A non-equipartition shockwave traveling in a dense circumstellar environment around SN2020oi

Abstract

We report the discovery and panchromatic followup observations of the young Type Ic supernova, SN2020oi, in M100, a grand design spiral galaxy at a mere distance of $14$ Mpc. We followed up with observations at radio, X-ray and optical wavelengths from only a few days to several months after explosion. The optical behaviour of the supernova is similar to those of other normal Type Ic supernovae. The event was not detected in the X-ray band but our radio observation revealed a bright mJy source ($L_{\nu }\approx 1.2\times 10^{27}{\mathrm{erg}\mathrm{s}}^{-1}{\mathrm{Hz}}^{-1}$). Given, the relatively small number of stripped envelope SNe for which radio emission is detectable, we used this opportunity to perform a detailed analysis of the comprehensive radio dataset we obtained. The radio emitting electrons initially experience a phase of inverse Compton cooling which leads to steepening of the spectral index of the radio emission. Our analysis of the cooling frequency points to a large deviation from equipartition at the level of ${\epsilon }_e/{\epsilon }_B\gtrsim 200$, similar to a few other cases of stripped envelope SNe. Our modeling of the radio data suggests that the shockwave driven by the SN ejecta into the circumstellar matter (CSM) is moving at $\sim 3\times 10^4{\mathrm{km}\mathrm{s}}^{-1}$. Assuming a constant mass-loss from the stellar progenitor, we find that the mass-loss rate is $\dot{M}\approx 1.4\times 10^{-4}{M}_{\odot }{\mathrm{yr}}^{-1}$, for an assumed wind velocity of $1000{\mathrm{km}\mathrm{s}}^{-1}$. The temporal evolution of the radio emission suggests a radial CSM density structure steeper than the standard $r^{-2}$.

arXiv commentSubmitted to ApJ (21 pages, 9 figures)

References in corpus (45)

• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Swift X-ray Telescope
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars
• The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• An online repository of Swift/XRT light curves of GRBs
• The Zwicky Transient Facility: Science Objectives
• An Empirical Relation between Sodium Absorption and Dust Extinction
• Confined Dense Circumstellar Material Surrounding a Regular Type II Supernova: The Unique Flash-Spectroscopy Event of SN 2013fs
• The Zwicky Transient Facility: Surveys and Scheduler
• A Wolf-Rayet-like progenitor of supernova SN 2013cu from spectral observations of a wind
• The Australia Telescope Compact Array Broadband Backend (CABB)
• Circumstellar Emission from Type Ib and Ic Supernovae
• A Relativistic Type Ibc Supernova Without a Detected Gamma-ray Burst
• The Zwicky Transient Facility: Observing System
• An embedded X-ray source shines through the aspherical AT2018cow: revealing the inner workings of the most luminous fast-evolving optical transients
• Proper image subtraction - optimal transient detection, photometry and hypothesis testing
• The Arcminute Microkelvin Imager
• The SED Machine: a robotic spectrograph for fast transient classification
• PTF12os and iPTF13bvn. Two stripped-envelope supernovae from low-mass progenitors in NGC 5806
• The GROWTH Marshal: A Dynamic Science Portal for Time-Domain Astronomy
• Optical and near-infrared observations of SN 2011dh - The first 100 days
• A Fully Automated Integral Field Spectrograph Pipeline for the SEDMachine: pysedm
• The Zwicky Transient Facility Alert Distribution System
• AT2018cow: a luminous millimeter transient
• Panchromatic Observations of SN 2011dh Point to a Compact Progenitor Star
• The Radio Evolution of the Ordinary Type Ic SN 2002ap
• Bolometric Corrections for optical light curves of Core-collapse Supernovae
• Early-time spectra of supernovae and their precursor winds: the luminous blue variable/yellow hypergiant progenitor of SN 2013cu
• An Early & Comprehensive Millimeter and Centimeter Wave and X-ray Study of Supernova 2011dh: A Non-Equipartition Blastwave Expanding into A Massive Stellar Wind
• A Digital Correlator Upgrade for the Arcminute MicroKelvin Imager
• The X-ray and radio emission from SN 2002ap: The importance of Compton scattering
• Radio and X-ray Observations of the Type Ic SN 2007gr Reveal an Ordinary, Non-relativistic Explosion
• Radio Observations Reveal Unusual Circumstellar Environments for Some Type Ibc Supernova Progenitors
• Radio and X-rays From SN 2013df Enlighten Progenitors of Type IIb Supernovae
• SN 2007bg: The Complex Circumstellar Environment Around One of the Most Radio-Luminous Broad-Lined Type Ic Supernovae
• AMI Galactic Plane Survey at 16 GHz: I -- Observing, mapping and source extraction
• Discovery and Early Multi-Wavelength Measurements of the Energetic Type Ic Supernova PTF12gzk: A Massive-Star Explosion in a Dwarf Host Galaxy
• Oxygen and helium in stripped-envelope supernovae
• The Carnegie Supernova Project I: methods to estimate host-galaxy reddening of stripped-envelope supernovae
• Electron Cooling in a Young Radio Supernova: SN 2012aw
• PTF12gzk - A Rapidly Declining, High-Velocity Type Ic Radio Supernova
• The Zwicky Transient Facility Bright Transient Survey I: Spectroscopic Classification and the Redshift Completeness of Local Galaxy Catalogs

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