The Final Season Reimagined: 30 Tidal Disruption Events from the ZTF-I Survey

Abstract

Tidal disruption events (TDEs) offer a unique way to study dormant black holes. While the number of observed TDEs has grown thanks to the emergence of wide-field surveys in the past few decades, questions regarding the nature of the observed optical, UV, and X-ray emission remain. We present a uniformly selected sample of 30 spectroscopically classified TDEs from the Zwicky Transient Facility Phase I survey operations with follow-up Swift UV and X-ray observations. Through our investigation into correlations between light-curve properties, we recover a shallow positive correlation between the peak bolometric luminosity and decay timescales. We introduce a new spectroscopic class of TDE, TDE-featureless, which are characterized by featureless optical spectra. The new TDE-featureless class shows larger peak bolometric luminosities, peak blackbody temperatures, and peak blackbody radii. We examine the differences between the X-ray bright and X-ray faint populations of TDEs in this sample, finding that X-ray bright TDEs show higher peak blackbody luminosities than the X-ray faint subsample. This sample of optically selected TDEs is the largest sample of TDEs from a single survey yet, and the systematic discovery, classification, and follow-up of this sample allows for robust characterization of TDE properties, an important stepping stone looking forward toward the Rubin era.

Synchrotron Afterglow Model for AT 2022cmc: Jetted Tidal Disruption Event or Engine-Powered Supernova?

“…Nevertheless, the luminous blue optical plateau phase, whose colors and estimated bolometric luminosity of ∼ 10 45 erg s −1 are indeed similar to those observed in opticallyselected TDEs (e.g. van Velzen et al 2021;Hammerstein et al 2023) as well as the jetted TDE candidate Swift J2058+05 (Cenko et al 2012), but not consistent with most other transient classes. Such high luminosity events are still rare among the optically-selected TDE population and are indeed characterized by spectra lacking emission or absorption lines (Hammerstein et al 2023), qualitatively similar to the featureless spectrum of the plateau phase in AT 2022cmc (Andreoni et al 2022).…”

“…van Velzen et al 2021;Hammerstein et al 2023) as well as the jetted TDE candidate Swift J2058+05 (Cenko et al 2012), but not consistent with most other transient classes. Such high luminosity events are still rare among the optically-selected TDE population and are indeed characterized by spectra lacking emission or absorption lines (Hammerstein et al 2023), qualitatively similar to the featureless spectrum of the plateau phase in AT 2022cmc (Andreoni et al 2022). Extremely luminous TDEs are challenging to explain in models for TDE optical emission which invoke shocks between tidal debris streams (e.g., Piran et al 2015;Ryu et al 2020) 2 and the specific implication in AT 2022cmc that efficient accretion onto the SMBH has already begun for the jet to be launched.…”

“…The host galaxy properties alone may also help discriminate between the two scenarios. In particular, while the hosts of the spectrally-featureless class of optically-selected TDEs prefer to reside near or above the red edge of the green valley in the color-magnitude diagram (Hammerstein et al 2023), the hosts of GRBs and superluminous SNe are generally bluer star-forming galaxies with low metallicity (Lunnan et al 2014;Perley et al 2016). Another potential discriminant is the future observation of an abrupt drop in the X-ray light curve as observed in other jetted TDE candidates (Zauderer et al 2013;Pasham et al 2015), which−if indeed the result of an accretion disk statechange occuring near the Eddington accretion rate−would not be consistent with a stellar-mass compact object.…”

Multi-messenger observations of Tidal Disruption Events

“…For a long time, none were detected in optical searches. Only in the last decade that suddenly changed [3], thanks to the advent of optical all-sky surveys such as Pan-STARRS [4], ASASSN [5], Gaia [6] or the Zwicky Transient Facility (ZTF) [7]. The rising number of optically discovered TDEs can be seen in Fig.…”

The Colorado Ultraviolet Transit Experiment Mission Overview

“…Small telescopes at ground-based sites have excelled at detecting and characterizing new objects in the time-variable sky, including supernovae eruptions (Dong et al 2016) and tidal disruption events (Hammerstein et al 2023) from the Zwicky Transient Facility (Masci et al 2019) and All Sky Automated Survey for SuperNovae (Holoien et al 2017). The impact of small telescopes has also been powerful for the detection of extrasolar planets, including many Jovian-sized planets from Wide-Angle Search for Planets (WASP; Pollacco et al 2006) and the Kilodegree Extremely Little Telescope (KELT; Pepper et al 2007), and some of the most promising rocky planets for study with JWST from the MEarth (Charbonneau et al 2009), Transiting Planets and Planetesimals Small Telescope (Gillon et al 2011), and Search for habitable Planets EClipsing ULtra-cOOl Stars (Burdanov et al 2018) facilities.…”