Observational Evidence for Expansion in the SSS spectra of Novae

Abstract

For several novae, a bright X-ray source with a spectrum resembling the class of Super Soft X-ray Sources (SSS) has been observed a few weeks to months after outburst. Novae are powered by explosive nuclear burning on the surface of a white dwarf, and enough energy is produced to power a radiatively driven wind. Owing to the evolution of the opacity of the ejecta, the observable spectrum gradually shifts from optical to soft X-rays (SSS phase). It has sometimes been assumed that at the beginning of the SSS phase no more mass loss occurs. However, high-resolution X-ray spectra of some novae have shown highly blue-shifted absorption lines, indicating a significant expansion. In this paper, I show that all novae that have been observed with X-ray gratings during their SSS phase show significant blue shifts. I argue that all models that attempt to explain the X-ray bright SSS phase have to accommodate the continued expansion of the ejecta.

4 pages, accepted for Astronomische Nachrichten

References in corpus (6)

• Supersoft X-ray Light Curve of RS Ophiuchi (2006)
• The SSS phase of RS Ophiuchi observed with Chandra and XMM-Newton I.: Data and preliminary Modeling
• High-resolution X-ray spectroscopy of the evolving shock in the 2006 outburst of RS Ophiuchi
• Optical and Supersoft X-ray Light Curve Models of Classical Nova V2491 Cygni: A New Clue to the Secondary Maximum
• Modeling CHANDRA Low Energy Transmission Grating Spectrometer Observations of Classical Novae with PHOENIX. I. V4743 Sagittarii
• Analysis of a XMM-Newton Spectrum of the Extremely Hot White Dwarf in Nova V4743 Sgr

Cited by in corpus (12)

• Optically thick outflows in ultraluminous supersoft sources
• M31N 2008-12a - the remarkable recurrent nova in M31: Pan-chromatic observations of the 2015 eruption
• XMM-Newton X-ray and UV observations of the fast nova V2491 Cyg during the supersoft source phase
• Obscuration effects in Super-Soft-Source X-ray spectra
• From X-ray dips to eclipse: Witnessing disk reformation in the recurrent nova USco
• Population of post-nova supersoft X-ray sources
• The Super-Soft Source Phase of the recurrent nova V3890 Sgr
• X-ray Study of Rekindled Accretion in the Classical Nova V2491 Cygni
• The complications of learning from Super Soft Source X-ray spectra
• Chandra observations of nova KT Eridani in outburst
• Application of hydrostatic local thermodynamic equilibrium atmosphere models to interpretations of supersoft X-ray source spectra
• Soft X-ray emission from the classical nova AT 2018bej