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