AEGIS-X: THE CHANDRA DEEP SURVEY OF THE EXTENDED GROTH STRIP

We present the AEGIS-X survey, a series of deep Chandra ACIS-I observations of the Extended Groth Strip. The survey comprises pointings at eight separate positions, each with nominal exposure of 200 ks, covering a total area of approximately 0.67 deg2 in a strip of length 2 degrees. We describe in detail an updated version of our data reduction and point-source-detection algorithms used to analyze these data. A total of 1325 band-merged sources have been found to a Poisson probability limit of 4 × 10−6, with limiting fluxes of 5.3 × 10−17 erg cm2 s−1 in the soft (0.5–2 keV) band and 3.8 × 10−16 erg cm−2 s−1 in the hard (2–10 keV) band. We present simulations verifying the validity of our source-detection procedure and showing a very small, <1.5%, contamination rate from spurious sources. Optical/NIR counterparts have been identified from the DEEP2, CFHTLS, and Spitzer/Infrared Array Camera (IRAC) surveys of the same region. Using a likelihood ratio method, we find optical counterparts for 76% of our sources, complete to RAB = 24.1, and, of the 66% of the sources that have IRAC coverage, 94% have a counterpart to a limit of 0.9 μJy at 3.6 μm (mAB = 23.8). After accounting for (small) positional offsets in the eight Chandra fields, the astrometric accuracy of Chandra positions is found to be 0.″8 rms; however, this number depends both on the off-axis angle and the number of detected counts for a given source. All data products described in this paper are made available via a public Web site.

[1]  S. Virani,et al.  Mid-Infrared Properties and Color Selection for X-Ray-Detected Active Galactic Nuclei in the MUSYC Extended Chandra Deep Field-South , 2008 .

[2]  M. Trichas,et al.  A new method for determining the sensitivity of X-ray imaging observations and the X-ray number counts , 2008, 0805.4417.

[3]  I. Smail,et al.  THE CHANDRA DEEP FIELD-SOUTH SURVEY: 4 Ms SOURCE CATALOGS , 2008, 0806.3968.

[4]  J. Silverman,et al.  Tracing the Mass-Dependent Star Formation History of Late-Type Galaxies Using X-Ray Emission: Results from the Chandra Deep Fields , 2008, 0803.3620.

[5]  E. L. Wright,et al.  A Catalog of Mid-Infrared Sources in the Extended Groth Strip , 2008, 0803.0748.

[6]  S. Virani,et al.  Mid-infrared Properties And Color-Selection For X-ray Detected Agn , 2007, 0803.0251.

[7]  J. N. Reeves,et al.  An XMM–Newton survey of broad iron lines in Seyfert galaxies , 2007, 0708.1305.

[8]  S. Finkelstein,et al.  Chandra X-Ray Sources in the LALA Cetus Field , 2007, 0707.3239.

[9]  D. Thompson,et al.  The XMM-Newton Wide-Field Survey in the COSMOS Field. III. Optical Identification and Multiwavelength Properties of a Large Sample of X-Ray-Selected Sources , 2006, astro-ph/0612358.

[10]  Nancy R. Evans,et al.  Chandra Multiwavelength Project X-Ray Point Source Catalog , 2006, astro-ph/0611840.

[11]  E. L. Wright,et al.  The All-Wavelength Extended Groth Strip International Survey (AEGIS) Data Sets , 2006, astro-ph/0607355.

[12]  S. Roweis,et al.  K-Corrections and Filter Transformations in the Ultraviolet, Optical, and Near-Infrared , 2006, astro-ph/0606170.

[13]  Martin Elvis,et al.  The Chandra COSMOS Survey , 2006 .

[14]  K. Nandra,et al.  The X-ray emission of Lyman break galaxies , 2006, astro-ph/0609123.

[15]  Vinay L. Kashyap,et al.  Bayesian Estimation of Hardness Ratios: Modeling and Computations , 2006 .

[16]  M. C. Cooper,et al.  A deep Chandra survey of the Groth Strip – II. Optical identification of the X‐ray sources , 2006, astro-ph/0606139.

[17]  Mid-Infrared Properties of X-Ray Sources in the Extended Groth Strip , 2005, astro-ph/0512618.

[18]  Martin G. Cohen,et al.  Absolute Calibration of the Infrared Array Camera on the Spitzer Space Telescope , 2005, astro-ph/0507139.

[19]  B. Garilli,et al.  The VVDS-VLA Deep Field II. Optical and near infrared identifications of VLA S(1.4GHz)>80 microJy sources in the VIMOS VLT Deep Survey VVDS-02h field , 2005, astro-ph/0506690.

[20]  O. University,et al.  XBootes: An X-Ray Survey of the NDWFS Bootes Field. I. Overview and Initial Results , 2005, astro-ph/0504084.

[21]  W. Brandt,et al.  DEEP EXTRAGALACTIC X-RAY SURVEYS , 2005, astro-ph/0501058.

[22]  J. Rhodes,et al.  A deep Chandra survey of the Groth Strip - I. The X-ray data , 2004, astro-ph/0410149.

[23]  R. Mushotzky,et al.  The Chandra Large Area Synoptic X-Ray Survey (CLASXS) of the Lockman Hole-Northwest: The X-Ray Catalog , 2004, astro-ph/0409087.

[24]  J. Newman,et al.  Evolution and Color Dependence of the Galaxy Angular Correlation Function: 350,000 Galaxies in 5 Square Degrees , 2004, astro-ph/0403423.

[25]  D. M. Alexander,et al.  Optical and Infrared Properties of the 2 Ms Chandra Deep Field North X-Ray Sources , 2003, astro-ph/0306212.

[26]  D. M. Alexander,et al.  The Chandra Deep Field North Survey. XV. Optically Bright, X-Ray-Faint Sources , 2003, astro-ph/0305086.

[27]  D. M. Alexander,et al.  The Chandra Deep Field North Survey. XIII. 2 Ms Point-Source Catalogs , 2003, astro-ph/0304392.

[28]  Garching,et al.  A deep VLA survey at 6 cm in the Lockman Hole , 2002, astro-ph/0211625.

[29]  W. Brandt,et al.  The Chandra Deep Field North Survey. XII. The Link between Faint X-Ray and Radio Source Populations , 2002, astro-ph/0207433.

[30]  W. N. Brandt,et al.  X-Ray, Optical, and Infrared Imaging and Spectral Properties of the 1 Ms Chandra Deep Field North Sources , 2002 .

[31]  D. M. Alexander,et al.  The Chandra Deep Field-North Survey. XI. X-Ray Emission from Luminous Infrared Starburst Galaxies , 2002, astro-ph/0202493.

[32]  Roberto Gilmozzi,et al.  Chandra Deep Field South: The 1 Ms Catalog , 2002 .

[33]  D. Lamb,et al.  A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data , 2001, astro-ph/0108429.

[34]  D. M. Alexander,et al.  The Chandra Deep Field North Survey. VI. The Nature of the Optically Faint X-Ray Source Population , 2001 .

[35]  E. Feigelson,et al.  The Chandra Deep Survey of the Hubble Deep Field-North Area. II. Results from the Caltech Faint Field Galaxy Redshift Survey Area , 2001 .

[36]  Ralf Bender,et al.  A Relationship between Nuclear Black Hole Mass and Galaxy Velocity Dispersion , 2000, astro-ph/0006289.

[37]  D. Merritt,et al.  A Fundamental Relation between Supermassive Black Holes and Their Host Galaxies , 2000, astro-ph/0006053.

[38]  Wolfgang Voges,et al.  Optical Identification of the ASCA Large Sky Survey , 2000 .

[39]  K. Banas,et al.  The Association of Supernova Remnants and Molecular Clouds in the Large Magellanic Cloud , 1995 .

[40]  D. Burrows,et al.  Determination of Confidence Limits for Experiments with Low Numbers of Counts , 1991 .

[41]  J. Dickey,et al.  H I in the Galaxy , 1990 .

[42]  N. Gehrels Confidence limits for small numbers of events in astrophysical data , 1986 .

[43]  A. Eddington,et al.  The correction of statistics for accidental error , 1940 .