title: A radio jet from the optical and x-ray bright stellar tidal disruption flare ASASSN-14li.
abstract: The tidal disruption of a star by a supermassive black hole leads to a short-lived thermal flare. Despite extensive searches, radio follow-up observations of known thermal stellar tidal disruption flares (TDFs) have not yet produced a conclusive detection. We present a detection of variable radio emission from a thermal TDF, which we interpret as originating from a newly launched jet. The multiwavelength properties of the source present a natural analogy with accretion-state changes of stellar mass black holes, which suggests that all TDFs could be accompanied by a jet. In the rest frame of the TDF, our radio observations are an order of magnitude more sensitive than nearly all previous upper limits, explaining how these jets, if common, could thus far have escaped detection.
authors.affiliation: Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA. sjoert@jhu.edu.
authors.forename: S
authors.initials: S
authors.lastname: van Velzen
authors.affiliation: Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK. International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth WA 6845, Australia.
authors.forename: G E
authors.initials: GE
authors.lastname: Anderson
authors.affiliation: Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Stone
authors.affiliation: Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: M
authors.initials: M
authors.lastname: Fraser
authors.affiliation: Department of Astrophysics, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Wevers
authors.affiliation: Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA.
authors.forename: B D
authors.initials: BD
authors.lastname: Metzger
authors.affiliation: Department of Astrophysics, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, Netherlands. SRON, Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, Netherlands.
authors.forename: P G
authors.initials: PG
authors.lastname: Jonker
authors.affiliation: Department of Physics, The George Washington University, 725 21st Street NW, Washington, DC 20052, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: van der Horst
authors.affiliation: Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK.
authors.forename: T D
authors.initials: TD
authors.lastname: Staley
authors.affiliation: Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Mendez
authors.affiliation: International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth WA 6845, Australia.
authors.forename: J C A
authors.initials: JC
authors.lastname: Miller-Jones
authors.affiliation: Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: S T
authors.initials: ST
authors.lastname: Hodgkin
authors.affiliation: Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK.
authors.forename: H C
authors.initials: HC
authors.lastname: Campbell
authors.affiliation: Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK.
authors.forename: R P
authors.initials: RP
authors.lastname: Fender