Related papers: Faint Source Counts from the Off-source fluctuatio…

We report the results of fluctuation analysis of the off-source field from the 1 Million second Chandra observation of the Hubble Deep Field-North (HDF-N). The distribution of the counts in cells has been compared with the expectations from…

We present the main results from our 940 ksec observation of the Chandra Deep Field South (CDFS), using the source catalog described in an accompanying paper (Giacconi et al. 2001). We extend the measurement of source number counts to…

It is assumed that the unresolved fraction of the X-ray background (XRB) consists of a truly diffuse component and a population of the weak sources below the present detection threshold. Albeit these weak sources are not observed directly,…

We investigate the X-ray number counts in the 1-2 Ms Chandra Deep Fields (CDFs) to determine the contributions of faint X-ray source populations to the extragalactic X-ray background (XRB). X-ray sources were separated into Active Galactic…

We present first results of the X-ray spectral analysis of the 500 ksec deep survey obtained with XMM-Newton on the Chandra Deep Field South (CDFS). Statistical distributions of spectral index and intrinsic absorption are derived for a…

We present 0.5-2 keV, 2-8 keV, 4-8 keV, and 0.5-8 keV cumulative and differential number counts (logN-logS) measurements for the recently completed ~4 Ms Chandra Deep Field-South (CDF-S) survey, the deepest X-ray survey to date. We…

We briefly report here on our ongoing X-ray spectroscopy and variability analyses of 136 faint X-ray sources discovered in the 2 Ms Chandra Deep Field North observations spanning 1.4x10-15 to 2x10-13 ergs s-1 cm-2. Most sources are…

We present Ginga measurements of the spatial fluctuations in the diffuse X-ray background. When combined with earlier results, the new data constrain the extragalactic log N - log S relation in the 2-10 keV energy band to a form close to…

We present results from 300 ks of X-ray observations of the Chandra Deep Field South. The field of the four combined exposures is now 0.1035 deg^2 and we reach a flux limit of 10^{-16} erg s^{-1} cm^{-2} in the 0.5-2 keV soft band and…

An analysis of the spatial fluctuations in 15 deep ASCA SIS0 images has been conducted in order to probe the 2-10 keV X-ray source counts down to a flux limit 2E-14 erg/cm2/s. Special care has been taken in modelling the fluctuations in…

We studied the X-ray variability of sources detected in the Chandra Deep Field South (Giacconi et al. 2002), nearly all of which are low to moderate z AGN (Tozzi et al. 2001). We find that 45% of the sources with >100 counts exhibit…

We present the first results of ChaMP X-ray source properties obtained from the initial sample of 62 observations. The data have been uniformly reduced and analyzed with techniques specifically developed for the ChaMP and then validated by…

We present our first results from 130 ks of X-ray observations obtained with the Advanced CCD Imaging Spectrometer on the Chandra X-ray Observatory. We reach a flux of 2 X 10^(-16) erg s^(-1) cm^(-2) in the 0.5-2 keV soft band and 2 X…

In this Paper we present the source catalog obtained from a 942 ks exposure of the Chandra Deep Field South (CDFS), using ACIS-I on the Chandra X-ray Observatory. Catalog generation proceeded simultaneously using two different methods; a…

We provide important new constraints on the nature and redshift distribution of optically faint (R>25) X-ray sources in the Chandra Deep Field South Survey. We show that we can derive accurate photometric redshifts for the spectroscopically…

We present results from a study of 2-8 keV X-ray sources detected by the Advanced CCD Imaging Spectrometer (ACIS) instrument on the Chandra X-ray Observatory in the field of the z=0.516 cluster CRSS J0030.5+2618. In our 63.5 arcmin^2 search…

The deepest extragalactic X-ray observation, the 2 Ms Chandra Deep Field North (CDF-N), resolves ~80% of the total extragalactic cosmic X-ray background (CXB) in the 1-2 keV band. Recent work has shown that 70% of the remaining CXB flux is…

The origin of the X-ray background, in particular at hard (2-10 keV) energies, has been a debated issue for more than 30 years. The Chandra deep fields provide the deepest look at the X-ray sky and are the best dataset to study the X-ray…

We have analyzed optically bright, X-ray faint [OBXF; i.e., log(fX/fR) < -2] sources identified in an 178.9 square arcminute area within the Chandra Deep Field-North (CDF-N) 2 Ms survey. We find 43 OBXF sources in this area, comprising ~15%…

We present results from a 221.9 ks Chandra exposure of the HDF-N and its vicinity, concentrating on the 8.6' X 8.7' area covered by the Caltech Faint Field Galaxy Redshift Survey (the `Caltech area'). The minimum detectable fluxes in the…