2017/11/20 by Anindita Mondal, G. C. Anupama, U. S. Kamath +3 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Dwarf nova #Gamma-ray bursts and supernovae #Nova (rocket) #Physics #Pulsars and Gravitational Waves Research #Spectroscopy #Stars #White dwarf #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stx2988
Accepted for publication in MNRAS. 15 pages, 26 figures and 6 tables
openalex publication_date 2017/11/20 · arxiv created 2017/11/21 · openalex created_date 2017/12/04 · arxiv updated 2017/12/27 · openalex updated_date 2026/08/05
Optical spectra of the 2006 outburst of RS Ophiuchi beginning one day after discovery to over a year after the outburst are presented here. The spectral evolution is found to be similar to that in previous outbursts. The early-phase spectra are dominated by hydrogen and helium (i and ii) lines. Coronal and nebular lines appear in the later phases. Emission line widths are found to narrow with time, which is interpreted as a shock expanding into the red giant wind. Using the photoionization code cloudy, spectra at nine epochs spanning 14 months after the outburst peak, thus covering a broad range of ionization and excitation levels in the ejecta, are modelled. The best-fitting model parameters indicate the presence of a hot white dwarf source with a roughly constant luminosity of 1.26 × 1037 erg s−1. During the first three months, the abundances (by number) of He, N, O, Ne, Ar, Fe, Ca, S and Ni are found to be above solar abundances; the abundances of these elements decreased in the later phase. Also presented are spectra obtained during quiescence. A photoionization model of the quiescent spectrum indicates the presence of a low-luminosity accretion disc. The helium abundance is found to be subsolar at quiescence.