New insights on the puzzling LMXB 1RXS J180408.9-342058: the intermediate state, the clocked type-I X-ray bursts and much more

Abstract

1RXS J180408.9--342058 is a low mass X-ray binary hosting a neutron star, which shows X-ray activity at very different mass-accretion regimes, from very faint to almost the Eddington luminosity. In this work, we present a comprehensive X-ray study of this source using data from the Neil Gehrels Swift Observatory, NuSTAR and INTEGRAL/JEM-X. In order to follow the spectral evolution, we analysed the 2015 outburst using Swift data and three Nustar observations. Besides the canonical hard and soft spectral states, we identified the rarely observed intermediate state. This was witnessed by the appeareance of the accretion disk emission in the spectrum (at $k{T}_{\mathrm{disk}}$ $\sim$0.7 keV) and the simultaneous cooling of the hot corona. In addition, we also unveiled a hard tail above 30 keV in this state. In the hard state, a thermal Comptonization model with two seed photons populations ($k{T}_{\mathrm{s},1}\sim 1.5$ keV and $k{T}_{\mathrm{s},2}\sim 0.4$ keV, respectively) and a hot Comptonising plasma, represents the physically best motivated scenario to describe the data. We also estimated a reflection fraction below 20% in all states, while no constraints on the inclination and only lower limits on the inner disk radius could be inferred. Finally, we studied a number of type-I X-ray bursts displayed from the source, one of them at the Eddington limit (observed with JEM-X). Their characteristics, combined with the clocked behaviour observed during the intermediate state, point out H/He composition for the accreted material, which makes unlikely the helium dwarf nature for the companion.

Accepted for publication in MNRAS

References in corpus (21)

• Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
• Six new candidate ultracompact X-ray binaries
• Black hole-like hysteresis and accretion states in neutron star low mass X-ray binaries
• Optical spectroscopy and photometry of SAX J1808.4-3658 in outburst
• Average hard X-ray emission from NS LMXBs: Observational evidence of different spectral states in NS LMXBs
• The behavior of subluminous X-ray transients near the Galactic center as observed using the X-ray telescope aboard Swift
• A new Comptonization model for low-magnetized accreting neutron stars in low mass X-ray binaries
• An in-depth study of a neutron star accreting at low Eddington rate: On the possibility of a truncated disk and an outflow
• Spectral variability of GX 339-4 in a hard-to-soft state transition
• The nature of very faint X-ray binaries; hints from light curves
• Suzaku broad-band spectrum of 4U 1705-44: Probing the Reflection component in the hard state
• BeppoSAX observation of 4U 1705-44: detection of hard X-ray emission in the soft state
• XMMU J174716.1-281048: a "quasi-persistent" very faint X-ray transient?
• The puzzling source IGR J17361-4441 in NGC 6388: a possible planetary tidal disruption event
• Disk reflection and a possible disk wind during a soft X-ray state in the neutron star low-mass X-ray binary 1RXS J180408.9-342058
• Study of the reflection spectrum of the accreting neutron star GX 3+1 using XMM-Newton and INTEGRAL
• INTEGRAL spectral variability study of the atoll 4U 1820-30: first detection of hard X-ray emission
• Disc-Jet coupling in the LMXB 4U1636-53 from INTEGRAL
• Spectral analysis of the dipping LMXB system XB 1916-053
• Outbursts in ultracompact X-ray binaries
• A $\sim$100 mHz QPO in the X-ray emission from IGR J17361-4441

Cited by in corpus (17)

• Science objectives of the Einstein Probe mission
• Polarization properties of weakly magnetized Neutron Stars in Low Mass X-ray Binaries
• The Galactic LMXB Population and the Galactic Centre Region
• Outflows and spectral evolution in the eclipsing AMXP SWIFT J1749.4-2807 with NICER, XMM-Newton and NuSTAR
• Reflection component in the Bright Atoll Source GX 9+9
• The accretion/ejection link in the neutron star X-ray binary 4U 1820-30 I: A boundary layer-jet coupling?
• Detection of Millihertz Quasi-Periodic Oscillations in the X-Ray Binary 1RXS J180408.9$-$342058
• Testing jet geometries and disk-jet coupling in the neutron star LMXB 4U 0614+091 with the internal shocks model
• Catalog of outbursts of neutron star LMXBs
• Partially accreted crusts of neutron stars
• Quasi-simultaneous Integral, Swift, And Nustar Observations Of The New X-ray Clocked Burster 1rxsj180408.9-342058
• Fe K$\alpha$ and Fe K$\beta$ line detection in the NuSTAR spectrum of the ultra-bright Z-source Scorpius X-1
• Investigating the nature and properties of MAXI J1810-222 with radio and X-ray observations
• Spectral analysis of the AMXP IGR J17591-2342 during its 2018 outburst
• Probing spectral and temporal evolution of the neutron star low-mass X-ray binary 4U 1724-30 with AstroSat
• AstroSat observation of rapid Type-I thermonuclear burst from the low mass X-ray binary GX 3+1
• Time Domain Astronomy with the THESEUS Satellite