2 research outputs found
Physical Properties of the X-ray Luminous SN 1978K in NGC 1313 from Multiwavelength Observations
We update the light curves from the X-ray, optical, and radio bandpasses
which we have assembled over the past decade, and present two observations in
the ultraviolet using the Hubble Space Telescope Faint Object Spectrograph. The
HRI X-ray light curve is constant within the errors over the entire observation
period. This behavior is confirmed in the ASCA GIS data obtained in 1993 and
1995. In the ultraviolet, we detected Ly-alpha, the [Ne IV] 2422/2424 A
doublet, the Mg II doublet at 2800 A, and a line at ~3190 A we attribute to He
I 3187. Only the Mg II and He I lines are detected at SN1978K's position. The
optical light curve is formally constant within the errors, although a slight
upward trend may be present. The radio light curve continues its steep decline.
The longer time span of our radio observations compared to previous studies
shows that SN1978K is in the same class of highly X-ray and radio-luminous
supernovae as SN1986J and SN1988Z. The [Ne IV] emission is spatially distant
from the location of SN1978K and originates in the pre-shocked matter. The Mg
II doublet flux ratio implies the quantity of line optical depth times density
of ~10^14 cm^-3 for its emission region. The emission site must lie in the
shocked gas.Comment: 32 pages, 13 figs; LaTeX with AASTEXv5; paper accepted, scheduled for
AJ, Dec 199