Related papers: The ASCA Hard Serendipitous Survey

We present main results from X-ray surveys performed with ASCA, focusing on the ASCA Large Sky Survey (LSS), the Lockman Hole deep survey, and the ASCA Medium Sensitivity Survey (AMSS or the GIS catalog project). The log N-log S relations,…

We have surveyed about 50 deg-2 of sky in the largely unexplored 5-10 keV band using the BeppoSAX MECS instrument, finding 180 sources. After correction for the non uniform sky coverage we find about 18 sources deg-2 with F(5-10keV) >=…

We present results on the X-ray spectra of the radio-loud, high-polarization quasar, PKS 1510-089, based on new data obtained using ASCA, and from archival ROSAT data. The X-ray spectrum obtained by ASCA is unusually hard, with the photon…

We present optical spectroscopic identifications of hard X-ray (5-10 keV) selected sources belonging to the HELLAS sample obtained with BeppoSAX down to a 5-10 keV flux limit of f_{5-10 keV}~3x10^-14 erg cm^-2 s^-1. The sample consists of…

We present a 2 - 10 keV ASCA observation of the field around the soft gamma repeater SGR1627-41. A quiescent X-ray source was detected in this observation whose position was consistent both with that of a recently discovered BeppoSAX X-ray…

We present results of ASCA deep exposure observations of the hardest X-ray source discovered in the ASCA Large Sky Survey (LSS) project, designated as AX J131501+3141. We extract its accurate X-ray spectrum, taking account of the…

ASCA's long look at the 288 millisecond radio pulsar, PSR J0631+1036, reveals coherent X-ray pulsation from this source for the first time. The source was first detected in the serendipitous Einstein observation and later identified as a…

Results are presented on the X-ray properties of 9 high-redshift (1.2 < z < 3.4) radio-loud quasars (RLQs) observed by ASCA (10 observations) and ROSAT (11 observations, for a subset of 6 quasars). New ASCA observations of S5 0014+81 (z =…

We report the first simultaneous measure of the X-ray broadband (0.1--200 keV) continuum and of the iron K-alpha fluorescent line profile in the Seyfert 1 galaxy MCG-6-30-15. Our data confirms the ASCA detection of a skewed and redshifted…

We report on the discovery of a narrow-emission-line object at z=0.672 detected in a deep ASCA survey. The object, AXJ0341.4-4453, has a flux in the 2--10keV band of 1.1+/-0.27 E-13 erg/s/cm**2, corresponding to a luminosity of 1.8E44 erg/s…

We present a composite 1-10 keV Seyfert 2 X-ray spectrum, derived from ASCA observations of a distance-limited sample of nearby galaxies. All 29 observed objects were detected. Above ~3 keV, the composite spectrum is inverted, confirming…

The ASCA satellite made 107 pointing observations on a 5 x 5 deg^2 region around the center of our Milky Way Galaxy (the Galactic Center) from 1993 to 1999. In the X-ray images of the 0.7--3 keV or 3--10 keV bands, we found 52 point sources…

We present the result of 27 ASCA observations of 26 radio-quiet quasars (RQQs) from the PG survey. All the RQQs were detected except 2 BALQSOs. We find the variability characteristics of the sources to be consistent with Seyf-1s. A powerlaw…

Here we report the X-ray spectral analysis of 5 high-redshift ($z \geq 2$) radio-quiet quasars (RQQs) observed with the ASCA satellite. A simple power law with Galactic absorption model well fits the data. There is no evidence of a…

To understand luminous AGNs in the z<1 universe, the ASCA AGN samples are the best at present. Combining the identified sample of AGNs from ASCA Large Sky Survey and Medium Sensitivity Survey, the sample of hard X-ray selected AGNs have…

We have made a series of joint spectral fits for two blank fields, the Lockman Hole and the Lynx-3A field, where a significant amount of both ASCA and ROSAT PSPC data exist after thorough screenings. The ASCA SIS, GIS and ROSAT PSPC spectra…

One of the few remaining astronomical bands (factor of $\sim$10 in energy range) still without an all-sky imaging survey is the hard x-ray band (10-600 keV). This is in spite of sensitive imaging all-sky surveys already conducted at soft…

We present Ginga measurements of the spatial fluctuations in the diffuse X-ray background. When combined with earlier results, the new data constrain the extragalactic log N - log S relation in the 2-10 keV energy band to a form close to…

We present Chandra and XMM observations of 12 bright (f(2-10 keV) > 10^-13 cgs) sources from the ASCA SHEEP (Search for the High Energy Extragalactic Population) survey. Most of these have been either not observed or not detected previously…

We have made cross-correlation analyses of (2 -- 15 keV) HEAO A2 and 1 keV ROSAT PSPC All-Sky Survey maps over a selected area ($\sim$ 4000 deg$^2$) with high galactic latitude (b>40 deg). We have calculated the correlations for the bright…