Browsing University of Hertfordshire by Author "Brightman, Murray"

Now showing items 1-11 of 11

    • An 8.56 keV absorption line in the hyperluminous X-ray source in NGC 4045: Ultra-fast outflow or cyclotron line? 

      Brightman, Murray; Kosec, Peter; Fürst, Felix; Earnshaw, Hannah; Heida, Marianne; Middleton, Matthew J; Stern, Daniel; Walton, Dominic J (2022-04-21)
      We report on the discovery of an absorption line at $E=8.56^{+0.05}_{-0.11}$ keV detected with a significance of $>3.3\sigma$ in the NuSTAR and XMM-Newton spectra of a newly discovered hyperluminous X-ray source (HLX, ...

    • An 8.56 keV Absorption Line in the Hyperluminous X-Ray Source in NGC 4045: Ultrafast Outflow or Cyclotron Line? 

      Brightman, Murray; Kosec, Peter; Fürst, Felix; Earnshaw, Hannah; Heida, Marianne; Middleton, Matthew J; Stern, Daniel; Walton, Dominic J (2022-04-21)
      We report on the discovery of an absorption line at E=8.56−0.11+0.05 keV detected with a significance of >3.3σ in the NuSTAR and XMM-Newton spectra of a newly discovered hyperluminous X-ray source (L X > 1041 erg s−1) in ...

    • Evolution of the spin, spectrum and super-orbital period of the ultraluminous X-ray pulsar M51 ULX7 

      Brightman, Murray; Bachetti, Matteo; Earnshaw, Hannah; Fürst, Felix; Heida, Marianne; Israel, Gian Luca; Pike, Sean; Stern, Daniel; Walton, Dominic J (2022-01-21)
      M51 ULX7 is among a small group of known ultra luminous X-ray pulsars (ULXPs). The neutron star powering the source has a spin period of 2.8 s, orbits its companion star with a period of 2 days, and a super orbital period ...

    • The high energy X-ray probe ( HEX-P ): studying extreme accretion with ultraluminous X-ray sources 

      Bachetti, Matteo; Middleton, Matthew J.; Pinto, Ciro; Gúrpide, Andrés; Walton, Dominic J.; Brightman, Murray; Lehmer, Bret; Roberts, Timothy P.; Vasilopoulos, Georgios; Alford, Jason; Amato, Roberta; Ambrosi, Elena; Dai, Lixin; Earnshaw, Hannah P.; El Byad, Hamza; García, Javier A.; Luca Israel, Gian; Jaodand, Amruta; Madsen, Kristin; Maitra, Chandreyee; Mandel, Shifra; Mori, Kaya; Pintore, Fabio; Ohsuga, Ken; Pilia, Maura; Stern, Daniel; Younes, George; Wolter, Anna (2023-11-27)
      Introduction: Ultraluminous X-ray sources (ULXs) represent an extreme class of accreting compact objects: from the identification of some of the accretors as neutron stars to the detection of powerful winds travelling at ...

    • A New Sample of Transient Ultraluminous X-Ray Sources Serendipitously Discovered by Swift/XRT 

      Brightman, Murray; Hameury, Jean-Marie; Lasota, Jean-Pierre; Baldi, Ranieri D.; Bruni, Gabriele; Cann, Jenna M.; Earnshaw, Hannah; Fürst, Felix; Heida, Marianne; Jaodand, Amruta; Lazzarini, Margaret; Middleton, Matthew J.; Walton, Dominic J.; Weaver, Kimberly A. (2023-07-03)
      Ultraluminous X-ray sources (ULXs) are our best laboratories for studying extreme super-Eddington accretion. Most studies of these objects are of relatively persistent sources; however, there is growing evidence to suggest ...

    • NuSTAR Observations of Candidate Subparsec Binary Supermassive Black Holes 

      Saade, M. Lynne; Brightman, Murray; Stern, Daniel; Connor, Thomas; Djorgovski, S. G.; D’Orazio, Daniel J.; Ford, K. E. S.; Graham, Matthew J.; Haiman, Zoltán; Jun, Hyunsung D.; Kammoun, Elias; Kraft, Ralph P.; McKernan, Barry; Vikhlinin, Alexei; Walton, Dominic J. (2024-05-01)
      We present an analysis of NuSTAR X-ray observations of three active galactic nuclei (AGN) that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey ...

    • NuSTAR Observations of Candidate Subparsec Binary Supermassive Black Holes 

      Saade, M. Lynne; Brightman, Murray; Stern, Daniel; Connor, Thomas; Djorgovski, S. G.; D’Orazio, Daniel J.; Ford, K. E. S.; Graham, Matthew J.; Haiman, Zoltán; Jun, Hyunsung D.; Kammoun, Elias; Kraft, Ralph P.; McKernan, Barry; Vikhlinin, Alexei; Walton, Dominic J. (2024-05-01)
      We present an analysis of NuSTAR X-ray observations of three active galactic nuclei (AGN) that were identified as candidate subparsec binary supermassive black hole (SMBH) systems in the Catalina Real-Time Transient Survey ...

    • Orbital Decay in M82 X-2 

      Bachetti, Matteo; Heida, Marianne; Maccarone, Thomas; Huppenkothen, Daniela; Israel, Gian Luca; Barret, Didier; Brightman, Murray; Brumback, McKinley; Earnshaw, Hannah P.; Forster, Karl; Fürst, Felix; Grefenstette, Brian W.; Harrison, Fiona A.; Jaodand, Amruta D.; Madsen, Kristin K.; Middleton, Matthew; Pike, Sean N.; Pilia, Maura; Poutanen, Juri; Stern, Daniel; Tomsick, John A.; Walton, Dominic J.; Webb, Natalie; Wilms, Jörn (2022-10-05)
      M82 X-2 is the first pulsating ultraluminous X-ray source discovered. The luminosity of these extreme pulsars, if isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer ...

    • Probing the nature of the low state in the extreme ultraluminous X-ray pulsar NGC 5907 ULX1 

      Fuerst, F.; Walton, D. J.; Israel, Gian Luca; Bachetti, M.; Barret, D.; Brightman, Murray; Earnshaw, H. P.; Fabian, A.; Heida, M.; Imbrogno, M.; Middleton, M. J.; Pinto, C.; Salvaterra, R.; Roberts, T. P.; Castillo, G. A. Rodríguez; Webb, N. (2023-04-12)
      NGC 5907 ULX1 is the most luminous ultra-luminous X-ray pulsar (ULXP) known to date, reaching luminosities in excess of 1e41 erg/s. The pulsar is known for its fast spin-up during the on-state. Here, we present a long-term ...

    • The Variability Behavior of NGC 925 ULX-3 

      Earnshaw, Hannah P.; Brightman, Murray; Harrison, Fiona A.; Heida, Marianne; Jaodand, Amruta; Middleton, Matthew J.; Roberts, Timothy P.; Walton, Dominic J. (2022-07-25)
      We report the results of a 2019–2021 monitoring campaign with Swift and associated target-of-opportunity observations with XMM-Newton and NuSTAR, examining the spectral and timing behavior of the highly variable ultraluminous ...

    • X-ray absorption and reprocessing in the z ∼ 2.5 lensed quasar 2MASS J1042+1641 

      Walton, Dominic; Reynolds, Mark; Stern, Daniel; Brightman, Murray; Lemon, Cameron (2022-10-19)
      We present new broad-band X-ray observations of the z ∼ 2.5 lensed quasar 2MASS J1042+1641, combining XMM–Newton, Chandra, and NuSTAR to provide coverage of the X-ray spectrum over the 0.3–40 keV bandpass in the observed ...