Abstract
ABSTRACT We report the discovery of transient radio emission from the nearby optically discovered tidal disruption event (TDE) ASASSN-14li (distance of 90 Mpc), making it the first typical TDE detected in the radio, and unambiguously pointing to the formation of a non-relativistic outflow with a kinetic energy of ≈(4–10) × 1047 erg, a velocity of ≈12,000–36,000 km s−1, and a mass of ≈3 × 10−5–7 × 10−4 M ⊙. We show that the outflow was ejected on 2014 August 11–25, in agreement with an independent estimate of the timing of super-Eddington accretion based on the optical, ultraviolet, and X-ray observations, and that the ejected mass corresponds to about 1%–10% of the mass accreted in the super-Eddington phase. The temporal evolution of the radio emission also uncovers the circumnuclear density profile, &rgr; ( R ) ∝ R − 2.5 ?> on a scale of about 0.01 pc, a scale that cannot be probed via direct measurements even in the nearest supermassive black holes. Our discovery of radio emission from the nearest well-studied TDE to date, with a radio luminosity lower than all previous limits, indicates that non-relativistic outflows are ubiquitous in TDEs, and that future, more sensitive, radio surveys will uncover similar events.
Highlights
The tidal disruption of stars by supermassive black holes (SMBH) lights up dormant systems and can be used to probe accretion and outflow processes
We report the discovery of transient radio emission from the nearby optically-discovered tidal disruption events (TDEs) ASASSN-14li, making it the first typical TDE detected in the radio, and unambiguously pointing to the formation of a non-relativistic outflow with a kinetic energy of ≈ 4−10×1047 erg, a velocity of ≈ 12, 000 − 36, 000 km s−1, and a mass of ≈ 3 × 10−5 − 7 × 10−4 M⊙
Most TDEs detected within the past decade have been followed up in the radio, but no “typical” TDEs have been convincingly detected (Bower et al 2013; van Velzen et al 2013). (Weak radio emission has been seen in one or two TDE host galaxies, but the emission does not appear to be transient and these detections have been attributed to AGN activity; van Velzen et al 2013.) due to the large distances of most TDEs discovered to date, the resulting upper limits are only able to rule out the presence of off-axis relativistic jets similar to those observed in gamma ray bursts or in Sw J1644+57
Summary
The tidal disruption of stars by supermassive black holes (SMBH) lights up dormant systems and can be used to probe accretion and outflow processes. (Weak radio emission has been seen in one or two TDE host galaxies, but the emission does not appear to be transient and these detections have been attributed to AGN activity; van Velzen et al 2013.) due to the large distances of most TDEs discovered to date, the resulting upper limits are only able to rule out the presence of off-axis relativistic jets similar to those observed in gamma ray bursts or in Sw J1644+57 (van Velzen et al 2013; Chornock et al 2014). We report the discovery and follow-up of transient radio emission from ASASSN14li.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
