Detailed Radio View on Two Stellar Explosions and Their Host Galaxy: XRF080109/SN2008D and SN2007uy in NGC2770

TL;DR

This study provides a detailed radio analysis of two supernovae in galaxy NGC2770, revealing insights into their emission, host galaxy environment, and potential for future low-frequency observations.

Contribution

It offers the first extensive radio emission measurements of SN2008D and SN2007uy, including VLBI data and molecular gas analysis, enhancing understanding of their explosion mechanisms and host galaxy.

Findings

Radio flux measurements over 600 days at multiple frequencies.

VLBI observations of supernovae at two epochs.

Analysis of molecular gas indicating high star formation rate.

Abstract

The galaxy NGC2770 hosted two core-collapse supernova explosions, SN2008D and SN2007uy, within 10 days of each other and 9 years after the first supernova of the same type, SN1999eh, was found in that galaxy. In particular SN2008D attracted a lot of attention due to the detection of an X-ray outburst, which has been hypothesized to be caused by either a (mildly) relativistic jet or the supernova shock breakout. We present an extensive study of the radio emission from SN2008D and SN2007uy: flux measurements with the Westerbork Synthesis Radio Telescope and the Giant Metrewave Radio Telescope, covering ~600 days with observing frequencies ranging from 325 MHz to 8.4 GHz. The results of two epochs of global Very Long Baseline Interferometry observations are also discussed. We have examined the molecular gas in the host galaxy NGC2770 with the Arizona Radio Observatory 12-m telescope, and present the implications of our observations for the star formation and seemingly high SN rate in this galaxy. Furthermore, we discuss the near-future observing possibilities of the two SNe and their host galaxy at low radio frequencies with the Low Frequency Array.