SDSS J1056+5516: A Triple AGN or an SMBH Recoil Candidate?

Kalfountzou, E.; Santos-Lleo, M.; Trichas, M.

doi:10.3847/2041-8213/aa9b2d

Cited by 28 publications

(20 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While there is no confirmed detection of a recoiling SMBH yet, several candidates have been suggested over the years (e.g. Caldwell et al 2014;Kalfountzou, Santos Lleo & Trichas 2017;Chiaberge et al 2018). Interestingly, the galaxies with the two largest cores, IC 1101 and A2261-BCG, show an offset between the outer isophotes and the cored region, consistent with simulations of repeated passages of an SMBH through the core (Dullo, Graham & Knapen 2017;Dullo 2019).…”

Section: G R Av I Tat I O Na L Wav E R E C O I Lsupporting

confidence: 66%

Formation of the largest galactic cores through binary scouring and gravitational wave recoil

Nasim

Gualandris

Read

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Massive elliptical galaxies are typically observed to have central cores in their projected radial light profiles. Such cores have long been thought to form through ‘binary scouring’ as supermassive black holes (SMBHs), brought in through mergers, form a hard binary and eject stars from the galactic centre. However, the most massive cores, like the ∼3 kpc core in A2261-BCG, remain challenging to explain in this way. In this paper, we run a suite of dry galaxy merger simulations to explore three different scenarios for central core formation in massive elliptical galaxies: ‘binary scouring’, ‘tidal deposition’ and ‘gravitational wave (GW) induced recoil’. Using the griffin code, we self-consistently model the stars, dark matter and SMBHs in our merging galaxies, following the SMBH dynamics through to the formation of a hard binary. We find that we can only explain the large surface brightness core of A2261-BCG with a combination of a major merger that produces a small ∼1 kpc core through binary scouring, followed by the subsequent GW recoil of its SMBH that acts to grow the core size. Key predictions of this scenario are an offset SMBH surrounded by a compact cluster of bound stars and a non-divergent central density profile. We show that the bright ‘knots’ observed in the core region of A2261-BCG are best explained as stalled perturbers resulting from minor mergers, though the brightest may also represent ejected SMBHs surrounded by a stellar cloak of bound stars.

show abstract

Section: G R Av I Tat I O Na L Wav E R E C O I Lsupporting

confidence: 66%

Formation of the largest galactic cores through binary scouring and gravitational wave recoil

Nasim

Gualandris

Read

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…While there is no confirmed detection of a recoiling SMBH yet, several candidates have been suggested over the years (e.g. Caldwell et al 2014;Kalfountzou et al 2017;Chiaberge et al 2018). Interestingly, the galaxies with the two largest cores, IC 1101 and A2261-BCG, show an offset between the outer isophotes and the cored region, consistent with simulations of repeated passages of an SMBH through the core (Dullo et al 2017;Dullo 2019).…”

Section: Gravitational Wave Recoilsupporting

confidence: 68%

Formation of the largest galactic cores through binary scouring and gravitational wave recoil

Nasim,

Gualandris,

Read

et al. 2020

Preprint

View full text Add to dashboard Cite

Massive elliptical galaxies are typically observed to have central cores in their projected radial light profiles. Such cores have long been thought to form through 'binary scouring' as supermassive black holes (SMBHs), brought in through mergers, form a hard binary and eject stars from the galactic centre. However, the most massive cores, like the ∼ 3 kpc core in A2261-BCG, remain challenging to explain in this way. In this paper, we run a suite of dry galaxy merger simulations to explore three different scenarios for central core formation in massive elliptical galaxies: 'binary scouring', 'tidal deposition' and 'gravitational wave (GW) induced recoil'. Using the griffin code, we self-consistently model the stars, dark matter and SMBHs in our merging galaxies, following the SMBH dynamics through to the formation of a hard binary. We find that we can only explain the large surface brightness core of A2261-BCG with a combination of a major merger that produces a small ∼ 1 kpc core through binary scouring, followed by the subsequent GW recoil of its SMBH that acts to grow the core size. We show that this same model can also explain the bright 'knots' observed in the core region of A2261-BCG. A key prediction of this scenario is an offset SMBH surrounded by a compact cluster of bound stars. We note that a core in the surface brightness profile does not imply a three-dimensional region of (nearly) constant density, but rather a shallow cusp in space density scaling as ∼ r −0.5 .

show abstract

“…Comerford & Greene (2014) estimated that 4%-8% of Type II AGNs are in galaxy mergers, so these systems may be quite common. Triple-SMBH systems, in which a merger with a third galaxy occurs before the initial SMBH binary forms, can also be difficult to distinguish from recoiling SMBHs (Civano et al 2010;Kalfountzou et al 2017).…”

Section: Introductionmentioning

confidence: 99%

AGNs on the Move: A Search for Off-nuclear AGNs from Recoiling Supermassive Black Holes and Ongoing Galaxy Mergers with the Zwicky Transient Facility

Ward

Gezari

Frederick

et al. 2021

ApJ

View full text Add to dashboard Cite

A supermassive black hole (SMBH) ejected from the potential well of its host galaxy via gravitational wave recoil carries important information about the mass ratio and spin alignment of the pre-merger SMBH binary. Such a recoiling SMBH may be detectable as an active galactic nucleus (AGN) broad-line region offset by up to 10 kpc from a disturbed host galaxy. We describe a novel methodology using forward modeling with The Tractor to search for such offset AGNs in a sample of 5493 optically variable AGNs detected with the Zwicky Transient Facility (ZTF). We present the discovery of nine AGNs that may be spatially offset from their host galaxies and are candidates for recoiling SMBHs. Five of these offset AGNs exhibit double-peaked broad Balmer lines, which may have arisen from unobscured accretion disk emission, and four show radio emission indicative of a relativistic jet. The fraction of double-peaked emitters in our spatially offset AGN sample is significantly larger than the 16% double-peaked emitter fraction observed for ZTF AGNs overall. In our sample of variable AGNs we also identified 52 merging galaxies, including a new spectroscopically confirmed dual AGN. Finally, we detected the dramatic rebrightening of SDSS 1133, a previously discovered variable object and recoiling SMBH candidate, in ZTF. The flare was accompanied by the reemergence of strong P Cygni line features, indicating that SDSS 1133 may be an outbursting luminous blue variable star.

show abstract

SDSS J1056+5516: A Triple AGN or an SMBH Recoil Candidate?

Cited by 28 publications

References 46 publications

Formation of the largest galactic cores through binary scouring and gravitational wave recoil

Formation of the largest galactic cores through binary scouring and gravitational wave recoil

Formation of the largest galactic cores through binary scouring and gravitational wave recoil

AGNs on the Move: A Search for Off-nuclear AGNs from Recoiling Supermassive Black Holes and Ongoing Galaxy Mergers with the Zwicky Transient Facility

Contact Info

Product

Resources

About