Data · dataset · 2025
Chandra Large-Area Synoptic X-Ray Survey of Lockman Hole-NW
Listed in NASA Data Portal
Description
This table contains the X-ray catalog and basic results from the wide-area, moderately deep Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest (LHNW) field (Yang et al. 2004), as well as the results from optical and near-infrared photometric and spectroscopic observations of these X-ray sources (Steffen et al. 2004). The nine ACIS-I fields cover a contiguous solid angle of 0.4 square degrees and reach fluxes of 5 x 10<sup>-16</sup> ergs/cm<sup>2</sup>/s (0.4 - 2 keV) and 3 x 10<sup>-15</sup> ergs/cm<sup>2</sup>/s (2 - 8 keV).
(Note that fields LHNW 1-3 were observed during 2001 April 30-May 17, and that the rest of the fields were observed during 2002 April 29-May 4). This survey bridges the gap between ultra-deep pencil-beam surveys, such as the Chandra Deep Fields (CDFs), and shallower, large-area surveys, allowing a better probe of the X-ray sources that contribute most of the 2 - 10 keV cosmic X-ray background (CXB). A total of 525 X-ray point sources and four extended sources were found.
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There are B, V, R, I, and z' photometry for 521 (99%) of the 525 sources in the X-ray catalog and spectroscopic redshifts for 271 (52%), including 20 stars. The authors did not find evidence for redshift groupings of the X-ray sources, like those found in the Chandra Deep Field surveys, because of the larger solid angle covered by this survey. They separated the X-ray sources by optical spectral type and examined the colors, apparent and absolute magnitudes, and redshift distributions for the broad-line and non-broad-line active galactic nuclei.
Combining their wide-area survey with other Chandra and XMM-Newton hard X-ray surveys, they find a definite lack of luminous, high accretion rate sources at z < 1, consistent with previous observations that showed that super-massive black hole growth is dominated at low redshifts by sources with low accretion rates. This table was created by the HEASARC in May 2005 from the merger of 3 CDS tables, corresponding to Tables 2 and 3 from Yang et al. 2005 and Table 1 of Steffen et al. (2005): <p> <pre> J/AJ/128/1501/table2.dat J/AJ/128/1501/table3.dat J/AJ/128/1483/table1.dat </pre> This is a service provided by NASA HEASARC .
Links
Get the data
- Resource heasarc.gsfc.nasa.gov/W3Browse/all/clasxs.html ↗
download · from data nasa gov
- Resource heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets=&table=clasxs ↗
download · from data nasa gov
Where it is published
- NASA Data Portal dataset page data.nasa.gov/dataset/chandra-large-area-synoptic-x-ray-survey-of-lockman-ho… ↗
landing page · from data nasa gov
Catalogue records · 1
- CKAN API data.nasa.gov/api/3/action/package_show?id=0e5cbcb8-e6cf-48b4-b5bb-14433ecee… ↗
metadata API · from data nasa gov
Topics
- Inferred from text
- Tabular 65%
Provenance · 1 source records, 7 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| NASA Data Portal | 0e5cbcb8-e6cf-48b4-b5bb-14433ecee923 | 12 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| 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 |