Investigation of the Outburst Activity of the Black Hole Candidate GRS 1739-278

• Main Authors: Bykov, Sergey D, Filippova, Ekaterina V, Mereminskiy, Ilya A, Semena, Andrey N, Lutovinov, Alexander A
• Format: Journal Article
• Language: English
• Published: 25-04-2019
• Subjects: Physics - High Energy Astrophysical Phenomena
• DOI: 10.48550/arxiv.1904.11535

Astronomy Letters, 2019, Vol. 45, No. 3, pp. 127-146 We have performed a joint spectral and timing analysis of the outburst of GRS
1739-278 in 2014 based on Swift and INTEGRAL data. We show that during this
outburst the system exhibited both intermediate states: hard and soft. Peaks of
quasi-periodic oscillations (QPOs) in the frequency range 0.1-5 Hz classified
as type-C QPOs have been detected from the system. Using Swift/BAT data we show
that after the 2014 outburst the system passed to the regime of mini-outburst
activity: apart from the three mini-outbursts mentioned in the literature, we
have detected four more mini-outbursts with a comparable (~20 mCrab) flux in
the hard energy band (15-50 keV). We have investigated the influence of the
accretion history on the outburst characteristics: the dependence of the peak
flux in the hard energy band in the low/hard state on the time interval between
the current and previous peaks has been found (for the outbursts during which
the system passed to the high/soft state).