Cooling of Accretion Disc Coronae by Type I X-ray Bursts

Abstract

Understanding the persistent emission is crucial for studying type I X-ray bursts, which provide insight into neutron star properties. Although accretion disc coronae appear to be common in many accreting systems, their fundamental properties remain insufficiently understood. Recent work suggests that Type I X-ray bursts from accreting neutron stars provide an opportunity to probe the characteristics of coronae. Several studies have observed hard X-ray shortages from the accretion disk during an X-ray burst implying strong coronal cooling by burst photons. Here, we use the plasma emission code EQPAIR to study the impact of X-ray bursts on coronae, and how the coronal and burst properties affect the coronal electron temperatures and emitted spectra. Assuming a constant accretion rate during the burst, our simulations show that soft photons can cool coronal electrons by a factor of $\gtrsim 10$ and cause a reduction of emission in the $30$-$50$ keV band to $\lesssim 1\%$ of the pre-burst emission. This hard X-ray drop is intensified when the coronal optical depth and aspect ratio is increased. In contrast, depending on the properties of the burst and corona, the emission in the $8$-$24$ keV band can either increase, by a factor of $\gtrsim 20$, or decrease, down to $\lesssim 1\%$ of the pre-burst emission. An increasing accretion rate during the X-ray burst reduces the coronal cooling effects and the electron temperature drop can be mitigated by $\gtrsim 60\%$. These results indicate that changes of the hard X-ray flux during an X-ray burst probe the geometrical properties of the corona.

arXiv comment12 pages, 7 figures, MNRAS in press

References in corpus (38)

• Modelling the behaviour of accretion flows in X-ray binaries
• Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
• The Mass and Radius of the Neutron Star in EXO 1745-248
• Radiative Processes, Spectral States and Variability of Black-Hole Binaries
• Hard X-ray Emission From Low Mass X-ray Binaries
• Neutron star stiff equation of state derived from cooling phases of the X-ray burster 4U 1724-307
• Correlations between X-ray and radio spectral properties of accreting black holes
• Evidence for accretion rate change during type I X-ray bursts
• Models of Type I X-Ray Bursts in 4U 1820-30
• The X-ray spectrum of the atoll source 4U 1608-52
• Evidence for enhanced persistent emission during sub-Eddington thermonuclear bursts
• Broad-band spectra of Cyg X-1 and correlations between spectral characteristics
• The Evolution of the Accretion Disk around 4U 1820-30 During a Superburst
• Accretion disks and coronae in the X-ray flashlight
• The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-ray Background
• Spectral Fits to the 1999 Aql X-1 Outburst Data
• A bright thermonuclear X-ray burst simultaneously observed with Chandra and RXTE
• Reflection spectra from an accretion disc illuminated by a neutron star X-ray burst
• Low-mass X-ray binaries in the bulge of the Milky Way
• On the Dynamics of Suddenly Heated Accretion Disks around Neutron Stars
• NICER Observes the Effects of an X-Ray Burst on the Accretion Environment in Aql X-1
• Time-dependent models of two-phase accretion discs around black holes
• A dichotomy between the hard state spectral properties of black hole and neutron star X-ray~binaries
• Type-I X-ray bursts reveal a fast co-evolving behavior of the corona in an X-ray binary
• The hard X-ray shortages prompted by the clock bursts in GS 1826--238
• Chandra and RXTE Spectra of the Burster GS 1826-238
• Insight-HXMT observations of 4U~1636-536: Corona cooling revealed with single short type-I X-ray burst
• X-ray burst induced spectral variability in 4U 1728-34
• X-ray bursts as a probe of the corona: the case of XRB 4U 1636-536
• Deviations from the Flux-Recurrence Time Relationship in GS 1826-238: Potential Transient Spectral Changes
• The hard X-ray behavior of Aql X-1 during type-I bursts
• Probing the effects of a thermonuclear X-ray burst on the neutron star accretion flow with NuSTAR
• Simulating the Collapse of a Thick Accretion Disk due to a Type I X-ray Burst from a Neutron Star
• Possible hard X-ray shortages in bursts from KS 1731-260 and 4U 1705-44
• Wide band observations of the X-ray burster GS 1826-238
• Burst-induced coronal cooling in GS 1826-24 The clock wagging its tail
• The Physics of Hybrid Thermal/Non-Thermal Plasmas
• Hot Corona Properties of Swift/BAT detected AGN

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• Quenching and recovery of persistent X-ray emission during a superburst in 4U 1820$-$30
• Probing spectral and temporal evolution of the neutron star low-mass X-ray binary 4U 1724-30 with AstroSat
• Radiation Driven Warping of Accretion Discs Due to X-ray Bursts
• Insight-HXMT observations on thermonuclear X-ray bursts from 4U~1608--52 in the low/hard state: the energy-dependant hard X-ray deficit and cooling saturation of the corona
• On the impact of an intermediate duration X-ray burst on the accretion environment in IGR J17062-6143
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