Mid-infrared spectroscopy of the highly reddened nova PGIR19brv / AT2019qwf with IRTF + SpeX
ATel #13732; K. De (Caltech) on behalf of the Palomar Gattini-IR collaboration
on 13 May 2020; 21:25 UT
Credential Certification: Kishalay De (kde@astro.caltech.edu)
Subjects: Infra-Red, Nova, Transient
On UT 2020-05-12, we obtained mid-infrared spectroscopic follow-up with the NASA Infrared Telescope Facility (IRTF) of the highly reddened galactic nova PGIR19brv / AT2019qwf, that was discovered and first classified by the Palomar Gattini-IR survey (De et al. 2020, PASP, 132, 1008; ATel #13130). Subsequent follow-up photometry and spectroscopy in the optical and near-infrared indicated a slow evolving Fe II type nova (ATel #13149, #13258, #13283, #13301 and #13340), as well as a recent radio detection (ATel #13653) likely from thermal emission of the expanding ejecta. The data were obtained in the LXD_Long mode of SpeX (Proposal 2020A111; PI: De) covering 1.9 micron to 5.3 micron for a total exposure time of 360 s on the science target, at a phase of ~ 250 days after outburst.
The nova is clearly detected in the continuum throughout the wavelength range. We identify several emission lines of H including the 6-10 transition at 5.12 micron, 5-7 transition at 4.65 micron, 4-5 transition at 4.05 micron, 6-15 transition at 3.90 micron, 6-16 transition at 3.81 micron and 4-7 transition at 2.16 micron. The typical FWHM of the lines is ~ 1400 km/s. In addition, we identify emission lines from He I at 2.05 micron and weaker features from C I around 2.1 micron. We do not find evidence of a thermal emission excess component in the mid-infrared from dust.
Further follow-up observations are encouraged. We thank the IRTF staff, in particular Adwin Boogert and Brian Cabreira for supporting these observations soon after the recent resumption of operations.
