scholarly journals The host galaxies of Seyfert type 1 nuclei

1994 ◽  
Vol 266 (4) ◽  
pp. 953-971 ◽  
Author(s):  
J. K. Kotilainen ◽  
M. J. Ward
Keyword(s):  
Host Galaxies ◽  
Seyfert Type

scholarly journals LLAMA: The MBH–σ⋆ relation of the most luminous local AGNs

2020 ◽  
Vol 634 ◽  
pp. A114 ◽  
Author(s):  
Turgay Caglar ◽  
Leonard Burtscher ◽  
Bernhard Brandl ◽  
Jarle Brinchmann ◽  
Richard I. Davies ◽  
...  
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Velocity Dispersion ◽  
Signal To Noise Ratio ◽  
Broad Line ◽  
Host Galaxies ◽  
Spatially Resolved ◽  
Stellar Velocity ◽  
Black Hole Masses

Context. The MBH–σ⋆ relation is considered a result of coevolution between the host galaxies and their supermassive black holes. For elliptical bulge hosting inactive galaxies, this relation is well established, but there is still discussion concerning whether active galaxies follow the same relation. Aims. In this paper, we estimate black hole masses for a sample of 19 local luminous active galactic nuclei (AGNs; LLAMA) to test their location on the MBH–σ⋆ relation. In addition, we test how robustly we can determine the stellar velocity dispersion in the presence of an AGN continuum and AGN emission lines, and as a function of signal-to-noise ratio. Methods. Supermassive black hole masses (MBH) were derived from the broad-line-based relations for Hα, Hβ, and Paβ emission line profiles for Type 1 AGNs. We compared the bulge stellar velocity dispersion (σ⋆) as determined from the Ca II triplet (CaT) with the dispersion measured from the near-infrared CO (2-0) absorption features for each AGN and find them to be consistent with each other. We applied an extinction correction to the observed broad-line fluxes and we corrected the stellar velocity dispersion by an average rotation contribution as determined from spatially resolved stellar kinematic maps. Results. The Hα-based black hole masses of our sample of AGNs were estimated in the range 6.34 ≤ log MBH ≤ 7.75 M⊙ and the σ⋆CaT estimates range between 73 ≤ σ⋆CaT ≤ 227 km s−1. From the so-constructed MBH − σ⋆ relation for our Type 1 AGNs, we estimate the black hole masses for the Type 2 AGNs and the inactive galaxies in our sample. Conclusions. We find that our sample of local luminous AGNs is consistent with the MBH–σ⋆ relation of lower luminosity AGNs and inactive galaxies, after correcting for dust extinction and the rotational contribution to the stellar velocity dispersion.

scholarly journals Multi-wavelength Properties of Type 1 and Type 2 AGN Host Galaxies in the Chandra-COSMOS Legacy Survey

2019 ◽  
Vol 872 (2) ◽  
pp. 168 ◽  
Author(s):  
Hyewon Suh ◽  
Francesca Civano ◽  
Günther Hasinger ◽  
Elisabeta Lusso ◽  
Stefano Marchesi ◽  
...  
Keyword(s):  
Host Galaxies ◽  
Multi Wavelength

scholarly journals Examining supernova events in Type 1 active galactic nuclei

2020 ◽  
Vol 495 (4) ◽  
pp. 4419-4429
Author(s):  
Beatriz Villarroel ◽  
Iñigo Imaz ◽  
Elisabeta Lusso ◽  
Sébastien Comerón ◽  
M Almudena Prieto ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Detection Rate ◽  
Statistical Study ◽  
Galactic Nuclei ◽  
Core Collapse ◽  
Late Type ◽  
Host Galaxies ◽  
Specific Kind

ABSTRACT A statistical study of intermediate Palomar Transient Factory supernovae (SNe) in Type 1 active galactic nuclei (AGNs) has shown a major deficit of supernovae around Type 1 AGN host galaxies, with respect to Type 2 AGN hosts. The aim of this work is to test whether there is any preference for Type 1 AGNs to host SN of a specific kind. Through the analysis of SN occurrence and their type (thermonuclear versus core-collapse), we can directly link the type of stars producing the SN events, thus this is an indirect way to study host galaxies in Type 1 AGNs. We examine the detection fractions of SNe, the host galaxies and compare the sample properties to typical host galaxies in the Open Supernova Catalog (OSC). The majority of the host galaxies in the AGN sample are late type, similar to typical galaxies hosting SN within the OSC. The findings are supportive of a deficiency of SNe near Type 1 AGNs, although we cannot with certainty assess the overall detection fractions of SNe in Type 1 AGNs relative to other SN host galaxies. We can state that Type 1 AGN has equal detection fractions of thermonuclear versus core-collapse SNe. However, we note the possibility of a higher detection rate of core-collapse supernovae in Type 1 AGN with insecure AGN classifications.

scholarly journals The Extragalactic X-Ray and γ-ray Backgrounds

1990 ◽  
Vol 139 ◽  
pp. 345-356
Author(s):  
G. Setti
Keyword(s):  
Big Bang ◽  
Prima Facie ◽  
Baryon Density ◽  
Primordial Nucleosynthesis ◽  
X Ray ◽  
Γ Ray ◽  
X Ray Background ◽  
Seyfert Type ◽  
Number Of Authors

The long-standing problem of the origin of the extragalactic X-ray background (XRB) is reviewed. Although the shape of the spectrum in the 3–100 keV interval is suggestive of an optically thin bremsstrahlung at ~ 40 keV, the interpretation in terms of a hot intergalactic gas (IGG) requires a rather extreme energy supply and a gas density conflicting with the baryon density upper limit derived from primordial nucleosynthesis calculations in the standard hot big-bang model. A summary discussion of the estimated contributions from the integrated X-ray emission of known classes of extragalactic discrete sources at a reference energy of 2 keV is given. Although these estimates are still uncertain, the subtraction of a “minimum” contribution drastically modifies the 40 keV thermal shape, which is the prima facie evidence of a hot IGG. AGNs are the main contributors. Low luminosity AGNs (Seyfert type 1 nuclei) at redshift z = 1 − 2 may in fact saturate the 2 keV XRB, but their observed hard X-ray spectra are on the average unlike (much too steep) that of the XRB. This has led a number of authors to postulate new classes of sources and some exotic models which are briefly summarized. However, if a recently proposed unified scheme of AGNs holds, then the bulk of the XRB intensity can be explained independently of the observed spectral differences and with a mild cosmological evolution. The origin of the extragalactic γ-ray background is briefly commented upon in the concluding remarks.

scholarly journals Stellar Photometric Structures of the Host Galaxies of Nearby Type 1 Active Galactic Nuclei

2017 ◽  
Vol 232 (2) ◽  
pp. 21 ◽  
Author(s):  
Minjin Kim ◽  
Luis C. Ho ◽  
Chien Y. Peng ◽  
Aaron J. Barth ◽  
Myungshin Im
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Host Galaxies

Seyfert Type 1 galaxies observed with the HEAO 1 scanning modulation collimator

1980 ◽  
Vol 235 ◽  
pp. 355 ◽  
Author(s):  
R. G. Dower ◽  
H. V. Bradt ◽  
R. E. Doxsey ◽  
M. D. Johnston ◽  
R. E. Griffiths
Keyword(s):  
Modulation Collimator ◽  
Seyfert Type

scholarly journals An Estimate of the Local Active Black Hole Mass Function and the Distribution Function of Eddington Ratios

2009 ◽  
Vol 5 (S267) ◽  
pp. 266-266
Author(s):  
Andreas Schulze ◽  
Lutz Wisotzki
Keyword(s):  
Black Hole ◽  
Mass Function ◽  
Distribution Functions ◽  
Black Hole Mass ◽  
Host Galaxies ◽  
Underlying Distribution ◽  
Black Hole Growth ◽  
Hole Growth ◽  
Black Hole Masses

The observed relations between the black hole mass and the properties of the spheroidal galaxy component imply a close connection between the growth of supermassive black holes and the evolution of their host galaxies. An effective approach to study black hole growth is to measure black hole masses and Eddington ratios of well-defined type 1 AGN samples and determine the underlying distribution functions.

scholarly journals Subaru Hyper Suprime-Cam view of quasar host galaxies at z < 1

2020 ◽  
Vol 72 (5) ◽  
Author(s):  
Toru Ishino ◽  
Yoshiki Matsuoka ◽  
Shuhei Koyama ◽  
Yuya Saeda ◽  
Michael A Strauss ◽  
...  
Keyword(s):  
Sample Selection ◽  
Stellar Mass ◽  
Small Sample ◽  
Sloan Digital Sky Survey ◽  
Host Galaxy ◽  
Mass Relation ◽  
Host Galaxies ◽  
Sky Survey ◽  
Local Relation

Abstract Active galactic nuclei (AGNs) are key in understanding the coevolution of galaxies and supermassive black holes (SMBHs). AGN activity is thought to affect the properties of their host galaxies via a process called “AGN feedback,” which drives the coevolution. From a parent sample of 1151 z &lt; 1 type-1 quasars from the Sloan Digital Sky Survey quasar catalog, we detected the host galaxies of 862 of them in the high-quality grizy images of the Subaru Hyper Suprime-Cam survey. The unprecedented combination of the survey area and depth allowed us to perform a statistical analysis of the quasar host galaxies, with small sample variance. We fitted the radial image profile of each quasar as a linear combination of the point spread function and the Sérsic function, decomposing the images into the quasar nucleus and the host galaxy components. We found that the host galaxies are massive, with stellar mass Mstar ≳ 1010 $M_\odot$, and are mainly located on the green valley. This trend is consistent with a scenario in which star formation in the host galaxies is suppressed by AGN feedback, that is, AGN activity may be responsible for the transition of these galaxies from the blue cloud to the red sequence. We also investigated the SMBH mass to stellar mass relation of the z &lt; 1 quasars, and found a consistent slope with the local relation, while the SMBHs may be slightly undermassive. However, the above results are subject to our sample selection, which biases against host galaxies with low masses and/or large quasar-to-host flux ratios.

scholarly journals X-ray absorption in INTEGRAL active galactic nuclei

2020 ◽  
Vol 639 ◽  
pp. A5
Author(s):  
A. Malizia ◽  
L. Bassani ◽  
J. B. Stephen ◽  
A. Bazzano ◽  
P. Ubertini
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Axial Ratio ◽  
Host Galaxy ◽  
Host Galaxies ◽  
X Ray ◽  
Line Region ◽  
Absorbing Material

In this work the INTEGRAL hard X-ray selected sample of active galactic nuclei (AGN) has been used to investigate the possible contribution of absorbing material distributed within the host galaxies to the total amount of NH measured in the X-ray band. We collected all the available axial ratio measurements of the galaxies hosting our AGN together with their morphological information and found that for our hard X-ray selected sample as well there is a deficit of edge-on galaxies hosting type 1 AGN. We estimate that in our hard X-ray selected sample there is a deficit of 24% (±5%) of type 1 AGN. Possible bias in redshift has been excluded, as we found the same effect in a well-determined range of z where the number and the distributions of the two classes are statistically the same. Our findings clearly indicate that material located in the host galaxy on scales of hundreds of parsecs and not aligned with the putative absorbing torus of the AGN can contribute to the total amount of column density. This galactic absorber could be large enough to hide the broad line region of some type 1 AGN, thus causing their classification as type 2 objects and giving rise to the deficiency of type 1 objects in edge-on galaxies.

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