- ID:
- ivo://CDS.VizieR/J/PASJ/53/445
- Title:
- ASCA Deep survey in Lockman Hole Field
- Short Name:
- J/PASJ/53/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of deep observations of the Lockman Hole field with the ASCA SIS, covering 926arcmin^2^ in the 1-7keV energy range, with a sensitivity 3-5 times deeper than the previous ASCA larger area surveys. Utilizing the results of the ROSAT Ultra Deep survey, we have detected 32, 25, and 15 sources in the 1-7, 1-2, and 2-7keV bands, and only 4, 4, and 1 sources remain unidentified, respectively. The average hardness of the sources detected in the 1-7keV band with fluxes of between 10^-14^ and 10^-13^erg/cm^2^/s corresponds to a photon index of 1.65+/-0.10. Type-2 AGNs show significantly harder spectra than type-1s, which can be explained by absorption column densities of N_H_~10^22-23^cm^-2 at the source redshifts. Fifteen sources are detected in the hard-band (2-7keV), consisting of six type-1 AGNs, six type-2 AGNs, one star, one cluster of galaxies, and one unidentified source. Type-2 AGNs make up a major part of hard X-ray populations in the 2-7keV band at a flux level of 3x10^-14^erg/cm^2^/s (2-7 keV). The redshift distributions of type-1 and type-2 AGNs suggest a lack of high luminosity (optically-defined) type-2 AGNs with intrinsic N_H_<10^23^cm^-2, n the redshift range z~1-2 and/or with intrinsic luminosities larger than 3x10^44^erg/s (2-10keV at source frame).
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- ID:
- ivo://CDS.VizieR/J/ApJS/134/77
- Title:
- ASCA Galactic Plane Survey faint X-ray sources
- Short Name:
- J/ApJS/134/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The X-ray emission from the central region of the Galactic plane, |l|<~45{deg} and |b|<~0.4{deg}, was studied in the 0.710keV energy band with a spatial resolution of ~3' with the Advanced Satellite for Cosmology and Astrophysics (ASCA) observatory. We developed a new analysis method for the ASCA data to resolve discrete sources from the extended Galactic ridge X-ray emission (GRXE). We successfully resolved 163 discrete sources with an X-ray flux down to 10^-12.5^ergs/cm^2^/s and determined the intensity variations of the GRXE as a function of the Galactic longitude with a spatial resolution of about 1{deg}.
- ID:
- ivo://CDS.VizieR/J/ApJ/518/656
- Title:
- ASCA Large Sky Survey
- Short Name:
- J/ApJ/518/656
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out the first wide-area unbiased survey with the ASCA satellite in the 0.7-10keV band around a north Galactic-pole region covering a continuous area of 7deg^2^ (Large Sky Survey; LSS). To make the best use of ASCA's capabilities, we developed a new source-detection method in which the complicated detector responses are fully taken into account. Applying this method to the entire LSS data independently in the total (0.7-7keV), hard (2-10keV), and soft (0.7-2keV) bands, we detected 107 sources altogether, with sensitivity limits of 6x10^-14^ (0.7-7keV), 1x10^-13^ (2-10keV), and 2x10^-14^ergs/s/cm^2^ (0.7-2keV), respectively. A complete list of the detected sources is presented.
- ID:
- ivo://CDS.VizieR/J/PASJ/55/161
- Title:
- ASCA sources in the SMC
- Short Name:
- J/PASJ/55/161
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We made 22 observations on the Small Magellanic Cloud (SMC) and covered full regions of the main body and the eastern wing by the end of the ASCA mission. We detected 106 discrete sources with a criterion of S/N>5 and performed systematic analyses on all of the sources. We determined the source positions with an ~40" error radius (90% confidence) for sources detected in the central 20' radius of the GIS. We detected coherent pulsations from 17 sources. Among them, eight were newly discovered during this study. We classified most of these pulsars as X-ray binary pulsars (XBPs) based on their properties, such as the flux variability and the existence of an optical counterpart. We detected X-ray emission from eight supernova remnants (SNRs). Based on these ASCA results and further information from ROSAT, SAX, RXTE, CGRO, Chandra, and XMM-Newton, we compiled comprehensive catalogues of discrete X-ray sources in the Small Magellanic Cloud.
- ID:
- ivo://CDS.VizieR/J/ApJS/133/1
- Title:
- GIS catalog project : source catalog
- Short Name:
- J/ApJS/133/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first X-ray source catalog of the ASCA Medium Sensitivity Survey (AMSS, or the GIS catalog project), constructed from data at Galactic latitudes |b|>10{deg} observed between 1993 May and 1996 December. The catalog utilizes 368 combined fields and contains 1343 sources with the detection significance above 5{sigma} either in the survey bands of 0.7-7keV, 2-10keV, or 0.7-2keV, including target sources. For each source, the ASCA source name, position, a 90% error radius, count rates in the three bands, detection significances, fluxes, and a hardness ratio are provided. With extensive simulations, we carefully evaluate the data quality of the catalog. Results from cross-correlation with other existing catalogs are briefly summarized.
- ID:
- ivo://CDS.VizieR/J/ApJS/161/185
- Title:
- GIS catalog project : source catalog II
- Short Name:
- J/ApJS/161/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In succession to the first ASCA Medium Sensitivity Survey catalog (AMSS-I), we present the second X-ray source catalog (AMSS-II), constructed from the Gas Imaging Spectrometer (GIS) data covering Galactic latitudes |b|>10{deg} observed between 1997 January and 2000 May. The AMSS-II catalog uses 306 fields and contains a total of 1190 sources detected with significance of >5{sigma} in either the 0.7-7, 2-10, or 0.7-2keV band. The AMSS-I and AMSS-II catalogs list a total of 2533 sources from an area of 278{deg}^2^ and provides a unique database of X-ray sources in the flux range of 10^-13^-10^-11^ergs/cm^2^/s (0.7-10keV). We summarize statistical properties of a complete X-ray sample consisting of 1969 serendipitous selected from AMSS-I and AMSS-II.
- ID:
- ivo://CDS.VizieR/VI/117
- Title:
- Observation Log from ASCA
- Short Name:
- VI/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- ASCA (Advanced Satellite for Cosmology and Astrophysics) is the fourth Japanese X-ray astronomy satellite launched on February 20, 1993 (see Tanaka et al., 1994PASJ...46L..37T) The collaboration between Japanese and US scientists has been carried out in the developments of the X-ray telescopes, the X-ray CCD cameras, and software. ASCA observed more than 3000 targets before stopping scientific observations as a consequence of a huge solar flare occured in mid July, 2000. ISAS continued monitoring operation until the ASCA reentered the atmosphere on March 2, 2001. Scientific instrumentation of ASCA consists of four X-ray telescopes and corresponding focal plane detectors. Focal plane detectors are two X-ray CCD cameras (SIS: Solid-state Imaging Spectrometers) and two Gas Imaging Spectrometers (GIS). With these detectors, ASCA covers the energy range of 0.5-10 keV. This catalogue is a copy of the ASCA Observation log from the Data ARchive and Transmission System (DARTS), provided by the PLAIN center at ISAS/JAXA, Japan. All the ASCA data have been public. The data is archived in a target-oriented (strictly speaking, observation-oriented) structure, i.e., all the data produced from an observation is put into a directory --- although some exceptions exist for observations in very early epoch. Each dataset includes telemetry data, data products (event files, images, energy spectra, light curves, etc.), and calibration data. ISAS provides the telemetry and calibration data, and ASCA data processing center in ADF (Astrophysics Data Facility) at NASA/GSFC reproduces the data products.
