Absolute Magnitude Distributions and Light Curves of Stripped-Envelope Supernovae

Abstract

The absolute visual magnitudes of three Type IIb, 11 Type Ib, and 13 Type Ic supernovae (collectively known as stripped-envelope supernovae) are studied by collecting data on the apparent magnitude, distance, and interstellar extinction of each event. Weighted and unweighted mean absolute magnitudes of the combined sample, as well as various subsets of the sample, are reported. The limited sample size and the considerable uncertainties, especially those associated with extinction in the host galaxies, prevent firm conclusions regarding differences between the absolute magnitudes of supernovae of Types Ib and Ic, and regarding the existence of separate groups of overluminous and normal-luminosity stripped-envelope supernovae. The spectroscopic characteristics of the events of the sample are considered. Three of the four overluminous events are known to have had unusual spectra. Most but not all of the normal-luminosity events have had typical spectra. The light curves of stripped-envelope supernovae are collected and compared. Because SN 1994I in M51 was very well observed, it often is regarded as the prototypical Type Ic supernova, but it has the fastest light curve in the sample. Light curves are modeled by means of a simple analytical technique that, combined with a constraint on E/M from spectroscopy, yields internally consistent values of ejected mass, kinetic energy, and nickel mass.

Two type Ic supernovae in low-metallicity, dwarf galaxies: diversity of explosions

“…All data are plotted in the R-band except for SN 1997ef which is plotted in the V-band due to a lack of coverage in the R-band. As previously mentioned, SNe Ic are known to be a heterogeneous group both in terms of their absolute peakmagnitude range and their lightcurve shapes (see Richardson et al 2006), not to mention their spectral properties (see Sect. 3).…”

“…Richardson et al (2002) and Richardson et al (2006) have tentatively suggested a case for two groups of strippedenvelope SNe (SNe IIb, Ib and Ic); one normal-luminosity set with mean M V = −17.7 and an over-luminous set with mean M V = −20.08. In Fig.…”

“…This stripping is thought to occur either via binary interaction or mass-loss resulting from the strong stellar winds suffered during the life-time of the progenitor star Smartt (2009). As a class SNe Ic are known to exhibit a broad range in both luminosity and light-curve shape (Richardson et al 2006); a heterogeneity also displayed in their spectra (Matheson et al 2001;Elmhamdi et al 2006). Interest in this class of SN has been rejuvenated in the past decade with confirmed association of SNe Ic with long-duration Gamma-Ray Bursts (GRBs).…”

Relative frequencies of supernovae types: dependence on host galaxy magnitude, galactocentric radius, and local metallicity

“…Thus, to avoid biasing our sample against or in favor of one of the SN subtypes, we have to cut it at V HEL < 5000 km s −1 . Richardson et al (2006) produced absolute magnitudes for Ib and Ic, of −17.98 (scatter of 0.46), and −18.14 (0.48) respectively for the so-called "normal" ones. These values are similar and slightly brighter than the "normal Ibc" taken from Richardson et al (2002), so SNIb and SNIc should be biased neither against each other, nor against SNII adopting V HEL < 5000 km s −1 .…”

The discovery and classification of 16 supernovae at high redshifts in ELAIS-S1

“…Assuming the peak magnitudes to be normally distributed around the mean is consistent with observations, cf. Richardson et al (2002) and Richardson et al (2006). The range in peak absolute magnitudes considered is given by…”