SN Refsdal: photometry and time delay measurements of the first Einstein cross supernova Academic Article uri icon

abstract

  • We present the first year of Hubble Space Telescope imaging of the unique supernova (SN)" Refsdal," a gravitationally lensed SN at z= 1.488±0.001 with multiple images behind the galaxy cluster MACS J1149. 6+ 2223. The first four observed images of SN Refsdal (images S1–S4) exhibited a slow rise (over~ 150 days) to reach a broad peak brightness around 2015 April 20. Using a set of light curve templates constructed from SN 1987A-like peculiar Type II SNe, we measure time delays for the four images relative to S1 of 4±4 (for S2), 2±5 (S3), and 24±7 days (S4). The measured magnification ratios relative to S1 are 1.15±0.05 (S2), 1.01±0.04 (S3), and 0.34±0.02 (S4). None of the template light curves fully captures the photometric behavior of SN Refsdal, so we also derive complementary measurements for these parameters using polynomials to represent the intrinsic light curve shape. These …

publication date

  • March 17, 2016