Applying the expanding photosphere and standardized candle methods to Type II-Plateau supernovae at cosmologically significant redshifts

Abstract

Based on optical imaging and spectroscopy of the Type II-Plateau SN 2013eq, we present a comparative study of commonly used distance determination methods based on Type II supernovae. The occurrence of SN 2013eq in the Hubble flow (z = 0.041 ± 0.001) prompted us to investigate the implications of the difference between "angular" and "luminosity" distances within the framework of the expanding photosphere method (EPM) that relies upon a relation between flux and angular size to yield a distance. Following a re-derivation of the basic equations of the EPM for SNe at non-negligible redshifts, we conclude that the EPM results in an angular distance. The observed flux should be converted into the SN rest frame and the angular size, θ, has to be corrected by a factor of (1 + z) 2 . Alternatively, the EPM angular distance can be converted to a luminosity distance by implementing a modification of the angular size. For SN 2013eq, we find EPM luminosity distances of D L = 151 ± 18 Mpc and D L = 164 ± 20 Mpc by making use of different sets of dilution factors taken from the literature. Application of the standardized candle method for Type II-P SNe results in an independent luminosity distance estimate (D L = 168 ± 16 Mpc) that is consistent with the EPM estimate.

Supernova 2018aoq and a distance to Seyfert galaxy NGC 4151

“…The EPM provides estimates of distance independent of extragalactic distance ladder. The method requires high-quality spectroscopic and photometric monitoring of SNe and was applied mostly to nearby objects (e.g., Hamuy et al 2001;Takáts & Vinkó 2006;Jones et al 2009;Bose & Kumar 2014), although recently it became possible to perform the EPM on SNe at cosmologically significant redshifts (e.g., Gall et al 2016Gall et al , 2018. The other method for distance determinations using SNe II-P is the Standardized Candle Method (SCM) (Hamuy & Pinto 2002), based on a correlation between the luminosity and the expansion velocity of SNe during the plateau phase.…”

History of Supernovae as Distance Indicators

“…A direct comparison of EPM and SCM has been presented for nearby supernovae (Olivares et al 2010) demonstrating that both methods provide similar distances within the respective uncertainties. At cosmological distances, such a comparison will be a direct test of general relativity as a metric theory of gravitation (Wagoner 1977;Gall et al 2016). Gall et al (2016) demonstrated an extension to higher redshifts, albeit not yet at the cosmologically interesting level, for both methods for a single supernova (SN 2013eq at z D 0:04).…”

“…At cosmological distances, such a comparison will be a direct test of general relativity as a metric theory of gravitation (Wagoner 1977;Gall et al 2016). Gall et al (2016) demonstrated an extension to higher redshifts, albeit not yet at the cosmologically interesting level, for both methods for a single supernova (SN 2013eq at z D 0:04).…”

Astronomical Distance Determination in the Space Age

“…Quite interestingly, the two methods can give consistent results, up to cosmological distances (e.g. Gall et al, 2016).…”