Insight-HXMT observations of a possible fast transition from jet to wind dominated state during a huge flare of GRS~1915+105

Abstract

We present the analysis of the brightest flare that was recorded in the \emph{Insight}-HMXT data set, in a broad energy range (2$-$200 keV) from the microquasar GRS~1915+105 during an unusual low-luminosity state. This flare was detected by \emph{Insight}-HXMT among a series of flares during 2 June 2019 UTC 16:37:06 to 20:11:36, with a 2-200 keV luminosity of 3.4$-$7.27$\times 10^{38}$ erg s${}^{-1}$. Basing on the broad-band spectral analysis, we find that the flare spectrum shows different behaviors during bright and faint epochs. The spectrum of the flare can be fitted with a model dominated by a power-law component. Additional components show up in the bright epoch with a hard tail and in the faint epoch with an absorption line $\sim$ 6.78 keV. The reflection component of the latter is consistent with an inner disk radius $\sim$ 5 times larger than that of the former. These results on the giant flare during the "unusual" low-luminosity state of GRS~1915+105 may suggest that the source experiences a possible fast transition from a jet-dominated state to a wind-dominated state. We speculate that the evolving accretion disk and the large-scale magnetic field may play important roles in this peculiar huge flare.

References in corpus (11)

• X-ray Properties of Black-Hole Binaries
• The role of the reflection fraction in constraining black hole spin
• Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite
• A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass
• The Medium Energy (ME) X-ray telescope onboard the Insight-HXMT astronomy satellite
• The obscured X-ray binaries V404 Cyg, Cyg X-3, V4641 Sgr, and GRS 1915+105
• A NICER View of a Highly-Absorbed Flare in GRS 1915+105
• The large-scale magnetic field of a thin accretion disk with outflows
• Disk-Wind Connection During the Heartbeats of GRS 1915+105
• The impact of thermal winds on the outburst lightcurves of black hole X-ray binaries
• The power of the jets accelerated by the coronal magnetic field

Cited by in corpus (12)

• NICER, NuSTAR and Insight-HXMT views to the newly discovered black hole X-ray binary Swift J1727.8--1613
• Observations of a black hole X-ray binary indicate formation of a magnetically arrested disk
• The large-scale magnetic field advected in the corona of a thin accretion disk
• The disk wind in GRS 1915+105 as seen by Insight-HXMT
• The dynamical structure of the outflows driven by a large-scale magnetic field
• Global Accretion Properties of Black Hole X-Ray Binaries: A Phenomenological Perspective
• Time resolved spectroscopy of a GRS 1915+105 flare during its unusual low state using AstroSat
• Dimming GRS 1915+105 observed with NICER and Insight--HXMT
• Likely detection of magnetic field related LFQPO in the soft X-ray re-brightening of GRS~1915+105
• A possible jet and corona configuration for Swift J1727.8--1613 during the hard state
• Exploring the accretion-ejection geometry of GRS 1915+105 in the obscured state with future X-ray spectro-polarimetry
• Test the growth models of black hole by jointing LIGO and Insight-HXMT observations