Day-timescale variability in the radio light curve of the Tidal Disruption Event AT2022cmc: confirmation of a highly relativistic outflow
arXiv:2301.12770 · doi:10.1093/mnras/stad344
Abstract
Tidal disruption events (TDEs) are transient, multi-wavelength events in which a star is ripped apart by a supermassive black hole. Observations show that in a small fraction of TDEs, a short-lived, synchrotron emitting jet is produced. We observed the newly discovered TDE AT2022cmc with a slew of radio facilities over the first 100 days after its discovery. The light curve from the AMI-LA radio interferometer shows day-timescale variability which we attribute to a high brightness temperature emitting region as opposed to scintillation. We measure a brightness temperature of 2x10^15 K, which is unphysical for synchrotron radiation. We suggest that the measured high brightness temperature is a result of relativistic beaming caused by a jet being launched at velocities close to the speed of light along our line of sight. We infer from day-timescale variability that the jet associated with AT2022cmc has a relativistic Doppler factor of at least 16, which corresponds to a bulk Lorentz factor of at least 8 if we are observing the jet directly on axis. Such an inference is the first conclusive evidence that the radio emission observed from some TDEs is from relativistic jets because it does not rely on an outflow model. We also compare the first 100 days of radio evolution of AT2022cmc with that of the previous bright relativistic TDE, Swift J1644, and find a remarkable similarity in their evolution.
arXiv comment7 pages, 4 figures. Accepted for publication in MNRAS
References in corpus (43)
- The NumPy array: a structure for efficient numerical computation
- Towards a unified model for black hole X-ray binary jets
- Unsteady Outflow Models for Cosmological Gamma-Ray Bursts
- On characterising the variability properties of X-ray light curves from active galaxies
- Jets in GRBs
- WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
- Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array
- Superluminal motion of a relativistic jet in the neutron star merger GW170817
- A relativistic jetted outburst from a massive black hole fed by a tidally disrupted star
- Discovery of the Onset of Rapid Accretion by a Dormant Massive Black Hole
- Doppler factors, Lorentz factors and viewing angles for quasars, BL Lacertae objects and radio galaxies
- Multi-Epoch VLBA Observations of EGRET-Detected Quasars and BL Lac Objects: Superluminal Motion of Gamma-Ray Bright Blazars
- Swift J2058.4+0516: Discovery of a Possible Second Relativistic Tidal Disruption Flare?
- An Accurate Flux Density Scale from 50 MHz to 50 GHz
- An extremely luminous panchromatic outburst from the nucleus of a distant galaxy
- The Arcminute Microkelvin Imager
- Radio Monitoring of the Tidal Disruption Event Swift J164449.3+573451. I. Jet Energetics and the Pristine Parsec-Scale Environment of a Supermassive Black Hole
- Swift J1112.2-8238: A Candidate Relativistic Tidal Disruption Flare
- The Angular Size and Proper Motion of the Afterglow of GRB 030329
- Radio Monitoring of the Tidal Disruption Event Swift J164449.3+573451. II. The Relativistic Jet Shuts Off and a Transition to Forward Shock X-ray/Radio Emission
- Bulk Lorentz factors of Gamma-Ray Bursts
- An extremely powerful long-lived superluminal ejection from the black hole MAXI J1820+070
- A very luminous jet from the disruption of a star by a massive black hole
- VAST: An ASKAP Survey for Variables and Slow Transients
- Radio Monitoring of the Tidal Disruption Event Swift J164449.3+573451. III. Late-time Jet Energetics and a Deviation from Equipartition
- A Digital Correlator Upgrade for the Arcminute MicroKelvin Imager
- Radio Variability in Seyfert Nuclei
- The Birth of a Relativistic Jet Following the Disruption of a Star by a Cosmological Black Hole
- F-GAMMA: Variability Doppler factors of blazars from multiwavelength monitoring
- A VLA search for 5 GHz radio transients and variables at low Galactic latitudes
- A 22-year Southern Sky Survey for Transient and Variable Radio Sources using the Molonglo Observatory Synthesis Telescope
- Internal shocks at the origin of the flat spectral energy distribution of compact jets
- The radio afterglow of Swift J1644+57 reveals a powerful jet with fast core and slow sheath
- Optical measurement of superluminal motion in the neutron-star merger GW170817
- AMI Galactic Plane Survey at 16 GHz: I -- Observing, mapping and source extraction
- Lorentz Factor Constraint from the very early external shock of the gamma-ray burst ejecta
- Radio Afterglows of Very High Energy Gamma-Ray Bursts 190829A and 180720B
- Quasi-Periodic Variations in X-ray Emission and Long-Term Radio Observations: Evidence for a Two-Component Jet in Sw J1644+57
- A search for long-timescale, low-frequency radio transients
- Modeling the kinematics of the decelerating jets from the black hole X-ray binary MAXI J1348630
- Origin of the Counter-Rotating Gas in NGC 1596
- No apparent superluminal motion in the first-known jetted tidal disruption event Swift J1644+5734
- CHILES VERDES: Radio variability at an unprecedented depth and cadence in the COSMOS field
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- Searching for Radio Transients with Inverted Spectra in Epoch 1 of VLASS and VCSS, and Identification of a Sample of Candidate Relativistic Nuclear Transients
- Characterising EP241107a: Multiwavelength Observations of an Einstein Probe-detected Fast X-ray Transient
- NEW-MUSIC: The Next-generation Extended-Wavelength Multiband Sub/millimeter Inductance Camera
- Numerical Modeling of Relativistic Effects in Synchrotron-Emitting Shocks
- Synchrotron break frequencies of mildly-to-highly relativistic outflows observed off-axis