scholarly journals SpitzerUncovers Active Galactic Nuclei Missed by Optical Surveys in Seven Late‐Type Galaxies

2008 ◽  
Vol 677 (2) ◽  
pp. 926-942 ◽  
Author(s):  
S. Satyapal ◽  
D. Vega ◽  
R. P. Dudik ◽  
N. P. Abel ◽  
T. Heckman
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Late Type ◽  
Optical Surveys

scholarly journals Examining supernova events in Type 1 active galactic nuclei

2020 ◽  
Vol 495 (4) ◽  
pp. 4419-4429
Author(s):  
Beatriz Villarroel ◽  
Iñigo Imaz ◽  
Elisabeta Lusso ◽  
Sébastien Comerón ◽  
M Almudena Prieto ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Detection Rate ◽  
Statistical Study ◽  
Galactic Nuclei ◽  
Core Collapse ◽  
Late Type ◽  
Host Galaxies ◽  
Specific Kind

ABSTRACT A statistical study of intermediate Palomar Transient Factory supernovae (SNe) in Type 1 active galactic nuclei (AGNs) has shown a major deficit of supernovae around Type 1 AGN host galaxies, with respect to Type 2 AGN hosts. The aim of this work is to test whether there is any preference for Type 1 AGNs to host SN of a specific kind. Through the analysis of SN occurrence and their type (thermonuclear versus core-collapse), we can directly link the type of stars producing the SN events, thus this is an indirect way to study host galaxies in Type 1 AGNs. We examine the detection fractions of SNe, the host galaxies and compare the sample properties to typical host galaxies in the Open Supernova Catalog (OSC). The majority of the host galaxies in the AGN sample are late type, similar to typical galaxies hosting SN within the OSC. The findings are supportive of a deficiency of SNe near Type 1 AGNs, although we cannot with certainty assess the overall detection fractions of SNe in Type 1 AGNs relative to other SN host galaxies. We can state that Type 1 AGN has equal detection fractions of thermonuclear versus core-collapse SNe. However, we note the possibility of a higher detection rate of core-collapse supernovae in Type 1 AGN with insecure AGN classifications.

scholarly journals The dependence of mass and environment on the secular processes of AGNs in terms of morphology, colour, and specific star-formation rate

2018 ◽  
Vol 620 ◽  
pp. A113 ◽  
Author(s):  
M. Argudo-Fernández ◽  
I. Lacerna ◽  
S. Duarte Puertas
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Galactic Nuclei ◽  
Stellar Mass ◽  
High Mass ◽  
Late Type ◽  
Star Forming ◽  
Isolated Galaxies

Context. Galaxy mass and environment play a major role in the evolution of galaxies. In the transition from star-forming to quenched galaxies, active galactic nuclei (AGNs) also have a principal action therein. However, the connections between these three actors are still uncertain. Aims. In this work we investigate the effects of stellar mass and the large-scale structure (LSS) environment on the fraction of optical nuclear activity in a population of isolated galaxies, where AGN would not be triggered by recent galaxy interactions or mergers. Methods. As a continuation of a previous work, we focus on isolated galaxies to study the effect of stellar mass and the LSS in terms of morphology (early- and late-type), colour (red and blue), and specific star-formation rate (quenched and star-forming). To explore where AGN activity is affected by the LSS, we separate galaxies into two groups, of low- and high mass, respectively, and use the tidal strength parameter to quantify the effects. Results. We found that AGN is strongly affected by stellar mass in “active” galaxies (namely late-type, blue, and star-forming), but that mass has no influence on “quiescent” galaxies (namely early-type, red, and quenched), at least for masses down to 1010 M⊙. In relation to the LSS, we found an increase in the fraction of star-forming nuclei galaxies with denser LSS in low-mass star-forming and red isolated galaxies. Regarding AGN, we find a clear increase in the fraction of AGNs with denser environment in quenched and red isolated galaxies, independently of the stellar mass. Conclusions. Active galactic nuclei activity appears to be “mass triggered” in active isolated galaxies. This means that AGN activity is independent of the intrinsic properties of the galaxies, but is dependent on their stellar mass. On the other hand, AGN activity appears to be “environment triggered” in quiescent isolated galaxies, where the fraction of AGNs as a function of specific star formation rate and colour increases from void regions to denser LSS, independently of stellar mass.

INVESTIGATION OF INTRADAY VARIABILITY OF ACTIVE GALACTIC NUCLEI IN OPTICAL AND RADIO RANGES

2010 ◽  
Vol 1 (2) ◽  
pp. 111-115
Author(s):  
O. E. Volvach ◽  
L. N. Volvach ◽  
V. S. Bichkova ◽  
M. S. Kardashev ◽  
M. G. Larionov ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Intraday Variability

Hubble Space Telescopeand Ground‐based Observations of I Zw 1 and MRK 486 and the Variability of Polarization in Radio‐quiet Active Galactic Nuclei

1997 ◽  
Vol 488 (1) ◽  
pp. 202-215 ◽  
Author(s):  
Paul S. Smith ◽  
Gary D. Schmidt ◽  
Richard G. Allen ◽  
Dean C. Hines
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei

Faint Sources in theEUVESurvey: Identification of White Dwarfs, Active Late‐Type Stars, and Galactic Nuclei

1997 ◽  
Vol 486 (1) ◽  
pp. 179-196 ◽  
Author(s):  
Elisha Polomski ◽  
Stephane Vennes ◽  
John R. Thorstensen ◽  
Mihalis Mathioudakis ◽  
Emilio E. Falco
Keyword(s):  
White Dwarfs ◽  
Galactic Nuclei ◽  
Late Type

Polarization Variability of Active Galactic Nuclei and X‐Ray Binaries

1997 ◽  
Vol 487 (1) ◽  
pp. 142-152 ◽  
Author(s):  
Gang Bao ◽  
Petr Hadrava ◽  
Paul J. Wiita ◽  
Ying Xiong
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
X Ray ◽  
X Ray Binaries

Statistics of Active Galactic Nuclei in Rich Clusters Revisited

1998 ◽  
Vol 502 (1) ◽  
pp. 134-140 ◽  
Author(s):  
M. J. Way ◽  
R. A. Flores ◽  
H. Quintana
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei
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