Optical and near-IR observations of the faint and fast 2008ha-like supernova 2010ae

Abstract

A comprehensive set of optical and near-infrared (NIR) photometry and spectroscopy is presented for the faint and fast 2008ha-like supernova (SN) 2010ae. Contingent on the adopted value of host extinction, SN 2010ae reached a peak brightness of −13.8 > M V > −15.3 mag, while modeling of the UVOIR light curve suggests it produced 0.003-0.007 M of 56 Ni, ejected 0.30−0.60 M of material, and had an explosion energy of 0.04-0.30 × 10 51 erg. The values of these explosion parameters are similar to the peculiar SN 2008ha -for which we also present previously unpublished early phase optical and NIR light curves -and places these two transients at the faint end of the 2002cx-like SN population. Detailed inspection of the post-maximum NIR spectroscopic sequence indicates the presence of a multitude of spectral features, which are identified through SYNAPPS modeling to be mainly attributed to Co ii. Comparison with a collection of published and unpublished NIR spectra of other 2002cx-like SNe, reveals that a Co ii footprint is ubiquitous to this subclass of transients, providing a link to Type Ia SNe. A visual-wavelength spectrum of SN 2010ae obtained at +252 days past maximum shows a striking resemblance to a similar epoch spectrum of SN 2002cx. However, subtle differences in the strength and ratio of calcium emission features, as well as diversity among similar epoch spectra of other 2002cx-like SNe indicates a range of physical conditions of the ejecta, highlighting the heterogeneous nature of this peculiar class of transients.

The type Iax supernova, SN 2015H

“…SN 2010ae was undetected up to five days before discovery . Using this limit, combined with data from Stritzinger et al (2014), we estimate a rise time to r-band maximum of 10 ± 2 d. Based on limited premaximum detections of SN 2007qd ), we estimate a rise time to r-band maximum of 11 ± 5 d. In addition to the above objects, we examined the unfiltered light curve of SN 2004cs presented by Foley et al (2013) and found a rise time of ∼9.0 ± 1.1 days. In order to estimate the rise time of SN 2008ha, Foley et al (2009) stretched the light curve of SN 2005hk, and found a rise time of ∼10 days to B-band maximum.…”

Light-curve and spectral properties of ultrastripped core-collapse supernovae leading to binary neutron stars

“…Their origin is still under discussion (e.g., Foley et al 2016). Although many of them have peak magnitudes brighter than −17 mag (see Foley et al 2016 for a summary) and are thus too bright to be ultra-stripped SNe, some of them do have fainter peak luminosity (e.g., Stritzinger et al 2014;McClelland et al 2010). We take one faint SN 2002cx-like SN, SN 2007qd (McClelland et al 2010, which is in the expected peak luminosity range for ultra-stripped SNe, and compare its spectrum at the peak luminosity with our synthetic spectra.…”

Growing evidence that SNe Iax are not a one-parameter family

“…Using the empirical relation derived by Pettini & Pagel (2004) with the N2 index, we find a host metallicity of 12 + log(O/H) = 8. 2008ha, 2010ae, and 2012Z (Foley et al 2009Stritzinger et al 2014;Yamanaka et al 2015), respectively. SNe Iax therefore appear to show no preference for either sub-or super-solar 5 environments.…”

“…Most notably, SNe Iax can be fainter than normal SNe Ia (Li et al 2003) by up to five magnitudes (Valenti et al 2009;Foley et al 2009). They also display large variations in their light curve shapes, which show a broader range of decline rates 0.3 ∆m 15 (r) 1.1 (SN 2009ku, SN 2008ha, Narayan et al 2011Stritzinger et al 2014, respectively), and rise times, from ∼10 d (SN 2010ae, Stritzinger et al 2014;Magee et al 2016) to ∼22 d (SN 2005hk, Phillips et al 2007Magee et al 2016), when compared to normal SNe Ia. The fact that many SNe Iax have neither well-constrained peak magnitudes nor decline rates, and even fewer have secure rise time measurements, has further added to the difficulty in interpreting the observed behaviour of SNe Iax.…”