scholarly journals HerMES: disentangling active galactic nuclei and star formation in the radio source population

2015 ◽  
Vol 452 (4) ◽  
pp. 4111-4127 ◽  
Author(s):  
J. I. Rawlings ◽  
M. J. Page ◽  
M. Symeonidis ◽  
J. Bock ◽  
A. Cooray ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Radio Source ◽  
Galactic Nuclei ◽  
Source Population

scholarly journals Constraining photoionization models with a reprojected optical diagnostic diagram

2020 ◽  
Vol 499 (4) ◽  
pp. 5749-5764 ◽  
Author(s):  
Xihan Ji ◽  
Renbin Yan
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Theoretical Models ◽  
Line Ratio ◽  
Star Forming ◽  
Optical Diagnostic ◽  
Diagnostic Diagram ◽  
Upper Limits ◽  
Nitrogen Abundance

ABSTRACT Optical diagnostic diagrams are powerful tools to separate different ionizing sources in galaxies. However, the model-constraining power of the most widely used diagrams is very limited and challenging to visualize. In addition, there have always been classification inconsistencies between diagrams based on different line ratios, and ambiguities between regions purely ionized by active galactic nuclei (AGNs) and composite regions. We present a simple reprojection of the 3D line ratio space composed of [N ii]λ6583/H α, [S ii]λλ6716, 6731/H α, and [O iii]λ5007/H β, which reveals its model-constraining power and removes the ambiguity for the true composite objects. It highlights the discrepancy between many theoretical models and the data loci. With this reprojection, we can put strong constraints on the photoionization models and the secondary nitrogen abundance prescription. We find that a single nitrogen prescription cannot fit both the star-forming locus and AGN locus simultaneously, with the latter requiring higher N/O ratios. The true composite regions stand separately from both models. We can compute the fractional AGN contributions for the composite regions, and define demarcations with specific upper limits on contamination from AGN or star formation. When the discrepancy about nitrogen prescriptions gets resolved in the future, it would also be possible to make robust metallicity measurements for composite regions and AGNs.

scholarly journals Intensity ratios for XDR/PDR identification

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
C.-E. Green ◽  
M. R. Cunningham ◽  
J. A. Green ◽  
J. R. Dawson ◽  
P. A. Jones ◽  
...  
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
Active Galactic Nuclei ◽  
Intensity Ratio ◽  
Galactic Nuclei ◽  
Relative Influence ◽  
Calculation Methods ◽  
X Ray ◽  
Ratio Calculation ◽  
Intensity Ratios

AbstractThe intensity ratios of HCO+/HCN and HNC/HCN (1-0) reveal the relative influence of star formation and active galactic nuclei (AGN) or black holes on the circum-nuclear gas of a galaxy, allowing the identification of X-ray dominated regions (XDRs) and Photon-dominated regions (PDRs). It is not always clear in the literature how this intensity ratio calculation has been, or should be performed. This paper discusses ratio calculation methods for interferometric data.

scholarly journals STAR FORMATION RATES FROM [C II] 158 μm AND MID-INFRARED EMISSION LINES FOR STARBURSTS AND ACTIVE GALACTIC NUCLEI

2014 ◽  
Vol 790 (1) ◽  
pp. 15 ◽  
Author(s):  
L. Sargsyan ◽  
A. Samsonyan ◽  
V. Lebouteiller ◽  
D. Weedman ◽  
D. Barry ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Infrared Emission ◽  
Emission Lines ◽  
Mid Infrared

scholarly journals ONGOING AND CO-EVOLVING STAR FORMATION IN zCOSMOS GALAXIES HOSTING ACTIVE GALACTIC NUCLEI

2009 ◽  
Vol 696 (1) ◽  
pp. 396-410 ◽  
Author(s):  
J. D. Silverman ◽  
F. Lamareille ◽  
C. Maier ◽  
S. J. Lilly ◽  
V. Mainieri ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei

scholarly journals Star Formation Rates in Lyman Break Galaxies: Radio Stacking of LBGs in the COSMOS Field and the Sub‐μJy Radio Source Population

2008 ◽  
Vol 689 (2) ◽  
pp. 883-888 ◽  
Author(s):  
C. L. Carilli ◽  
Nicholas Lee ◽  
P. Capak ◽  
E. Schinnerer ◽  
K.‐S. Lee ◽  
...  
Keyword(s):  
Star Formation ◽  
Radio Source ◽  
Source Population ◽  
Lyman Break Galaxies

AGN Feedback and its Importance to Galaxy Evolution in the Era of the ngVLA

2018 ◽  
Vol 14 (A30) ◽  
pp. 78-81
Author(s):  
Kristina Nyland
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galaxy Evolution ◽  
Angular Resolution ◽  
Galactic Nuclei ◽  
Gas Content ◽  
Large Array ◽  
Very Large Array ◽  
Frequency Coverage ◽  
Evolutionary Role

AbstractEnergetic feedback by Active Galactic Nuclei (AGN) plays an important evolutionary role in the regulation of star formation (SF) on galactic scales. However, the effects of this feedback as a function of redshift and galaxy properties such as mass, environment and cold gas content remain poorly understood. The broad frequency coverage (1 to 116 GHz), high collecting area (about ten times higher than the Karl G. Jansky Very Large Array), and superb angular resolution (maximum baselines of at least a few hundred km) of the proposed next-generation Very Large Array (ngVLA) are uniquely poised to revolutionize our understanding of AGN and their role in galaxy evolution.

scholarly journals DO MODERATE-LUMINOSITY ACTIVE GALACTIC NUCLEI SUPPRESS STAR FORMATION?

2009 ◽  
Vol 692 (1) ◽  
pp. L19-L23 ◽  
Author(s):  
Kevin Schawinski ◽  
Shanil Virani ◽  
Brooke Simmons ◽  
C. Megan Urry ◽  
Ezequiel Treister ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei

scholarly journals The duty cycle of radio galaxies revealed by LOFAR: remnant and restarted radio source populations in the Lockman Hole

2020 ◽  
Vol 496 (2) ◽  
pp. 1706-1717 ◽  
Author(s):  
Stanislav S Shabala ◽  
Nika Jurlin ◽  
Raffaella Morganti ◽  
Marisa Brienza ◽  
Martin J Hardcastle ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Radio Source ◽  
Low Frequency ◽  
Galactic Nuclei ◽  
Radio Jets ◽  
Modelling Analysis ◽  
Self Consistent ◽  
Large Populations ◽  
Source Populations ◽  
Lockman Hole

ABSTRACT Feedback from radio jets associated with active galactic nuclei (AGNs) plays a profound role in the evolution of galaxies. Kinetic power of these radio jets appears to show temporal variation, but the mechanism(s) responsible for this process are not yet clear. Recently, the LOw Frequency ARray (LOFAR) has uncovered large populations of active, remnant, and restarted radio jet populations. By focusing on LOFAR data in the Lockman Hole, in this work we use the Radio AGNs in Semi-Analytic Environments (RAiSE) dynamical model to present the first self-consistent modelling analysis of active, remnant, and restarted radio source populations. Consistent with other recent work, our models predict that remnant radio lobes fade quickly. Any high (>10 per cent) observed fraction of remnant and restarted sources therefore requires a dominant population of short-lived jets. We speculate that this could plausibly be provided by feedback-regulated accretion.

scholarly journals Enhanced star formation in narrow-line Seyfert 1 active galactic nuclei revealed bySpitzer

2010 ◽  
Vol 403 (3) ◽  
pp. 1246-1260 ◽  
Author(s):  
E. Sani ◽  
D. Lutz ◽  
G. Risaliti ◽  
H. Netzer ◽  
L. C. Gallo ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Narrow Line
Sign in / Sign up

Export Citation Format

Share Document