3 edition of High redshift QSOs and the X-ray background found in the catalog.
High redshift QSOs and the X-ray background
Chris Impey
Published
1994
by National Aeronautics and Space Administration, National Technical Information Service, distributor in [Washington, DC, Springfield, Va
.
Written in English
Edition Notes
| Statement | principal investigator: Chris Impey. |
| Series | [NASA contractor report] -- NASA CR-195112., NASA contractor report -- NASA CR-195112. |
| Contributions | United States. National Aeronautics and Space Administration. |
| The Physical Object | |
|---|---|
| Format | Microform |
| Pagination | 1 v. |
| ID Numbers | |
| Open Library | OL14707056M |
@MISC{Manners_thex-ray, author = {J. Manners and O. Almaini and A. Lawrence}, title = {The X-ray variability of high-redshift QSOs}, year = {}} Share. OpenURL. Abstract. Rapid X-ray variability appears to be very common in AGN (e.g. Turner ). Light curves can often look qualitatively very different, but they generally appear completely. This book provides a comprehensive account of the scientific results on high-redshift galaxies accumulated during the past ten years. Apart from summarizing and critically discussing the wealth of observational data, the observational methods which made it possible to study these very distant and extremely faint objects are described in detail.
Because of its capability to make extremely deep, high-resolution images of high-redshift galaxies, ALMA is an excellent and unique instrument for observing submillimeter galaxies (SMGs), for studying gravitational lensing, and for resolving the mm / submm extragalactic background light, which likely originates from fainter normal galaxies. density of less luminous QSOs at high redshift. Here we present a search for high-z QSOs, identified in the two GOODS fields on the basis of deep imaging in the optical (with HST) and X-ray (with Chandra), and discuss the allowed space density of QSOs .
The X-ray variability of high redshift QSOs. By J C Manners, O Almaini and A Lawrence. Get PDF ( KB) Abstract. We present an analysis of X-ray variability in a sample of radio quiet quasars taken from the ROSAT archive, covering a redshift range The analysis of optical colors and X-ray spectra indicates that high redshift, X-ray-selected QSOs have optical properties not significantly different from those of optically selected, bright QSOs, even if a non-negligible fraction (~20%, i.e., the outliers of Figure 4) would not have been selected by the Casey et al. optical color–color.
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High redshift QSOs and the x ray background Item Preview remove-circle. Get this from a library. High redshift QSOs and the X-ray background. [Chris Impey; United States. National Aeronautics and Space Administration.]. The LBQS sample also yields a new constraint on the contribution of high redshift QSO's to the X-ray background.
An initial requirement is knowledge of the X-ray properties (alpha OX) as a function of redshift. Integration over the evolving luminosity function of the LBQS then gives the QSO contribution to the source : Chris Impey. Get this from a library.
The X-ray properties of high redshift, optically selected QSOs. [Scott F Anderson; University of Washington. Department of Astronomy.; United States. National Aeronautics and Space Administration.]. The LBQS sample also yields a new constraint on the contribution of high redshift QSO's to the X-ray background.
An initial requirement is knowledge of the X-ray properties (alpha(sub OX)) as a function of redshift. Integration over the evolving luminosity function of the LBQS then gives the QSO contribution to the source countsAuthor: Chris Impey.
The authors describe a program aimed at characterizing the X-ray emission of high redshift QSOs. They have obtained slitless spectra of 50 high galactic latitude fields previously imaged at very high levels of sensitivity by the Einstein Observatory, generally for original goals unrelated to QSOs.
The X-Ray Properties of High-Redshift Quasi-stellar Objects. Sensitive X-ray information is presented for about 90 previously uncataloged high-redshift, optically selected QSOs. Two high-redshift subsets of this larger data base are emphasized: (1) a 'complete' sample of 37 objects with z = -and B of or less and (2) a sample of 78 QSOs that span a narrow range in redshift and.
We present a new measurement of the space density of high-redshift (z ), X-ray-selected quasi-stellar objects (QSOs) obtained by exploiting the. In order to study the X-ray properties of high redshift QSOs, I have taken grism/grens plates covering 17 deg.('2) of sky previously imaged to very sensitive X-ray flux levels with the Einstein Observatory.
Following optical selection of the QSO, the archived X-ray image is examined to extract an X-ray flux detection or a sensitive upper limit. Very few QSOs will be suitable background sources for this test, both on luminosity grounds and because most high-redshift QSOs will have their light blocked by a Lyman-limit absorber (galaxy or diffuse cloud) at smaller redshifts.
Frantic searches turned up a few candidates, either at z > for HST or z > for HUT. X-ray properties of high redshift, optically selected QSOs.
(OCoLC) Online version: Anderson, Scott F. X-ray properties of high redshift, optically selected QSOs. (OCoLC) Material Type: Thesis/dissertation, Government publication, National government publication: Document Type: Book: All Authors / Contributors.
Here we present a search for high-z QSOs, identified in the two GOODS fields on the basis of deep imaging in the optical (with HST) and X-ray (with Chandra), and discuss the allowed space density. For a very high column, NH _ cm-2 as used by Madau et al.
(), QSOs will be visible only in the hard X-ray band, whatever their redshift, and therefore the hard ( keV) XRB spectrum and counts may provide the strongest constraint on the existence of a highly obscured QSO.
This book presents a review of the current observational knowledge and understanding of the cosmic X- ray background, discovered 30 years ago. The most relevant observational features of the cosmic X-ray background, its spectrum, high galactic latitude isotropy on all angular scales and its source content, are reviewed in detail.
Recently we can add the discovery that the low-redshift companion to the BL Lac object AO + is itself a BAL QSO (Burbidge et al. AJ) and the X-ray discovery of QSOs at z=, on either side of NGC (Burbidge A&Al1; neither of these last two citations is to the obvious Burbidge).
However, the solution of. Deep X-ray surveys have shown that the cosmic X-ray background (XRB) is largely due to accretion onto supermassive black holes, integrated over cosmic time.
The characteristic hard spectrum of the XRB can be explained if about % of the light produced by accretion and black hole growth is absorbed by gas and dust.
The total AGN light inferred from the XRB is consistent with the total mass. Published by Elsevier Science Ltd. THE X-RAY BACKGROUND At soft X-ray energies (below 2keV) almost all of the XRB has been resolved into discrete sources, most of which turn out to be broad-line QSOs (Shanks et alHasinger et al ).
The X-ray spectra of ordinary QSOs, however, are too steep to explain the XRB at higher energies. high redshift QSOs to the X-ray background. An initial requirement is knowledge of the X-ray properties (aox) as a function of redshift.
Integration over the evolving luminosity function of the LBQS then gives the QSO contribution to the source counts. The Cosmic X-Ray Background and QSOs to B X-ray properties of high redshift quasars were probed using grism/grens plates covering 13 sq deg of.
CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): In order to study systematically the soft X-ray emission of Active Galactic Nuclei (AGNs) at medium to high redshifts, we have analyzed ROSAT PSPC and HRI data of QSOs at ≤ z ≤ selected from the second deepest ROSAT PSPC survey carried out in by McHardy et al.
(). In short, the cumulative mass density from the optical QSO counts due to accretion onto high redshift QSOs ( QSOs. Furthermore, I have neglected the contribution to the SBH.The Discovery of a High Redshift X-Ray Emitting QSO Very Close to the Nucleus of NGC Pasquale Galianni1, E.
M. Burbidge2, H. Arp3, V. Junkkarinen2, G. Burbidge2, Stefano Zibetti3 ABSTRACT A strong X-ray source only 8′′ from the nucleus of the Sy2 galaxy NGC in Stephan’s Quintet has been discovered by Chandra. We have identified the.As a consequence, at present, the number density of QSOs at high redshift is not well known.
Recently, the Sloan Digital Sky Survey (SDSS) has produced a breakthrough, discovering QSOs up to z= [8] and building a sample of six QSOs with z>
