PS18kh: A New Tidal Disruption Event with a Non-axisymmetric Accretion Disk
2019
We present the discovery of PS18kh, a tidal disruption event (TDE) discovered
at the center of SDSS J075654.53+341543.6 ($d\simeq337$ Mpc) by the Pan-STARRS
Survey for Transients. Our dataset includes pre-discovery survey data from
Pan-STARRS, the All-Sky Automated Survey for Supernovae (ASAS-SN), and the
Asteroid Terrestrial-impact Last Alert System (ATLAS) as well as high-cadence,
multi-wavelength follow-up data from ground-based telescopes and Swift,
spanning from 56 days before peak light until 75 days after. The optical/UV
emission from PS18kh is well-fit as a blackbody with temperatures ranging from
$T\simeq14000$ K to $T\simeq22000$ K and it peaked at a luminosity of
$L\simeq9.8\times10^{43}$ ergs s$^{-1}$. PS18kh radiated
$E=(3.82\pm0.25)\times10^{50}$ ergs over the period of observation, with
$(1.58\pm0.22)\times10^{50}$ ergs being released during the rise to peak.
Spectra of PS18kh show a changing, boxy/double-peaked H$\alpha$ emission
feature, which becomes more prominent over time. Using a wind$+$elliptical
disk$+$spiral arm model, we model the physical properties of the accretion disk
and the stellar debris following the disruption of the star, finding that the
stellar debris initially absorbs the emission from the disk but becomes
optically thin over time. The disk has an inner radius of $r_{\rm
in}\sim500r_{\rm g}$ and an outer radius of $r_{\rm out}\sim15000r_{\rm g}$.
- Correction
- Cite
- Save
- Machine Reading By IdeaReader
0
References
2
Citations
NaN
KQI