Radio and X-ray monitoring of the accreting millisecond X-ray pulsar IGR J17591-2342 in outburst

Abstract

IGR J17591$-$2342 is a new accreting millisecond X-ray pulsar (AMXP) that was recently discovered in outburst in 2018. Early observations revealed that the source's radio emission is brighter than that of any other known neutron star low-mass X-ray binary (NS-LMXB) at comparable X-ray luminosity, and assuming its likely $\gtrsim 6$ kpc distance. It is comparably radio bright to black hole LMXBs at similar X-ray luminosities. In this work, we present the results of our extensive radio and X-ray monitoring campaign of the 2018 outburst of IGR J17591$-$2342. In total we collected 10 quasi-simultaneous radio (VLA, ATCA) and X-ray (Swift-XRT) observations, which make IGR J17591$-$2342 one of the best-sampled NS-LMXBs. We use these to fit a power-law correlation index $\beta =0.37_{-0.40}^{+0.42}$ between observed radio and X-ray luminosities ( $L_{\mathrm{R}}\propto L_{\mathrm{X}}^{\beta }$). However, our monitoring revealed a large scatter in IGR J17591$-$2342's radio luminosity (at a similar X-ray luminosity, $L_{\mathrm{X}}\sim 10^{36}$ erg s${}^{-1}$, and spectral state), with $L_{\mathrm{R}}\sim 4\times 10^{29}$ erg s${}^{-1}$ during the first three reported observations, and up to a factor of 4 lower $L_{\mathrm{R}}$ during later radio observations. Nonetheless, the average radio luminosity of IGR J17591$-$2342 is still one of the highest among NS-LMXBs, and we discuss possible reasons for the wide range of radio luminosities observed in such systems during outburst. We found no evidence for radio pulsations from IGR J17591$-$2342 in our Green Bank Telescope observations performed shortly after the source returned to quiescence. Nonetheless, we cannot rule out that IGR J17591$-$2342 becomes a radio millisecond pulsar during quiescence.

12 pages, 3 figures, 2 tables, accepted for publication in MNRAS

References in corpus (16)

• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• An online repository of Swift/XRT light curves of GRBs
• A Radio Pulsar/X-ray Binary Link
• Discovery of coherent millisecond X-ray pulsations in Aql X-1
• The radio/X-ray domain of black hole X-ray binaries at the lowest radio luminosities
• Intermittent millisecond X-ray pulsations from the neutron-star X-ray transient SAX J1748.9-2021 in the globular cluster NGC 6440
• A rapidly-changing jet orientation in the stellar-mass black hole V404 Cygni
• General-Relativistic Simulations of Four States of Accretion onto Millisecond Pulsars
• Disk-jet coupling in low-luminosity accreting neutron stars
• Radio monitoring of the hard state jets in the 2011 outburst of MAXI J1836-194
• Prolonged sub-luminous state of the new transitional pulsar candidate CXOU J110926.4-650224
• Jet quenching in the neutron star low-mass X-ray binary 1RXS J180408.9$-$342058
• The luminosity dependence of thermally-driven disc winds in low-mass X-ray binaries
• Indications of non-conservative mass-transfer in AMXPs
• Chandra-HETGS Characterization of an Outflowing Wind in the accreting millisecond pulsar IGR J17591-2342
• The dynamics of Galactic centre pulsars: constraining pulsar distances and intrinsic spin-down

Cited by in corpus (17)

• A new radio census of neutron star X-ray binaries
• Search for continuous gravitational waves from 20 accreting millisecond X-ray pulsars in O3 LIGO data
• Low-Mass X-ray Binaries
• The MAVERIC Survey: Chandra/ACIS Catalog of Faint X-ray sources in 38 Galactic globular clusters
• High-energy characteristics of the accretion-powered millisecond pulsar IGR J17591-2342 during its 2018 outburst
• The Flare-Dominated Accretion Mode of a Radio-Bright Candidate Transitional Millisecond Pulsar
• The MAVERIC Survey: New compact binaries revealed by deep radio continuum observations of the Galactic globular cluster Terzan 5
• The MAVERIC Survey: Variable Jet-Accretion Coupling in Luminous Accreting Neutron Stars in Galactic Globular Clusters
• The accretion/ejection link in the neutron star X-ray binary 4U 1820-30 I: A boundary layer-jet coupling?
• Radio monitoring of transient Be/X-ray binaries and the inflow-outflow coupling of strongly-magnetized accreting neutron stars
• Simultaneous X-ray and radio observations of the transitional millisecond pulsar candidate CXOU J110926.4-650224. The discovery of a variable radio counterpart
• The MAVERIC survey: A catalogue of radio sources in southern globular clusters from the Australia Telescope Compact Array
• Quasi-Simultaneous Radio/X-ray Observations of the Candidate Transitional Millisecond Pulsar 3FGL J1544.6-1125 During its Low-Luminosity Accretion-Disc State
• AstroSat timing and spectral analysis of the accretion-powered millisecond X-ray pulsar IGR J17591--2342
• Analytical model of millisecond pulsar PSR J0514-4002A
• An unusual type-I X-ray burst from the neutron star X-ray binary IGR J17591-2342: a double-photospheric-radius-expansion burst?
• Multiwavelength study of 1eRASS J085039.9-421151 with eROSITA NuSTAR and X-shooter