Hosts and environments of low luminosity active galaxies in the local universe: the care and feeding of weak AGN

2021 ◽  
Author(s):  
John Kenneth Parejko
2009 ◽  
Vol 5 (S267) ◽  
pp. 210-210
Author(s):  
M. S. Seigar ◽  
D. Kennefick ◽  
J. Kennefick ◽  
C. H. S. Lacy ◽  
J. C. Berrier ◽  
...  

Work done to date on the SMBH mass function has brought to light some interesting puzzles, the best known of which is cosmic downsizing. The solution to this problem is based upon the methodology by which we determine SMBH masses, which comes mainly from studies of active galaxies. The most massive SMBHs cease to be active at earlier epochs than their less massive counterparts, thus leading to an apparent decrease in the SMBH mass function with time. The larger SMBHs should still be present in the local Universe, but they lie in quiescent galaxies. This lack of certainty reflects the biggest gap in the observational record – the mass of SMBHs in quiescent galaxies.


1996 ◽  
Vol 168 ◽  
pp. 175-182 ◽  
Author(s):  
D.S. Mathewson ◽  
V.L. Ford

Peculiar velocity measurements of 2500 southern spiral galaxies show large-scale flows in the direction of the Hydra-Centaurus clusters which fully participate in the flow themselves. The flow is not uniform over this region and seems to be associated with the denser regions which participate in the flow of amplitude about 400km/s. In the less dense regions the flow is small or non-existent. This makes the flow quite asymmetric and inconsistent with that expected from large-scale, parallel streaming flow that includes all galaxies out to 6000km/s as previously thought. The flow cannot be modelled by a Great Attractor at 4300km/s or the Centaurus clusters at 3500km/s. Indeed, from the density maps derived from the redshift surveys of “optical” and IRAS galaxies, it is difficult to see how the mass concentrations can be responsible particularly as they themselves participate in the flow. These results bring into question the generally accepted reason for the peculiar velocities of galaxies that they arise solely as a consequence of infall into the dense regions of the universe. To the N. of the Great Attractor region, the flow increases and shows no sign of diminishing out to the redshift limit of 8000km/s in this direction. We may have detected flow in the nearest section of the Great Wall.


2010 ◽  
Vol 726 (1) ◽  
pp. L6 ◽  
Author(s):  
A. J. Cuesta ◽  
T. E. Jeltema ◽  
F. Zandanel ◽  
S. Profumo ◽  
F. Prada ◽  
...  
Keyword(s):  

2019 ◽  
Vol 15 (S356) ◽  
pp. 226-226
Author(s):  
Viola Allevato

AbstractThe presence of a super massive BH in almost all galaxies in the Universe is an accepted paradigm in astronomy. How these BHs form and how they co-evolve with the host galaxy is one of the most intriguing unanswered problems in modern Cosmology and of extreme relevance to understand the issue of galaxy formation. Clustering measurements can powerfully test theoretical model predictions of BH triggering scenarios and put constraints on the typical environment where AGN live in, through the connection with their host dark matter halos. In this talk, I will present some recent results on the AGN clustering dependence on host galaxy properties, such as galaxy stellar mass, star formation rate and specific BH accretion rate, based on X-ray selected Chandra COSMOS Legacy Type 2 AGN. We found no significant AGN clustering dependence on galaxy stellar mass and specif BHAR for Type 2 COSMOS AGN at mean z ∼ 1.1, with a stellar - halo mass relation flatter than predicted for non active galaxies in the Mstar range probed by our sample. We also observed a negative clustering dependence on SFR, with AGN hosting halo mass increasing with decreasing SFR. Mock catalogs of active galaxies in hosting dark matter halos with logMh[Msun] > 12.5, matched to have the same X-ray luminosity, stellar mass and BHAR of COSMOS AGN predict the observed Mstar - Mh, BHAR - Mh and SFR-Mh relations, at z ∼ 1.


2019 ◽  
Vol 15 (S356) ◽  
pp. 295-298
Author(s):  
Betelehem Bilata-Woldeyes ◽  
Mirjana Pović ◽  
Zeleke Beyoro-Amado ◽  
Tilahun Getachew-Woreta ◽  
Shimeles Terefe

AbstractStudying the morphology of a large sample of active galaxies at different wavelengths and comparing it with active galactic nuclei (AGN) properties, such as black hole mass (MBH) and Eddington ratio (λEdd), can help us in understanding better the connection between AGN and their host galaxies and the role of nuclear activity in galaxy formation and evolution. By using the BAT-SWIFT hard X-ray public data and by extracting those parameters measured for AGN and by using other public catalogues for parameters such as stellar mass (M*), star formation rate (SFR), bolometric luminosity (Lbol), etc., we studied the multiwavelength morphological properties of host galaxies of ultra-hard X-ray detected AGN and their correlation with other AGN properties. We found that ultra hard X-ray detected AGN can be hosted by all morphological types, but in larger fractions (42%) they seem to be hosted by spirals in optical, to be quiet in radio, and to have compact morphologies in X-rays. When comparing morphologies with other galaxy properties, we found that ultra hard X-ray detected AGN follow previously obtained relations. On the SFR vs. stellar mass diagram, we found that although the majority of sources are located below the main sequence (MS) of star formation (SF), still non-negligible number of sources, with diverse morphologies, is located on and/or above the MS, suggesting that AGN feedback might have more complex influence on the SF in galaxies than simply quenching it, as it was suggested in some of previous studies.


2018 ◽  
Vol 863 (2) ◽  
pp. 134 ◽  
Author(s):  
Tiffany Hsyu ◽  
Ryan J. Cooke ◽  
J. Xavier Prochaska ◽  
Michael Bolte
Keyword(s):  

2015 ◽  
Vol 578 ◽  
pp. A110 ◽  
Author(s):  
M. Argudo-Fernández ◽  
S. Verley ◽  
G. Bergond ◽  
S. Duarte Puertas ◽  
E. Ramos Carmona ◽  
...  

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