A Multi‐Transition HCN and HCO+Study of 12 Nearby Active Galaxies: Active Galactic Nucleus versus Starburst Environments

2008 ◽  
Vol 677 (1) ◽  
pp. 262-275 ◽  
Author(s):  
M. Krips ◽  
R. Neri ◽  
S. García‐Burillo ◽  
S. Martín ◽  
F. Combes ◽  
...  
Keyword(s):  
Active Galactic Nucleus ◽  
Active Galaxies ◽  
Galaxies Active

Millimetre Continuum Observations of AGNs and IRAS Galaxies

1996 ◽  
Vol 13 (2) ◽  
pp. 182-182
Author(s):  
Ray Norris
Keyword(s):  
Active Galactic Nucleus ◽  
Black Body ◽  
Active Galaxies ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Starburst Galaxy ◽  
H Ii Regions ◽  
Synchrotron Emission ◽  
Compact Array ◽  
Three Components

The 3 mm radio continuum emission from active galaxies consists of three components: (1)Synchrotron emission from the active galactic nucleus (AGN), which is over 1 Jy in 3C273 but which is not significant in most of the types of galaxy considered here.(2)Free–free emission from H II regions. The flux of this in a starburst galaxy is typically of the order of 10 mJy and could be imaged with a 3 mm-capable Australia Telescope Compact Array (ATCA).(3)Emission from the tail of the 50–100 K black-body spectrum of the dust. For example, the dust in Arp 220 (redshift of 0·02) at a temperature of 50 K has a flux of 30 mJy at 3 mm. Interestingly, this flux does not decrease substantially with redshift, as the decrease in brightness is compensated for by the redshifting of the steep edge of the blackbody curve, and so infrared-bright galaxies can be studied up to high redshifts with existing instruments.

VLBI Imaging of Luminous Infrared Galaxies: Active Galactic Nucleus Cores in Markarian 231, UGC 5101, and NGC 7469

2003 ◽  
Vol 592 (2) ◽  
pp. 804-818 ◽  
Author(s):  
Carol J. Lonsdale ◽  
Colin J. Lonsdale ◽  
Harding E. Smith ◽  
Philip J. Diamond
Keyword(s):  
Active Galactic Nucleus ◽  
Infrared Galaxies ◽  
Luminous Infrared Galaxies ◽  
Ngc 7469 ◽  
Galaxies Active

scholarly journals Star formation history in barred spiral galaxies – active galactic nucleus feedback

2017 ◽  
Vol 469 (3) ◽  
pp. 3722-3737 ◽  
Author(s):  
Fidèle Robichaud ◽  
David Williamson ◽  
Hugo Martel ◽  
Daisuke Kawata ◽  
Sara L. Ellison
Keyword(s):  
Star Formation ◽  
Active Galactic Nucleus ◽  
Spiral Galaxies ◽  
Star Formation History ◽  
Formation History ◽  
Barred Spiral Galaxies ◽  
Galaxies Active

scholarly journals AGN/Starburst Connection

2014 ◽  
Vol 1 (1) ◽  
pp. 84-89
Author(s):  
Eleonora Sani
Keyword(s):  
Star Formation ◽  
Active Galactic Nucleus ◽  
High Redshift ◽  
Active Galaxies ◽  
Nuclear Region ◽  
Physical Processes ◽  
Geometrical Properties ◽  
High Redshift Universe ◽  
Intense Star Formation

Two main physical processes characterize the activity in the nuclear region of active galaxies: an intense star formation (starburst, SB) and an Active Galactic Nucleus (AGN). While the existence of a starburst-AGN connection is undisputed, still it is not clear which process dominates the energetic output in both local and high redshift Universe. Moreover there is no consensus on whether AGN fueling is synchronous with star formation or follows it during a post-starburst phase. Here I first review how to disentangle the relative SB-AGN contribution, then I focus on the physical and geometrical properties of the circumnuclear environment.

Testing the link between mergers and AGN in the Arp 245 system

2020 ◽  
Vol 15 (S359) ◽  
pp. 192-194
Author(s):  
Elismar Lösch ◽  
Daniel Ruschel-Dutra
Keyword(s):  
Star Formation ◽  
Active Galactic Nucleus ◽  
Spherical Surface ◽  
Galaxy Mergers ◽  
Nuclear Activity ◽  
Upper Limit ◽  
Spherical Surfaces ◽  
Galactic Centers ◽  
Merger Event ◽  
Major Merger

AbstractGalaxy mergers are known to drive an inflow of gas towards galactic centers, potentia- lly leading to both star formation and nuclear activity. In this work we aim to study how a major merger event in the ARP 245 system is linked with the triggering of an active galactic nucleus (AGN) in the NGC galaxy 2992. We employed three galaxy collision numerical simulations and calculated the inflow of gas through four different concentric spherical surfaces around the galactic centers, estimating an upper limit for the luminosity of an AGN being fed the amount of gas crossing the innermost spherical surface. We found that these simulations predict reasonable gas inflow rates when compared with the observed AGN luminosity in NGC 2992.

Exploring the X-ray universe via timing: mass of the active galactic nucleus black hole XMMUJ134736.6+173403

2019 ◽  
Vol 15 (S356) ◽  
pp. 348-350
Author(s):  
Eva Šrámková ◽  
K. Goluchová ◽  
G. Török ◽  
Marek A. Abramowicz ◽  
Z. Stuchlík ◽  
...  
Keyword(s):  
Black Hole ◽  
Frequency Ratio ◽  
Active Galactic Nucleus ◽  
Periodic Modulation ◽  
X Ray ◽  
Upper Limit ◽  
M 10 ◽  
Frequency Ratios ◽  
Quasiperiodic Oscillations ◽  
Twin Peak

AbstractA strong quasi-periodic modulation has recently been revealed in the X-ray flux of the X-ray source XMMUJ134736.6+173403. The two observed twin-peak quasiperiodic oscillations (QPOs) exhibit a 3:1 frequency ratio and strongly support the evidence for the presence of an active galactic nucleus black hole (AGN BH). It has been suggested that detections of twin-peak QPOs with commensurable frequency ratios and scaling of their periods with BH mass could provide the basis for a method intended to determine the mass of BH sources, such as AGNs. Assuming the orbital origin of QPOs, we calculate the upper and lower limit on the AGN BH mass M, reaching M ≍ 107–109M⊙. Compared to mass estimates of other sources, XMMUJ134736.6+173403 appears to be the most massive source with commensurable QPO frequencies, and its mass represents the current observational upper limit on the AGN BH mass obtained from the QPO observations.

Clustering dependence of Chandra COSMOS Legacy AGN on host galaxy properties

2019 ◽  
Vol 15 (S356) ◽  
pp. 226-226
Author(s):  
Viola Allevato
Keyword(s):  
Dark Matter ◽  
Formation Rate ◽  
Stellar Mass ◽  
Active Galaxies ◽  
Host Galaxy ◽  
Mass Star ◽  
Mass Relation ◽  
Dark Matter Halos ◽  
X Ray

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.

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