CHANG-ES V: NUCLEAR OUTFLOW IN A VIRGO CLUSTER SPIRAL AFTER A TIDAL DISRUPTION EVENT
- Department of Physics, Engineering Physics, and Astronomy, Queen's University, Kingston, Ontario, K7L 3N6 (Canada)
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn (Germany)
- Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States)
- US Planck Data Center, The California Institute of Technology, MC 220-6, Pasadena, CA 91125 (United States)
- Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA, Dwingeloo (Netherlands)
- Physics and Space Sciences Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States)
We have observed the Virgo Cluster spiral galaxy, NGC 4845, at 1.6 and 6 GHz using the Karl G. Jansky Very Large Array, as part of the Continuum Halos in Nearby Galaxies—an EVLA Survey (CHANG-ES). The source consists of a bright unresolved core with a surrounding weak central disk (1.8 kpc diameter). The core is variable over the 6 month timescale of the CHANG-ES data and has increased by a factor of ≈6 since 1995. The wide bandwidths of CHANG-ES have allowed us to determine the spectral evolution of this core, which peaks between 1.6 and 6 GHz (it is a Gigahertz-peaked spectrum source). We show that the spectral turnover is dominated by synchrotron self-absorption and that the spectral evolution can be explained by adiabatic expansion (outflow), likely in the form of a jet or cone. The CHANG-ES observations serendipitously overlap in time with the hard X-ray light curve obtained by Nikolajuk and Walter (2013), which they interpret as due to a tidal disruption event (TDE) of a super-Jupiter mass object around a 10{sup 5} M{sub ⊙} black hole. We outline a standard jet model, provide an explanation for the observed circular polarization, and quantitatively suggest a link between the peak radio and peak X-ray emission via inverse Compton upscattering of the photons emitted by the relativistic electrons. We predict that it should be possible to resolve a young radio jet via VLBI as a result of this nearby TDE.
- OSTI ID:
- 22525546
- Journal Information:
- Astrophysical Journal, Vol. 809, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
CHANG-ES. III. UGC 10288—An edge-on galaxy with a background double-lobed radio source
Compact Resolved Ejecta in the Nearest Tidal Disruption Event