0000000000293614
AUTHOR
James Miller-jones
showing 4 related works from this author
On the nature of the soft γ-ray emission in the hard state of the black hole transient GRS 1716-249
2020
The black hole transient GRS 1716-249 was monitored from the radio to the gamma-ray band during its 2016-2017 outburst. This paper focuses on the Spectral Energy Distribution (SED) obtained in 2017 February-March, when GRS 1716-249 was in a bright hard spectral state. The soft gamma-ray data collected with the INTEGRAL/SPI telescope show the presence of a spectral component which is in excess of the thermal Comptonisation emission. This component is usually interpreted as inverse Compton emission from a tiny fraction of non-thermal electrons in the X-ray corona. We find that hybrid thermal/non-thermal Comptonisation models provide a good fit to the X/gamma-ray spectrum of GRS 1716-249. The …
Linking Jet Emission, X‐Ray States, and Hard X‐Ray Tails in the Neutron Star X‐Ray Binary GX 17 \documentclass{aastex} \usepackage{amsbsy} \usepackag…
2007
We present the results from simultaneous radio (Very Large Array) and X-ray (Rossi-X-ray Timing Explorer) observations of the Z-type neutron star X-ray binary GX~17+2. The aim is to assess the coupling between X-ray and radio properties throughout its three rapidly variable X-ray states and during the time-resolved transitions. These observations allow us, for the first time, to investigate quantitatively the possible relations between the radio emission and the presence of the hard X-ray tails and the X-ray state of the source. The observations show: 1) a coupling between the radio jet emission and the X-ray state of the source, i.e. the position in the X-ray hardness-intensity diagram (HI…
Discovery and Identification of MAXI J1621-501 as a Type I X-Ray Burster with a Super-orbital Period
2019
MAXI J1621-501 is the first Swift/XRT Deep Galactic Plane Survey transient that was followed up with a multitude of space missions (NuSTAR, Swift, Chandra, NICER, INTEGRAL, and MAXI) and ground-based observatories (Gemini, IRSF, and ATCA). The source was discovered with MAXI on 2017 October 19 as a new, unidentified transient. Further observations with NuSTAR revealed 2 Type I X-ray bursts, identifying MAXI J1621-501 as a Low Mass X-ray Binary (LMXB) with a neutron star primary. Overall, 24 Type I bursts were detected from the source during a 15 month period. At energies below 10 keV, the source spectrum was best fit with three components: an absorbed blackbody with kT = 2.3 keV, a cutoff p…
The long outburst of the black hole transient GRS 1716-249 observed in the X-ray and radio band
2018
We present the spectral and timing analysis of X-ray observations performed on the Galactic black hole transient GRS 1716-249 during the 2016-2017 outburst. The source was almost continuously observed with the Neil Gehrels Swift Observatory from December 2016 until October 2017. The X-ray hardness ratio and timing evolution indicate that the source approached the soft state three times during the outburst, even though it never reached the canonical soft spectral state. Thus, GRS 1716-249 increases the number of black hole transients showing outbursts with "failed" state transition. During the softening events, XRT and BAT broadband spectral modeling, performed with thermal Comptonization pl…