500 days of SN 2013dy: spectra and photometry from the ultraviolet to the infrared

Pan, Y. -C. and Foley, R. J. and Kromer, M. and Fox, O. D. and Zheng, W. and Vinkó, József (2015) 500 days of SN 2013dy: spectra and photometry from the ultraviolet to the infrared. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 452 (4). pp. 4307-4325. ISSN 0035-8711

Preview

Text 1504.02396.pdf Available under License Creative Commons Attribution. Download (5MB) | Preview

Abstract

SN 2013dy is a Type Ia supernova for which we have compiled an extraordinary dataset spanning from 0.1 to ∼ 500 days after explosion. We present 10 epochs of ultraviolet (UV) through near-infrared (NIR) spectra with HST /STIS, 47 epochs of optical spectra (15 of them having high resolution), and more than 500 photometric observations in the BVrRiIZYJH bands. SN 2013dy has a broad and slowly declining light curve (∆m15(B) = 0.92 mag), shallow Si ii λ6355 absorption, and a low velocity gradient. We detect strong C II in our earliest spectra, probing unburned progenitor material in the outermost layers of the SN ejecta, but this feature fades within a few days. The UV continuum of SN 2013dy, which is strongly affected by the metal abun- dance of the progenitor star, suggests that SN 2013dy had a relatively high-metallicity progenitor. Examining one of the largest single set of high-resolution spectra for a SN Ia, we find no evidence of variable absorption from circumstellar material. Com- bining our UV spectra, NIR photometry, and high-cadence optical photometry, we construct a bolometric light curve, showing that SN 2013dy had a maximum lumi- nosity of 10.0+4.8 −3.8 × 1042 erg s−1. We compare the synthetic light curves and spectra of several models to SN 2013dy, finding that SN 2013dy is in good agreement with a solar-metallicity W7 model.

Actions (login required)

Edit Item