Studies of Peculiar Black Holes with Gemini Telescopes

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1 Studies of Peculiar Black Holes with Gemini Telescopes Minjin Kim (KASI) In collaboration with Luis Ho (KIAA), Myungshin Im (Seoul National University), Peter Jonker (SRON), Francesca Onori (SRON)

2 Contents 1. Intermediate-mass Black Hole candidate (Kim et al. 2017, ApJL, 844, 21) 2. Follow-up studies of nuclear transients (Future work)

3 Origin of Supermassive Black Hole most distant z~7.5 (0.7Gyr) : MBH ~ M MBH,init > M (Intermediate mass BH?) Banados et al. 2018

4 Origin of SMBH Controversy? We suppose that the initial black holes form via a coherent collapse. This probably implies Mbh > Formation of lower mass holes would be less efficient, for at least two reasons. Primordial clouds of mass less than 10 9 M are readily disrupted by supernova-driven winds (Dekel and Silk 1986). Given the observed efficiency of black hole formation, the formation of black holes of mass below 10 6 M is likely to be inhibited. Silk & Rees 1998

5 Intermediate-mass Black Holes (IMBH) M BH - Missing link between stellar mass BH and supermassive BH - Extremely rare in the present-day universe Merloni & Heinz 2013

6 Ultraluminous X-ray sources (ULXs) off-nucleus L x-ray > erg s -1 strong candidates of IMBHs very faint optical counterpart often associated with low-metallicity HII region (can be stellar mass black holes)

7 New ULX in NGC LX-ray ~ erg s -1 - NH << cm -2 - L5GHz ~ W Hz -1 SDSS g-band + Chandra + Radio Kim et al. 2015

8 Magellan/IMACS spectrum of the ULX Appears to be associated with the host galaxy (NGC 5252) AGN-like spectrum Kim et al. 2015

9 Gemini/GMOS IFU Follow-up GMOS/IFU observation Kim et al. 2017

10 Gemini/GMOS IFU Follow-up Relatively low σ (20-30 km/s) and high [OIII]/Hβ -> shock is unlikely to be responsible for the ionization Sign of rotation : Mdyn ~ M (upper limit of BH mass) Kim et al. 2017

11 Origin of the ULX? nucleus of a merging dwarf?! Kim et al. 2017

12 Summary (1) We found an IMBH (or SMBH) candidate possibly accreted onto NGC Upper limit of BH mass ~ M Origin : nucleus of a merging dwarf? Follow-up : stellar mass with NIR photometry (WHT)

13 Variability Tree Nuclear Transient Asteroids Extrinsic Intrinsic AGN Rotation Eclipse Stars Stars Microlensing Eclipse Rotation Eclipse Eruptive Cataclysmic Pulsation Secular Asteroid occultation EA Eclipsing binary EB EW Credit : L. Eyer & N. Mowlavi (03/2009) Planetary transits ELL FKCOM Single red giants β Per, α Vir SXA SX Arietis MS (B0-A7) with strong B fields ACV RCB BY Dra RS CVn Binary red giants α 2 Canes Venaticorum MS (B8-A7) with strong B fields DY Per UV Ceti Red dwarfs (K-M stars) FU PMS WR ZAND Symbiotic SN Supernovae GCAS Be stars LBV S Dor SPBe λ Eri N Novae ACYG α Cygni Hot OB Supergiants β Cephei UG Dwarf novae BCEP SPB PG 1159 (DO,V GW Vir) He/C/O-WDs Slowly pulsating B stars (PG , Betsy) long period sdb SXPHE SX Phoenicis PV Tel He star V361 Hya (EC14026) short period sdb V1093 Her V777 Her (DBV) He-WDs ZZ Ceti (DAV) H-WDs PMS δ Scuti DST δ Scuti Solar-like roap Photom. RR RR Lyrae GDOR FG Sge Sakurai, V605 Aql γ Doradus CEP δ Cepheids SR M CW Miras Semiregulars L SARV Irregulars Small ampl. red var. RV Period R Hya (Miras) δ Cep (Cepheid) RV Tau (W Vir) Type II Ceph.

14 Nuclear Transients Tidal Disruption Event (TDE) Change-look AGNs AGN variability

15 Tidal Disruption Event (TDE) L~T -3/5 PS1-10jh (Gezari et al. 2012)

16 Tidal Disruption Event (TDE) 1000s of TDE? Credit : Gezari

17 Tidal Disruption Event (TDE) Importance of TDE Major population of supermassive black hole (inactive galaxy) Detailed accretion physics BH-galaxy relation (BH mass measurement) Central stellar distribution Possible candidates for binary BHs and intermediatemass BH

18 Tidal Disruption Event (TDE) Known Issue? Nobs << NPredicted ( galaxy -1 yr -1 ) Host galaxy bias (mostly in E+A galaxy) Accretion mechanism (strong optical continuum and HeII enhancement)

19 TDE spectrum (Host Galaxy : E+A) Arcavi et al. 2014

20 TDE spectrum (He II enhancement) Arcavi et al. 2014

21 Monitoring of TDE spectrum Variability in brightness and kinematics of He II and Balmer lines : Key to understand detailed physics in the accretion process Host Properties : physical mechanism for enhancing TDE -> requiring high S/N spectrum iptf16fnl (Blagorodnova et. al. 2017)