm$^{-2}$s$^{-1}$ in the soft…

Astrophysics · Physics 2009-11-10 S. Basilakos , M. Plionis , A. Georgakakis , I. Georgantopoulos

We present the analysis of 31 observations of 20 bright Compton thin Seyfert 2s, in the 0.1-200 keV band, performed with the BeppoSAX satellite. The sample consists of all Seyfert 2s in the BeppoSAX public archive, with a 2-10 keV flux…

Astrophysics · Physics 2009-11-07 G. Risaliti

The clustering properties of the highest energy cosmic rays and their correlations with candidate sources are re-examined using the most recently available AGASA data and a rigorous correlation analysis. The statistical methodology…

Astrophysics · Physics 2007-05-23 William S. Burgett , Mark R. O'Malley

The origin of the hard (2-10 keV) X-ray background has remained mysterious for over 35 years. Most of the soft (0.5-2 keV) X-ray background has been resolved into discrete sources, which are primarily quasars; however, these sources do not…

Astrophysics · Physics 2017-05-10 R. F. Mushotzky , L. L. Cowie , A. J. Barger , K. A. Arnaud

We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the 2 deg2 COSMOS field (XMM-COSMOS). A significant positive signals have been…

For more than a decade, Alpha Centauri AB (G2V+K1V) has been observed by Chandra, in a long-term program to follow coronal (T~1MK) activity cycles of the two sunlike stars. Over 2008.4-2017.8, nineteen HRC-I exposures were taken, each about…

Solar and Stellar Astrophysics · Physics 2018-11-28 Thomas R. Ayres

We report on the identification of the X/soft gamma-ray source AX J183039-1002 detected with ASCA and INTEGRAL/IBIS. The source, which has an observed 20-100 keV flux of about 8.6 x 10^-11 erg/cm^2/s, is inside a diffuse radio supernova…

Astrophysics of Galaxies · Physics 2009-11-13 L. Bassani , R. Landi , R. Campana , V. A. McBride , A. J. Dean , A. J. Bird , D. A. Green , P. Ubertini , A. De Rosa

We have used non-simultaneous Ginga, ASCA and ROSAT observations to investigate the complex X-ray spectrum of the Seyfert 2 galaxy Mrk 3. We find that the composite spectrum can be well described in terms of a heavily cut-off hard X-ray…

Astrophysics · Physics 2009-10-30 R. G. Griffiths , R. S. Warwick , I. Georgantopoulos , C. Done , D. A. Smith

We present a systematic analysis of the X-ray spectral properties of a sample of 22 ``narrow-line'' Seyfert 1 galaxies for which data are available from the ASCA public archive. Many of these sources, which were selected on the basis of…

Astrophysics · Physics 2008-11-26 S. Vaughan , J. Reeves , R. Warwick , R , Edelson