Abstract:
Taking into account a range of parameters determined from the evolution-
ary models and available observational data, the detailed non-LTE spectrum
for the primary star and the irradiated donor star in the AM CVn system SDSS
J0926+3624 are constructed based on the TLUSTY stellar atmosphere code. The
combined spectrum of the primary and the donor stars along with a multi-color
blackbody spectrum of the accretion disk that reproduces a detailed numerical
model is compared to the SDSS optical spectrum of the system. The photometric
flux of the primary star inferred from eclipse observations is compared with the
synthetic spectrum. The model fit of the two independent observations provides
an upper limit on the distance of the system for different effective temperatures of
the primary. In addition, an upper limit on the combined flux of the disk and the
donor in the infrared region wherein the contribution of the primary is negligible
is also determined. It is shown that the spectrum of a sufficiently cool donor can
exhibit emission lines due to irradiation from a hot primary and the emission
features should be detectable in the infrared even though the contribution of the
flux from the disk dominates. Thus, it is pointed out that infrared observations
of the system would provide important information on the thermal state of the
donor as well as useful insight on the thermal properties of the primary star and
the accretion disk.
