scholarly journals Large-scale variations of the cosmic X-ray background and the X-ray emissivity of the local Universe

2008 ◽  
Vol 483 (2) ◽  
pp. 425-435 ◽  
Author(s):  
M. Revnivtsev ◽  
S. Molkov ◽  
S. Sazonov
Keyword(s):  
Large Scale ◽  
Local Universe ◽  
X Ray ◽  
X Ray Background

scholarly journals An additional production mechanism for the diffuse x-ray background

2012 ◽  
Vol 8 (S295) ◽  
pp. 267-267
Author(s):  
Allan D. Ernest ◽  
Matthew P. Collins ◽  
Graeme L. White
Keyword(s):  
Large Scale ◽  
Quantum States ◽  
Production Mechanism ◽  
X Ray ◽  
Additional Production ◽  
X Ray Background

AbstractWe propose a mechanism that contributes energy and particles to the diffuse x-ray halos of galaxies and clusters, based on the dark quantum states of large-scale gravity wells.

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 Microwave Background Radiation

1990 ◽  
Vol 139 ◽  
pp. 333-343 ◽  
Author(s):  
G. De Zotti ◽  
L. Danese ◽  
L. Toffolatti ◽  
A. Franceschini
Keyword(s):  
Large Scale ◽  
Background Radiation ◽  
High Redshift ◽  
Dust Emission ◽  
Radio Sources ◽  
Microwave Background ◽  
Satisfactory Explanation ◽  
X Ray ◽  
Microwave Background Radiation ◽  
X Ray Background

We review the data on the spectrum and isotropy of the microwave background radiation and the astrophysical processes that may produce spectral distortions and anisotropies. As yet no fully satisfactory explanation has been found for the submillimeter excess observed by Matsumoto et al. (1988). The most precise data at λ > 1 mm disagree with nonrelativistic comptonization models which match the excess. Distortions produced by a very hot intergalactic medium yielding the X-ray background do not fit the submillimeter data. Very special requirements must be met for the interpretation in terms of high-redshift dust emission to work.Reported anisotropies on scales of several degrees and of tens of arcsec may be produced, at least in part, by discrete sources. Because the best experiments at cm wavelengths are close to the confusion limit, they provide interesting information on the large-scale distribution of radio sources.

Spectra and large-scale isotropy of the cosmic X-ray background from ASCA observations

1998 ◽  
Vol 319 (1-2) ◽  
pp. 68-68 ◽  
Author(s):  
Y. Ishisaki ◽  
Y. Ueda ◽  
T. Takahashi ◽  
H. Inoue ◽  
Y. Ogasaka ◽  
...  
Keyword(s):  
Large Scale ◽  
X Ray ◽  
X Ray Background

The Large‐Scale Structure of the X‐Ray Background and Its Cosmological Implications

2002 ◽  
Vol 580 (2) ◽  
pp. 672-684 ◽  
Author(s):  
S. P. Boughn ◽  
R. G. Crittenden ◽  
G. P. Koehrsen
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
X Ray ◽  
X Ray Background

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 X-Ray Background Fluctuations from Discrete Sources with a Varying Density Contrast

1990 ◽  
Vol 139 ◽  
pp. 416-417 ◽  
Author(s):  
Honguang Bi ◽  
P. Mészáros ◽  
A. Mészáros
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Step Function ◽  
Scale Structure ◽  
Density Contrast ◽  
X Ray ◽  
Constant Height ◽  
X Ray Background ◽  
Spherical Voids

In two previous publications (Mészáros and Mészáros 1988 “Paper I”; Bagoly, Mészáros, and Mészáros 1988 “Paper II”), we have studied the fluctuations of the X-ray background (XRB) expected if the XRB is produced by discrete sources distributed as galaxies. The distribution of matter was assumed to follow the large-scale structure in the form of spherical clusters (superclusters) or spherical voids. In Paper I the density contrast of XRB sources inside and outside structures was taken to be a step function of constant height, whereas in Paper II we introduced arbitrary density contrasts (independent of redshift) and allowed for a redshift evolution of the luminosity of the sources. This led to predicted angular fluctuations of the XRB, which, when we compared them with the HEAO–1 observational limit (Shafer 1983), allowed us to set limits on the type and density of structures.

scholarly journals Formation and evolution of the local interstellar environment: combined constraints from nucleosynthetic and X-ray data

2020 ◽  
Vol 498 (4) ◽  
pp. 5532-5540
Author(s):  
Yusuke Fujimoto ◽  
Mark R Krumholz ◽  
Shu-ichiro Inutsuka ◽  
Alan P Boss ◽  
Larry R Nittler
Keyword(s):  
Large Scale ◽  
Galactic Plane ◽  
X Ray ◽  
Stellar Feedback ◽  
Formation History ◽  
Crossing Time ◽  
Antarctic Snow ◽  
Formation And Evolution ◽  
X Ray Background ◽  
Spiral Arm

ABSTRACT Several observations suggest that the Solar system has been located in a region affected by massive stellar feedback for at least a few Myr; these include detection of live 60Fe in deep-sea archives and Antarctic snow, the broad angular distribution of 26Al around the Galactic plane seen in all-sky γ-ray maps, and the all-sky soft X-ray background. However, our position inside the Galactic disc makes it difficult to fully characterize this environment, and our limited time baseline provides no information about its formation history or relation to large-scale galactic dynamics. We explore these questions by using an N-body + hydrodynamics simulation of a Milky-Way-like galaxy to identify stars on Sun-like orbits whose environments would produce conditions consistent with those we observe. We find that such stars are uncommon but not exceptionally rare. These stars are found predominantly near the edges of spiral arms, and lie inside kpc-scale bubbles that are created by multiple generations of star formation in the arm. We investigate the stars’ trajectories and find that the duration of the stay in the bubble ranges from 20 to 90 Myr. The duration is governed by the crossing time of stars across the spiral arm. This is generally shorter than the bubble lifetime, which is ∼100 Myr as a result of the continuous gas supply provided by the arm environment.

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