Journal Article

Jet X-Ray Properties of EXO 1846-031 During Its 2019 Outburst

Nath, Sujoy Kumar, Chang, Hsiang-Kuang, Bhowmick, Riya, Debnath, Dipak

2025

Overview

The Galactic X-ray transient EXO 1846-031 was first discovered during an outburst in 1985 by the EXOSAT mission. The source remained in a quiescent state for nearly 34 years after the first outburst. The source started its second outburst on 23 July 2019. We studied the accretion flow properties using the Two Component Advective Flow (TCAF) paradigm of this 2019 outburst. During the outburst, the source went through all the four spectral states, though, due to data constraints, it was not possible to define the date of the state transitions during the declining intermediate states. During this outburst, the black hole candidate (BHC) exhibited significant jet activity. In the TCAF solution, the model normalization is expected to remain constant for a given source. Therefore, any need for a significantly different normalization to achieve a better spectral fit suggests the presence of additional X-ray contributions from components not accounted for in the current TCAF model fit’s file. By comparing with the expected normalization, we estimate the X-ray contribution originating from jets and outflows. We further analyze the origin of the jet. Our analysis shows that, on some days, up to ∼92% of the total X-ray flux originates from the base of the jet itself.

• Publisher: MDPI AG
• Subject: accretion / accretion discs / Accretion disks / Analysis / Astronomical research / binaries / black holes / Black holes (Astronomy) / EXO 1846-031 / Radiation / Viscosity / X-rays