XBootes: An X-ray survey of the NDWFS Bootes field. II. The X-ray source catalog

Almus Kenter, Stephen S. Murray, William R. Forman, Christine Jones, Paul Green, Christopher S. Kochanek, Alexey Vikhlinin, Daniel Fabricant, Giovani Fazio, Katherine Brand, Michael J.I. Brown, Arjun Dey, Buell T. Jannuzi, Joan Najita, Brian McNamara, Joseph Shields, Marcia Rieke

Research output: Contribution to journalArticlepeer-review

118 Scopus citations


We present results from a Chandra survey of the 9 deg 2 Bootes field of the NOAO Deep Wide-Field Survey (NDWFS). This XBootes survey consists of 126 separate contiguous ACIS-I observations each of approximately 5000 s in duration. These unique Chandra observations allow us to search for large-scale structure and to calculate X-ray source statistics over a wide, contiguous field of view with arcsecond angular resolution and uniform coverage. Optical spectroscopic follow-up observations and the rich NDWFS data set will allow us to identify and classify these X-ray-selected sources. Using wavelet decomposition, we detect 4642 point sources with n ≥ 2 counts. In order to keep our detections ∼99% reliable, we limit our list to sources with n ≥ 4 counts. For a 5000 s observation and assuming a canonical unabsorbed active galactic nucleus (AGN) type X-ray spectrum, a 4 count on-axis source corresponds to a flux of 4.7 × 10 -15 ergs cm -2 s -1 in the soft (0.5-2 keV) band, 1.5 × 10 -14 ergs cm -2 s -1 in the hard (2-7 keV) band, and 7.8 × 10 -15 ergs cm -2 s -1 in the full (0.5-7 keV) band. The full 0.5-7 keV band n ≥ 4 count list has 3293 point sources. In addition to the point sources, 43 extended sources have been detected, consistent with the depth of these observations and the number counts of clusters. We present here the X-ray catalog for the XBootes survey, including source positions, X-ray fluxes, hardness ratios, and their uncertainties. We calculate and present the differential number of sources per flux density interval, N(S), for the point sources. In the soft (0.5-2 keV) band, N(S) is well fitted by a broken power law with slope of 2.60 -0.12 +0.11 at bright fluxes and 1.74 -0.22 +0.28 for faint fluxes. The hard source N(S) is well described by a single power law with an index of -2.93 -0.09 +0.09.

Original languageEnglish (US)
Pages (from-to)9-20
Number of pages12
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Nov 2005


  • Catalogs
  • Galaxies: active
  • Surveys
  • X-rays: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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