Transition to a hard state of 1RXP J130159.6-635806
ATel #251; M. Chernyakova (ISDC, Geneva), P. Shtykovsky (IKI, Moscow), A. Lutovinov (IKI, Moscow), M. Revnivtsev (IKI, Moscow/MPA, Garching), T. Courvoisier (ISDC, Geneva), R. Walter (ISDC, Geneva), S. Shaw (ISDC, Geneva), G. Cocco (CNR, Bologna), D. Attie (CEA/Saclay), C. Budtz-Jorgensen (DSRI, Copenhagen), W. Hermsen (SRON, Utrecht), R. Much (ESTEC, Noordwijk)
on 14 Mar 2004; 11:22 UT
Credential Certification: Masha Chernyakova (Masha.Chernyakova@obs.unige.ch)
Subjects: X-ray, Transient
We report a detection of a transition to a hard state
during the possible outburst of a ROSAT source 1RXP J130159.6-635806,
located approximately 10 arc minutes from PSR 1259-63.
Source was observed with XMM-Newton observatory on 29 January 2004.
In the 1-10 keV energy band its intensity (~1.4E-10 ergs/cm2/s ) was
found to be approximately order of magnitude higher than was observed with
ASCA on Aug.13, 1995. The source spectrum in the 0.5-10 keV energy band
can be described by a simple powerlaw with photon index ~0.5 and
interstellar absorption ~2.E22 cm^{-2}. Comparison with ASCA
results (photon index ~2.5) have shown that the source spectrum is now
much harder with approximately the same value of the absorption.
This fact points probably on a transition to the hard state.
Several days later, on 7 February 2004, the source was observed with the
INTEGRAL observatory during the routine galactic plane scan. The
source was detected in the 18-60 keV energy band with intensity of 11 mCrab.
Note that it was a first detection of this source in hard energies, that
supports an assumption of the transition to a hard state. In
the next INTEGRAL observation of this region on 19 February 2004 the source
was no longer detected at a significant level.
