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Related papers: X-rays from the High-Redshift Universe: The Chandr…

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The 2 Ms Chandra Deep Field-North survey provides the deepest view of the Universe in the 0.5--8.0 keV X-ray band. In this brief review we investigate the diversity of X-ray selected sources and focus on the constraints placed on AGNs…

Astrophysics · Physics 2009-09-29 D. M. Alexander , F. E. Bauer , W. N. Brandt , A. E. Hornschemeier

We present results of a study of 12 dust-reddened quasars with 0.4 < z < 2.65 and reddenings in the range 0.15 < E(B-V) < 1.7. We obtained ACIS-S X-ray spectra of these quasars, estimated the column densities towards them, and hence…

Astrophysics · Physics 2009-11-10 Tanya Urrutia , Mark Lacy , Michael D. Gregg , Robert H. Becker

The NASA/ISO Key Project on active galactic nuclei (AGN) seeks to better understand the broad-band spectral energy distributions (SEDs) of these sources from radio to X-rays, with particular emphasis on infrared properties. The ISO sample…

We present the results of Chandra observations of six radio-loud quasars (RLQs) and one optically bright radio-quiet quasar (RQQ) at z = 4.1-4.4. These observations cover a representative sample of RLQs with moderate radio-loudness (R ~…

Astrophysics · Physics 2009-11-10 L. C. Bassett , W. N. Brandt , D. P. Schneider , C. Vignali , G. Chartas , G. P. Garmire

The 13hr XMM-Newton/Chandra deep survey is the first of two extremely deep XMM-Newton fields observed by the XMM-OM consortium. A 120 ks Chandra mosaic, covering 0.2 square degrees, provides sensitive, confusion-free point source detection…

We present Chandra X-ray observations of 14 radio-loud quasars at redshifts $3 < z < 4$, selected from a well-defined sample. All quasars are detected in the 0.5-7.0 keV energy band, and resolved X-ray features are detected in five of the…

Chandra observations show the importance of the X-ray band for studying the evolution of galaxies. Binary X-ray sources are an easily detectable tracer of the stellar population. Chandra studies of these populations are giving us insights…

Astrophysics · Physics 2007-05-23 G. Fabbiano

In the two parts of this contribution we describe two related XMM-Newton programs. The first part summarizes our study of the X-ray spectral properties and variability of z>4 quasars (Shemmer et al. 2005). The second part presents…

Astrophysics · Physics 2007-05-23 Ohad Shemmer , Niel Brandt

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…

Astrophysics · Physics 2009-09-17 P. Gandhi , C. S. Crawford , A. C. Fabian , R. M. Johnstone

We have searched in the XMM-Newton public archive for quasars in the Sloan Digital Sky Survey (SDSS) First Data Release (DR1), and found 55 lying in the field of a XMM-Newton observation with exposure times >20 ksec (as of August, 2004).…

Astrophysics · Physics 2009-11-13 G. Risaliti , M. Elvis , ;

We briefly review how X-ray observations of high-redshift active galactic nuclei (AGNs) at z = 4-7 have played a critical role in understanding their basic demographics as well as their physical processes; e.g., absorption by nuclear…

High Energy Astrophysical Phenomena · Physics 2017-05-10 W. N. Brandt , F. Vito

We present followup optical g', r', and i', imaging and spectroscopy of serendipitous X-ray sources detected in 6 archival Chandra, images included in the Chandra, Multiwavelength Project (ChaMP). Of the 486 X-ray sources detected between…

We present the X-ray analysis of the largest flux-limited complete sample of blazar candidates at z>4 selected from the Cosmic Lens All Sky Survey (CLASS). After obtaining a nearly complete (24/25) X-ray coverage of the sample (from…

Astrophysics of Galaxies · Physics 2019-09-25 L. Ighina , A. Caccianiga , A. Moretti , S. Belladitta , R. Della Ceca , L. Ballo , D. Dallacasa

We present an optical and NIR catalog for the X-ray sources in the 2 Ms Chandra observation of the Hubble Deep Field-North region. We have high-quality multicolor images of all 503 X-ray point sources and reliable spectroscopic redshifts…

We briefly review some recent results from Chandra and XMM-Newton studies of the highest redshift (z > 4) active galactic nuclei (AGNs). Specific topics covered include radio-quiet quasars, radio-loud quasars, moderate-luminosity AGNs in…

Astrophysics · Physics 2009-11-10 W. N. Brandt , C. Vignali , B. D. Lehmer , L. A. Lopez , D. P. Schneider , I. V. Strateva

We present broadband properties of sources in the Chandra Deep Field-North with spectroscopic redshifts. The high luminosity and redshift bins are dominated by typical quasars. The intermediate redshift (z = 0.7-1.5) and luminosity ranges…

Astrophysics · Physics 2007-05-23 S. Frank , Patrick S. Osmer , S. Mathur

We present new Chandra observations of seven luminous quasars at $z>6.5$. Combined with archival Chandra observations of all other known quasars, they form nearly complete X-ray observations of all currently known $z\sim7$ quasars with…

This "pedagogical" review describes the key Chandra and XMM-Newton extragalactic surveys to date and details some of their implications for AGN physics and evolution. We additionally highlight two topics of current widespread interest: (1)…

Astrophysics · Physics 2015-06-24 W. N. Brandt , D. M. Alexander , F. E. Bauer , C. Vignali

Extragalactic X-ray surveys are exceptionally powerful tools for studying the evolution of supermassive black holes and their host galaxies, by detecting large numbers of active galactic nuclei (AGN) and star-forming galaxies over a wide…

High Energy Astrophysical Phenomena · Physics 2009-04-29 Ryan C. Hickox

I review the operational capabilities of the Chandra X-ray Observatory, including some of the spectacular results obtained by the general observer community. A natural theme of this talk is that Chandra is revealing outflows of great…

Astrophysics · Physics 2009-11-10 Daniel A. Schwartz