2005/01/13 by K. Werner, J. J. Drake · 1 citation
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Emission spectrum #Line (geometry) #Photosphere #Physics #Spectral line #Stars #Stellar, planetary, and galactic studies #White dwarf #astro-ph
paper · pdf · doi:10.1051/0004-6361:20042057
accepted for publication in A&A
arxiv created 2005/01/13 · openalex publication_date 2005/04/11 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
H 1504+65 is a young white dwarf with an effective temperature of 200 000 K and is the hottest post-AGB star ever analysed with detailed model atmospheres. Chandra LETG+HRC-S spectra have revealed the richest X-ray absorption line spectrum recorded from a stellar photosphere to date. The line forming regions in this extremely hot photosphere produce many transitions in absorption that are also observed in emission in cool star coronae. We have performed a detailed comparison of Chandra spectra of H 1504+65 with those of Procyon and α Cen A and B. State of the art non-LTE model spectra for the hot white dwarf have enabled us to identify a wealth of absorption lines from highly ionized O, Ne and Mg. In turn, these features have allowed us to identify coronal lines whose origins were hitherto unknown.