scholarly journals Radio Loud Far-Infrared Galaxies

1990 ◽  
Vol 124 ◽  
pp. 309-314 ◽  
Author(s):  
Arjun Dey ◽  
Wil van Breugel ◽  
Joseph C. Shields
Keyword(s):  
Star Formation ◽  
Radio Emission ◽  
Point Source ◽  
Optical Imaging ◽  
Radio Galaxy ◽  
Far Infrared ◽  
Infrared Galaxies ◽  
Galaxy Interactions ◽  
First Results ◽  
Radio Survey

AbstractWe present the first results of a multiwavelength study of IRAS galaxies with excess radio emission. The sample was selected by cross-correlating the IRAS Faint Source Survey (for |b| ≥ 50°) and the Point Source Catalogue (for 10° < |b| < 50°) with the Texas radio survey. Recent optical (imaging and spectroscopic) and radio (VLA) observations are discussed. These observations will be used to investigate possible connections between radio galaxy activity, star formation and galaxy interactions.

Hidden Star Formation: The Ultraviolet Perspective

2002 ◽  
Vol 12 ◽  
pp. 489-492 ◽  
Author(s):  
G.R. Meurer ◽  
T.M. Heckman ◽  
M. Seibert ◽  
J. Goldader ◽  
D. Calzetti ◽  
...  
Keyword(s):  
Star Formation ◽  
High Redshift ◽  
Formation Rate ◽  
Flux Ratio ◽  
Far Infrared ◽  
Infrared Galaxies ◽  
Luminous Infrared Galaxies ◽  
Lyman Break Galaxies ◽  
Highly Sensitive ◽  
Dust Absorption

AbstractMany recent estimates of the star formation rate density at high redshift rely on rest-frame ultraviolet (UV) data. These are highly sensitive to dust absorption. Applying a correlation between the far-infrared (FIR) to UV flux ratio and UV color found in local starbursts to galaxy samples out toz∼ 3, one can account for most of the FIR background. However, the correlation is based on a sample that does not include the most extreme starbursts, Ultra Luminous Infrared Galaxies (ULIGs). Our new UV images of ULIGs show that their FIR fluxes are underpredicted by this correlation by factors ranging from 7 to 70. We discuss how ULIGs compare to the various types of high-zgalaxies: sub-mm sources, Lyman Break Galaxies, and Extremely Red Objects.

scholarly journals Are quiescent galaxies truly devoid of star formation? The mid-, far-infrared and radio properties of quiescent galaxies at z = 0.1 - 3

2015 ◽  
Vol 11 (S319) ◽  
pp. 97-100
Author(s):  
Allison W. S. Man
Keyword(s):  
Star Formation ◽  
Radio Emission ◽  
Rest Frame ◽  
Far Infrared ◽  
Attenuation Curve ◽  
Selection Technique ◽  
Dust Attenuation ◽  
Ubiquitous Presence ◽  
Selection Of

AbstractQuiescent galaxy candidates are typically identified by their low unobscured star formation rates from deep field photometric surveys. However, their selection technique relies on the assumption of a universal dust attenuation curve. It is important to verify the selection through independent SFR indicators at longer wavelengths. Current mid-, far-infrared and radio surveys are limited to detecting only galaxies with very strong star formation or AGN activity. Here, I present the first comprehensive stacking results across mid-, far-infrared and radio wavelengths using Spitzer, Herschel and VLA data in the COSMOS field (Man et al. 2014). We find that the rest-frame NUV-r and r-J color criteria, combined with low 24 μm emission, provides a robust selection of truly quiescent galaxies out to z = 3. Additionally, we find evidence of radio emission in excess of the expected total star formation in quiescent galaxies at z ~ 0-1.5, indicative of a ubiquitous presence of low-luminosity radio AGN among them.

scholarly journals Superluminal Behaviour of the Double-Lobed Radio Galaxy 3C111

1988 ◽  
Vol 129 ◽  
pp. 105-106
Author(s):  
Eugen Preuss ◽  
Walter Alef ◽  
Kenneth I. Kellermann
Keyword(s):  
Radio Emission ◽  
Time Dependence ◽  
Radio Galaxy ◽  
Monitoring Program ◽  
Radio Galaxies ◽  
Scale Structure ◽  
Small Scale ◽  
Broad Line ◽  
First Results ◽  
First Time

Due to sensitivity problems only about a dozen of the powerful double-lobed radio galaxies have so far been mapped with VLBI. Even less is known about the time dependence of the small scale structure in these objects (Preuss and Alef, 1987). We have recently reported the first results of our monitoring program of classical double sources. We observed strong changes of the pc-scale structure in 3C111 (Götz et al., 1987) and 3C390.3 (Alef et al., 1987) implying “superluminal behaviour” in both sources. This is the first time that such a phenomenon has been found in lobe-dominated radio galaxies. Both objects are Broad Line Radio Galaxies of type N, and their radio emission from m to cm wavelengths is dominated by their outer lobes which are ∼300 kpc apart (H0 = 50 km/s/Mpc).

scholarly journals Accretion and star formation in ‘radio-quiet’ quasars

2019 ◽  
Vol 15 (S356) ◽  
pp. 204-208
Author(s):  
Sarah V. White ◽  
Matt J. Jarvis ◽  
Eleni Kalfountzou ◽  
Martin J. Hardcastle ◽  
Aprajita Verma ◽  
...  
Keyword(s):  
Star Formation ◽  
Radio Emission ◽  
Galactic Nuclei ◽  
Far Infrared ◽  
Black Hole Accretion ◽  
Wide Range ◽  
Star Formation Histories ◽  
The Universe ◽  
Hole Accretion ◽  
Infrared Data

AbstractRadio observations allow us to identify a wide range of active galactic nuclei (AGN), which play a significant role in the evolution of galaxies. Amongst AGN at low radio-luminosities is the ‘radio-quiet’ quasar (RQQ) population, but how they contribute to the total radio emission is under debate, with previous studies arguing that it is predominantly through star formation. In this talk, SVW summarised the results of recent papers on RQQs, including the use of far-infrared data to disentangle the radio emission from the AGN and that from star formation. This provides evidence that black-hole accretion, instead, dominates the radio emission in RQQs. In addition, we find that this accretion-related emission is correlated with the optical luminosity of the quasar, whilst a weaker luminosity-dependence is evident for the radio emission connected with star formation. What remains unclear is the process by which this accretion-related emission is produced. Understanding this for RQQs will then allow us to investigate how this type of AGN influences its surroundings. Such studies have important implications for modelling AGN feedback, and for determining the accretion and star-formation histories of the Universe.

scholarly journals The radio emission from far-infrared galaxies: Seyfert or starburst?

1988 ◽  
Vol 234 (3) ◽  
pp. 773-782 ◽  
Author(s):  
R. P. Norris ◽  
David A. Allen ◽  
P. F. Roche
Keyword(s):  
Radio Emission ◽  
Far Infrared ◽  
Infrared Galaxies

scholarly journals Submillimeter Surveys at High Redshift

2002 ◽  
Vol 12 ◽  
pp. 469-472
Author(s):  
Amy J. Barger
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
High Redshift ◽  
Large Fraction ◽  
Far Infrared ◽  
Star Formation History ◽  
Infrared Galaxies ◽  
Small Admixture ◽  
Formation History ◽  
Ultraluminous Infrared Galaxies

AbstractDeep submillimeter (submm) surveys offer an unobscured view of dust-enshrouded star formation or AGN activity at high red-shifts. SCUBA observations above 2 mJy have resolved 20 – 30% of the far-infrared (FIR) background into discrete sources and have revealed the existence of a distant population of galaxies with properties similar to those of local ultraluminous infrared galaxies. A large fraction of the submm sources have extremely faint optical/near-infrared (NIR) counterparts and hence are inaccessible to optical spectroscopy. Millimetric redshift estimation places the submm population atz= 1 to 3. While the cumulative surface density of the submm sources is low, they are so luminous that if powered mainly by star formation, they dominate the high redshift star formation history. Recent combined SCUBA submm andChandrahard X-ray studies suggest that the majority of the submm sources are star formers with only a small admixture of obscured AGN.

Tracing young SMBHs in the dusty distant universe – a Chandra view of DOGs

2020 ◽  
Vol 15 (S359) ◽  
pp. 17-21
Author(s):  
Karín Menéndez-Delmestre ◽  
Laurie Riguccini ◽  
Ezequiel Treister
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Far Infrared ◽  
Host Galaxy ◽  
X Ray ◽  
Star Forming ◽  
Near Ir ◽  
X Ray Imaging ◽  
Combined Use ◽  
Dusty Galaxies

AbstractThe coexistence of star formation and AGN activity has geared much attention to dusty galaxies at high redshifts, in the interest of understanding the origin of the Magorrian relation observed locally, where the mass of the stellar bulk in a galaxy appears to be tied to the mass of the underlying supermassive black hole. We exploit the combined use of far-infrared (IR) Herschel data and deep Chandra ˜160 ksec depth X-ray imaging of the COSMOS field to probe for AGN signatures in a large sample of >100 Dust-Obscured Galaxies (DOGs). Only a handful (˜20%) present individual X-ray detections pointing to the presence of significant AGN activity, while X-ray stacking analysis on the X-ray undetected DOGs points to a mix between AGN activity and star formation. Together, they are typically found on the main sequence of star-forming galaxies or below it, suggesting that they are either still undergoing significant build up of the stellar bulk or have started quenching. We find only ˜30% (6) Compton-thick AGN candidates (NH > 1024 cm–2), which is the same frequency found within other soft- and hard-X-ray selected AGN populations. This suggests that the large column densities responsible for the obscuration in Compton-thick AGNs must be nuclear and have little to do with the dust obscuration of the host galaxy. We find that DOGs identified to have an AGN share similar near-IR and mid-to-far-IR colors, independently of whether they are individually detected or not in the X-ray. The main difference between the X-ray detected and the X-ray undetected populations appears to be in their redshift distributions, with the X-ray undetected ones being typically found at larger distances. This strongly underlines the critical need for multiwavelength studies in order to obtain a more complete census of the obscured AGN population out to higher redshifts. For more details, we refer the reader to Riguccini et al. (2019).

scholarly journals A z = 2.5 protocluster associated with the radio galaxy MRC 2104-242: star formation and differing mass functions in dense environments

2014 ◽  
Vol 440 (4) ◽  
pp. 3262-3274 ◽  
Author(s):  
E. A. Cooke ◽  
N. A. Hatch ◽  
S. I. Muldrew ◽  
E. E. Rigby ◽  
J. D. Kurk
Keyword(s):  
Star Formation ◽  
Radio Galaxy ◽  
Mass Functions
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