UV/Optical Detections of Candidate Tidal Disruption Events by GALEX and CFHTLS Gezari et al. 2007 Looking for detections of stellar material accreting onto quiescent black hole TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.:

SMBH Mass Function How are SMBH masses derived? Outstanding questions OIII kinematics – M-σ* Relations with bulge mass / luminosity – M-L* Reverberation mapping Only good for nearby (or bright) stuff Only good if active Outstanding questions How do they coevolve with their hosts? How does mass scale with redshift?

Tidal Disruption Magorrian & Tremaine predict 103-105 yrs between events For too large a mass, RT < RS Can use tD to constrain MBH Aquire tD from power-law decay in consumption rate (n=5/3) From energy argument K is related to spinup k=1 no spinup, k=3 near breakup speed M6=MBH/106

Previous Candidates NGC 4552 has a “mini-AGN” In 1995 experienced UV flare L ~ 1039 ergs/s ROSAT (1990-91) detected several soft X-ray flares L ~ 1042 – 1044 ergs/s No previous AGN activities in hosts Derived rate of 10-5 yr-1 per galaxy Agrees with Magorrian & Tremaine rate

Searching for New Candidates GALEX DIS Optical counterparts in CFHTLS 80 deg2 coverage (0.02 sr) Rule out hard X-ray emitters (AGNs) Must rule out type II SNe Fit to power law decay (n=5/3, monotonic) Find tD => MBH

Ruled Out UV Outbursts Do not have monotonic decreases in UV flux

Ruled Out Type II SNe Only 2 candidates left

Candidate D1-9 BC03 fits early-type galaxy at z=0.326 I-band contours from CFHTLS UV/optical variable in center

Candidate D1-9 Solid line is 5/3rds power law => 2004.0 Dashed line is with fixed tD at 2004.0, n=1.1 n allowed to vary = 3.4+-0.4 td = 2003.2+-0.2 Dot dash line is detection of soft x-ray source

Candidate D3-13 Z=0.3698

Candidate D3-13 With n=5/3, tD = 2003.3 With variable n = 3+-2, tD = 2002+-2 With tD fixed to 2003.7, n = 0.82

Black Hole Masses D1-9 on left, D3-13 on right Vertical line is min mass of star from mass accreted In maximally spinning BH, Rms=Rg Rbb>Rg gives max BH Mass Max mass is also consistent with MBH<Mcrit for solar type star

Spectral Energy Densities Two black-body spectra fit with solid lines

Things I Did Not Cover The full energy argument getting to MBH Expected detection rates