500days of ASASSN-18pg multiwavelength obs.

DOI

We present nearly 500 days of observations of the tidal disruption event (TDE) ASASSN-18pg, spanning from 54 days before peak light to 441 days after peak light. Our data set includes X-ray, UV, and optical photometry, optical spectroscopy, radio observations, and the first published spectropolarimetric observations of a TDE. ASASSN-18pg was discovered on 2018 July 11 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d=78.6Mpc; with a peak UV magnitude of m~14, it is both one of the nearest and brightest TDEs discovered to-date. The photometric data allow us to track both the rise to peak and the long-term evolution of the TDE. ASASSN-18pg peaked at a luminosity of L~2.4x10^44^erg/s, and its late-time evolution is shallower than a flux {propto}t^-5/3^ power-law model, similar to what has been seen in other TDEs. ASASSN-18pg exhibited Balmer lines and spectroscopic features consistent with Bowen fluorescence prior to peak, which remained detectable for roughly 225days after peak. Analysis of the two-component H{alpha} profile indicates that, if they are the result of reprocessing of emission from the accretion disk, the different spectroscopic lines may be coming from regions between ~10 and ~60 lt-days from the black hole. No X-ray emission is detected from the TDE, and there is no evidence of a jet or strong outflow detected in the radio. Our spectropolarimetric observations indicate that the projected emission region is likely not significantly aspherical, with the projected emission region having an axis ratio of >~0.65.

Identifier
DOI http://doi.org/10.26093/cds/vizier.18980161
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/898/161
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/898/161
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/898/161
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/898/161
Provenance
Creator Holoien T.W.-S.; Auchettl K.; Tucker M.A.; Shappee B.J.; Patel S.G.,Miller-Jones J.C.A.; Mockler B.; Groenewald D.N.; Hinkle J.T.; Brown J.S.,Kochanek C.S.; Stanek K.Z.; Chen P.; Dong S.; Prieto J.L.; Thompson T.A.,Beaton R.L.; Connor T.; Cowperthwaite P.S.; Dahmen L.; French K.D.,Morrell N.; Buckley D.A.H.; Gromadzki M.; Roy R.; Coulter D.A.,Dimitriadis G.; Foley R.J.; Kilpatrick C.D.; Piro A.L.; Rojas-Bravo C.,Siebert M.R.; van Velzen S.
Publisher CDS
Publication Year 2021
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics