A Unified Theory of Jetted Tidal Disruption Events: From Promptly Escaping Relativistic to Delayed Transrelativistic Jets
| Autor: | Teboul, Odelia, Metzger, Brian D. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Only a tiny fraction ~ 1% of stellar tidal disruption events (TDE) generate powerful relativistic jets evidenced by luminous hard X-ray and radio emissions. We propose that a key property responsible for both this surprisingly low rate and a variety of other observations is the typically large misalignment {\psi} between the orbital plane of the star and the spin axis of the supermassive black hole (SMBH). Such misaligned disk/jet systems undergo Lense-Thirring precession together about the SMBH spin axis. We find that TDE disks precess sufficiently rapidly that winds from the accretion disk will encase the system on large scales in a quasi-spherical outflow. We derive the critical jet efficiency {\eta} > {\eta}crit for both aligned and misaligned precessing jets to successfully escape from the disk-wind ejecta. As {\eta}crit is higher for precessing jets, less powerful jets only escape after alignment with the SMBH spin. Alignment can occur through magneto-spin or hydrodynamic mechanisms, which we estimate occur on typical timescales of weeks and years, respectively. The dominant mechanism depends on {\eta} and the orbital penetration factor \b{eta}. Hence depending only on intrinsic parameters of the event {{\psi},{\eta},\b{eta}}, we propose that each TDE jet can either escape prior to alignment, thus exhibiting erratic X-ray light curve and two-component radio afterglow (e.g., Swift J1644+57) or escape after alignment. Relatively rapid magneto-spin alignments produce relativistic jets exhibiting X-ray power-law decay and bright afterglows (e.g., AT2022cmc), while long hydrodynamic alignments give rise to late jet escape and delayed radio flares (e.g., AT2018hyz). Comment: 17 pages, 7 figures, 1 table |
| Databáze: | arXiv |
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