XBootes: An X-Ray Survey of the NDWFS Bootes Field. I. Overview and Initial Results
Abstract
We obtained a 5 ks deep Chandra X-ray Observatory ACIS-I map of the 9.3 deg2 Bootes field of the NOAO Deep Wide-Field Survey. Here we describe the data acquisition and analysis strategies leading to a catalog of 4642 (3293) point sources with 2 or more (4 or more) counts, corresponding to a limiting flux of roughly 4(8)×10-15 ergs cm-2 s-1 in the 0.5-7 keV band. These Chandra XBootes data are unique in that they constitute the widest contiguous X-ray field yet observed to such a faint flux limit. Because of the extraordinarily low background of the ACIS, we expect only 14% (0.7%) of the sources to be spurious. We also detected 43 extended sources in this survey. The distribution of the point sources among the 126 pointings (ACIS-I has a 16'×16' field of view) is consistent with Poisson fluctuations about the mean of 36.8 sources per pointing. While a smoothed image of the point source distribution is clumpy, there is no statistically significant evidence of large-scale filamentary structure. We do find however, that for θ>1', the angular correlation function of these sources is consistent with previous measurements, following a power law in angle with slope ~-0.7. In a 1.4 deg2 sample of the survey, approximately 87% of the sources with 4 or more counts have an optical counterpart to R~26 mag. As part of a larger program of optical spectroscopy of the NDWFS Bootes area, spectra have been obtained for ~900 of the X-ray sources, most of which are quasars or active galactic nuclei.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- November 2005
- DOI:
- 10.1086/444378
- arXiv:
- arXiv:astro-ph/0504084
- Bibcode:
- 2005ApJS..161....1M
- Keywords:
-
- Galaxies: Active;
- Surveys;
- X-Rays: Galaxies;
- Astrophysics
- E-Print:
- 18 Pages, 10 figures (AASTex Preprint format)