AHUBBLEDIAGRAM FROM TYPE II SUPERNOVAE BASED SOLELY ON PHOTOMETRY: THE PHOTOMETRIC COLOR METHOD

Abstract

We present a Hubble diagram of type II supernovae using corrected magnitudes derived only from photometry, with no input of spectral information. We use a data set from the Carnegie Supernovae Project I (CSP) for which optical and near-infrared light-curves were obtained. The apparent magnitude is corrected by two observables, one corresponding to the slope of the plateau in the V band and the second a colour term. We obtain a dispersion of 0.44 mag using a combination of the (V − i) colour and the r band and we are able to reduce the dispersion to 0.39 mag using our golden sample. A comparison of our photometric colour method (PCM) with the standardised candle method (SCM) is also performed. The dispersion obtained for the SCM (which uses both photometric and spectroscopic information) is 0.29 mag which compares with 0.43 mag from the PCM, for the same SN sample. The construction of a photometric Hubble diagram is of high importance in the coming era of large photometric wide-field surveys, which will increase the detection rate of supernovae by orders of magnitude. Such numbers will prohibit spectroscopic follow-up in the vast majority of cases, and hence methods must be deployed which can proceed using solely photometric data.

A Type II Supernova Hubble Diagram from the CSP-I, SDSS-II, and SNLS Surveys*

“…Anderson et al (2014) found that more luminous SNeII have higher s 2 (steeper decline, >1.15 mag per 100 days), confirming previous studies finding that traditional SNeIIL are more luminous than SNeIIP (Patat et al 1994;Richardson et al 2014). Using this correlation and adding a color term, de Jaeger et al (2015) succeeded in reducing the scatter in the low-redshift SNeII Hubble diagram ( = z 0.01 0.04 -) to a level of ∼0.4 mag (±0.05 mag), which corresponds to a precision of 18% in distances.…”

“…Many other works have used an updated version of the SCM where a color correction is added in order to take into account the hostgalaxy extinction. All these studies (Nugent et al 2006;Poznanski et al 2009Poznanski et al , 2010D'Andrea et al 2010;Olivares et al 2010;de Jaeger et al 2015) have confirmed the use of SNeII as distance indicators, finding similar dispersion in the Hubble diagram (0.25-0.30 mag). Recently, de Jaeger et al (2015) suggested a new method using corrected magnitudes derived only from photometry.…”

“…To date, several methods have been developed to standardize SNeII, such as 1. the "Expanding Photosphere Method" (EPM) developed by Kirshner & Kwan (1974), 2. the "Spectral-fitting Expanding Atmosphere Method" (SEAM; Baron et al 2004 andupdated in Dessart et al 2008), 3. the "Standard Candle Method" (SCM) introduced by Hamuy & Pinto (2002), 4. the "Photospheric Magnitude Method" (PMM), which is a generalization of the SCM over various epochs (Rodríguez et al 2014), and 5. the most recent technique, the "Photometric Color Method" (PCM; de Jaeger et al 2015).…”

“…Differences between the expansion histories are extremely small and distinguishing between them will require measurements extending far back in time. The main purpose of the current work is to build a Hubble diagram using the SCM and the PCM as achieved in de Jaeger et al (2015) but adding higher redshift SN samples such as the Sloan Digital Sky Survey II Supernova Survey (SDSS-II SN; Frieman et al 2008;Sako et al 2014) and the Supernova Legacy Survey (SNLS; Astier et al 2006;Perrett et al 2010).…”

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

“…Nugent et al 2006;Poznanski et al 2009). Techniques relying solely on photometric data are also being explored (de Jaeger et al 2015). The obvious advantage of being significantly less demanding in terms of the data required, comes A&A 592, A129 (2016) at the cost of lowered accuracy compared to the SCM.…”