Abstract:
Galactic black hole candidate GX 339-4 underwent several outbursting phases in the past two and a half decades at
irregular intervals of 2–3 years. The nature of these outbursts in terms of the duration, number of peaks, maximum
peak intensity, and so on varies. We present a possible physical reason behind the variation of the outbursts. From
a physical point of view, if the supply of matter from the companion is roughly constant, the total energy released
in an outburst is expected to be proportional to the quiescent period prior to the outburst when the matter is
accumulated. We use archival data of RXTE/ASM from 1996 January to 2011 June and of MAXI/GSC from
2009 August to 2020 July. Five initial outbursts of GX 339-4 between 1997 and 2011 were observed by ASM and
showed a good linear relation between the accumulation period and the amount of energy released in each outburst,
but the outbursts after 2013 behaved quite differently. The 2013, 2017–2018, and 2018–2019 outbursts were of
short duration and incomplete or “failed” in nature. We suggest that the matter accumulated during the quiescent
periods prior to these outbursts was not cleared through accretion due to a lack of viscosity. The leftover matter
was cleared in the very next outbursts. Our study thus sheds light on long-term accretion dynamics in outbursting
sources.
