scholarly journals Studying the Evolving Universe with XMM-Newton and Chandra

2003 ◽  
Vol 214 ◽  
pp. 46-58 ◽  
Author(s):  
Günther Hasinger
Keyword(s):  
Black Holes ◽  
High Resolution ◽  
Absorption Line ◽  
Large Scale ◽  
Cosmic Time ◽  
Supermassive Black Holes ◽  
Redshift Distribution ◽  
X Ray ◽  
X Ray Background

Two X-ray observatories, the NASA observatory Chandra and the ESA mission XMM-Newton, provide powerful new diagnostics of the “hot universe”. In this article I review recent X–ray observations of the evolving universe. First indications of the warm/hot intergalactic medium, tracing out the large scale structure of the universe, have been obtained lately in sensitive Chandra and XMM-Newton high resolution absorption line spectroscopy of bright blazars. High resolution X–ray spectroscopy and imaging also provides important new constraints on the physical condition of the cooling matter in the centers of clusters, requiring major modifications to the standard cooling flow models. One possibility is, that the supermassive black hole in the giant central galaxies significantly energizes the gas in the cluster.XMM-Newton and Chandra low resolution spectroscopy detected significant Fe Kα absorption features in the spectrum of the ultraluminous, high redshift lensed broad absorption line QSO APM 08279+5255, yielding new insights in the outflow geometry and in particular indicate a supersolar Fe/O ratio. Chandra high resolution imaging spectroscopy of the nearby ultraluminous infrared galaxy and obscured QSO NGC 6240 for the first time gave evidence of two active supermassive black holes in the same galaxy, likely bound to coalesce in the course of the ongoing major merger in this galaxy.Deep X–ray surveys have shown that the cosmic X-ray background (XRB) is largely due to the accretion onto supermassive black holes, integrated over the cosmic time. These surveys have resolved more than 80 % of the 0.1–10 keV X-ray background into discrete sources. Optical spectroscopic identifications show that the sources producing the bulk of the X-ray background are a mixture of obscured (type–1) and unobscured (type–2) AGNs, as predicted by the XRB population synthesis models. A class of highly luminous type–2 AGN, so called QSO-2s, has been detected in the deepest Chandra and XMM-Newton surveys. The new Chandra AGN redshift distribution peaks at much lower redshifts (z ≈ 0.7) than that based on ROSAT data, indicating that the evolution of Seyfert galaxies occurs at significantly later cosmic time than that of QSOs.

scholarly journals 9.18. Galactic winds in active galaxies

1998 ◽  
Vol 184 ◽  
pp. 417-418 ◽  
Author(s):  
S. Veilleux ◽  
J. Bland-Hawthorn ◽  
G. Cecil ◽  
P. Shopbell
Keyword(s):  
Absorption Line ◽  
Galaxy Formation ◽  
Large Scale ◽  
Large Scale Structure ◽  
Active Galaxies ◽  
Large Scale Circulation ◽  
X Ray ◽  
Hubble Sequence ◽  
Galactic Winds ◽  
X Ray Background

The effects of large-scale galactic winds in active galaxies may be far-reaching. It has been suggested that the Hubble sequence can be understood in terms of a galaxy's greater ability to sustain winds with increasing bulge-to-disk ratio. The large-scale circulation of gas associated with these galactic winds might help explain the mass-metallicity relation between galaxies and the metallicity-radius relation within galaxies. Galactic winds probably contribute non-negligibly to the cosmic X-ray background and may be involved in the quasar absorption-line phenomenon. The cosmological implications of the wind phenomenon have been widely explored in the context of proto-galaxies and quasars. The extremely energetic galactic winds that were likely associated with galaxy formation almost certainly played a key role in heating and ionizing the intergalactic medium at high redshifts and may have created the seeds for the large-scale structure we see today.

scholarly journals The X-Ray Background and the AGN Luminosity Function

1999 ◽  
Vol 183 ◽  
pp. 200-209
Author(s):  
G. Hasinger
Keyword(s):  
Black Holes ◽  
Luminosity Function ◽  
Cosmic Time ◽  
Volume Density ◽  
Energy Bands ◽  
X Ray ◽  
Normal Galaxies ◽  
X Ray Background ◽  
Acid Test

ROSAT deep and shallow surveys have provided an almost complete inventory of the constituents of the soft X-ray background which led to a population synthesis model for the whole X-ray background with interesting cosmological consequences. According to this model the X-ray background is the “echo” of mass accretion onto supermassive black holes, integrated over cosmic time. A new determination of the soft X-ray luminosity function of active galactic nuclei (AGN) is consistent with pure density evolution, and the comoving volume density of AGN at redshift 2–3 approaches that of local normal galaxies. This indicates that many larger galaxies contain black holes and it is likely that the bulk of the black holes was produced before most of the stars in the universe. However, only X-ray surveys in the harder energy bands, where the maximum of the energy density of the X-ray background resides, will provide the acid test of this picture.

scholarly journals The Multiwavelength AGN Population and the X-ray Background

2013 ◽  
Vol 9 (S304) ◽  
pp. 188-194
Author(s):  
Ezequiel Treister ◽  
Claudia M. Urry ◽  
Kevin Schawinski ◽  
Brooke D. Simmons ◽  
Priyamvada Natarajan ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Density ◽  
Large Fraction ◽  
Supermassive Black Holes ◽  
X Rays ◽  
X Ray ◽  
Black Hole Growth ◽  
Hole Growth ◽  
X Ray Background

AbstractIn order to fully understand galaxy formation we need to know when in the cosmic history are supermassive black holes (SMBHs) growing more intensively, in what type of galaxies this growth is happening and what fraction of these sources are invisible at most wavelengths due to obscuration. Active Galactic Nuclei (AGN) population synthesis models that can explain the spectral shape and intensity of the cosmic X-ray background (CXRB) indicate that most of the SMBH growth occurs in moderate-luminosity (LX~ 1044 erg/s) sources (Seyfert-type AGN), at z~ 0.5−1 and in heavily obscured but Compton-thin, NH~ 1023cm−2, systems. However, this is not the complete history, as a large fraction of black hole growth does not emit significantly in X-rays either due to obscuration, intrinsic low luminosities or large distances. The integrated intensity at high energies indicates that a significant fraction of the total black hole growth, 22%, occurs in heavily-obscured systems that are not individually detected in even the deepest X-ray observations. We further investigate the AGN triggering mechanism as a function of bolometric luminosity, finding evidence for a strong connection between significant black hole growth events and major galaxy mergers from z~ 0 to z~ 3, while less spectacular but longer accretion episodes are most likely due to other (stochastic) processes. AGN activity triggered by major galaxies is responsible for ~60% of the total black hole growth. Finally, we constrain the total accreted mass density in supermassive black holes at z > 6, inferred via the upper limit derived from the integrated X-ray emission from a sample of photometrically selected galaxy candidates. We estimate an accreted mass density <1000 M⊙Mpc−3 at z~ 6, significantly lower than the previous predictions from some existing models of early black hole growth and earlier prior observations.

scholarly journals A survey of AGN and supermassive black holes in the COSMOS Survey

2006 ◽  
Vol 2 (S238) ◽  
pp. 287-290 ◽  
Author(s):  
Chris D. Impey ◽  
Jon R. Trump ◽  
Pat J. McCarthy ◽  
Martin Elvis ◽  
John P. Huchra ◽  
...  
Keyword(s):  
Black Holes ◽  
Large Scale ◽  
Supermassive Black Holes ◽  
Host Galaxy ◽  
Data Set ◽  
X Ray ◽  
Cosmic Evolution ◽  
Early Results ◽  
Multi Wavelength ◽  
History Of

AbstractThe Cosmic Evolution Survey (COSMOS) is an HST/ACS imaging survey of 2 square degrees centered on RA = 10:00:28.6, Dec = + 02:12:21 (J2000). While the primary goal of the survey is to study evolution of galaxy morphology and large scale structure, an extensive multi-wavelength data set allows for a sensitive survey of AGN. Spectroscopy of optical counterparts to faint X-ray and radio sources is being carried out with the Magallen (Baade) Telescope and the ESO VLT. By achieving ∼80 redshift completeness down to I AB = 3, the eventual yield of AGN will be ∼1100 over the whole field.Early results on supermassive black holes are described. The goals of the survey include a bolometric census of AGN down to moderate luminosities, the cosmic evolution and fueling history of the central engines, and a study of AGN environments on scales ranging from the host galaxy to clusters and superclusters.

scholarly journals AGN and the Demographics of Supermassive Black Holes

2002 ◽  
Vol 184 ◽  
pp. 335-342
Author(s):  
Richard F. Green
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Large Scale ◽  
Velocity Dispersion ◽  
Cosmic Time ◽  
Volume Density ◽  
Supermassive Black Holes ◽  
High Angular Resolution ◽  
Bulge Formation ◽  
Black Hole Masses

AbstractHigh angular resolution observations from WFPC and STIS now allow well-constrained dynamical measurement of the masses of supermassive black holes (SMBH) in nearby galaxies. An initial statistical analysis by Magorrian et al. showed that 97% of bulges host SMBH. Black hole mass is correlated moderately with bulge luminosity and strongly with the velocity dispersion of the whole bulge, suggesting that black hole formation may be an intrinsic aspect of bulge formation. Black hole masses for AGN determined from reverberation mapping fall on the same relationship with bulge velocity dispersion as those determined from stellar dynamical measurements. The prospect is therefore that the large-scale distribution of black hole masses in distant quasars may be determined through relatively straightforward measurement. Integral constraints show consistency between the total AGN luminosity density and the total volume density in SMBH contained in galaxy bulges. The strong peak of the high-luminosity quasar luminosity function at early cosmic time is consistent with the association of the build-up of SMBH through accretion and bulge formation. Alternate scenarios requiring substantial build-up of the most massive black holes at later cosmic times are more difficult to reconcile with the evolution of the LF.

scholarly journals Local supermassive black holes, relics of active galactic nuclei and the X-ray background

2004 ◽  
Vol 351 (1) ◽  
pp. 169-185 ◽  
Author(s):  
A. Marconi ◽  
G. Risaliti ◽  
R. Gilli ◽  
L. K. Hunt ◽  
R. Maiolino ◽  
...  
Keyword(s):  
Black Holes ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
X Ray ◽  
X Ray Background

scholarly journals A Unified, Merger‐driven Model of the Origin of Starbursts, Quasars, the Cosmic X‐Ray Background, Supermassive Black Holes, and Galaxy Spheroids

2006 ◽  
Vol 163 (1) ◽  
pp. 1-49 ◽  
Author(s):  
Philip F. Hopkins ◽  
Lars Hernquist ◽  
Thomas J. Cox ◽  
Tiziana Di Matteo ◽  
Brant Robertson ◽  
...  
Keyword(s):  
Black Holes ◽  
Supermassive Black Holes ◽  
X Ray ◽  
X Ray Background

scholarly journals Molecules as tracers of galaxy evolution

2012 ◽  
Vol 8 (S292) ◽  
pp. 199-208 ◽  
Author(s):  
Susanne Aalto
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
High Resolution ◽  
Galaxy Evolution ◽  
Large Scale ◽  
Short Review ◽  
Stimulated Emission ◽  
Molecular Gas ◽  
Infrared Galaxies ◽  
Luminous Infrared Galaxies

AbstractStudying the molecular phase of the interstellar medium in galaxies is fundamental for the understanding of the onset and evolution of star formation and the growth of supermassive black holes. We can use molecules as observational tools exploiting them as tracers of chemical, physical and dynamical conditions. In this short review, key molecules (e.g. HCN, HCO+, HNC, HC3N, CN, H3O+) in identifying the nature of buried activity and its evolution are discussed including some standard astrochemical scenarios. Furthermore, we can use IR excited molecular emission to probe the very inner regions of luminous infrared galaxies (LIRGs) allowing us to get past the optically thick dust barrier of the compact obscured nuclei, e.g. in the dusty LIRG NGC4418. High resolution studies are often necessary to separate effects of excitation and radiative transport from those of chemistry - one example is absorption and effects of stimulated emission in the ULIRG Arp220. Finally, molecular gas in large scale galactic outflows is briefly discussed.

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