Data · dataset · 2025
Chandra Serendipitous Extragalactic X-Ray Source ID (SEXSI) Catalog
Listed in NASA Data Portal
The Serendipitous Extragalactic X-Ray Source Identification (SEXSI) program is designed to extend greatly the sample of identified extragalactic hard X-ray (2 - 10 keV) sources at intermediate fluxes (~10<sup>-13</sup> to 10<sup>-15</sup> erg/cm<sup>2</sup>/s).
Description
SEXSI, which studies sources selected from more than 2 deg<sup>2</sup>, provides an essential complement to the Chandra Deep Fields, which reach depths of 5 x 10<sup>-16</sup> erg/cm<sup>2</sup>/s (2 - 10 keV) but over a total area of less than 0.2 deg<sup>2</sup>.
In their published paper, the authors describe the characteristics of the survey and their X-ray data analysis methodology. They present the cumulative flux distribution for the X-ray sample of 1034 hard sources and discuss the distribution of spectral hardness ratios. Their log N -log S in this intermediate flux range connects to those found in the Deep Fields, and by combining the data sets, they constrain the hard X-ray population over the flux range in which the differential number counts change slope and from which the bulk of the 2 - 10 keV X-ray background arises.
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They further investigate the log N - log S distribution separately for soft and hard sources in the sample, finding that while a clear change in slope is seen for the softer sample, the hardest sources are well described by a single power law down to the faintest fluxes, consistent with the notion that they lie at lower average redshift. In the SEXSI program, fields were selected with high Galactic latitude (|b| > 20 degrees) and with declinations accessible to the optical facilities available to the authors (declination > -20 degrees).
They used observations taken with Chandra's Advanced Camera for Imaging Spectroscopy (ACIS I- and S-modes; Bautz et al., 1998, Proc. SPIE, 3444, 210) only (for sensitivity in the hard band). All the fields presented in this paper have data that are available in the Chandra public archive.
This table was created by the HEASARC in June 2004 based on <a href="cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/596/944/table4">CDS Catalog J/ApJ/596/944/table4</a>.dat which is a representation of Table 4 from the published version. Note that it does not include the Soft-Band-Only Source Catalog (Table 6 in the published version of the paper). This is a service provided by NASA HEASARC .
Links
Get the data
- Resource heasarc.gsfc.nasa.gov/W3Browse/all/chansexsi.html ↗
download · from data nasa gov
- Resource heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets=&table=chansexsi ↗
download · from data nasa gov
Where it is published
- NASA Data Portal dataset page data.nasa.gov/dataset/chandra-serendipitous-extragalactic-x-ray-source-id-se… ↗
landing page · from data nasa gov
Catalogue records · 1
- CKAN API data.nasa.gov/api/3/action/package_show?id=7baea464-2860-42fe-bc35-303a82561… ↗
metadata API · from data nasa gov
Topics
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| NASA Data Portal | 7baea464-2860-42fe-bc35-303a82561af0 | 11 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| concepts[modality].local:modality:imaging | enrichment · data nasa gov | keyword-concept-rules@1.0.0 | title+description (75%) |
| concepts[modality].local:modality:tabular | enrichment · data nasa gov | keyword-concept-rules@1.0.0 | title+description (65%) |
| created_date | source · data nasa gov | connector:data_nasa_gov@1.0.0 | |
| description | source · data nasa gov | connector:data_nasa_gov@1.0.0 | /notes |
| license_text | source · data nasa gov | connector:data_nasa_gov@1.0.0 | |
| publication_date | source · data nasa gov | connector:data_nasa_gov@1.0.0 | |
| title | source · data nasa gov | connector:data_nasa_gov@1.0.0 | /title |
| updated_date | source · data nasa gov | connector:data_nasa_gov@1.0.0 |