LOSS Revisited - I: Unraveling correlations between supernova rates and
  galaxy properties, as measured in a reanalysis of the Lick Observatory
  Supernova Search
  Most types of supernovae (SNe) have yet to be connected with their progenitor
stellar systems. Here, we reanalyze the 10-year SN sample collected during
1998-2008 by the Lick Observatory Supernova Search (LOSS) in order to constrain
the progenitors of SNe Ia and stripped-envelope SNe (SE SNe, i.e., SNe~IIb, Ib,
Ic, and broad-lined Ic). We matched the LOSS galaxy sample with spectroscopy
from the Sloan Digital Sky Survey and measured SN rates as a function of galaxy
stellar mass, specific star formation rate, and oxygen abundance (metallicity).
We find significant correlations between the SN rates and all three galaxy
properties. The SN Ia correlations are consistent with other measurements, as
well as with our previous explanation of these measurements in the form of a
combination of the SN Ia delay-time distribution and the correlation between
galaxy mass and age. The ratio between the SE SN and SN II rates declines
significantly in low-mass galaxies. This rules out single stars as SE~SN
progenitors, and is consistent with predictions from binary-system progenitor
models. Using well-known galaxy scaling relations, any correlation between the
rates and one of the galaxy properties examined here can be expressed as a
correlation with the other two. These redundant correlations preclude us from
establishing causality - that is, from ascertaining which of the galaxy
properties (or their combination) is the physical driver for the difference
between the SE SN and SN II rates. We outline several methods that have the
potential to overcome this problem in future works.
