Fundamental differences in the radio properties of red and blue quasars: evolution strongly favoured over orientation

Klindt, L.; Alexander, D. M.; Rosario, D. J.; Lusso, Elisabeta; Fotopoulou, S.

doi:10.1093/mnras/stz1771

Cited by 78 publications

(241 citation statements)

References 108 publications

(157 reference statements)

Supporting

Mentioning

199

Contrasting

Order By: Relevance

“…Fig. 2 compares the radio source density of the C3GHz, S82 and FIRST parent sample QSOs matched to the three different radio survey catalogues, using a search radius 1.5 times the survey beam size for S82 and C3GHz, and 10 for FIRST (to be consistent with Klindt et al 2019), as a function of the 5σ sensitivity limit for each survey; 70% of the parent QSOs are detected in C3GHz, an order of magnitude greater than in FIRST. The cutouts illustrate a compact (i.e., unresolved) radio source at the different survey resolutions.…”

Section: Radio Datamentioning

confidence: 94%

“…The overall quasar selection process used is similar to that adopted in Klindt et al (2019). However, in our work we now select QSOs from the SDSS DR14 Quasar Catalogue (Pâris et al 2018), as opposed to Klindt et al (2019) who used the SDSS DR7 catalogue (Schneider et al 2010), which provides a factor ≈ 5 improvement in sample size, as well as going almost two magnitudes deeper in the optical. In this section we describe our selection strategy, the radio surveys utilised, and the key measurements extracted from the multi-wavelength data in the SDSS.…”

Section: Data Sets and Methodsmentioning

confidence: 99%

“…(Lake et al 2011), and required a detection with a signal-to-noise ratio (SNR) of greater than 2 in the WISE W1, W2 and W3 bands. As in Klindt et al (2019), we only selected QSOs with redshifts between 0.2 < z < 2.4: the higher redshift cut ensures there is no contamination from the Lyman break in the g * band and the lower redshift cut ensures we only consider luminous QSOs in our sample. The need for a WISE detection in the three bands and the restriction of 0.2 < z < 2.4 reduced the number of QSOs to 218 747, the full parent sample; see Fig.…”

Section: Figurementioning

confidence: 99%

“…We used data from two high spatial resolution VLA radio surveys: VLA Stripe 82 (S82; Hodge et al 2011) and VLA-COSMOS 3 GHz (C3GHz; Smolčić et al 2017a), which we describe in more detail below. To better place these data into context with our earlier Klindt et al (2019) paper, we also describe the VLA FIRST survey used in that work. Fig.…”

Section: Radio Datamentioning

confidence: 99%

“…However, there is a small but significant subset with redder optical-infrared colours (coined as "red QSOs"). Although red QSOs have been well studied in the literature (Webster et al 1995;Serjeant & Rawlings 1996;Kim & Elvis 1999; E-mail: victoria.fawcett@durham.ac.uk Richards et al 2003;Glikman et al 2007;Georgakakis et al 2009;Urrutia et al 2009;Banerji et al 2012;Glikman et al 2012;Kim & Im 2018;Klindt et al 2019), their exact nature remains unclear.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Fawcett

Alexander

Rosario

et al. 2020

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We have recently used the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey to show that red quasars have fundamentally different radio properties to typical blue quasars: a significant (factor ≈ 3) enhancement in the radio-detection fraction, which arises from systems around the radio-quiet threshold with compact (< 5 ) radio morphologies. To gain greater insight into these physical differences, here we use the DR14 Sloan Digital Sky Survey (SDSS) and more sensitive, higher resolution radio data from the Very Large Array (VLA) Stripe 82 (S82) and VLA-COSMOS 3 GHz (C3GHz) surveys. With the S82 data, we perform morphological analyses at a resolution and depth three times that of the FIRST radio survey, and confirm an enhancement in radio-faint and compact red quasars over typical quasars; we now also find tentative evidence for an enhancement in red quasars with slightly extended radio structures (16-43 kpc at z = 1.5). These analyses are complemented by C3GHz, which is deep enough to detect radio emission from star-formation processes. From our data we find that the radio enhancement from red quasars is due to AGN activity on compact scales ( 43 kpc) for radio-intermediate-radio-quiet sources (−5 < R < −3.4, where R = L 1.4GHz /L 6µm ), which decreases at R < −5 as the radio emission from star-formation starts to dilute the AGN component. Overall our results argue against a simple orientation scenario and are consistent with red quasars representing a younger, earlier phase in the overall evolution of quasars.

show abstract

Section: Radio Datamentioning

confidence: 94%

Section: Data Sets and Methodsmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Section: Radio Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Fawcett

Alexander

Rosario

et al. 2020

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

Do stellar-mass and super-massive black holes have similar dining habits?

Arcodia

Ponti

Merloni

et al. 2020

A&A

View full text Add to dashboard Cite

Over the years, numerous attempts have been made to connect the phenomenology and physics of mass accretion onto stellar-mass and super-massive black holes in a scale-invariant fashion. In this paper, we explore this connection at the radiatively efficient (and non-jetted) end of accretion modes by comparing the relationship between the luminosity of the accretion disc and corona in the two source classes. Motivated by the apparently tight relationship between these two quantities in active galactic nuclei (AGNs), we analyse 458 RXTE-PCA archival observations of the X-ray binary (XRB) GX 339–4, using this object as an exemplar for the properties of XRBs in general. We focus on the soft and soft-intermediate states, which have been suggested to be analogous to radiatively efficient AGNs. The observed scatter in the log Ldisc − log Lcorona relationship of GX 339–4 is high (∼0.43 dex) and significantly larger than in a representative sample of radiatively efficient, non- or weakly jetted AGNs (∼0.30 dex). At first glance, this would appear contrary to the hypothesis that the systems simply scale with mass. On the other hand, we also find that GX 339–4 and our AGN sample show different accretion rate and power-law index distributions, with the latter in particular being broader in GX 339–4 (dispersion of ∼0.16 cf. ∼0.08 for AGN). GX 339–4 also shows an overall softer slope, with a mean value of ∼2.20 as opposed to ∼2.07 for the AGN sample. Remarkably, once similarly broad Γ and ṁ distributions are selected, the AGN sample overlaps nicely with GX 339–4 observations in the mass-normalised log Ldisc − log Lcorona plane, with a scatter of ∼0.30 − 0.33 dex in both cases. This indicates that a mass-scaling of properties might hold after all, with our results being consistent with the disc-corona systems in AGNs and XRBs exhibiting the same physical processes, albeit under different conditions for instance in terms of temperature, optical depth and/or electron energy distribution in the corona, heating-cooling balance, coronal geometry and/or black hole spin.

show abstract

What is the origin of the stacked radio emission in radio-undetected quasars?

Retana-Montenegro

2022

A&A

View full text Add to dashboard Cite

Radio emission in the brightest radio quasars can be attributed to processes inherent to active galactic nuclei (AGN) powered by super massive black holes (SMBHs), while the physical origins of the radio fluxes in quasars without radio detections have not been established with full certainly. Deep radio surveys carried out with the Low Frequency ARray (LOFAR) are at least one order of magnitude more sensitive for objects with typical synchrotron spectra than previous wide-area high-frequency surveys ( > 1.0 GHz). With the enhanced sensitivity that LOFAR offers, we investigate the radio-infrared continuum of LOFAR radio-detected quasars (RDQs) and LOFAR radio-undetected quasars (RUQs) in the 9.3 deg2 NOAO Deep Wide-field survey (NDWFS) of the Boötes field; RUQs are quasars that are individually undetected at a level of ≥5σ in the LOFAR observations. To probe the nature of the radio and infrared emission, where direct detection is not possible due to the flux density limits, we used a median image stacking procedure. This was done in the radio frequencies of 150 MHz, 325 MHz, 1.4 GHz and 3.0 GHz, and in nine infrared bands between 8 and 500 μm. The stacking analysis allows us to probe the radio-luminosity for quasars that are up to one order of magnitude fainter than the ones detected directly. The radio and infrared photometry allow us to derive the median spectral energy distributions of RDQs and RUQs in four contiguous redshift bins between 0 < z < 6.15. The infrared photometry is used to derive the infrared star-formation rate (SFR) through SED fitting, and is compared with two independent radio-based star-formation (SF) tracers using the far-infrared radio correlation (FIRC) of star-forming galaxies. We find a good agreement between our radio and infrared SFR measurements and the predictions of the FIRC. Moreover, we use the FIRC predictions to establish the level of the contribution due to SMBH accretion to the total radio-luminosity. We show that SMBH accretion can account for ∼5−41% of the total radio-luminosity in median RUQs, while for median RDQs the contribution is ∼50−84%. This implies that vigorous SF activity is coeval with SMBH growth in our median stacked quasars. We find that median RDQs have higher SFRs that agree well with those of massive star-forming main sequence galaxies, while median RUQs present lower SFRs than RDQs. Furthermore, the behavior of the radio-loudness parameter (R = log10(Lrad/LAGN)) is investigated. For quasars with R ≥ −4.5, the radio-emission is consistent with being dominated by SMBH accretion, while for low radio luminosity quasars with R < −4.5 the relative contribution of SF to the radio fluxes increases as the SMBH component becomes weaker. We also find signatures of SF suppression due to negative AGN feedback in the brightest median RDQs at 150 MHz. Finally, taking advantage of our broad spectral coverage, we studied the radio spectra of median RDQs and RUQs. The spectral indices of RUQs and RDQs do not evolve significantly with redshift, but they become flatter towards lower frequencies.

show abstract

Fundamental differences in the radio properties of red and blue quasars: evolution strongly favoured over orientation

Cited by 78 publications

References 108 publications

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars

Do stellar-mass and super-massive black holes have similar dining habits?

What is the origin of the stacked radio emission in radio-undetected quasars?

Contact Info

Product

Resources

About