Radio and X-ray observations of the luminous Fast Blue Optical Transient AT2020xnd

Abstract

We present deep X-ray and radio observations of the Fast Blue Optical Transient (FBOT) AT2020xnd/ZTF20acigmel at $z=0.2433$ from $13$d to $269$d after explosion. AT2020xnd belongs to the category of optically luminous FBOTs with similarities to the archetypal event AT2018cow. AT2020xnd shows luminous radio emission reaching $L_{\nu }\approx 8\times 10^{29}$ergs${}^{-1}$Hz${}^{-1}$ at 20GHz and $75$d post explosion, accompanied by luminous and rapidly fading soft X-ray emission peaking at $L_X\approx 6\times 10^{42}$ergs${}^{-1}$. Interpreting the radio emission in the context of synchrotron radiation from the explosion's shock interaction with the environment we find that AT2020xnd launched a high-velocity outflow ($v\sim$0.1-0.2$c$) propagating into a dense circumstellar medium (effective $\dot{M}\approx 10^{-3}{M}_{\mathrm{sol}}$yr${}^{-1}$ for an assumed wind velocity of $v_w=1000$kms${}^{-1}$). Similar to AT2018cow, the detected X-ray emission is in excess compared to the extrapolated synchrotron spectrum and constitutes a different emission component, possibly powered by accretion onto a newly formed black hole or neutron star. These properties make AT2020xnd a high-redshift analog to AT2018cow, and establish AT2020xnd as the fourth member of the class of optically-luminous FBOTs with luminous multi-wavelength counterparts.

21 pages, 6 figures, 6 tables. Submitted to ApJ

References in corpus (20)

• X-ray Properties of Black-Hole Binaries
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• The Zwicky Transient Facility: Science Objectives
• The 1% Concordance Hubble Constant
• Rapidly-Evolving and Luminous Transients from Pan-STARRS1
• Circumstellar Emission from Type Ib and Ic Supernovae
• An optimized algorithm for multi-scale wideband deconvolution of radio astronomical images
• The Zwicky Transient Facility Bright Transient Survey. II. A Public Statistical Sample for Exploring Supernova Demographics
• Radio interferometric gain calibration as a complex optimization problem
• Radio Properties of Tidal Disruption Events
• Non-linear Kalman filters for calibration in radio interferometry
• An extremely powerful long-lived superluminal ejection from the black hole MAXI J1820+070
• The Koala: A Fast Blue Optical Transient with Luminous Radio Emission from a Starburst Dwarf Galaxy at $z=0.27$
• A mildly relativistic outflow from the energetic, fast-rising blue optical transient CSS161010 in a dwarf galaxy
• A Luminous, Fast Rising UV-Transient Discovered by ROTSE: a Tidal Disruption Event?
• Gamma-ray Thermalization and Leakage from Millisecond Magnetar Nebulae: Towards a Self-Consistent Model for Superluminous Supernovae
• uGMRT observations of a Fast and Blue Optical Transient -- AT 2018cow
• Rapidly Evolving Transients from the Hyper Suprime-Cam SSP Transient Survey
• A detailed radio study of the energetic, nearby and puzzling GRB 171010A

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• The soft X-ray transient EP241021a: A cosmic explosion with a complex off-axis jet and cocoon from a massive progenitor
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• Luminous Fast Blue Optical Transients and Type Ibn/Icn SNe from Wolf-Rayet/Black Hole Mergers