For several decades, astronomers have speculated that a hapless star\u00a0could wander too close to a super massive black hole (SMBH) and be\u00a0torn apart by tidal forces. It has only been with the recent advent of\u00a0numerous wide field transient surveys that such events have been\u00a0detected in the form of giant-amplitude, luminous flares of\u00a0electromagnetic radiation from the centers of otherwise quiescent\u00a0galaxies. The discoveries, spanning the whole electromagnetic spectrum\u00a0from X-rays, over UV, optical and near-infrared events, to a small number of events\u00a0launching relativistic radio jets, have caused widespread excitement,\u00a0as we can use these tidal disruption events (TDEs) to study the mass\u00a0of SMBHs in quiescent galaxies, the stellar populations and dynamics\u00a0in galactic nuclei, the physics of black hole accretion under extreme\u00a0conditions including the potential to detect relativistic effects near\u00a0the SMBH, and the physics of radio jet formation and evolution in a
\npristine environment. Whereas active galactic nuclei (such as quasars)\u00a0host SMBHs that are supplied by steady streams of fuel for hundreds or\u00a0even thousands of years, TDEs offer a unique opportunity to study a\u00a0single SMBH under feeding conditions that change over timescales of\u00a0days or months. TDEs offer our only hope of studying the evolution of
\ntheir accretion disks for a wide range of mass accretion rates and\u00a0feeding timescales. In addition, because the rate of TDEs is massively\u00a0enhanced in binary black hole systems, TDEs are expected to point us\u00a0to galaxies that are likely to host compact binary SMBHs. At a later\u00a0stage in the binary SMBH evolution, LISA will study the gravitational\u00a0waves emitted when such binaries merge. In the next few years, the\u00a0largest growth area will be in the greatly expanded surveys of the\u00a0transient sky (such as the Gaia satellite, ZTF, LSST, the eROSITA\u00a0satellite, SKA) that will reveal how SMBHs shine by ripping apart\u00a0orbiting stars and swallowing the stellar debris. The idea of the proposed\u00a0book was conceived during two ISSI team meetings and will serve as the\u00a0“handbook” providing the current state of the art and challenges as\u00a0we go into the era of the big surveys that will discover thousands of\u00a0new events.<\/p>\n
(The figure shows stills from a simulation of a tidal disruption event and is adapted from Rosswog, Ramirez-Ruiz, Hix 2009).<\/p>\n","protected":false},"excerpt":{"rendered":"
For several decades, astronomers have speculated that a hapless star\u00a0could wander too close to a super massive black hole (SMBH) and be\u00a0torn apart by tidal forces. It has only been with the recent advent of\u00a0numerous wide field transient surveys that … Continue reading