e-Article
ZTF Early Observations of Type Ia Supernovae. I. Properties of the 2018 Sample
Document Type
article
Author
Yao, Y; Miller, AA; Kulkarni, SR; Bulla, M; Masci, FJ; Goldstein, DA; Goobar, A; Nugent, P; Dugas, A; Blagorodnova, N; Neill, JD; Rigault, M; Sollerman, J; Nordin, J; Bellm, EC; Cenko, SB; De, K; Dhawan, S; Feindt, U; Fremling, C; Gatkine, P; Graham, MJ; Graham, ML; Ho, AYQ; Hung, T; Kasliwal, MM; Kupfer, T; Laher, RR; Perley, DA; Rusholme, B; Shupe, DL; Soumagnac, MT; Taggart, K; Walters, R; Yan, L
Source
Astrophysical Journal. 886(2)
Subject
Language
Abstract
Early-time observations of Type Ia supernovae (SNe Ia) are essential to constrain the properties of their progenitors. In this paper, we present high-quality light curves of 127 SNe Ia discovered by the Zwicky Transient Facility (ZTF) in 2018. We describe our method to perform forced point-spread function photometry, which can be applied to other types of extragalactic transients. With a planned cadence of six observations per night (three g + three r), all of the 127 SNe Ia are detected in both g and r bands more than 10 days (in the rest frame) prior to the epoch of g-band maximum light. The redshifts of these objects range from z = 0.0181 to 0.165; the median redshift is 0.074. Among the 127 SNe, 50 are detected at least 14 days prior to maximum light (in the rest frame), with a subset of nine objects being detected more than 17 days before g-band peak. This is the largest sample of young SNe Ia collected to date; it can be used to study the shape and color evolution of the rising light curves in unprecedented detail. We discuss six peculiar events in this sample: one 02cx-like event ZTF18abclfee (SN 2018crl), one Ia-CSM SN ZTF18aaykjei (SN 2018cxk), and four objects with possible super-Chandrasekhar mass progenitors: ZTF18abhpgje (SN 2018eul), ZTF18abdpvnd (SN 2018dvf), ZTF18aawpcel (SN 2018cir), and ZTF18abddmrf (SN 2018dsx).