The role of active galactic nuclei in galaxy evolution in terms of radial pressure

2019 ◽  
Vol 15 (S356) ◽  
pp. 299-301
Author(s):  
Biressa Tolu ◽  
Abate Feyissa

AbstractIrrespective of whether Active Galactic Nuclei (AGN) is cored with Supermassive Black Holes (SMBH) or not, there is a general consensus that observations indicate that the AGN plays fundamental role in galaxy evolution. The accretion disc powered fueling of the AGN and counter-feedback on its environment in the form of stress-energy-momentum along the radial component and an associated polodial jets seems viable model. On the theoretical ground there is no unified theory that compromise the observations. But there are pull of such diverse physics simulated to describe the observational works. So, there is unsettled theoretical framework how the activity of the AGN plays role in the evolution of host galaxy. Motivated by this we studied the role of AGN on its host galaxy evolution where General relativistic (GR) Magnetohydrodynamics (MHD) equation is considered to derive radial pressure that invokes star forming cold gases. Methodologically the central engine of the AGN is considered with SMBH/pseudo-SMBH. Locally, around the AGN, Reissner-Nordstrom-de Sitter metric is considered that reduces to the Schwarzschoild-de Sitter (SdS) background. Geometrically, a simple spherical geometry is superimposed with central disc structure assumed by cored void mass ablating model. The results of the work indicates that the AGN plays role in galaxy evolution, especially in the nearby environment. Also we report that the adjacent envelope to the AGN seems quiet with no activity in formation.

2020 ◽  
Vol 15 (S359) ◽  
pp. 307-311
Author(s):  
Anelise Audibert ◽  
Françoise Combes ◽  
Santiago García-Burillo ◽  
Kalliopi Dasyra

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.


2005 ◽  
Vol 631 (2) ◽  
pp. 762-772 ◽  
Author(s):  
Jong‐Hak Woo ◽  
C. Megan Urry ◽  
Roeland P. van der Marel ◽  
Paulina Lira ◽  
Jose Maza

2019 ◽  
Vol 15 (S359) ◽  
pp. 51-56
Author(s):  
Vincenzo Mainieri

AbstractIn this proceeding I will summarize our on-going observational campaign to characterize Active Galactic Nuclei (AGN) driven ionized gas outflows at z ˜ 2 and assess their impact on galaxy evolution. The results are mostly derived from a recently completed SINFONI/VLT Large Programme named SUPER, conducted with Adaptive Optics to reach a spatial resolution of ˜2 kpc at z ˜ 2.


2005 ◽  
Vol 627 (1) ◽  
pp. 97-124 ◽  
Author(s):  
Matthew O’Dowd ◽  
C. Megan Urry

2017 ◽  
Vol 842 (2) ◽  
pp. 95 ◽  
Author(s):  
C. Mancuso ◽  
A. Lapi ◽  
I. Prandoni ◽  
I. Obi ◽  
J. Gonzalez-Nuevo ◽  
...  

2011 ◽  
Vol 738 (1) ◽  
pp. 16 ◽  
Author(s):  
D. Clay Hambrick ◽  
Jeremiah P. Ostriker ◽  
Thorsten Naab ◽  
Peter H. Johansson

2019 ◽  
Vol 622 ◽  
pp. A13 ◽  
Author(s):  
V. H. Mahatma ◽  
M. J. Hardcastle ◽  
W. L. Williams ◽  
P. N. Best ◽  
J. H. Croston ◽  
...  

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.


2019 ◽  
Vol 15 (S356) ◽  
pp. 170-170
Author(s):  
Jari Kotilainen

AbstractWe present first results from our study of the host galaxies and environments of quasars in Galaxy And Mass Assembly (GAMA), a multiwavelength photometric and spectroscopic survey for ∼300,000 galaxies over ∼300 deg2, to a limiting magnitude of r ∼ 20 mag. We use a GAIA-selected sample of ∼350 quasars at z < 0.3 in GAMA. For all the quasars, we determine all surrounding GAMA galaxies and measure their star formation (SF) rate and SF history, and the host galaxy morphology and group membership of the quasars. As a comparison sample of inactive galaxies, we use 1000 subsets of galaxies in GAMA, matched in redshift and galaxy stellar mass to the quasars. We find that quasar activity does not depend on the large-scale environment (cluster/group/void), although quasars tend to prefer satellite location in their environment. Compared to inactive galaxies, quasars are preferentially hosted in bulge-dominated galaxies and have higher SF rates, both overall and averaged over the last 10 and 100 Myr. Quasars also have shorter median SF timescales, shorter median time since the last SF burst, and higher metallicity than inactive galaxies. We discuss these results in terms of triggering mechanisms of the quasar activity and the role of quasars in galaxy evolution.


Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 188
Author(s):  
Marco Berton ◽  
Emilia Järvelä

It is well known that active galactic nuclei (AGN) show various forms of interaction with their host galaxy, in a number of phenomena generally called AGN feedback. In particular, the relativistic plasma jets launched by a fraction of AGN can strongly affect their environment. We present here a study of the [O III] λλ4959,5007 lines in a diverse sample of early evolution stage AGN–specifically narrow-line Seyfert 1 galaxies. Radio imaging observations of all of the sources enable a division to jetted and non-jetted sources, and exploiting this we show that the ionized gas properties are significantly influenced by the presence of the jets, as we often find the [O III] lines (blue-)shifted with respect to their restframe wavelength. We also show how the radio morphology and the radio spectral index do not seem to play a role in the origin of the [O III] shifts, thus suggesting that the source inclination is not relevant to the lines displacement. We do not find a strong relation between the [O III] line properties and the bolometric luminosity, suggesting that within our sample radiatively driven outflows do not seem to have a significant contribution to the [O III] line kinematics. We finally suggest that [O III] shifts may be a good proxy to identify the presence of relativistic jets. Additional studies, especially with integral-field spectroscopy, will provide a deeper insight into the relation between jets and their environment in early evolution stage AGN.


2019 ◽  
Vol 15 (S356) ◽  
pp. 247-251
Author(s):  
Biny Sebastian ◽  
Preeti Kharb ◽  
Christopher P. O’ Dea ◽  
Jack F. Gallimore ◽  
Stefi A. Baum ◽  
...  

AbstractThe role of starburst winds versus active galactic nuclei (AGN) jets/winds in the formation of the kiloparsec scale radio emission seen in Seyferts is not yet well understood. In order to be able to disentangle the role of various components, we have observed a sample of Seyfert galaxies exhibiting kpc-scale radio emission suggesting outflows, along with a comparison sample of starburst galaxies, with the EVLA B-array in polarimetric mode at 1.4 GHz and 5 GHz. The Seyfert galaxy NGC 2639, shows highly polarized secondary radio lobes, not observed before, which are aligned perpendicular to the known pair of radio lobes. The additional pair of lobes represent an older epoch of emission. A multi-epoch multi-frequency study of the starburst-Seyfert composite galaxy NGC 3079, reveals that the jet together with the starburst superwind and the galactic magnetic fields might be responsible for the well-known 8-shaped radio lobes observed in this galaxy. We find that many of the Seyfert galaxies in our sample show bubble-shaped lobes, which are absent in the starburst galaxies that do not host an AGN.


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