Speaker
Ms
Kate Alexander
(Harvard-Smithsonian Center for Astrophysics)
Description
We present radio observations of the type Ic supernova 1994I, reanalyzed as part of a
search for radio transients in M51 conducted using archival data from the Very Large
Array. The data includes a detailed 4.9 GHz light curve of SN 1994I and three
spectra of this object from epochs on April 10, May 4, and August 8, 1994, each
spanning frequencies of 1.5-22.5 GHz. We find that the spectra and the light curve
are well-fit by a synchrotron self-absorption model, assuming an explosion date of
1994 March 30.0 UT. The radio emission from the SN peaks in the 4.9 GHz band 40 days
after the estimated explosion date, reaching a maximum flux of 16.8 mJy.
Furthermore, we calculate physical properties of the explosion at the three epochs
with full spectra and estimate a pre-explosion mass loss rate of ~2-5 x 10e-5 solar
masses per year, which is consistent with a Wolf-Rayet progenitor for the SN. We
also present preliminary results of our survey of radio transient sources in M51. We
find no detections in 31 epochs of 10-20 minute duration spanning a period of 6
months, placing a 2-sigma upper limit of 17 per square degree for the source density
of transients above 500 microJy.
Primary author
Ms
Kate Alexander
(Harvard-Smithsonian Center for Astrophysics)
Co-authors
Dr
Alicia Soderberg
(Harvard-Smithsonian Center for Astrophysics)
Dr
Laura Chomiuk
(Harvard-Smithsonian Center for Astrophysics)
