The X-ray properties of normal galaxies

X-Ray Emission from Normal Galaxies

X-Ray Astronomy with the Einstein Satellite - Astrophysics and Space Science Library ◽

10.1007/978-94-009-8459-2_9 ◽

1981 ◽

pp. 153-172 ◽

Cited By ~ 2

Author(s):

L. Van Speybroeck ◽

J. Bechtold

Keyword(s):

X Ray ◽

Normal Galaxies

X-Ray Study of Normal Galaxies with Ginga

Windows on Galaxies - Astrophysics and Space Science Library ◽

10.1007/978-94-009-0543-6_31 ◽

1990 ◽

pp. 243-253 ◽

Cited By ~ 3

Author(s):

T. Ohashi ◽

K. Makishima ◽

T. Mihara ◽

T. Tsuru ◽

H. Awaki ◽

...

Keyword(s):

X Ray ◽

Normal Galaxies

Chandra COSMOS Legacy Survey: Clustering dependence of Type 2 active galactic nuclei on host galaxy properties

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936191 ◽

2019 ◽

Vol 632 ◽

pp. A88

Author(s):

V. Allevato ◽

A. Viitanen ◽

A. Finoguenov ◽

F. Civano ◽

H. Suh ◽

...

Keyword(s):

Active Galactic Nuclei ◽

Large Scale ◽

Formation Rate ◽

Galactic Nuclei ◽

Stellar Mass ◽

Host Galaxy ◽

X Ray ◽

Normal Galaxies ◽

Massive Halos

Aims. We perform clustering measurements of 800 X-ray selected Chandra COSMOS Legacy (CCL) Type 2 active galactic nuclei (AGN) with known spectroscopic redshift to probe the halo mass dependence on AGN host galaxy properties, such as galaxy stellar mass Mstar, star formation rate (SFR), and specific black hole accretion rate (BHAR; λBHAR) in the redshift range z = [0−3]. Methods. We split the sample of AGN with known spectroscopic redshits according to Mstar, SFR and λBHAR, while matching the distributions in terms of the other parameters, including redshift. We measured the projected two-point correlation function wp(rp) and modeled the clustering signal, for the different subsamples, with the two-halo term to derive the large-scale bias b and corresponding typical mass of the hosting halo. Results. We find no significant dependence of the large-scale bias and typical halo mass on galaxy stellar mass and specific BHAR for CCL Type 2 AGN at mean z ∼ 1, while a negative dependence on SFR is observed, i.e. lower SFR AGN reside in richer environment. Mock catalogs of AGN, matched to have the same X-ray luminosity, stellar mass, λBHAR, and SFR of CCL Type 2 AGN, almost reproduce the observed Mstar − Mh, λBHAR − Mh and SFR–Mh relations, when assuming a fraction of satellite AGN fAGNsat ∼ 0.15. This corresponds to a ratio of the probabilities of satellite to central AGN of being active Q ∼ 2. Mock matched normal galaxies follow a slightly steeper Mstar − Mh relation, in which low mass mock galaxies reside in less massive halos than mock AGN of similar mass. Moreover, matched mock normal galaxies are less biased than mock AGN with similar specific BHAR and SFR, at least for Q > 1.

Revised activity types for Markarian galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314003263 ◽

2013 ◽

Vol 9 (S304) ◽

pp. 41-42

Author(s):

A. M. Mickaelian ◽

H. V. Abrahamyan ◽

G. S. Harutyunyan ◽

G. M. Paronyan

Keyword(s):

Ir Spectra ◽

Wavelength Range ◽

Spectroscopic Data ◽

Active Galaxies ◽

The Other ◽

Optical Range ◽

X Ray ◽

Normal Galaxies ◽

Activity Types ◽

Uv Excess

AbstractThe sample of Markarian galaxies consists of 1515 UV-excess galaxies containing many active galaxies, both AGN and Starburst (SB). Several catalogs of Markarian galaxies have been published; however activity types are based on old spectroscopic data. The SDSS spectroscopy and some other recent spectral observations allow classify or re-classify many of Markarian galaxies, altogether we have retrieved and studied 779 SDSS and 300 other spectra. Out of 779 SDSS spectra, we have classified 533 HII, 31 Composites, 12 LINERs, 4 S2.0, 5 S1.9, 8 S1.8, 5 NLS1.5, 11 S1.5, 8 NLS1.2, 21 S1.2, 4 NLS1, 4 S1.0, 2 QSO, 11 AGN (without an exact class), 52 Em (HII or AGN), 65 Abs, and 3 Stars. On the other hand, the galaxies are being classified depending on the fact in which wavelength range they have been observed and studied. E.g. some Sy2 type galaxies turn to be Sy1 when classified in IR. Many hidden AGN (in X-ray and IR) appear to be normal galaxies in optical range. So for better understanding, IR spectra are necessary as well.

The true nature of IRAS-selected, X-ray-luminous 'normal' galaxies in the ROSAT all-sky survey

The Astrophysical Journal ◽

10.1086/187549 ◽

1994 ◽

Vol 433 ◽

pp. L65 ◽

Cited By ~ 13

Author(s):

Edward C. Moran ◽

Jules P. Halpern ◽

David J. Helfand

Keyword(s):

True Nature ◽

X Ray ◽

Normal Galaxies ◽

Sky Survey

Diffuse cosmic X-rays from non-thermal intergalactic bremsstrahlung

Symposium - International Astronomical Union ◽

10.1017/s0074180900004587 ◽

1970 ◽

Vol 37 ◽

pp. 392-401

Author(s):

Joseph Silk

Keyword(s):

Cosmic Rays ◽

Intergalactic Medium ◽

Energy Requirement ◽

Cosmic Ray ◽

X Rays ◽

Degree Of Ionization ◽

X Ray ◽

Normal Galaxies ◽

X Ray Background ◽

High Degree

The diffuse X-ray background between 1 keV and 1 MeV is interpreted as non-thermal bremsstrahlung in the intergalactic medium. The observed break in the X-ray spectrum at ∼40 keV yields the heat input to the intergalactic medium, the break being produced by ionization losses of sub-cosmic rays. Proton bremsstrahlung is found not to yield as satisfactory an agreement with observations as electron bremsstrahlung: excessive heating tends to occur. Two alternative models of cosmic ray injection are discussed, one involving continuous injection by evolving sources out to a redshift of about 3, and the other model involving injection by a burst of cosmic rays at a redshift of order 10. The energy density of intergalactic electrons required to produce the observed X-rays is ∼ 10−4 eV/cm3. Assuming a high density (∼ 10−5 cm−3) intergalactic medium, the energy requirement for cosmic ray injection by normal galaxies is ∼ 1058–59ergs/galaxy in sub-cosmic rays. The temperature evolution of the intergalactic medium is discussed, and we find that a similar energy input is also required to explain the observed high degree of ionization (if 3C9 is at a cosmological distance).

UHURU Results on Extragalactic X-Ray Sources

Symposium - International Astronomical Union ◽

10.1017/s0074180900100373 ◽

1973 ◽

Vol 55 ◽

pp. 171-183 ◽

Cited By ~ 2

Author(s):

Edwin M. Kellogg

Keyword(s):

High Latitude ◽

Luminosity Function ◽

Optical Data ◽

Clusters Of Galaxies ◽

X Rays ◽

Total Contribution ◽

X Ray ◽

Normal Galaxies ◽

X Ray Background ◽

Individual Galaxies

Data from the UHURU satellite have provided a list of more than forty high latitude sources (|b| > 20°). X-rays have been detected from among the nearest normal galaxies, giant radio galaxies, Seyferts, QSOs and clusters of galaxies. The cluster sources appear to be extended by several hundred kiloparsecs as well as being very luminous. These cluster sources have systematic differences in their X-ray spectra from individual galaxies.About twenty sources are not reliably identified so far. A few of these are located near undistinguished 3C or MSH radio sources. The rest are either located near distant clusters or undistinguished bright galaxies, or are too far south, so that we have not sufficient optical data to allow a thorough search for possible association with clusters or unusual individual galaxies.The luminosity function for weak, high latitude X-ray sources is determined, and the contribution of sources just below the UHURU threshold of detectability to observed fluctuations in the diffuse X-ray background is evaluated. The total contribution of all observed types of extragalactic sources to the X-ray background is estimated.

The X-Ray Background and the AGN Luminosity Function

Symposium - International Astronomical Union ◽

10.1017/s007418090013253x ◽

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.