Caltech-NRAO Stripe 82 Survey (CNSS). III. The First Radio-discovered Tidal Disruption Event, CNSS J0019+00
Journal article, 2020

We present the discovery of a nuclear transient with the Caltech-NRAO Stripe 82 Survey (CNSS), a dedicated radio transient survey carried out with the Karl G. Jansky Very Large Array (VLA). This transient, CNSS J001947.3+003527, exhibited a turn-on over a timescale of less than or similar to 1 yr, increasing in flux density at 3 GHz from <0.14 mJy in 2014 February to 4.4 0.1 mJy in 2015 March, reaching a peak luminosity of around 2015 October. The association of CNSS J0019+00 with the nucleus (Gaia and our very-long baseline interferometry positions are consistent to within 1 pc) of a nearby S0 Seyfert galaxy at 77 Mpc, together with the radio spectral evolution, implies that this transient is most likely a tidal disruption event (TDE). Our equipartition analysis indicates the presence of a similar to 15,000 km s(-1) outflow, having energy similar to 10(49) erg. We derive the radial density profile for the circumnuclear material in the host galaxy to be proportional to R-2.5. All of these properties suggest resemblance with radio-detected thermal TDEs like ASASSN-14li and XMMSL1 J0740-85. No significant X-ray or optical emission is detected from CNSS J0019+00, although this may simply be due to the thermal emission being weak during our late-time follow-up observations. From the CNSS survey we have obtained the first unbiased measurement of the rate of radio TDEs, R(>500 mu Jy) of about 2 x 10(-3) deg(-2), or equivalently a volumetric rate of about 10 Gpc(-3) yr(-1). This rate implies that all-sky radio surveys such as the VLA Sky Survey and those planned with ASKAP, will find many tens of radio TDEs over the next few years.

Author

M. M. Anderson

California Institute of Technology (Caltech)

K. P. Mooley

California Institute of Technology (Caltech)

National Radio Astronomy Observatory

G. Hallinan

California Institute of Technology (Caltech)

D. Dong

California Institute of Technology (Caltech)

E. S. Phinney

California Institute of Technology (Caltech)

A. Horesh

The Hebrew University Of Jerusalem

Stephen Bourke

Chalmers, Space, Earth and Environment, Onsala Space Observatory

S. B. Cenko

NASA Goddard Space Flight Center

University of Maryland

D. Frail

National Radio Astronomy Observatory

S. R. Kulkarni

California Institute of Technology (Caltech)

S. Myers

National Radio Astronomy Observatory

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 903 2 116

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.3847/1538-4357/abb94b

More information

Latest update

12/3/2020