Quasars That Have Transitioned from Radio-quiet to Radio-loud on Decadal Timescales Revealed by VLASS and FIRST

Nyland, Kristina; Dong, Dillon; Patil, Pallavi; Lacy, Mark; Velzen, S. van; Kimball, Amy; Sarbadhicary, Sumit K.; Hallinan, Gregg; Baldassare, Vivienne; Clarke, T. E.; Goulding, Andy D.; Greene, Jenny E.; Hughes, Andrew K.; Kassim, N. E.; Kunert-Bajraszewska, M.; Maccarone, Thomas J.; Mooley, K. P.; Mukherjee, Dipanjan; Peters, Wendy; Petrov, Leonid; Polisensky, Emil; Rujopakarn, W.; Whittle, M.; Vaccari, M.

doi:10.3847/1538-4357/abc341

Cited by 81 publications

(97 citation statements)

References 146 publications

(181 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The transition from radio-quiet to radio-loud phase in this source coincided with changes in its accretion disk luminosity, which we interpret as a result of an enhancement in the SMBH accretion rate. Very recently the detection of changing-state AGNs has been also reported by Nyland et al (2020) as a result of the VLASS survey. Their quasars show a large flux density increase in the S band and convex radio spectra, as in our CNSS objects.…”

Section: Introductionmentioning

confidence: 77%

Caltech-NRAO Stripe 82 Survey (CNSS). V. AGNs That Transitioned to Radio-loud State

Wołowska¹,

Kunert-Bajraszewska²,

Mooley

et al. 2021

ApJ

Self Cite

View full text Add to dashboard Cite

A recent multiyear Caltech-NRAO Stripe 82 Survey revealed a group of objects that appeared as new radio sources after >5-20 yr of absence. They are transient phenomena with respect to the Faint Images of the Radio Sky at Twenty Centimeters survey and constitute the first unbiased sample of renewed radio activity. Here we present a follow-up, radio, optical, and X-ray study of them. The group consists of 12 sources, both quasars and galaxies with wide redshift (0.04 < z < 1.7) and luminosity ( < > -L 22 log W Hz 24.5Their radio properties in the first phase of activity, namely the convex spectra and compact morphology, allow them all to be classified as gigahertz-peaked spectrum (GPS) sources. We conclude that the spectral changes are a consequence of the evolution of newly born radio jets. Our observations show that over the next few years of activity the GPS galaxies keep the convex shape of the spectrum, while GPS quasars rapidly transform into flatspectrum sources, which may result in them not being recognized as young sources. The wide range of bolometric luminosities, black hole masses, and jet powers among the transient sources indicates even greater population diversity in the group of young radio objects. We also suggest that small changes of the accretion disk luminosity (accretion rate) may be sufficient to ignite low-power radio activity that evolves on the scale of decades. Unified Astronomy Thesaurus concepts: Active galaxies (17); AGN host galaxies (2017); Radio galaxies (1343); Quasars (1319); Radio loud quasars (1349); Radio quiet quasars (1354); Supermassive black holes (1663); Active galactic nuclei (16); Galaxy evolution (594)

show abstract

Section: Introductionmentioning

confidence: 77%

Caltech-NRAO Stripe 82 Survey (CNSS). V. AGNs That Transitioned to Radio-loud State

Wołowska¹,

Kunert-Bajraszewska²,

Mooley

et al. 2021

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…AGN are known to display variability at all wavelengths, and have been observed to launch new jets (78). However, it is difficult to explain a 15s X-ray flare from an AGN.…”

Section: Consistency Checksmentioning

confidence: 99%

A transient radio source consistent with a merger-triggered core collapse supernova

Dong

Hallinan

Nakar

et al. 2021

Science

View full text Add to dashboard Cite

A core-collapse supernova occurs when exothermic fusion ceases in the core of a massive star, typically due to exhaustion of nuclear fuel. Theory predicts that fusion could be interrupted earlier, by merging of the star with a compact binary companion. We report a luminous radio transient, VT J121001+495647, found in the Very Large Array Sky Survey. The radio emission is consistent with supernova ejecta colliding with a dense shell of material, potentially ejected by binary interaction in the centuries prior to explosion. We associate the supernova with an archival X-ray transient, which implies a relativistic jet was launched during the explosion. The combination of an early relativistic jet and late-time dense interaction is consistent with expectations for a mergerdriven explosion. Main Text:Most massive stars (those > 8 solar masses, M⊙) are born in close binaries, within which expansion of one star during its evolution can lead to mass transfer with the companion (1,2). In some systems, the faster evolving (more massive) star explodes as a supernova, leaving behind a compact object (neutron star or black hole) remnant in a close orbit with its companion. When the companion (second star) later expands, it transfers mass in the other direction, onto the compact object. Systems of this type with wide orbits have been observed in the Milky Way (3). Those with closer orbits undergo unstable mass transfer, causing the compact object to spiral into the atmosphere of the massive star, forming a common envelope binary.During the common envelope phase, the outer atmosphere of the donor star becomes unbound, forming a dense and expanding toroidal shell around the binary (4). The physics of the common envelope are difficult to model. Some inspirals halt before reaching the donor's core. This process is a leading candidate for producing the close double-compact-object binaries detected by gravitational wave observatories (5). Other systems are expected to spiral inwards until the compact object reaches the star's core. Theory predicts that some of these systems tidally disrupt the core, forming a rapidly accreting neutrino-cooled disk (6). This energetic accretion is predicted to launch a jet and cause a merger-driven explosion (6,7,8).We performed a systematic blind search for radio transients in the Very Large Array Sky Survey (VLASS) (9). We identified and followed up luminous point sources associated with galaxies closer than 200 megaparsec (Mpc) that are present in the first half-epoch (Epoch 1.1; Sep 2017 -Feb 2018 of the survey but absent from the earlier (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005) Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey (10, 11). The most luminous source we identified was VLASS transient VT J121001+495647 (hereafter abbreviated VT 1210+4956), located in an offnuclear region of the dwarf star-forming galaxy SDSS J121001.38+495641.7 (fig. 1) (12). This galaxy has stellar mass ~ 10 9.2 M⊙, specific star formation rate ~0.25 M⊙ Gyr -1 M⊙ -1 and ...

show abstract

“…Radio flickering and transient events have been documented in the nuclei of some LLAGN, particularly Seyferts (e.g. Wrobel 2000;Mundell et al 2009;Giannios & Metzger 2011;Baldi et al 2015a;Mattila et al 2018;Williams et al 2019;Nyland et al 2020).…”

Section: Low-luminosity Agn and Disc-jet Couplingmentioning

confidence: 99%

LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] – radio connection

Baldi

Williams

Beswick

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

What determines the nuclear radio emission in local galaxies? To address this question, we combine optical [O iii] line emission, robust black hole (BH) mass estimates, and high-resolution e-MERLIN 1.5-GHz data, from the LeMMINGs survey, of a statistically complete sample of 280 nearby optically active (LINER and Seyfert) and inactive [H ii and absorption line galaxies (ALGs)] galaxies. Using [O iii] luminosity ($L_{\rm [O\, \small {III}]}$) as a proxy for the accretion power, local galaxies follow distinct sequences in the optical–radio planes of BH activity, which suggest different origins of the nuclear radio emission for the optical classes. The 1.5-GHz radio luminosity of their parsec-scale cores (Lcore) is found to scale with BH mass (MBH) and [O iii] luminosity. Below MBH ∼ 106.5 M⊙, stellar processes from non-jetted H ii galaxies dominate with $L_{\rm core} \propto M_{\rm BH}^{0.61\pm 0.33}$ and $L_{\rm core} \propto L_{\rm [O\, \small {III}]}^{0.79\pm 0.30}$. Above MBH ∼ 106.5 M⊙, accretion-driven processes dominate with $L_{\rm core} \propto M_{\rm BH}^{1.5-1.65}$ and $L_{\rm core} \propto L_{\rm [O\, \small {III}]}^{0.99-1.31}$ for active galaxies: radio-quiet/loud LINERs, Seyferts, and jetted H ii galaxies always display (although low) signatures of radio-emitting BH activity, with $L_{\rm 1.5\, GHz}\gtrsim 10^{19.8}$ W Hz−1 and MBH ≳ 107 M⊙, on a broad range of Eddington-scaled accretion rates ($\dot{m}$). Radio-quiet and radio-loud LINERs are powered by low-$\dot{m}$ discs launching sub-relativistic and relativistic jets, respectively. Low-power slow jets and disc/corona winds from moderately high to high-$\dot{m}$ discs account for the compact and edge-brightened jets of Seyferts, respectively. Jetted H ii galaxies may host weakly active BHs. Fuel-starved BHs and recurrent activity account for ALG properties. In conclusion, specific accretion–ejection states of active BHs determine the radio production and the optical classification of local active galaxies.

show abstract

Quasars That Have Transitioned from Radio-quiet to Radio-loud on Decadal Timescales Revealed by VLASS and FIRST

Cited by 81 publications

References 146 publications

Caltech-NRAO Stripe 82 Survey (CNSS). V. AGNs That Transitioned to Radio-loud State

Caltech-NRAO Stripe 82 Survey (CNSS). V. AGNs That Transitioned to Radio-loud State

A transient radio source consistent with a merger-triggered core collapse supernova

LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] – radio connection

Contact Info

Product

Resources

About