Optical echelle spectrscopy of PNV J17224490-4137160

ATel #16004; Steve Shore (Univ. Pisa), Stephane Charbonnel, Pascal Le Du, Olivier Garde, Lionel Mulato, Thomas Petit (2SPOT, Chile; ARAS Group)
on 22 Apr 2023; 18:08 UT
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Credential Certification: S. N. Shore (shore@df.unipi.it)

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We report continuing medium resolution spectroscopy of the newly announced classical nova (and possible gamma-ray source) in Scorpius (ATel #16002, #16003). Spectra were obtained on 2023 Apr. 22.25 UT (MJD(mid)= 60056.80) in remote operation (Chile) using an RC12 reflector with sShel echelle fibre spectrograph (R=11000) and an ATIK 460ex camera for a total exposure of 3600 sec (with 16 exposures of 1200 sec) in the range 3850 - 7600A. The lines are all complex, the ejecta are still clearly optically quite opaque and continuing monitoring is strongly advised. For the Balmer lines, all transitions show strong absorption with widths of order 500 km/s with absorption components detected on all lines through Heps, Halpha: -3000 k/s, -1800; Hbeta - Hdelta show the same features with decreasing relative optical depth. There is a hint, from the Hbeta and higher transitions, of an absorption feature at -1000 km/s that does not appear distinctly on Halpha. In all cases, the absorptions show asymmetric profiles (shaded to the red). The Na I D1, D2 show a single strong absorption at -1700 km/s (D line abs components separated with a velocity range of about 600 km/s with broad emission P Cyg-like and red wing to > +2000 km/s). A comparison with the Balmer lines shows absorption at -3100 km/s but this is likely Fe I 5851 at about -1700 km/s. For the metal ions, some examples include Fe II 5018, 5169 at -1700 km/s; Si II 6347/70, -1700; Mg I 5183 (unblended) absorption at -1700 km/s, the rest of the multiplet is too blended with Fe II; Mg II 4481: -1720; Ca I 4226 shows a possible weak absorption but at lower velocity, -1400 km/s; Ca II H,K: -1700, broad and strong high velocity absorption. There may be C II 7236 in absorption at -2000 km/s but it is severely blended with terrestrial lines. There are no detected neutral helium transitions (e.g., He I 4471, 5896, 6678, 7065). Interstellar features include Na I (equivalent widths: D1 1.16A, D2 0.97 A); Ca II K (0.71A), Ca II H (0.46A); DIBS 5780 (0.5A), 5793 (0.1A), 6613 (0.2A). The Na I ISM line ratio is consistent with a significant extinction (saturation), the profile is clearly composite (-65, -40 [+/- 5] km/s]), Ca IIis also composite with at least two components (-60, -4 [+/-7]) km/s, the blue component being substantially broader than Na I D.

ARAS Database: Novae