scholarly journals The physical properties and impact of AGN outflows from high to low redshift

2019 ◽  
Vol 15 (S359) ◽  
pp. 212-220
Author(s):  
Giacomo Venturi ◽  
Alessandro Marconi
Keyword(s):  
Physical Properties ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Critical Role ◽  
Galactic Nuclei ◽  
Observational Evidence ◽  
Host Galaxies ◽  
Major Player ◽  
The Impact ◽  
Kinematic Properties

AbstractFeedback from active galactic nuclei (AGN) on their host galaxies, in the form of gas outflows capable of quenching star formation, is considered a major player in galaxy evolution. However, clear observational evidence of such major impact is still missing; uncertainties in measuring outflow properties might be partly responsible because of their critical role in comparisons with models and in constraining the impact of outflows on galaxies. Here we briefly review the challenges in measuring outflow physical properties and present an overview of outflow studies from high to low redshift. Finally, we present highlights from our MAGNUM survey of nearby AGN with VLT/MUSE, where the high intrinsic spatial resolution (down to ˜ 10 pc) allows us to accurately measure the physical and kinematic properties of ionised gas outflows.

Density diagnostics of photoionized outflows in active galactic nuclei

2019 ◽  
Vol 15 (S350) ◽  
pp. 274-277
Author(s):  
Junjie Mao
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
State Of The Art ◽  
Density Measurement ◽  
Galactic Nuclei ◽  
Next Generation ◽  
Host Galaxies ◽  
Current Generation ◽  
X Ray ◽  
The Impact

AbstractPhotoionized outflows in active galactic nuclei (AGNs) are thought to influence their circumnuclear and host galactic environment. However, the distance of the outflow with respect to the black hole is poorly constrained, which limits our understanding of the kinetic power by the outflow. Therefore, the impact of AGN outflows on their host galaxies is uncertain. If the density of the outflow is known, its distance can be derived. Density measurement via variability studies and density sensitive lines have been used, albeit not very effective in the X-ray band. Good measurements are rather demanding or challenging for the current generation of (grating) spectrometers. The next generation of spectrometers will certainly provide data with better quality and large quantity, leading to tight constraints on the location and the kinetic power of AGN outflows. This contribution summarizes the state-of-the-art in this field.

scholarly journals Feeding and feedback in nuclei of galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 307-311
Author(s):  
Anelise Audibert ◽  
Françoise Combes ◽  
Santiago García-Burillo ◽  
Kalliopi Dasyra
Keyword(s):  
High Resolution ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Galactic Nuclei ◽  
Radio Galaxies ◽  
Host Galaxy ◽  
Molecular Gas ◽  
Molecular Outflows ◽  
Radio Jets ◽  
The Impact

AbstractOur aim is to explore the close environment of Active Galactic Nuclei (AGN) and its connection to the host galaxy through the morphology and dynamics of the cold gas inside the central kpc in nearby AGN. We report Atacama Large Millimeter/submillimeter Array (ALMA) observations of AGN feeding and feedback caught in action in NGC613 and NGC1808 at high resolution (few pc), part of the NUclei of GAlaxies (NUGA) project. We detected trailing spirals inside the central 100 pc, efficiently driving the molecular gas into the SMBH, and molecular outflows driven by the AGN. We present preliminary results of the impact of massive winds induced by radio jets on galaxy evolution, based on observations of radio galaxies from the ALMA Radio-source Catalogue.

scholarly journals On the Evolutionary Connection Between AGNs and GALEX UV-Excess Early-Type Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 458-458
Author(s):  
Hyun-Jin Bae ◽  
Kiyun Yun ◽  
Yumi Choi ◽  
Suk-Jin Yoon
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Galactic Nuclei ◽  
Accurate Information ◽  
Early Type ◽  
Host Galaxies ◽  
Evolutionary Connection ◽  
Uv Excess

The interplay between active galactic nuclei (AGNs) and their host galaxies' star-formation activities is one of the central topics in pursuing an understanding of galaxy evolution. With the advent of the Galaxy Evolution Explorer (GALEX), we have much more accurate information than ever about the recent star formation (RSF) histories of early-type galaxies within ~ 1.5 Gyr in the local universe. Using a subset of ~ 1000 GALEX/SDSS type 2 AGN-host early-type galaxies (E/S0) based on the emission-line ratio diagnosis, we explore how AGNs affect the RSF histories of the early-type hosts and vice versa. In this contribution, we present a preliminary yet interesting result on the intimate connection between AGN activity and the RSF histories of early-type galaxies.

scholarly journals The rise of active galactic nuclei in the galaxy evolution and assembly semi-analytic model

2020 ◽  
Vol 496 (3) ◽  
pp. 3943-3960
Author(s):  
Fabio Fontanot ◽  
Gabriella De Lucia ◽  
Michaela Hirschmann ◽  
Lizhi Xie ◽  
Pierluigi Monaco ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Large Fraction ◽  
Formation Rate ◽  
Galactic Nuclei ◽  
Analytic Model ◽  
The Galaxy ◽  
The Impact ◽  
Cold Gas

ABSTRACT We present a new implementation of the GAlaxy Evolution and Assembly (gaea) semi-analytic model, that features an improved modelling of the process of cold gas accretion on to supermassive black hole (SMBHs), derived from both analytic arguments and high-resolution simulations. We consider different scenarios for the loss of angular momentum required for the available cold gas to be accreted on to the central SMBHs, and we compare different combinations of triggering mechanisms, including galaxy mergers and disc instabilities in star-forming discs. We compare our predictions with the luminosity function (LF) observed for active galactic nuclei (AGNs) and we confirm that a non-instantaneous accretion time-scale (either in the form of a low-angular momentum reservoir or as an assumed light-curve evolution) is needed in order to reproduce the measured evolution of the AGN-LF and the so-called AGN-downsizing trend. Moreover, we also study the impact of AGN feedback, in the form of AGN-driven outflows, on the SF properties of model galaxies, using prescriptions derived both from empirical studies and from numerical experiments. We show that AGN-driven outflows are effective in suppressing the residual star formation rate in massive galaxies (>1011 M⊙) without changing their overall assembly history. These winds also affect the SFR of lower mass galaxies, resulting in a too large fraction of passive galaxies at <1010 M⊙. Finally, we study the Eddington ratio distribution as a function of SMBH mass, showing that only objects more massive than 108 M⊙ are already in a self-regulated state as inferred from observations.

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 LoTSS DR1: Double-double radio galaxies in the HETDEX field

2019 ◽  
Vol 622 ◽  
pp. A13 ◽  
Author(s):  
V. H. Mahatma ◽  
M. J. Hardcastle ◽  
W. L. Williams ◽  
P. N. Best ◽  
J. H. Croston ◽  
...  
Keyword(s):  
Life Cycle ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Control Sample ◽  
Galactic Nuclei ◽  
Radio Galaxies ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Significant Difference ◽  
Double Radio Galaxies

Context. Double-double radio galaxies (DDRGs) represent a short but unique phase in the life-cycle of some of the most powerful radio-loud active galactic nuclei (RLAGN). These galaxies display large-scale remnant radio plasma in the intergalactic medium left behind by a past episode of active galactic nuclei (AGN) activity, and meanwhile, the radio jets have restarted in a new episode. The knowledge of what causes the jets to switch off and restart is crucial to our understanding of galaxy evolution, while it is important to know if DDRGs form a host galaxy dichotomy relative to RLAGN. Aims. The sensitivity and field of view of LOFAR enables the observation of DDRGs on a population basis rather than single-source observations. Using statistical comparisons with a control sample of RLAGN, we may obtain insights into the nature of DDRGs in the context of their host galaxies, where physical differences in their hosts compared to RLAGN as a population may allow us to infer the conditions that drive restarting jets. Methods. We utilised the LOFAR Two-Metre Sky Survey (LoTSS) DR1, using a visual identification method to compile a sample of morphologically selected candidate DDRGs, showing two pairs of radio lobes. To confirm the restarted nature in each of the candidate sources, we obtained follow-up observations with the Karl. G. Jansky Very Large Array (VLA) at higher resolution to observe the inner lobes or restarted jets, the confirmation of which created a robust sample of 33 DDRGs. We created a comparison sample of 777 RLAGN, matching the luminosity distribution of the DDRG sample, and compared the optical and infrared magnitudes and colours of their host galaxies. Results. We find that there is no statistically significant difference in the brightness of the host galaxies between double-doubles and single-cycle RLAGN. The DDRG and RLAGN samples also have similar distributions in WISE mid-infrared colours, indicating similar ages of stellar populations and dust levels in the hosts of DDRGs. We conclude that DDRGs and “normal” RLAGN are hosted by galaxies of the same type, and that DDRG activity is simply a normal part of the life cycle of RLAGN. Restarted jets, particularly for the class of low-excitation radio galaxies, rather than being a product of a particular event in the life of a host galaxy, must instead be caused by smaller scale changes, such as in the accretion system surrounding the black hole.

scholarly journals Multiwavelength surveys for Active Galactic Nuclei

2019 ◽  
Vol 15 (S356) ◽  
pp. 11-11
Author(s):  
William Nielsen Brandt
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Future Prospects ◽  
Host Galaxies ◽  
General Survey ◽  
Anisotropic Emission

AbstractMost of what we know about active galactic nuclei (AGNs) has been driven, or at least strongly shaped, by our methods for finding them, and multiwavelength AGN surveys have achieved remarkable successes in recent decades. I will present a broad, and thus necessarily shallow, review of such multiwavelength AGN surveys. I will first present some brief introductory points on, e.g., general survey approaches, AGN luminosities, host galaxies, and anisotropic emission/obscuration. I will then review many of the key current surveys and their results, separating these into ground-based and space-based surveys. Finally, I will discuss some future prospects including essential remaining questions and “discovery space” considerations.

scholarly journals Excitation mechanism in the intracluster filaments surrounding the Brightest Cluster Galaxies

2019 ◽  
Vol 15 (S359) ◽  
pp. 185-187
Author(s):  
Fiorella L. Polles
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Elliptical Galaxies ◽  
Cluster Galaxies ◽  
Cooling Flow ◽  
Submillimeter Wavelengths ◽  
Hot Plasma ◽  
Brightest Cluster Galaxies ◽  
Multi Phase ◽  
The Impact

AbstractMulti-phase filamentary structures surrounding giant elliptical galaxies at the center of cool-core clusters, the Brightest Cluster Galaxies (BCGs), have been detected from optical to submillimeter wavelengths. The source of the ionisation in the filaments is still debated. Studying the excitation of these structures is key to our understanding of Active Galactic Nuclei (AGN) feedback in general, and more precisely of the impact of environmental and local effects on star formation. One possible contributor to the excitation of the filaments is the thermal radiation from the cooling of the hot plasma surrounding the BCGs, the so-called cooling flow.

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 Galaxy Evolution Studies with the SPace IR Telescope for Cosmology and Astrophysics (SPICA): The Power of IR Spectroscopy

2017 ◽  
Vol 34 ◽  
Author(s):  
L. Spinoglio ◽  
A. Alonso-Herrero ◽  
L. Armus ◽  
M. Baes ◽  
J. Bernard-Salas ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Formation Rate ◽  
Cosmic Time ◽  
Galactic Nuclei ◽  
Large Area ◽  
Radiation Fields ◽  
James Webb Space Telescope ◽  
Large Telescopes

AbstractIR spectroscopy in the range 12–230 μm with the SPace IR telescope for Cosmology and Astrophysics (SPICA) will reveal the physical processes governing the formation and evolution of galaxies and black holes through cosmic time, bridging the gap between the James Webb Space Telescope and the upcoming Extremely Large Telescopes at shorter wavelengths and the Atacama Large Millimeter Array at longer wavelengths. The SPICA, with its 2.5-m telescope actively cooled to below 8 K, will obtain the first spectroscopic determination, in the mid-IR rest-frame, of both the star-formation rate and black hole accretion rate histories of galaxies, reaching lookback times of 12 Gyr, for large statistically significant samples. Densities, temperatures, radiation fields, and gas-phase metallicities will be measured in dust-obscured galaxies and active galactic nuclei, sampling a large range in mass and luminosity, from faint local dwarf galaxies to luminous quasars in the distant Universe. Active galactic nuclei and starburst feedback and feeding mechanisms in distant galaxies will be uncovered through detailed measurements of molecular and atomic line profiles. The SPICA’s large-area deep spectrophotometric surveys will provide mid-IR spectra and continuum fluxes for unbiased samples of tens of thousands of galaxies, out to redshifts of z ~ 6.

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