scholarly journals Host galaxies and large-scale structures of active galactic nuclei

2015 ◽  
Vol 11 (A29B) ◽  
pp. 113-123 ◽  
Author(s):  
Ryan C. Hickox ◽  
Stephanie M. LaMassa ◽  
John D. Silverman ◽  
Alexander Kolodzig
Keyword(s):  
Active Galactic Nuclei ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Galaxy Mergers ◽  
Host Galaxies ◽  
Large Scale Structures ◽  
Star Formation In Galaxies ◽  
Statistical Studies ◽  
Scale Structures ◽  
Extragalactic Surveys

AbstractOur understanding of the cosmic evolution of supermassive black holes (SMBHs) has been revolutionized by the advent of large multiwavelength extragalactic surveys, which have enabled detailed statistical studies of the host galaxies and large-scale structures of active galactic nuclei (AGN). We give an overview of some recent results on SMBH evolution, including the connection between AGN activity and star formation in galaxies, the role of galaxy mergers in fueling AGN activity, the nature of luminous obscured AGN, and the connection between AGN and their host dark matter halos. We conclude by looking to the future of large-scale extragalactic X-ray and spectroscopic surveys.

scholarly journals FM6: Summary of Session #5 on Accretion and Feedback in Active Galactic Nuclei

2015 ◽  
Vol 11 (A29B) ◽  
pp. 101-112
Author(s):  
Laura Brenneman
Keyword(s):  
Active Galactic Nuclei ◽  
Large Scale ◽  
Galaxy Cluster ◽  
Galactic Nuclei ◽  
Starburst Galaxies ◽  
X Ray ◽  
Large Scale Structures ◽  
Scale Structures

AbstractFocus Meeting 6 of the IAU 2015 Symposium centered around the topic of “X-ray Surveys of the Hot and Energetic Universe.” Within this two-day meeting seven sessions (31 total talks) were presented, whose topics included galaxy cluster physics and evolution, cluster cosmological studies, AGN demographics and X-ray binary populations, first quasars, accretion and feedback, large-scale structures, and normal and starburst galaxies. Herein, I summarize the results presented during session #5, which focused on AGN accretion and feedback. Six authors contributed their work to our session: Laura Brenneman, Kazushi Iwasawa, Massimo Gaspari, Michaela Hirschmann, Franz Bauer and Yuan Liu. I provide a brief introduction below, followed by the details of the presentations of each author in the order in which the presentations were given.

scholarly journals THE EVOLUTION AND ENVIRONMENTS OF X-RAY EMITTING ACTIVE GALACTIC NUCLEI IN HIGH-REDSHIFT LARGE-SCALE STRUCTURES

2012 ◽  
Vol 746 (2) ◽  
pp. 155 ◽  
Author(s):  
N. Rumbaugh ◽  
D. D. Kocevski ◽  
R. R. Gal ◽  
B. C. Lemaux ◽  
L. M. Lubin ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Large Scale ◽  
High Redshift ◽  
Galactic Nuclei ◽  
X Ray ◽  
Large Scale Structures ◽  
Scale Structures

scholarly journals Probing the cool ISM in galaxies via 21 cm H i absorption

2012 ◽  
Vol 8 (S292) ◽  
pp. 188-188
Author(s):  
J. R. Allison ◽  
E. M. Sadler ◽  
S. J. Curran ◽  
S. N. Reeves
Keyword(s):  
Spectral Line ◽  
Active Galactic Nuclei ◽  
Large Scale ◽  
Galactic Nuclei ◽  
Host Galaxies ◽  
The Galaxy ◽  
Early Type Galaxy ◽  
Finding Method ◽  
Compact Array ◽  
Cold Gas

AbstractRecent targeted studies of associated H i absorption in radio galaxies are starting to map out the location, and potential cosmological evolution, of the cold gas in the host galaxies of Active Galactic Nuclei (AGN). The observed 21 cm absorption profiles often show two distinct spectral-line components: narrow, deep lines arising from cold gas in the extended disc of the galaxy, and broad, shallow lines from cold gas close to the AGN (e.g. Morganti et al. 2011). Here, we present results from a targeted search for associated H i absorption in the youngest and most recently-triggered radio AGN in the local universe (Allison et al. 2012b). So far, by using the recently commissioned Australia Telescope Compact Array Broadband Backend (CABB; Wilson et al. 2011), we have detected two new absorbers and one previously-known system. While two of these show both a broad, shallow component and a narrow, deep component (see Fig. 1), one of the new detections has only a single broad, shallow component. Interestingly, the host galaxies of the first two detections are classified as gas-rich spirals, while the latter is an early-type galaxy. These detections were obtained using a spectral-line finding method, based on Bayesian inference, developed for future large-scale absorption surveys (Allison et al. 2012a).

scholarly journals On the Environments of Giant Radio Galaxies

2021 ◽  
Author(s):  
Ting-Wen Lan ◽  
J Xavier Prochaska
Keyword(s):  
Large Scale ◽  
Radio Galaxies ◽  
Sloan Digital Sky Survey ◽  
Host Galaxies ◽  
Homogeneous Sample ◽  
Large Scale Structures ◽  
Radio Jets ◽  
Sky Survey ◽  
Scale Structures ◽  
Control Samples

Abstract We test the hypothesis that environments play a key role in enabling the growth of enormous radio structures spanning more than 700 kpc, an extreme population of radio galaxies called giant radio galaxies (GRGs). To achieve this, we explore (1) the relationships between the occurrence of GRGs and the surface number density of surrounding galaxies, including satellite galaxies and galaxies from neighboring halos, as well as (2) the GRG locations towards large-scale structures. The analysis is done by making use of a homogeneous sample of 110 GRGs detected from the LOFAR Two-metre Sky Survey in combination with photometric galaxies from the DESI Legacy Imaging Surveys and a large-scale filament catalog from the Sloan Digital Sky Survey. Our results show that the properties of galaxies around GRGs are similar with that around the two control samples, consisting of galaxies with optical colors and luminosity matched to the properties of the GRG host galaxies. Additionally, the properties of surrounding galaxies depend on neither their relative positions to the radio jet/lobe structures nor the sizes of GRGs. We also find that the locations of GRGs and the control samples with respect to the nearby large-scale structures are consistent with each other. These results demonstrate that there is no correlation between the GRG properties and their environments traced by stars, indicating that external galaxy environments are not the primary cause of the large sizes of the radio structures. Finally, regarding radio feedback, we show that the fraction of blue satellites does not correlate with the GRG properties, suggesting that the current epoch of radio jets have minimal influence on the nature of their surrounding galaxies.

scholarly journals On the slow quenching of ℳ* galaxies: heavily obscured AGNs clarify the picture

2020 ◽  
Vol 495 (4) ◽  
pp. 4237-4247
Author(s):  
Thibaud Moutard ◽  
Nicola Malavasi ◽  
Marcin Sawicki ◽  
Stéphane Arnouts ◽  
Shruti Tripathi
Keyword(s):  
Physical Properties ◽  
Active Galactic Nuclei ◽  
Rest Frame ◽  
Galactic Nuclei ◽  
Galaxy Mergers ◽  
Host Galaxies ◽  
Quenching Mechanism ◽  
X Ray ◽  
Quenching Process ◽  
Primary Driver

ABSTRACT We investigate the connection between X-ray and radio-loud active galactic nuclei (AGNs) and the physical properties of their evolved and massive host galaxies, focussing on the mass-related quenching channel followed by $\mathcal {M}^\star (\simeq 10^{10.6} \, \mathrm{M}_\odot)$ galaxies in the rest-frame NUV–r versus r–K (NUVrK) colour diagram at 0.2 < z < 0.5. While our results confirm that (1) radio-loud AGNs are predominantly hosted by already-quenched and very massive ($M_*\gt 10^{11}\, \mathrm{M}_\odot$) galaxies, ruling out their feedback as a primary driver of $\mathcal {M}^\star$ galaxy quenching, we found that (2) X-ray AGNs affected by heavy obscuration of their soft X-ray emission are mostly hosted by $\mathcal {M}^\star$ galaxies that are in the process of quenching. This is consistent with a quenching scenario that involves mergers of (gas-poor) $\mathcal {M}^\star$ galaxies after the onset of the quenching process, i.e. a scenario where $\mathcal {M}^\star$ galaxy mergers are not the cause but rather an aftermath of the quenching mechanism(s). In that respect, we discuss how our results may support a picture where the slow quenching of $\mathcal {M}^\star$ galaxies happens due to halo–halo mergers along cosmic filaments.

scholarly journals Slow and massive: low-spin SMBHs can grow more

2019 ◽  
Vol 489 (1) ◽  
pp. 1373-1378 ◽  
Author(s):  
Kastytis Zubovas ◽  
Andrew King
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Large Scale ◽  
Size Dependence ◽  
Galactic Nuclei ◽  
Host Galaxy ◽  
Host Galaxies ◽  
The Galaxy ◽  
Mass Increment

Abstract Active galactic nuclei (AGNs) probably control the growth of their host galaxies via feedback in the form of wide-angle wind-driven outflows. These establish the observed correlations between supermassive black hole (SMBH) masses and host galaxy properties, e.g. the spheroid velocity dispersion σ. In this paper we consider the growth of the SMBH once it starts driving a large-scale outflow through the galaxy. To clear the gas and ultimately terminate further growth of both the SMBH and the host galaxy, the black hole must continue to grow its mass significantly, by up to a factor of a few, after reaching this point. The mass increment ΔMBH depends sensitively on both galaxy size and SMBH spin. The galaxy size dependence leads to ΔMBH ∝ σ5 and a steepening of the M–σ relation beyond the analytically calculated M ∝ σ4, in agreement with observation. Slowly spinning black holes are much less efficient in producing feedback, so at any given σ the slowest spinning black holes should be the most massive. Current observational constraints are consistent with this picture, but insufficient to test it properly; however, this should change with upcoming surveys.

scholarly journals The Evolution of AGN Host Galaxies: From Blue to Red and the Influence of Large‐Scale Structures

2008 ◽  
Vol 675 (2) ◽  
pp. 1025-1040 ◽  
Author(s):  
J. D. Silverman ◽  
V. Mainieri ◽  
B. D. Lehmer ◽  
D. M. Alexander ◽  
F. E. Bauer ◽  
...  
Keyword(s):  
Large Scale ◽  
Host Galaxies ◽  
Large Scale Structures ◽  
Scale Structures

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Sign in / Sign up

Export Citation Format

Share Document