SALT high resolution optical spectroscopy of the highly reddened Galactic nova PNV J16484962-4457032

ATel #11290; E. Aydi (South African Astronomical Observatory, University of Cape Town), D. A. H. Buckley (SAAO), S. Mohamed (SAAO, UCT), P. A. Whitelock (SAAO, UCT)
on 12 Feb 2018; 16:39 UT
Credential Certification: David Buckley (dibnob@saao.ac.za)

Subjects: Optical, Nova

We report on high-resolution spectroscopy of PNV J16484962-4457032, confirmed by J. Strader et al. (ATel #11289) as a Fe II-type nova, obtained on 2018 February 12.1 (UTC, HJD 2458161.6), using the High Resolution Spectrograph (HRS; Crause et al. 2014, Proc. SPIE, 91476) on the Southern African Large Telescope (SALT). Observations were taken in the LR mode of HRS, covering a spectral range of 3800-8900Å at a resolution of R ~ 14,000. The data were reduced with the SALT HRS MIDAS pipeline (Kniazev et al. 2016, MNRAS 459, 3068).

The spectrum is dominated by emission lines of H I, Fe II, O I, Na I, Al II, Ca II, Mg I and Mg II (see below a full list of the line identifications). We note the absence of P Cygni absorption in the spectrum. The lines have rounded profiles with a FWHM of around 1700 ± 100 km/s (for Hα and Hβ). The emission lines and their profiles are characteristic of classical novae of the Fe II spectroscopic class.

We can identify the interstellar Na I (D1) and (D2) absorption features. These lines have EW(D2) = 1.3 ± 0.05Å and EW(D1) = 1.1 ± 0.05Å. Using the empirical relations of Poznaski et al. 2012 (MNRAS, 426, 1465), we derive E(B-V) = 9.66 ± 1.7 and Av ~ 30.0 ± 1.7 towards the nova, consistent with the high extinction towards the nova from the Galactic reddening maps.

Line identifications:
H I (Balmer): 4102, 4340, 4861 and 6563Å
Ca II: 8498, 9542 and 8662Å
Na I: 5686, 5892 and 6159Å
O I: 7773 and 8446Å
Al II: 4663, 6237, 6830 and 7471Å
Mg I: 5178 and 5528Å
Mg II: 7896 and 8232Å
[O I]: 5577, 6300 and 6364Å

Fe II lines:
Multiplet (37): 4629Å
Multiplet (38) 4584Å
Multiplet (42): 4924, 5018, 5169 and 5425Å
Multiplet (46): 5991 and 6084Å
Multiplet (48): 5317, 5363 and 5414Å
Multiplet (49): 5198, 5235, 5276, 5317 and 5425Å
Multiplet (55): 5535Å
Multiplet (74): 6148, 6248, 6417 and 6456Å

Possible lines:
H I: 8454, 8598 and 8750Å
N II: 5479Å
C I: 8335Å

Unidentified emission features at:
4397, 4445, 5130, 5330, 5373, 5499, 6677, 6717, 6800, 8683 and 8717Å