Post-maximum near infrared spectra of SN 2014J: A search for interaction signatures

Abstract

We present near infrared (NIR) spectroscopic and photometric observations of the nearby Type Ia SN 2014J. The seventeen NIR spectra span epochs from +15.3 to +92.5 days after $B$-band maximum light, while the $JH{K}_s$ photometry include epochs from $-$10 to +71 days. This data is used to constrain the progenitor system of SN 2014J utilizing the Pa$\beta$ line, following recent suggestions that this phase period and the NIR in particular are excellent for constraining the amount of swept up hydrogen-rich material associated with a non-degenerate companion star. We find no evidence for Pa$\beta$ emission lines in our post-maximum spectra, with a rough hydrogen mass limit of $\lesssim$0.1 $M_{\odot }$, which is consistent with previous limits in SN 2014J from late-time optical spectra of the H$\alpha$ line. Nonetheless, the growing dataset of high-quality NIR spectra holds the promise of very useful hydrogen constraints.

10 pages, 3 Figures, 2 Tables. Accepted for publication in the ApJ Letters