Table · dataset · 2026
Selected Area 57 XMM-Newton X-Ray Source Catalog
Listed in IVOA Registry (Virtual Observatory)
The maximum number density of Active Galactic Nuclei (AGNs), as deduced from X-ray studies, occurs at z >= 1, with lower luminosity objects peaking at smaller redshifts.
Description
Optical studies lead to a different evolutionary behaviour, with a number density peaking at z ~ 2 independently of the intrinsic luminosity, but this result is limited to active nuclei brighter than the host galaxy. A selection based on optical variability can detect low luminosity AGNs (LLAGNs), where the host galaxy light prevents the identification by non-stellar colours.
The authors collected X-ray data in a field where there existed an optically-selected sample of "variable galaxies", i.e. variable objects with diffuse appearance, in order to investigate the X-ray and optical properties of the population of AGNs, particularly of low luminosity ones, where the host galaxy is visible. They observed a field of ~ 0.2 deg<sup>2</sup> in the Selected Area 57, for 67 ks with XMM-Newton.
Read the rest (3 more)
They correlated the list of detected X-ray sources with a photographic survey of SA 57, complete to B_J ~ 23 and with the available spectroscopic data. They obtained a catalog of 140 X-ray sources to limiting fluxes of 5 x 10<sup>-16</sup> and 2 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s in the 0.5 - 2 keV and 2 - 10 keV bands, respectively, 98 of which are identified in the optical bands.
The X-ray detection of part of the variability-selected candidates confirms their AGN nature. Diffuse variable objects populate the low luminosity side of the sample. Only 25/44 optically-selected QSOs are detected in X-rays. 15% of all QSOs in the field have X/O < 0.1.
Additional information on the likely optical counterparts of 98 of the X-ray sources is available in the reference paper, e.g., in Table 3. This table was created by the HEASARC in September 2007 based on CDS table J/A+A/469/1211 file table2.dat. This is a service provided by NASA HEASARC .
Links
Where it is published
- Reference page heasarc.gsfc.nasa.gov/W3Browse/all/sa57xmm.html ↗
landing page · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/nasa.heasarc/sa57xmm ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- X-Ray
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Tabular 65%
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://nasa.heasarc/sa57xmm | 15 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:x-ray | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].local:modality:tabular | enrichment · IVOA Registry | keyword-concept-rules@1.0.0 | title+description (65%) |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |