Title:
MAXI Hard X-ray Observations of TDEs

Abstract:
I will present results from TDE studies using MAXI, 
which has successfully monitored hard X-ray (> 2 keV) all-sky with 
a period of 92 minutes since 2009 August. Four TDE candidates were detected 
by systematically searching the first 37-month data at 4--10 keV. 
Utilizing the sample less-biased against absorption, we derived 
the first hard X-ray luminosity function (XLF) of TDEs, which gives 
an occurrence rate of TDEs per unit volume as a function of 
peak luminosity and redshift (TK+16). The XLF takes account of 
the mass function of SMBHs, that of disrupted stars, the specific 
TDE rate as a function of SMBH mass, and the fraction of TDEs with relativistic jets. 
The intrinsic fraction of the jet-accompanying events was estimated to be 0.0007%-34%. 
Also, it was found that at z < 1.5 the contamination of the hard X-ray luminosity functions 
of AGNs by TDEs is not significant and hence that their contribution to 
the growth of SMBHs is negligible at the redshifts. Subsequently to this first study, 
we further have made precise calibration of MAXI data up to 2016 July, 
and published the 7-year MAXI X-ray source catalog at high latitudes (TK+18). 
Transient-object surveys on various time scales are also now on-going, 
and these results will help to understand the origin of hard X-ray emission 
with a stronger constraint on the jetted-TDE fraction.