scholarly journals Active Galactic Nuclei Feedback and the Origin and Fate of the Hot Gas in Early-type Galaxies

2018 ◽  
Vol 856 (2) ◽  
pp. 115 ◽  
Author(s):  
Silvia Pellegrini ◽  
Luca Ciotti ◽  
Andrea Negri ◽  
Jeremiah P. Ostriker
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Early Type ◽  
Hot Gas

scholarly journals Hot gaseous atmospheres of rotating galaxies observed with XMM–Newton

2020 ◽  
Vol 499 (4) ◽  
pp. 5163-5174
Author(s):  
A Juráňová ◽  
N Werner ◽  
P E J Nulsen ◽  
M Gaspari ◽  
K Lakhchaura ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Active Galactic Nuclei ◽  
Spiral Galaxy ◽  
Galactic Nuclei ◽  
X Ray ◽  
Hot Gas ◽  
Heating And Cooling ◽  
Theoretical Predictions ◽  
Central Regions ◽  
Gaseous Atmospheres

ABSTRACT X-ray emitting atmospheres of non-rotating early-type galaxies and their connection to central active galactic nuclei have been thoroughly studied over the years. However, in systems with significant angular momentum, processes of heating and cooling are likely to proceed differently. We present an analysis of the hot atmospheres of six lenticulars and a spiral galaxy to study the effects of angular momentum on the hot gas properties. We find an alignment between the hot gas and the stellar distribution, with the ellipticity of the X-ray emission generally lower than that of the optical stellar emission, consistent with theoretical predictions for rotationally supported hot atmospheres. The entropy profiles of NGC 4382 and the massive spiral galaxy NGC 1961 are significantly shallower than the entropy distribution in other galaxies, suggesting the presence of strong heating (via outflows or compressional) in the central regions of these systems. Finally, we investigate the thermal (in)stability of the hot atmospheres via criteria such as the TI- and C-ratio, and discuss the possibility that the discs of cold gas present in these objects have condensed out of the hot atmospheres.

scholarly journals HIDDEN ACTIVE GALACTIC NUCLEI IN EARLY-TYPE GALAXIES

2016 ◽  
Vol 823 (2) ◽  
pp. 112 ◽  
Author(s):  
Alessandro Paggi ◽  
Giuseppina Fabbiano ◽  
Francesca Civano ◽  
Silvia Pellegrini ◽  
Martin Elvis ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Early Type

scholarly journals AGN jet feedback on a moving mesh: lobe energetics and X-ray properties in a realistic cluster environment

2019 ◽  
Vol 490 (1) ◽  
pp. 343-349 ◽  
Author(s):  
Martin A Bourne ◽  
Debora Sijacki ◽  
Ewald Puchwein
Keyword(s):  
Active Galactic Nuclei ◽  
Galaxy Cluster ◽  
Galactic Nuclei ◽  
Moving Mesh ◽  
X Ray ◽  
Cluster Galaxies ◽  
Hot Gas ◽  
Brightest Cluster Galaxies ◽  
Cluster Environment ◽  
Very High

ABSTRACT Jet feedback from active galactic nuclei (AGN) harboured by brightest cluster galaxies is expected to play a fundamental role in regulating cooling in the intracluster medium (ICM). While observations and theory suggest energy within jet lobes balances ICM radiative losses, the modus operandi of energy communication with the ICM remains unclear. We present simulations of very high resolution AGN-driven jets launching in a live, cosmological galaxy cluster, within the moving mesh code arepo. As the jet propagates through the ICM the majority of its energy, which is initially in the kinetic form, thermalizes quickly through internal shocks and inflates lobes of very hot gas. The jets effectively heat the cluster core, with PdV work and weather-aided mixing being the main channels of energy transfer from the lobes to the ICM, while strong shocks and turbulence are subdominant. We additionally present detailed mock X-ray maps at different stages of evolution, revealing clear cavities surrounded by X-ray bright rims, with lobes being detectable for up to ∼108 yr even when magnetic draping is ineffective. We find bulk motions in the cluster can significantly affect lobe propagation, offsetting them from the jet direction and imparting bulk velocities that can dominate over the buoyantly rising motion.

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 LOFAR view of FR 0 radio galaxies

2020 ◽  
Vol 642 ◽  
pp. A107
Author(s):  
A. Capetti ◽  
M. Brienza ◽  
R. D. Baldi ◽  
G. Giovannini ◽  
R. Morganti ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Surface Brightness ◽  
Low Frequency ◽  
Galactic Nuclei ◽  
Early Type ◽  
Resolution Limit ◽  
Low Surface Brightness ◽  
Continuous Population ◽  
Extended Emission ◽  
Radio Power

We explore the low-frequency radio properties of the sources in the Fanaroff-Riley class 0 catalog (FR0CAT) as seen by the Low-Frequency ARray (LOFAR) observations at 150 MHz. This sample includes 104 compact radio active galactic nuclei (AGN) associated with nearby (z <  0.05) massive early-type galaxies. Sixty-six FR0CAT sources are in the sky regions observed by LOFAR and all of them are detected, usually showing point-like structures with sizes of ≲3–6 kpc. However, 12 FR 0s present resolved emission of low surface brightness, which contributes between 5% and 40% of the total radio power at 150 MHz, usually with a jetted morphology extending between 15 and 50 kpc. No extended emission is detected around the other FR 0s, with a typical luminosity limit of ≲5  ×  1022 W Hz−1 over an area of 100 kpc × 100 kpc. The spectral slopes of FR 0s between 150 MHz and 1.4 GHz span a broad range (−0.7 ≲ α ≲ 0.8) with a median value of ᾱ ∼ 0.1; 20% of them have a steep spectrum (α ≳ 0.5), which is an indication of the presence of substantial extended emission confined within the spatial resolution limit. The fraction of FR 0s showing evidence for the presence of jets, by including both spectral and morphological information, is at least ∼40%. This study confirms that FR 0s and FR Is can be interpreted as two extremes of a continuous population of jetted sources, with the FR 0s representing the low end in size and radio power.

scholarly journals WISE mid-infrared properties of compact active galactic nuclei selected from the high radio frequency AT20G survey

2020 ◽  
Vol 494 (1) ◽  
pp. 923-940
Author(s):  
R Chhetri ◽  
A Kimball ◽  
R D Ekers ◽  
E K Mahony ◽  
E M Sadler ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
High Frequency ◽  
Angular Size ◽  
Galactic Nuclei ◽  
Host Galaxy ◽  
High Angular Resolution ◽  
Wide Field ◽  
Early Type ◽  
Mid Infrared ◽  
Radio Frequencies

ABSTRACT Past studies of compact active galactic nuclei (AGNs), the dominant population at high radio frequencies, selected them using flat spectral index criteria. This biases the sample due to the steepening of AGN spectra at high radio frequencies. We improve upon this by selecting 3610 compact AGNs using their angular size information ($\lesssim$0.15 arcsec scale) from the Australia Telescope 20 GHz (AT20G) high-angular resolution catalogue. We cross-match these against the Wide-field Infrared Survey Explorer AllWISE catalogue and present a catalogue with 3300 (91 per cent) matches, 91 (3 per cent) rejects, and 219 (6 per cent) non-detections that are excellent high-redshift candidates. Of the matched compact AGNs, 92 per cent exhibit QSO mid-infrared colours (W1−W2 &gt; 0.5). Therefore, our sample of high frequency compact sources has a very high rate of identification with mid-infrared QSOs. We find counterparts for 88 per cent of 387 compact steep-spectrum (CSS) sources in the AT20G survey, 82 ± 5 per cent of which exhibit QSO mid-infrared colours and have moderate redshifts (zmedian = 0.82), while those dominated by host galaxy colours in mid-infrared have lower redshifts (zmedian = 0.13). The latter classified into late- and early-type galaxies using their mid-infrared colours shows a majority (68 ± 4 per cent) have colours characteristic of late-type galaxies. Thus, we find that a larger fraction of these CSS sources are embedded in hosts with higher gas densities than average early-type galaxies. We compare mid-infrared colours of our AGNs against those reported for AGNs primarily selected using non-radio techniques. This shows that mid-infrared SED of high frequency selected compact radio AGN is comparatively less red, possibly due to contributions from their hosts.

scholarly journals High-Resolution Observations of the M81 Nucleus

1989 ◽  
Vol 134 ◽  
pp. 513-514
Author(s):  
William C. Keel
Keyword(s):  
High Resolution ◽  
Active Galactic Nuclei ◽  
Radio Source ◽  
Galactic Nuclei ◽  
Line Spectrum ◽  
Narrow Line ◽  
Early Type ◽  
X Ray

The nucleus of the nearby Sb galaxy M81 has been shown to exhibit many of the features prominent in luminous active galactic nuclei: a variable, compact VLBI radio source (Kellermann et al. 1976, Jones, Sramek and Terzian 1981), a central variable X-ray source (Elvis and van Speybroeck 1982, Fabbiano 1988), and broad wings of Balmer emission similar in extent to those typical to Seyfert 1 nuclei (Peimbert and Torres-Peimbert 1981, Shuder and Osterbrock 1981). The nucleus also shows a narrow-line spectrum in many ways typical of LINERs (Heckman 1980), now known to be representative of early-type spiral nuclei in general.

scholarly journals Active galactic nuclei feedback, quiescence and circumgalactic medium metal enrichment in early-type galaxies

2017 ◽  
Vol 468 (1) ◽  
pp. 751-768 ◽  
Author(s):  
Maximilian Eisenreich ◽  
Thorsten Naab ◽  
Ena Choi ◽  
Jeremiah P. Ostriker ◽  
Eric Emsellem
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Early Type ◽  
Metal Enrichment ◽  
Circumgalactic Medium
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