A flare in the optical spotted in the changing-look Seyfert NGC 3516

Storchi‐Bergmann

Monthly Notices of the Royal Astronomical Society

et al. 2021

We study the gas distribution and kinematics of the inner kpc of six moderately luminous (43.43 ≤ log Lbol ≤ 44.83) nearby (0.004 ≤ z ≤ 0.014) Seyfert galaxies observed with the Near-infrared Integral Field Spectrograph (NIFS) in the J(1.25μm) and K(2.2μm) bands. We analyse the most intense emission lines detected on these spectral wavebands: [Fe ii] 1.2570 μm and Paβ, which trace the ionised gas in the partially and fully ionised regions, and H2 2.1218 μm, that traces the hot (∼2000 K) molecular gas. The dominant kinematic component is rotation in the disc of the galaxies, except for the ionised gas in NGC 5899 which shows only weak signatures of a disc component. We find ionised gas outflow in four galaxies, while signatures of H2 outflows are seen in three galaxies. The ionised gas outflows display velocities of a few hundred km s−1, and their mass-outflow rates are in the range 0.005 − 12.49 M⊙yr−1. Their kinetic powers correspond to 0.005 − 0.7 per cent of the AGN bolometric luminosities. Besides rotation and outflows signatures in some cases, the H2 kinematics reveals also inflows in three galaxies. The inflow velocities are 50 − 80 km s−1and the mass inflow rates are in the range 1 − 9 × 10−4 M⊙yr−1 for hot molecular gas. These inflows might be only the hot skin of the total inflowing gas, which is expected to be dominated by colder gas. The mass inflow rates are lower than the current accretion rates to the AGN, and the ionised outflows are apparently disturbing the gas in the inner kpc.

Section: B2 Ngc 3516mentioning

confidence: 98%

Gemini NIFS survey of feeding and feedback in nearby active galaxies – V. Molecular and ionized gas kinematics

Storchi‐Bergmann

Monthly Notices of the Royal Astronomical Society

et al. 2021

“…NGC 3516 is a lenticular galaxy at a distance of 37 Mpc, classified as (R)SB0 0 ? (s), hosting a Sy1.2 nucleus, but recently the detection of a UV flare characterises this galaxy as a changing-look AGN (Ilić et al 2020). Figure 2 shows its flux distributions, velocity and velocity dispersion maps.…”

Section: B2 Ngc3516mentioning

confidence: 99%

Gemini NIFS survey of feeding and feedback in nearby Active Galaxies -- V. Molecular and Ionised Gas Kinematics

Bianchin,

Riffel,

Storchi-Bergmann

et al. 2021

Preprint

We study the gas distribution and kinematics of the inner kpc of six moderately luminous (43.43 ≤ log 𝐿 bol ≤ 44.83) nearby (0.004 ≤ 𝑧 ≤ 0.014) Seyfert galaxies observed with the Near-infrared Integral Field Spectrograph (NIFS) in the J(1.25𝜇m) and K(2.2𝜇m) bands. We analyse the most intense emission lines detected on these spectral wavebands: [Fe ] 1.2570 𝜇m and Pa𝛽, which trace the ionised gas in the partially and fully ionised regions, and H 2 2.1218 𝜇m, that traces the hot (∼ 2000 K) molecular gas. The dominant kinematic component is rotation in the disc of the galaxies, except for the ionised gas in NGC 5899 which shows only weak signatures of a disc component. We find ionised gas outflow in four galaxies, while signatures of H 2 outflows are seen in three galaxies. The ionised gas outflows display velocities of a few hundred km s −1 , and their mass-outflow rates are in the range 0.005 − 12.49 M yr −1 . Their kinetic powers correspond to 0.005 − 0.7 per cent of the AGN bolometric luminosities. Besides rotation and outflows signatures in some cases, the H 2 kinematics reveals also inflows in three galaxies. The inflow velocities are 50 − 80 km s −1 and the mass inflow rates are in the range 1 − 9 × 10 −4 M yr −1 for hot molecular gas. These inflows might be only the hot skin of the total inflowing gas, which is expected to be dominated by colder gas. The mass inflow rates are lower than the current accretion rates to the AGN, and the ionised outflows are apparently disturbing the gas in the inner kpc.

“…Also, some other types of AGN such as Changing-look AGN (CL-AGNs) as a new subpopulation (see e.g. notable case of NGC 3516, Shapovalova et al 2019, Ilić et al 2020, Feng et al 2021) challenge some fundamental physics of AGNs so that a possible explanantion for them is that CB-SMBHs with high eccentricities are able to trigger the CL transition through one orbit (see Wang and Bon 2020). This review focuses on RM and spectroastrometry observational signatures of CB-SMBHs with non-zero eccentricity from numerical simulations with particular attention to recent developments and open issues.…”

Section: Introductionmentioning

confidence: 99%

Investigating close binary supermassive black holes at high angular resolution

Kovačević

2021

SERBIAN ASTRON J

Self Cite

Gravitational waves (GW) in the nano-Hz domain are expected to be radiated by close-binaries of supermassive black holes (CB-SMBHs; components bound in a Keplerian binary at mutual distance less than ~ 0.1 pc), which are relicts of galaxy mergers and anticipated to be measured via the Pulsar Timing Array (PTA) technique. The challenge of present CB-SMBH investigations is that their signatures are elusive and not easily disentangled from a single SMBH. PTAs will typically have a glimpse of an early portion of the binary inspiral to catch the frequency evolution of the binary only with sufficiently high mass and initially high eccentricity. Thus, we have to make use of electromagnetic observations to determine orbital parameters of CB-SMBHs and test nano-Hz GW properties. The 2D reverberation mapping (RM) is a powerful tool for probing kinematics and geometry of ionized gas in the SMBHs (single or binary) vicinity, yet it can lose information due to projection on the line of sight of the observer. Nevertheless, spectroastrometry with AMBER, GRAVITY, and successors can provide an independent measurement of the emitting region's size, geometry, and kinematics. These two techniques combined can resolve CB-SMBHs. In this review, we focus on RM and spectroastrometry observational signatures of CB-SMBHs with non-zero eccentricity from recent simulations with particular attention to recent developments and open issues.