Browsing by Subject "x-ray-emission"

Now showing items 1-7 of 7

    • A search for optical bursts from the rotating radio transient j1819−1458 with ultracam - ii. simultaneous ultracam-lovell telescope observations 

      Dhillon, V. S.; Keane, E. F.; Marsh, T. R.; Stappers, B. W.; Copperwheat, C. M.; Hickman, R. D. G.; Jordan, C. A.; Kerry, P.; Kramer, M.; Littlefair, S. P.; Lyne, A. G.; Mignani, R. P.; Shearer, A. (Oxford University Press (OUP), 2011-05-18)
      The rotating radio transient (RRAT) J1819-1458 exhibits similar to 3ms bursts in the radio every similar to 3 min, implying that it is visible for only similar to 1 s per day. Assuming that the optical light behaves in a ...

    • Confirmation of the electron cyclotron maser instability as the dominant source of radio emission from very low mass stars and brown dwarfs 

      Hallinan, G.; Antonova, A.; Doyle, J. G.; Bourke, S.; Lane, C.; Golden, A. (IOP Publishing, 2008-09-01)
      We report on radio observations of the M8.5 dwarf LSR J1835+3259 and the L3.5 dwarf 2MASS J00361617+ 1821104, which provide the strongest evidence to date that the electron cyclotron maser instability is the dominant ...

    • Extreme ultraviolet explorerobservations of psr b0656+14 

      Edelstein, Jerry; Seon, Kwang‐Il; Golden, Aaron; Min, Kyoung‐Wook (IOP Publishing, 2000-08-20)
      The pulsar PSR B0656 + 14 has been observed at gamma-ray, X-ray, EUV, and optical energies. These data are consistent with emission originating from a thermal stellar surface augmented by a hot, thermal "polar-cap" ...

    • Modelling the radio pulses of an ultracool dwarf 

      Yu, S.; Hallinan, G.; Doyle, J. G.; MacKinnon, A. L.; Antonova, A.; Kuznetsov, A.; Golden, A.; Zhang, Z. H. (EDP Sciences, 2010-11-30)
      Context. Recently, unanticipated magnetic activity in ultracool dwarfs (UCDs, spectral classes later than M7) has emerged from a number of radio observations. The highly (up to 100%) circularly polarized nature and high ...

    • Rotational modulation of the radio emission from the m9 dwarf tvlm 513−46546: broadband coherent emission at the substellar boundary? 

      Hallinan, G.; Antonova, A.; Doyle, J. G.; Bourke, S.; Brisken, W. F.; Golden, A. (IOP Publishing, 2006-12-10)
      The Very Large Array was used to observe the ultracool rapidly rotating M9 dwarf TVLM 513-46546 simultaneously at 4.88 and 8.44 GHz. The radio emission was determined to be persistent, variable, and periodic at both ...

    • The creation of the helix planetary nebula (ngc 7293) by multiple events 

      Meaburn, J.; Boumis, P.; López, J. A.; Harman, D. J.; Bryce, M.; Redman, M. P.; Mavromatakis, F. (Oxford University Press (OUP), 2005-07-01)
      A deep continuum-subtracted image of NGC 7293 has been obtained in the light of the H alpha+[N II] emission lines. New images of two filamentary halo structures have been obtained, and a possible detection of a collimated ...

    • Volume-limited radio survey of ultracool dwarfs 

      Antonova, A.; Hallinan, G.; Doyle, J. G.; Yu, S.; Kuznetsov, A.; Metodieva, Y.; Golden, A.; Cruz, K. L. (EDP Sciences, 2013-01-01)
      Aims. We aim to increase the sample of ultracool dwarfs studied in the radio domain to allow a more statistically significant understanding of the physical conditions associated with these magnetically active objects. Methods. ...