Browsing University of Hertfordshire by Author "Graham, Matthew J."

Now showing items 1-4 of 4

    • Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars 

      Connor, Thomas; Stern, Daniel; Krone-Martins, Alberto; Djorgovski, S. G.; Graham, Matthew J.; Walton, Dominic J.; Delchambre, Ludovic; Ducourant, Christine; Teixeira, Ramachrisna; Campion, Jean-François Le; Brok, Jakob Sebastian den; Dobie, Dougal; Galluccio, Laurent; Jalan, Priyanka; Klioner, Sergei A.; Klüter, Jonas; Mahabal, Ashish A.; Negi, Vibhore; Nierenberg, Anna; Petit, Quentin; Jr, Sergio Scarano; Slezak, Eric; Sluse, Dominique; Spíndola-Duarte, Carolina; Surdej, Jean; Wambsganss, Joachim (2022-03-03)
      We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 ≲ z ≲ 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3-8.0 keV fluxes F 0.3-8.0 ≳ 5 ×10-14 ...

    • 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 ...

    • The Tidal Disruption Event AT2021ehb : Evidence of Relativistic Disk Reflection, and Rapid Evolution of the Disk-Corona System 

      Yao, Yuhan; Lu, Wenbin; Guolo, Muryel; Pasham, Dheeraj R.; Gezari, Suvi; Gilfanov, Marat; Gendreau, Keith C.; Harrison, Fiona; Cenko, S. Bradley; Kulkarni, S. R.; Miller, Jon M.; Walton, Dominic J.; García, Javier A.; Velzen, Sjoert van; Alexander, Kate D.; Miller-Jones, James C. A.; Nicholl, Matt; Hammerstein, Erica; Medvedev, Pavel; Stern, Daniel; Ravi, Vikram; Sunyaev, R.; Bloom, Joshua S.; Graham, Matthew J.; Kool, Erik C.; Mahabal, Ashish A.; Masci, Frank J.; Purdum, Josiah; Rusholme, Ben; Sharma, Yashvi; Smith, Roger; Sollerman, Jesper (2022-09-15)
      We present X-ray, UV, optical, and radio observations of the nearby ($\approx78$ Mpc) tidal disruption event (TDE) AT2021ehb/ZTF21aanxhjv during its first 430 days of evolution. AT2021ehb occurs in the nucleus of a galaxy ...