3 research outputs found
From the First Slovak Satellite to High Energy Astrophysics
In 2017 first Slovak satellite skCUBE was launched into space. Thanks to this experience where the all components were developed in-house and worked for the whole duration of the operations, on the basis of this successful mission a spin-off company Spacemanic was established
The peak-flux of GRB 221009A measured with GRBAlpha
The brightest gamma-ray burst ever observed, long-duration GRB 221009A, was
detected by GRBAlpha nano-satellite without saturation. We present light curves
of the prompt emission in 13 energy bands, from 80 keV to 950 keV, and perform
a spectral analysis to calculate the peak flux and peak isotropic-equivalent
luminosity. Since the satellite's attitude information is not available for the
time of this GRB, more than 200 incident directions were probed in order to
find the median luminosity and its systematic uncertainty. We found that the
peak flux in the keV range (observer frame) was
ph cms or
erg cms
and the fluence in the same energy range of the first GRB episode lasting 300
s, which was observable by GRBAlpha, was erg
cm or erg cm for
the extrapolated range of keV. We infer the isotropic-equivalent
released energy of the first GRB episode to be
erg in the
keV band (rest frame at ). The peak isotropic-equivalent luminosity in
the keV range (rest frame) was
erg s and the
bolometric peak isotropic-equivalent luminosity was
erg s (4 s
scale) in the keV range (rest frame). The peak emitted energy is
keV. Our measurement of
is consistent with the Yonetoku relation. It is
possible that, due to the spectral evolution of this GRB and orientation of
GRBAlpha at the peak time, the true values of peak flux, fluence,
, and are even higher. [abridged]Comment: 7 pages, 7 figures, 1 table, accepted for publication in Astronomy &
Astrophysic