Detection of Aql X-1 in Hard X-Ray State
ATel #259; S. V. Molkov, A. A. Lutovinov (IKI, Moscow), A. M. Cherepashchuk (SAI, Moscow), R. A. Sunyaev (IKI, Moscow; MPA Garching)
on 26 Mar 2004; 21:10 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Sergei Molkov (molkov@hea.iki.rssi.ru)
Subjects: X-ray, Gamma Ray, Request for Observations, Binary, Neutron Star, Transient
We report a detection of Aql X-1 in the unusual hard spectral
state. The source was significantly detected up to 150 keV
with INTEGRAL on 24-25 March, 2004 during the Sagitarius
Arm Tangent observations. Its spectrum can be described
by a simple powerlaw with the photon index of ~2.1 and flux of
~35 mCrab in both 18-60 and 60-120 keV energy bands.
We encourage the follow-up observations in different wavelengths.