Please use this identifier to cite or link to this item:
Title: Unveiling Vela: time variability of interstellar lines in the direction of the Vela supernova remnant – II. Na D and Ca ii
Authors: Kameswara Rao, N
Lambert, D. L
Reddy, A. B. S
Gupta, R
Muneer, S
Singh, H. P
Keywords: ISM: clouds;ISM: kinematics and dynamics;ISM: lines and bands;ISM: supernova remnants
Issue Date: May-2017
Publisher: Oxford University Press on behalf of the Royal Astronomical Society
Citation: Monthly Notices of the Royal Astronomical Society, Vol. 466, No. 4, pp. 1186-1192
Abstract: In a survey conducted between 2011 and 2012 of interstellar Na i D line profiles in the direction of the Vela supernova remnant (SNR), a few lines of sight showed dramatic changes in low-velocity absorption components with respect to profiles from 1993 to 1994 reported by Cha & Sembach. Three stars – HD 63578, HD 68217 and HD 76161 – showed large decrease in strength over the 1993–2012 interval. HD 68217 and HD 76161 are associated with the Vela SNR whereas HD 63578 is associated with γ2 Velorum wind bubble. Here, we present high spectral resolution observations of Ca ii K lines obtained with the Southern African Large Telescope towards these three stars along with simultaneous observations of Na i D lines. These new spectra confirm that the Na D interstellar absorption weakened drastically between 1993–1994 and 2011–2012 but show for the first time that the Ca ii K line is unchanged between 1993–1994 and 2015. This remarkable contrast between the behaviour of Na D and Ca ii K absorption lines is a puzzle concerning gas presumably affected by the outflow from the SNR and the wind from γ2 Velorum.
Description: Restricted Access
ISSN: 1365-2966
???metadata.dc.rights???: © Royal Astronomical Society
Appears in Collections:IIAP Publications

Files in This Item:
File Description SizeFormat 
Unveiling Vela time variability.pdfRestricted Access619.52 kBAdobe PDFView/Open    Request a copy

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.