Continued birghtening of GX 339-4 in X-rays
ATel #236; T. Belloni (INAF-OAB Merate), J. Homan (MIT), W. Cui (Purdue U.), J. Swank (NASA/GSFC)
on 16 Feb 2004; 22:54 UT
Credential Certification: Jeroen Homan (homan@merate.mi.astro.it)
Subjects: X-ray, Binary, Black Hole, Transient
Referred to by ATel #: 240, 243
A 4.4 ks observation of GX 339-4 with the Rossi X-ray Timing Explorer
(RXTE) on Feb. 14 showed that the source is still brightening (see ATEL
#231). The average net count rate in the Proportional Counter Array (PCA) was
~20 cts/s/unit (compared to ~1 cts/s/unit on Feb 1 and ~6 cts/s/unit on
Feb 6), and varied between ~5 and ~60 cts/s/unit. The energy spectrum of the
combined data from the PCA and the High-Energy X-ray Timing Experiment
(HEXTE) can be approximated by a power law with photon index ~1.5. We
measure an unabsorbed 3-100 keV flux of ~8e-10 ergs/cm^2/s. Timing
analysis of the PCA data shows strong band-limited noise with a 0.001-10
Hz fractional rms of ~47% with a break frequency around 7 mHz.
Observations at other wavelengths are encouraged.
