El Diablo - A TDE with a double-horned disk profile
Abstract
Tidal disruption events occur when the tidal force of a supermassive black hole overcomes an approaching star's self-gravity. A key issue in the TDE field is in determining the power source of observed optical and UV emission, thought to come either from reprocessed disk emission or collisions between stellar debris streams. I will present a new TDE, AT2018hyz, discovered by the ASAS-SN survey at an absolute magnitude -20 mag. Preliminary fits to Swift UVOT photometry suggest temperatures of 15,000K. High cadence spectra show broad Balmer lines and He I at early times, while He II makes an appearance later on. The Balmer lines evolve from a smooth broad profile, through an asymmetric double-peaked phase and back to smooth at late times. These complex line profiles and a flat Balmer decrement suggest the emission lines originate from a disk chromosphere analogous to those seen in cataclysmic variables. We also observe the possible presence of Bowen fluorescence lines, a feature recently discovered in a subset of 'N-rich' TDEs. I will discuss the physical conditions necessary to account for these features, and the implications of this important event for understanding TDEs.
- Publication:
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The Extragalactic Explosive Universe: the New Era of Transient Surveys and Data-Driven Discovery
- Pub Date:
- October 2019
- DOI:
- 10.5281/zenodo.3478092
- Bibcode:
- 2019eeu..confE..48S
- Keywords:
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- Zenodo community eeu2019