Herschel-ATLAS★: far-infrared properties of radio-loud and radio-quiet quasars

Kalfountzou, E.; Stevens, J. A.; Jarvis, Matt J.; Hardcastle, M. J.; Smith, Daniel; Bourne, N.; Dunne, L.; Ibar, E.; Eales, Stephen Anthony; Ivison, R. J.; Maddox, S.; Smith, M. W. L.; Valiante, Elisabetta; Zotti, G. de

doi:10.1093/mnras/stu782

Cited by 46 publications

(82 citation statements)

References 108 publications

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“…as a function of the 1.4 GHz radio luminosity and the radio loudness factor R. We do not find any obvious trends between the IR slope and the radio luminosity, or R in agreement with the work of (Kalfountzou et al 2014) and so our results in the FIR do not appear biased by the radio loud sources in the sample.…”

Section: Appendix B Synchrotron Versus Thermal Dust Emissionsupporting

confidence: 89%

HERSCHEL SURVEY OF THE PALOMAR-GREEN QSOs AT LOW REDSHIFT

Petric

Flagey

et al. 2015

ApJS

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We investigate the global cold dust properties of 85 nearby (z 0.5 ⩽ ) QSOs, chosen from the Palomar-Green sample of optically luminous quasars. We determine their infrared spectral energy distributions and estimate their rest-frame luminosities by combining Herschel data from 70 to 500 μm with near-infrared and mid-infrared measurements from the 2MASS and the Wide-Field Infrared Survey Explorer. In most sources the far-infrared (FIR) emission can be attributed to thermally heated dust. Single temperature modified blackbody fits to the FIR photometry give an average dust temperature for the sample of 33 K, with a standard deviation of 8 K, and an average dust mass of M 7 10 6  with a standard deviation of M 9 10 6  . Estimates of star formation rates that are based on the FIR continuum emission correlate with those based on the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature, however, the star formation rates estimated from the FIR continuum are higher than those estimated from the 11.3 μm PAH emission. We attribute this result to a variety of factors including the possible destruction of the PAHs and that, in some sources, a fraction of the FIR originates from dust heated by the active galactic nucleus and by old stars.

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Section: Appendix B Synchrotron Versus Thermal Dust Emissionsupporting

confidence: 89%

HERSCHEL SURVEY OF THE PALOMAR-GREEN QSOs AT LOW REDSHIFT

Petric

Flagey

et al. 2015

ApJS

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“…For purposes of comparison we have overplotted in Fig. 5 the mean flux densities obtained by Kalfountzou et al (2014b), hereafter K14b, (dashed lines) for low and high optical luminosity RLQs (red circles) and RQQs (blue squares). We note two main differences between our current results and those of K14b.…”

Section: Fir Emission In Rlqs Rqqs and Rgsmentioning

confidence: 99%

“…Moreover, it is also unclear how these processes depend on luminosity and radio-loudness and how they are observationally affected by orientation (e.g. Rosario et al 2012;Page et al 2012;Kalfountzou et al 2012Kalfountzou et al , 2014bChen et al 2015).…”

Section: Introductionmentioning

confidence: 99%

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Observational evidence that positive and negative AGN feedback depends on galaxy mass and jet power

Kalfountzou

Stevens

Jarvis

et al. 2017

Monthly Notices of the Royal Astronomical Society

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Several studies support the existence of a link between the AGN and star formation activity. Radio jets have been argued to be an ideal mechanism for direct interaction between the AGN and the host galaxy. A drawback of previous surveys of AGN is that they are fundamentally limited by the degeneracy between redshift and luminosity in flux-density limited samples. To overcome this limitation, we present far-infrared Herschel observations of 74 radio-loud quasars (RLQs), 72 radio-quiet quasars (RQQs) and 27 radio galaxies (RGs), selected at 0.9 < z < 1.1 which span over two decades in optical luminosity. By decoupling luminosity from evolutionary effects, we investigate how the star formation rate (SFR) depends on AGN luminosity, radio-loudness and orientation. We find that: 1) the SFR shows a weak correlation with the bolometric luminosity for all AGN sub-samples, 2) the RLQs show a SFR excess of about a factor of 1.4 compared to the RQQs, matched in terms of black hole mass and bolometric luminosity, suggesting that either positive radio-jet feedback or radio AGN triggering are linked to star-formation triggering and 3) RGs have lower SFRs by a factor of 2.5 than the RLQ sub-sample with the same BH mass and bolometric luminosity. We suggest that there is some jet power threshold at which radio-jet feedback switches from enhancing star formation (by compressing gas) to suppressing it (by ejecting gas). This threshold depends on both galaxy mass and jet power.

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“…Bower et al 2006;Werner et al 2013;Chen et al 2013b). However, a positive radio mode feedback has also been suggested (Silk & Nusser 2010;Kalfountzou et al 2012Kalfountzou et al , 2014Gaibler et al 2012). In this scenario, the radio jets drive shocks in the interstellar medium which enhance the star formation, something that has been observed for decades now (e.g.…”

Section: Introductionmentioning

confidence: 97%

Herschel-ATLAS: the connection between star formation and AGN activity in radio-loud and radio-quiet active galaxies

Gürkan¹,

Hardcastle²,

Jarvis³

et al. 2015

Mon. Not. R. Astron. Soc.

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We examine the relationship between star formation and AGN activity by constructing matched samples of local (0 < z < 0.6) radio-loud and radio-quiet AGN in the Herschel-ATLAS fields. Radio-loud AGN are classified as high-excitation and low-excitation radio galaxies (HERGs, LERGs) using their emission lines and WISE 22-µm luminosity. AGN accretion and jet powers in these active galaxies are traced by [OIII] emission-line and radio luminosity, respectively. Star formation rates (SFRs) and specific star formation rates (SSFRs) were derived using Herschel 250-µm luminosity and stellar mass measurements from the SDSS−MPA-JHU catalogue. In the past, star formation studies of AGN have mostly focused on high-redshift sources to observe the thermal dust emission that peaks in the far-infrared, which limited the samples to powerful objects. However, with Herschel we can expand this to low redshifts. Our stacking analyses show that SFRs and SSFRs of both radio-loud and radioquiet AGN increase with increasing AGN power but that radio-loud AGN tend to have lower SFR. Additionally, radio-quiet AGN are found to have approximately an order of magnitude higher SSFRs than radio-loud AGN for a given level of AGN power. The difference between the star formation properties of radio-loud and -quiet AGN is also seen in samples matched in stellar mass.

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Herschel-ATLAS★: far-infrared properties of radio-loud and radio-quiet quasars

Cited by 46 publications

References 108 publications

HERSCHEL SURVEY OF THE PALOMAR-GREEN QSOs AT LOW REDSHIFT

HERSCHEL SURVEY OF THE PALOMAR-GREEN QSOs AT LOW REDSHIFT

Observational evidence that positive and negative AGN feedback depends on galaxy mass and jet power

Herschel-ATLAS: the connection between star formation and AGN activity in radio-loud and radio-quiet active galaxies

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