黎卓 HB Perets, JC Lombardi Jr, SR Milcarek Jr JUNO会议，南京，2016/4/17-18 微型潮汐瓦解事件 (Micro-TDE) 黎卓 HB Perets, JC Lombardi Jr, SR Milcarek Jr JUNO会议，南京，2016/4/17-18 Perets et al. 2016 ApJ, arXiv:1602.07698

Tidal disruption events

Observed TDEs ROSAT Swift: jetted TDE

What about TDEs by stellar mass compact objects? Stellar mass COs smaller by >> 106  micro-TDE Radiation properties? Timescale, energy, luminosity, event rate…

Fall-back time . Low mass-ratio TDE: planet High mass-ratio partial TDE: star Remnant object affects the dynamic of marginally bound debris StarSmasher code: SPH . CO

BH: 10 Msun Star: 1 Msun, ~ 1 Rsun BH: 10 Msun Planet: 10-3 Msun, ~ 0.1 Rsun Decay faster: -7/3 Earlier: few ks -5/3 Sub Ms

Partial disruption

Accretion time circularization of bound debris disk/torus forms at rc=2Rp accretion time thick disk h~1 tmin~ a few 103 s

Light curve and energy Light curve could be more relevant to mass accretion rate tmin>>tacc: planet accretion rate = fall-back rate tmin<<tacc: star accretion rate << fall-back rate Released energy

CO+star/planet encounters may happen in dense stellar cluster: randomly binary/planetary system: natal kick of CO wide binary: multiple-scattering with field stars  highly eccentric orbits Quasi-stable triple system: secular evolution  close encounter

Dense cluster TDE happens once the closest distance is smaller than Rt The TD rate for one CO typically The TD rate for a stellar cluster For ~150 globular clusters in Milky Way BH: 10 Msun NS: 1.4Msun

Natal kick of CO Supernova kick; CO-merger kick TD probability after kick Core-collapse SN rate ~3/100yr per galaxy; TDE rate is 1.4E-6/yr for BHs (10Msun) per galaxy 3.4E-7/yr for NSs (1.4Msun) per galaxy (Neglect poorly known compact binary case, a<10AU)

Micro-TDE radiation Duration ~1E4s (True) energy ~ 1E52erg Super-Eddington: >1010Ledd; jetted Non-thermal Rate ~ a fewE-6 per yr per galaxy 10’s/yr Gpc3 (tens times GRB rate) X/gamma sky monitors may observe many micro-TDEs.

Ultra-long GRBs Liso ~1E49 erg/s T~1E4 s

Application: Ultra-long GRB 111209A SN 2011kl Short SN-GRB delay: <day compact binary; post common-envelope phase Greiner et al. 2015

Application: Short GRB 050709 x-ray flare 16 d after GRB NS-NS + planet: BH kick at birth  planet disruption Fox et al. 2005

Neutrino from micro-TDE accretion disc High mass accretion rate  hot disc  ignite neutrino production JUNO detection rate Neutrino energy/spectrum comparable to SN JUNO can detect 1 nu for SN at <~1Mpc 1 Micro-TDE per <108yr much rare  diffuse neutrino from micro-TDE Stacking search for EM-detected micro-TDE? X/gamma monitor – JUNO Nearby micro-TDE (lucky?)

Observations help to narrow down the large uncertainties.