The analyses of X-ray emission from classical novae during the outburst stage
have shown that the soft X-ray emission below 1 keV, which is thought to
originate from the photosphere of the white dwarf, is inconsistent with the
simple blackbody model of emission. Thus, ROSAT Position Sensitive
Proportional Counter (PSPC) archival data of the classical novae GQ Mus 1983
(GQ Mus) have been reanalyzed in order to understand the spectral development
in the X-ray wavelengths during the outburst stage. The X-ray spectra are
fitted with the hot white dwarf atmosphere emission models developed for the
remnants of classical novae near the Eddington luminosity. The post-outburst
X-ray spectra of the remnant white dwarf is examined in the context of
evolution on the Hertzsprung-Russell diagram using C-O enhanced atmosphere
models. The data obtained in 1991 August (during the ROSAT All Sky Survey)
indicate that the effective temperature is kT_e<54 eV (<6.2x10^5 K). The 1992
February data show that the white dwarf had reached an effective temperature in
the range 38.3-43.3 eV (4.4-5.1x10^5 K) with an unabsorbed X-ray flux (i.e.,
∼ bolometric flux) between 2.5x10^-9 and 2.3x10^-10 erg s^-1 cm^-2. We
show that the H burning at the surface of the WD had most likely ceased at the
time of the X-ray observations. Only the 1991 August data show evidence for
ongoing H burning.Comment: 17 pages and 3 figures. Accepted to be published in MNRA
