Estimated Distance to HETE J1900.1-2455
ATel #534; N. Kawai (TiTek) and M. Suzuki (RIKEN) for the HETE Team
on 22 Jun 2005; 20:17 UT
Credential Certification: Edward Morgan (ehmorgan@mit.edu)
Subjects: Binary, Neutron Star, Pulsar
Referred to by ATel #: 1098
We have performed further analyses of the initial X-ray outburst of
HETE J1900.1-2455 reported in Atel #516 and GCN Circular #3548. With
time-resolved spectral analysis, we find that its spectrum is consistent
with a blackbody throughout the burst for a duration of 30 seconds.
For the first 12 seconds, the bolometric flux stayed almost constant at
9 x 10^-8 erg/s/cm^2 while the spectral temperature dropped in
the middle. The temperature reached a peak at 2.4 keV, and then
gradually decreased. These features are all consistent with a type-I
X-ray burst with photospheric expansion. If we take the ceiling
energy flux as due to the Eddington limit of a neutron star with a
mass of 1.4 solar mass and He atmosphere, the distance to the source
is estimated as 5 kpc.
