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First high resolution ultraviolet (HST/STIS) and supporting optical spectroscopy (CHIRON/SMARTS, HRS/SALT) of V1369 Cen = Nova Cen 2013

ATel #6413; S. N. Shore (Univ. of Pisa, INFN-Pisa); G. J. Schwarz (AAS); F. M. Walter (SUNY-SB); S. Crawford (SAAO); P. A. Woudt (Univ. of Cape Town); R. E. Williams (STScI); E. Mason (INAF-OA Trieste); L. Izzo (Univ. of Rome - La Sapienza); K. L. Page, J. P. Osborne (Leicester); J-U Ness (ESA); S. Starrfield (ASU); C. E. Woodward (Univ. of Minnesota) ; P. Vaisanen, F. Marang, L. Crause, L. Tyas (SAAO)
on 24 Aug 2014; 00:35 UT
Distributed as an Instant Email Notice Novae
Credential Certification: S. N. Shore (shore@df.unipi.it)

Subjects: Optical, Ultra-Violet, Request for Observations, Nova

We report the preliminary results of the first ultraviolet observations of the classical nova V1369 Cen (Nova Cen 2013) with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope. High resolution spectra (1141-3072A) were obtained with HST/STIS on 2014 Aug. 12.3 UT using the E140H (R ~ 100000) and E230M gratings (R ~ 30000) with nearly simultaneous groundbased optical spectra obtained with CHIRON at CTIO (R ~80000) 4578-8761A) and the High Resolution Spectrograph on the Southern African Large Telescope (SALT) (R ~ 80000, Bramall, D.G. et al., 2012, Proc. SPIE, 8446, 84460-A1). The UV displays many similarities to the V339 Del spectra from 2014 Apr. (ATel#6088) and we report here integrated fluxes (not corrected for extinction) for the same lines for comparison: N V 1240 (5.3E-10), O I 1302 (9.4E-12), C II 1334 (1.3E-10), O V] 1371 (1.4e-11), C II 1335 (1.3E-10), O IV 1402 (1.2E-10, complex), N IV] 1486 (1.7E-10), C IV 1550 (9.0E-10), He II 1640 (8.6E-11), O III] 1665 (7.3E-11), N IV] 1718 (1.7E-11), N III] 1751 (3.4E-10), C III] 1909 (6.0E-10), C III 2296 (1.1E-11), C II 2324 (1.1E-10), O II 2470 (2.7E-11), Mg II 2800 (5.4E-11), C II 2836 (2.1E-11). All units are erg/s/cm^2. The Ly-alpha, N V 1240, and C IV 1550 resonance lines display P Cyg absorption troughs from about -1500 to -1800 km/s. The FWZI of the lines is ~ 3000 km/s. In general, the profiles are not strictly symmetric, the blueshifted emission is systematically stronger. The individual ions have distinctive profiles ranging from nearly featureless and flat-topped for low ionization to saddle-shaped profiles, with peaks at +/-500 km/s, for the highest ions. In the optical, the resonance lines [Fe VII] 3759, 5156A (poss. blend with [Fe VI] 5146A), 5276, 6087A, and [Ca V] 5309, 6387A are detected with similar profiles to the excited state lines He II 1640, 4686A. Fine structure is seen on all intercombination lines, especially N IV] and C III], at the same velocities with widths of about 100 km/s. The [F III] resonance lines are likely present at 2934A. Ar III] 7135A is present with a similar profile, like O III] 1660, 1667A. O II] 2470A is also present with a profile similar to [O I] 6300, 6364A. Emission lines are detected at 1814,1602, and 1575A. These lines were not detected in V339 Del (CO-type) but were present in V959 Mon (ONe-type). The [Ne III] 3869, 3967A lines are clearly present in the SALT spectrum. The Al III 1854, 1862A resonance lines are absent but two unidentified lines, 1846, 1861A (not Al III) are detected that were not present in V339 Del STIS spectra (but were reported as unidentified in RR Tel by Aufdenberg, J. P.1993, ApJS, 87, 337). The UV interstellar spectrum is very rich, including Ly-alpha. C I-III, N I, O I, Si II-IV, Fe II, Mg I/II, Si I/II, Al II. Using the C I 1260 and 1277, Na I 5889 (from the CHIRON spectra), Mg I 2852, and C II 1335 to compare with the LAB 21 cm H I profile, the range covered by the absorption is about 15% of the total column in H I from the 21 cm' this gives E(B-V) ~ 0.1 and N_H ~ 8E20/cm^2 (using Diplas A. & Savage B. D. 1994, ApJS, 93, 211). Scaling to V339 Del (E(B-V) ~ 0.2), the flux ratio is ~3 throughout the UV, suggesting a distance of ~ 2.4 kpc. The dereddened integrated flux (1150-3000A) is 1.2E-8 erg/s/cm^2. Observations at high resolution below 4000 A, in particular around the [Ne V] 3345, 3425A lines, is strongly encouraged. Some of the observations reported in this ATel were obtained with the Southern African Large Telescope (SALT) under DDT program 2014-1-DDT-002.