- 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).
« Previous |
1 - 10 of 14
|
Next »
Number of results to display per page
Search Results
- 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://nasa.heasarc/ascagps
- Title:
- ASCA Galactic Plane Survey of Faint X-Ray Sources
- Short Name:
- ASCAGPS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Sugizaki et al. (2001) have published a study of faint X-ray sources that were resolved in the ASCA Galactic Plane Survey and their contribution to the galactic ridge X-ray emission, and the present database contains their list of discrete sources. The X-ray emission from the central region of the Galactic plane, |l|<~45 degrees and |b|<~0.4 degrees, was studied in the 0.7 to 10 keV energy band with a spatial resolution of ~3' with the Advanced Satellite for Cosmology and Astrophysics (ASCA) observatory. The authors developed a new analysis method for the ASCA data to resolve discrete sources from the extended Galactic ridge X-ray emission (GRXE). Using the ASCA Gas Imaging Spectrometers (GISs), they successfully resolved 163 discrete sources with X-ray fluxes 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 degree. This database was created by the HEASARC in December 2001 based on the ADC/CDS Catalog J/ApJS/134/77/table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ascagis
- Title:
- ASCA GIS Source Catalog (AMSS-I + AMSS-II)
- Short Name:
- ASCAGIS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is the complete X-ray source catalog of the ASCA Medium Sensitivity Survey, AMSS, or the Gas Imaging Spectrometer (GIS) catalog project. It has been constructed from data for fields covering Galactic latitudes |b| > 10 degrees which were obtained with the GIS instrument onboard the ASCA satellite between 1993 May and 1996 December (part I) and between 1997 January and 2000 May (part II). Part I of this catalog (AMSS-I) utilizes 368 combined fields, and contains 1343 sources (including target sources) with detection significance above 5 sigma in at least one of the 3 survey bands of 0.7-7.0, 2-10, or 0.7-2.0 keV, while AMSS-II uses 306 fields, and contains a total of 1190 sources, using the same criteria. The AMSS-I and AMSS-II catalogs together contain 2533 sources from an area of 278 square degrees and provide a unique database of X-ray sources in the flux range of 10^-13 to 10^-11 erg cm^-2 s^-1 (0.7-10 keV). The published paper contains a summary of the statistical properties of a complete X-ray sample consisting of 1969 serendipitous sources selected from AMSS-I and AMSS-II. For each source, the ASCA source name, position, 90% error radius, count rates (both observed and as corrected for Galactic absorption) in the 3 energy bands, detection signifances and fluxes in the 3 energy bands, and hardness ratio and associated error are provided. This version of the Browse ASCAGIS table containing the combined AMSS-I and AMSS-II source lists was created by the HEASARC in February 2006 based on the CDS version of the AMSS-I source list (CDS catalog J/ApJS/133/1) and the electronic ApJS version of the AMSS-II source list. This is a service provided by NASA HEASARC .
- 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://nasa.heasarc/ascalss
- Title:
- ASCA Large Sky Survey
- Short Name:
- ASCALSS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ASCA Large Sky Survey (LSS) was the first wide-area unbiased survey with the ASCA satellite in the 0.7 - 10 keV band around the North Galactic Pole region covering a continuous area of 7 square degrees. To make the best use of ASCA's capabilities, the authors developed a new source detection method in which the complicated detector responses were fully taken into account. Applying this method to the entire LSS data independently in the total (0.7 - 7 keV), hard (2 - 10 keV), and soft (0.7 - 2 keV) bands, they detected 107 sources altogether, with sensitivity limits of 6 x 10<sup>-14</sup> (0.7 - 7 keV), 1 x 10<sup>-13</sup> (2 - 10 keV), and 2 x 10<sup>-14</sup> ergs/s/cm<sup>2</sup> (0.7 - 2 keV), respectively. The complete list of detected sources is presented in this table. The detection criteria that needed to be satisfied were: (i) the significance of the summed count rate of the GIS and the SIS should exceed 4.5, and (ii) the significance of either the GIS or the SIS should also exceed 3.5. This database was created by the HEASARC in December 2001 based on the ADC/CDS Catalog J/ApJ/518/656. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ascamaster
- Title:
- ASCA Master Catalog
- Short Name:
- ASCA
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ASCAMASTER table contains data on all ASCA observations that were ever in any of the following states: 'Accepted', 'Scheduled Long-Term', 'Scheduled Short-Term', 'Processed', and 'Archived'. The final status of an observation is given by the parameter Status. Specific dates that affect the status of an observation are listed as the parameters scheduled_date, observed_date, processed_date, archived_date, and cycle. Notice that, if one or more of the date parameters are empty for a given observation, this means that that those particular processes have not occurred: e.g., if observed_date is empty, this means that the planned observation was not observed. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ascaprspec
- Title:
- ASCAProposalInfo&Abstracts
- Short Name:
- ASCAPRSPEC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ASCAPRSPEC table was created for the purpose of providing a complete, accurate, and easily accessible tracking of ASCA proposal information. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ascao
- Title:
- ASCA Proposals
- Short Name:
- ASCAO
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ASCAO database contains the listing of accepted targets from all proposals submitted in repsonse to the ASCA Guest Observer (GO) Announcements of Opportunities (AOs), as well as the targets that were selected for the Performance Verification (PV) phase. The current version of ASCAO includes all accepted targets from AOs 1 through 8.5 inclusive. Notice that, since the accepted targets include Priority 3 ones of which only a fraction have or will actually be observed, some of the listed targets in this database will never have been observed. To obtain more detailed information about the status of particular targets, please consult either the Master ASCA database table (ASCAMASTER) or the ASCA Observing Log database table (ASCALOG). This database was last updated in August 2000 based on information provided by the ASCA Project. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ascasis
- Title:
- ASCA SIS Source Catalog
- Short Name:
- ASCASIS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This preliminary ASCA SIS Source Catalog contains a list of point sources detected by the Solid-state Imaging Spectrometers (SIS) on-board the ASCA Observatory. This catalog was generated by searching for point-like sources in all data available from the HEASARC's ASCA public archive (ASCAPUBLIC) as of 24 Oct 1996; and is populated by both target and serendipitous sources in the SIS field-of-view. For each catalogued source various information is available, which includes the celestial coordinates of the source, the count rate, the significance of detection, and the hardness ratio, total aperture counts, exposure time, and start time of the observation. In addition, a set of three GIF "thumbnail" images is available in the broad (0.5 - 12 keV), soft (2 < keV), and hard (> 2 keV) spectral bands centered on the apparent detection. These images are convenient for accessing the quality of the source detection. The current catalog is preliminary, the goal of the catalog authors being to make the SIS source list available as quickly as possible. To accomplish this, they took an incremental approach and placed their "work in progress" on-line, warts and all. They urge caution in using and citing these preliminary results, as they point out that the information is not, as yet, 100% reliable. This catalog was generated in January 1997 by Drs. Eric Gotthelf and Nicholas White and resulted from their search for point-like sources in all of the then-available SIS data files in the HEASARC's Public ASCA Data Archive as of 24 Oct 1996. The catalog is populated with both targeted and serendipitous sources that were present in the SIS field-of-view. This is a service provided by NASA HEASARC .
