Related papers: Hard X-ray observations of Extremely Red Objects

Models for the origin of the hard X-ray background have suggested that sources with the most accretion activity lie hidden in highly obscured AGN. We report on our study of hard, serendipitous sources in the fields of Chandra clusters with…

We measure the clustering of Extremely Red Objects (EROs) in ~8 deg^2 of the NOAO Deep Wide Field Survey Bo\"otes field in order to establish robust links between ERO z~1.2 and local galaxy z<0.1 populations. Three different color selection…

The 500ks Chandra ACIS-I observation of the field around the $z=6.31$ quasar SDSS J1030+0524 is currently the 5th deepest extragalactic X-ray survey. The rich multi-band coverage of the field allowed for an effective identification and…

We present X-ray spectra of 185 bright sources detected in the XMM-Newton deep survey of the Chandra Deep Field South, combining the three EPIC cameras. The 2-10 keV flux limit of the sample is 2e-15 erg/s/cm2. The sources are distributed…

We have measured the angular and spatial clustering of 671 K<18.40, R-K>5 Extremely Red Objects (EROs) from a 0.98 square degree sub-region of the NOAO Deep Wide-Field Survey (NDWFS). Our study covers nearly 5 times the area and has twice…

We present a small sample of Chandra X-ray sources selected from the fields of ACIS observations which probe fluxes around the break in the hard band source counts. The targets of these fields include 9 nearby galaxy clusters, 1 distant…

(abridged) We identify a numerically significant population of heavily obscured AGNs at z~0.5-1 in the Chandra Deep Field-South (CDF-S) and Extended Chandra Deep Field-South by selecting 242 X-ray undetected objects with infrared-based star…

We present the first results from the Distant Radio Galaxies Optically Non-detected in the SDSS (DRaGONS) Survey. Using a novel selection technique for identifying high redshift radio galaxy (HzRG) candidates, a large sample of bright…

We present optical spectroscopy of 62 objects selected from several samples of ultra steep spectrum (USS) radio sources. 46 of these are from our primary catalog, consisting of 669 sources with radio spectral indices alpha < -1.30 (S_nu ~…

The XBootes Survey is a 5-ks Chandra survey of the Bootes Field of the NOAO Deep Wide-Field Survey (NDWFS). This survey is unique in that it is the largest (9.3 deg^2), contiguous region imaged in X-ray with complementary deep optical and…

The Serendipitous Extragalactic X-ray Source Identification (SEXSI) Program is designed to expand significantly the sample of identified extragalactic hard X-ray sources at intermediate fluxes, 1e-13 erg/cm2/s < S_(2-10 keV) < 1e-15…

We present the first optical validation of an X-ray Line-Emitting Object (XLEO) discovered in the XMM-Newton observation of the Chandra Deep Field South. The object is an AGN at z_x ~ 0.66. An optical spectrum of the source indeed confirms…

This is the first paper in a series presenting and analyzing data for a K-selected sample of galaxies collected in order to identify and study galaxies at moderate to high redshift in rest-wavelength optical light. The sample contains 842…

We present a catalog of extremely red objects discovered using the NICMOS/HST parallel imaging database and ground-based optical follow-up observations. Within an area of 16 square arc-minutes, we detect 15 objects with $\rm R - F160W > 5$…

We construct a sample of X-ray bright optically faint active galactic nuclei by combining Subaru Hyper Suprime-Cam, XMM-Newton, and infrared source catalogs. 53 X-ray sources satisfying i band magnitude fainter than 23.5 mag and X-ray…

We report preliminary results from an arcsecond-resolution X-ray survey of nearby galaxies using ACIS on board Chandra. The total sample consists of 41 low-luminosity AGNs, including Seyferts, LINERs, and LINER/H II transition objects. In…

X-rays offer a reliable method to identify Active Galactic Nuclei (AGN). However, in the high-redshift Universe X-ray AGN are poorly sampled due to their relatively low space density and the small areas covered by X-ray surveys. In addition…

We have discovered an excess of extremely red objects (EROs) surrounding the z=2.69 quasar QSO 1213-0017 (UM 485). Optical/IR colors for these galaxies are consistent with z=1-2 ellipticals, and there are at least 5 galaxies with…

We present preliminary results from a novel search for X-ray Line Emitting Objects (XLEOs) in XMM-Newton images. Three sources have been detected in a test-run analysis of 13 XMM-Newton observations. The three objects found are most likely…

We analyze 18 sources that were found to show interesting properties of periodicity, very soft spectra and/or large long-term variability in X-rays in our project of classification of sources from the 2XMMi-DR3 catalog but were poorly…