H II region metallicity constraints near the site of the strongly lensed supernova “SN Refsdal” at redshift 1.49

Abstract

We present the local H II region metallicity near the site of the recently discovered multiply lensed supernova (SN; "SN Refsdal") at redshift 1.49. "SN Refsdal" is located at the outer spiral arm (∼7 kpc) of the lensed host galaxy, which we previously reported to exhibit a steep negative galactocentric metallicity gradient. Based on our updated near-infrared integral field spectroscopic data, the gas-phase metallicity averaged in an intrinsic radius of ∼550 pc surrounding an H ii region ∼200 pc away from the SN site is 12 + log(O/H)PP04N2 ≤ 8.67. The metallicity averaged over nine H II regions at similar galactocentric distances (∼5-7 kpc) as "SN Refsdal" is constrained to be 12 + log(O/H)PP04N2 ≤ 8.11. Given the fortuitous discovery of "SN Refsdal" in an advantageously lensed face-on spiral, this is the first observational constraint on the local metallicity environment of an SN site at redshift z > 1.