The 2–8 [CLC]ke[/CLC]V X-Ray Number Counts Determined from [ITAL]Chandra[/ITAL] Blank Field Observations
- 10 February 2002
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 566 (1) , L5-L8
- https://doi.org/10.1086/339545
Abstract
We present the 2-8 keV number counts from the 1 Ms Chandra observation of the Chandra Deep Field-North. We combine these with the number counts from a 78 ks exposure of the Hawaii Survey field SSA22 and with the number counts obtained in independent analyses of the Chandra Deep Field-South and the Hawaii Survey field SSA13 to determine the number counts from 2 × 10-16 to 10-13 ergs cm-2 s-1. Over this flux range, the contribution to the X-ray background is 1.1 × 10-11 ergs cm-2 s-1 deg-2. When the contributions above 10-13 ergs cm-2 s-1 from BeppoSAX or ASCA observations are included, the total rises to 1.4 × 10-11 ergs cm-2 s-1 deg-2. However, there appears to be substantial field-to-field variation in the counts in excess of the statistical uncertainties. When the statistical and flux-calibration uncertainties (in both the background and source measurements) are taken into account, as much as 0.5 × 10-11 ergs cm-2 s-1 deg-2 could still be present in an unresolved component.Keywords
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This publication has 20 references indexed in Scilit:
- The HELLAS2XMM Survey. I. The X‐Ray Data and the log N–log SRelationThe Astrophysical Journal, 2002
- The Chandra Deep Field North Survey. V. 1 M[CLC]s[/CLC] Source CatalogsThe Astronomical Journal, 2001
- Direct Detection of Warm Dark Matter in the X‐RayThe Astrophysical Journal, 2001
- The Deepest X-Ray Look at the UniverseThe Astrophysical Journal, 2001
- First Results from the X‐Ray and Optical Survey of theChandraDeep Field SouthThe Astrophysical Journal, 2001
- The Nature of the Hard X-Ray Background Sources: Optical, Near-Infrared, Submillimeter, and Radio PropertiesThe Astronomical Journal, 2001
- ASCA and ROSAT observations of the QSF3 field: the X-ray background in the 0.1-7 keV bandMonthly Notices of the Royal Astronomical Society, 1997
- The Origin of the X-Ray BackgroundAnnual Review of Astronomy and Astrophysics, 1992
- Intergalactic MatterAnnual Review of Astronomy and Astrophysics, 1972
- Evidence for x Rays From Sources Outside the Solar SystemPhysical Review Letters, 1962