Steep‐Spectrum Radio Emission from the Low‐Mass Active Galactic Nucleus GH 10

Wrobel, J. M.; Greene, Jenny E.; Ho, Luis C.; Ulvestad, J. S.

doi:10.1086/592041

Cited by 20 publications

(15 citation statements)

References 28 publications

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“…‡ Although NGC4697 and NGC4477 were included in our new 5 GHz VLA observations, the sensitivity and quality of the final images were not sufficient to detect them. We include a literature detection of NGC4697 (Wrobel et al 2008) as well as a detection of NGC4477 from project 12B-191 based on our own independent analysis. * For NGC5846, the flux density has been extrapolated from to 5 GHz using a spectral index of −0.03.…”

Section: Discussionmentioning

confidence: 99%

The atlas^3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

Nyland¹,

Young²,

Wrobel³

et al. 2016

Mon. Not. R. Astron. Soc.

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We present the results of a high-resolution, 5 GHz, Karl G. Jansky Very Large Array study of the nuclear radio emission in a representative subset of the ATLAS 3D survey of early-type galaxies (ETGs). We find that 51 ± 4% of the ETGs in our sample contain nuclear radio emission with luminosities as low as 10 18 W Hz −1 . Most of the nuclear radio sources have compact ( 25 − 110 pc) morphologies, although ∼10% display multi-component core+jet or extended jet/lobe structures. Based on the radio continuum properties, as well as optical emission line diagnostics and the nuclear X-ray properties, we conclude that the majority of the central 5 GHz sources detected in the ATLAS 3D galaxies are associated with the presence of an active galactic nucleus (AGN). However, even at sub-arcsecond spatial resolution, the nuclear radio emission in some cases appears to arise from low-level nuclear star formation rather than an AGN, particularly when molecular gas and a young central stellar population is present. This is in contrast to popular assumptions in the literature that the presence of a compact, unresolved, nuclear radio continuum source universally signifies the presence of an AGN. Additionally, we examine the relationships between the 5 GHz luminosity and various galaxy properties including the molecular gas mass and -for the first time -the global kinematic state. We discuss implications for the growth, triggering, and fueling of radio AGNs, as well as AGN-driven feedback in the continued evolution of nearby ETGs.

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Section: Discussionmentioning

confidence: 99%

The atlas^3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

Nyland¹,

Young²,

Wrobel³

et al. 2016

Mon. Not. R. Astron. Soc.

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“…The AGN selected based on broad emission lines behave like AGN powered by more massive black holes. In the radio, a small number of objects have deep follow-up observations but few are radio loud , Wrobel & Ho 2006, Wrobel et al 2008. More attention has been devoted to the X-rays (Greene & Ho 2007c, Dong et al 2012a, Yuan et al 2014, Plotkin et al 2016, using Chandra and XMM-Newton observations of sufficient depth to perform detailed spectral and timing analysis (Moran et al 2005, Dewangan et al 2008, Thornton et al 2008, Miniutti et al 2009, Ai et al 2011, Kamizasa et al 2012, Jin et al 2016.…”

Section: Optical Spectroscopic Selectionmentioning

confidence: 99%

Intermediate-Mass Black Holes

Greene,

Strader,

2019

Preprint

107

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We describe ongoing searches for intermediate-mass black holes with MBH≈ 100 − 10 5 M . We review a range of search mechanisms, both dynamical and those that rely on accretion signatures. We find:• Dynamical and accretion signatures alike point to a high fraction of 10 9 − 10 10 M galaxies hosting black holes with MBH ∼ 10 5 M . In contrast, there are no solid detections of black holes in globular clusters.• There are few observational constraints on black holes in any environment with MBH ≈ 100 − 10 4 M .• Considering low-mass galaxies with dynamical black hole masses and constraining limits, we find that the MBH-σ * relation continues unbroken to MBH∼ 10 5 M , albeit with large scatter. We believe the scatter is at least partially driven by a broad range in black hole mass, since the occupation fraction appears to be relatively high in these galaxies.• We fold the observed scaling relations with our empirical limits on occupation fraction and the galaxy mass function to put observational bounds on the black hole mass function in galaxy nuclei.• We are pessimistic that local demographic observations of galaxy nuclei alone could constrain seeding mechanisms, although either highredshift luminosity functions or robust measurements of off-nuclear black holes could begin to discriminate models.

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“…The spectral index of these four compact sources is steep (>0.7), so they are compact, steep-spectrum sources such as the low-mass AGN GH10 (Wrobel et al 2008). GH10 is found by Wrobel et al (2008) to resemble the Seyfert galaxies of the Palomar survey (Ho & Ulvestad 2001), which show compact radio cores sometimes slightly resolved into an elongated, jet-like outflow component and a wide range of radio luminosities (10 18 − 10 25 W Hz −1 ) and spectral indices (+0.5 to -1; Ho & Ulvestad 2001;Ulvestad & Ho 2001). The 43 dwarf galaxies with radio emission also show a wide range (though slightly narrower than the Palomar Seyferts) of radio luminosities and 35 of them are compact at 3 GHz.…”

Section: Radio Spectral Indexmentioning

confidence: 99%

Radio jets from AGNs in dwarf galaxies in the COSMOS survey: mechanical feedback out to redshift ∼3.4

Mezcua

Suh

Civano

2019

Monthly Notices of the Royal Astronomical Society

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Dwarf galaxies are thought to host the remnants of the early Universe seed black holes (BHs) and to be dominated by supernova feedback. However, recent studies suggest that BH feedback could also strongly impact their growth. We report the discovery of 35 dwarf galaxies hosting radio AGN out to redshift ∼3.4, which constitutes the highest-redshift sample of AGN in dwarf galaxies. The galaxies are drawn from the VLA-COSMOS 3 GHz Large Project and all are star-forming. After removing the contribution from star formation to the radio emission, we find a range of AGN radio luminosities of L AGN 1.4GHz ∼ 10 37 -10 40 erg s −1 . The bolometric luminosities derived from the fit of their spectral energy distribution are 10 42 erg s −1 , in agreement with the presence of AGN in these dwarf galaxies. The 3 GHz radio emission of most of the sources is compact and the jet powers range from Q jet ∼ 10 42 to 10 44 erg s −1 . These values, as well as the finding of jet efficiencies ≥ 10 % in more than 50% of the sample, indicate that dwarf galaxies can host radio jets as powerful as those of massive radio galaxies whose jet mechanical feedback can strongly affect the formation of stars in the host galaxy. We conclude that AGN feedback can also have a very strong impact on dwarf galaxies, either triggering or hampering star formation and possibly the material available for BH growth. This implies that those low-mass AGN hosted in dwarf galaxies might not be the untouched relics of the early seed BHs, which has important implications for seed BH formation models.

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Steep‐Spectrum Radio Emission from the Low‐Mass Active Galactic Nucleus GH 10

Cited by 20 publications

References 28 publications

The atlas^3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

The atlas^3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

Intermediate-Mass Black Holes

Radio jets from AGNs in dwarf galaxies in the COSMOS survey: mechanical feedback out to redshift ∼3.4

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Steep‐Spectrum Radio Emission from the Low‐Mass Active Galactic Nucleus GH 10

Cited by 20 publications

References 28 publications

The atlas3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

The atlas3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

Intermediate-Mass Black Holes

Radio jets from AGNs in dwarf galaxies in the COSMOS survey: mechanical feedback out to redshift ∼3.4

Contact Info

Product

Resources

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The atlas^3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies

The atlas^3DProject – XXXI. Nuclear radio emission in nearby early-type galaxies