Browsing University of Hertfordshire by Title

Now showing items 24029-24048 of 24147

    • X-ray emission from dwarf galaxies: IC 2574 revisited 

      Brinks, E.; Walter, F.; Kerp, J. (2003)

    • X-ray emission from the extended emission-line region of the powerful radio galaxy 3C 171 

      Hardcastle, M.J.; Massaro, F.; Harris, D.E. (2010)
      We present Chandra X-ray observations of the powerful radio galaxy 3C 171, which reveal an extended region of X-ray emission spatially associated with the well-known 10-kpc scale optical emission-line region around the ...

    • X-Ray Emission from the Hot Interstellar medium and Southwest Radio Lobe of the Nearby Radio Galaxy Centaurus A 

      Kraft, R.P.; Vazquez, S.E.; Forman, W.R.; Jones, C.; Murray, S.S.; Hardcastle, M.J.; Worrall, D.M.; Churazov, E. (2003-07)

    • X-ray emission from the nuclei, lobes and hot-gas environments of two FR II radio galaxies 

      Croston, J.H.; Birkinshaw, M.; Hardcastle, M.J.; Worrall, D.M. (2004-09)

    • The X-ray Emission of Low-Power Radio Galaxies 

      Worrall, D.M.; Birkinshaw, M.; Hardcastle, M.J. (Astronomical Society of the Pacific, 2003)
      A low-power radio galaxy generally emits X-rays from a compact X-ray core, its brighter kpc-scale radio jet, and a galaxy atmosphere. The core emission is normally predominantly radio related. The kpc-scale jet emission ...

    • X-ray flare candidates in short gamma-ray bursts 

      Margutti, R.; Chincarini, G.; Bernardini, M.G.; Zaninoni, E.; Margutti, R.; Berger, E.; Soderberg, A.M.; Chincarini, G.; Granot, J.; Guidorzi, C.; Gehrels, N.; Stamatikos, M.; Stamatikos, M.; Zaninoni, E. (2011-11-01)
      We present the first systematic study of X-ray flare candidates in short gamma-ray bursts (SGRBs) exploiting the large 6-year Swift data base with the aim to constrain the physical nature of such fluctuations. We find that ...

    • X-ray groups and clusters of galaxies in the Subaru–XMM Deep Field 

      Finoguenov, A.; Watson, M.; Tanaka, M.; Simpson, C.; Cirasuolo, M.; Dunlop, J.S.; Peacock, J.A.; Farrah, D.; Akiyama, M.; Ueda, Y.; Smolcic, V.; Stewart, G.; Rawlings, S.; van Breukelen, C.; Almaini, O.; Clewley, L.; Bonfield, D.; Jarvis, M.J.; Barr, J.M.; Foucaud, S.; McLure, R.J.; Sekiguchi, K.; Egami, E. (2010)
      We present the results of a search for galaxy clusters in the Subaru–XMM Deep Field (SXDF). We reach a depth for a total cluster flux in the 0.5–2 keV band of 2 × 10−15 erg cm−2 s−1 over one of the widest XMM–Newton ...

    • The X-ray jet and central structure of the active galaxy NGC 315 

      Worrall, D.M.; Birkinshaw, M.; Hardcastle, M.J. (2003-08)
      We report the Chandra detection of resolved X-ray emission of luminosity 3.5 × 1040 ergs s−1 (0.4–4.5 keV) and power-law energy spectral index = 1.5 ± 0.7 from a roughly 10 arcsec length of the north-west radio jet in ...

    • The X-ray jet and halo of PKS 0521-365 

      Birkinshaw, M.; Worrall, D.M.; Hardcastle, M.J. (2002-09)

    • X-Ray Nuclei in Radio Galaxies: Exploring the Roles of Hot and Cold Gas Accretion 

      Evans, D.A.; Hardcastle, M.J.; Croston, J.H. (Astronomical Society of the Pacific, 2008)
      We present results from Chandra and XMM-Newton spectroscopic observations of the nuclei of z < 0.5 radio galaxies and quasars from the 3CRR catalog, and examine in detail the dichotomy in the properties of low- and ...

    • The X-ray nuclei of intermediate-redshift radio sources 

      Hardcastle, M.J.; Evans, D.A.; Croston, J.H. (2006)
      We present a Chandra and XMM-Newton spectral analysis of the nuclei of the radio galaxies and radio-loud quasars from the 3CRR sample in the redshift range 0.1 < z < 0.5. In the range of radio luminosity sampled by these ...

    • X-ray observations of low-power radio galaxies from the B2 catalogue 

      Canosa, C.M.; Worrall, D.M.; Hardcastle, M.J.; Birkinshaw, M. (1999)
      We present an analysis of X-ray data, taken with ROSAT, for a well defined sample of low-power radio galaxies from the Bologna B2 catalogue. Where possible, the HRI has been used in order to take advantage of the higher ...

    • X-Ray Observations of Superbubbles in Dwarf Galaxies 

      Brinks, E.; Walter, F.; Kerp, J. (Revista Mexicana de Astronom a y Astrof sica, 2000)
      There is plenty of evidence from neutral hydrogen observations for a violent interstellar medium, dominated by hot-plasma filled superbubbles. However, there are few direct observations of their thermal X-ray emission from ...

    • X-ray properties of the Youngest Radio Sources and their Environments 

      Siemiginowska, Aneta; Sobolewska, Malgosia; Migliori, Giulia; Guainazzi, Matteo; Hardcastle, M.J.; Ostorero, Luisa; Stawarz, Lukasz (2016-05-23)
      We present the first results from our X-ray study of young radio sources classified as compact symmetric objects (CSOs). Using the Chandra X-ray Observatory we observed six CSOs for the first time in X-rays, and re-observed ...

    • The X-ray Ribs Within the Cocoon Shock of Cygnus A 

      Duffy, R. T.; Worrall, D. M.; Birkinshaw, M.; Nulsen, P. E. J.; Wise, M. W.; Vries, M. N. de; Snios, B.; Mathews, W. G.; Perley, R. A.; Hardcastle, M. J.; Rafferty, D. A.; McNamara, B. R.; Edge, A. C.; McKean, J. P.; Carilli, C. L.; Croston, J. H.; Godfrey, L. E. H.; Laing, R. A. (2018-06-01)
      We use new and archival Chandra observations of Cygnus A, totalling ~1.9Ms, to investigate the distribution and temperature structure of gas lying within the projected extent of the cocoon shock and exhibiting a rib-like ...

    • The X-ray spectra of the luminous LMXBs in NGC 3379 : field and globular cluster sources 

      Brassington, Nicola; Fabbiano, G.; Blake, S.; Zezas, A.; Angelini, L.; Davies, R. L.; Gallagher, J.; Kalogera, V.; Kim, D. -W.; King, A. R.; Kundu, A.; Trinchieri, G.; Zepf, S. (2010-12)
      From a deep multi-epoch Chandra observation of the elliptical galaxy NGC 3379 we report the spectral properties of eight luminous LMXBs (L-X > 1.2 x 10(38) erg s(-1)). We also present a set of spectral simulations, produced ...

    • X-Ray Studies of Radio-Loud AGN 

      Mingo Fernandez, Beatriz (University of Hertfordshire, 2013-05-24)
      In this thesis I use X-ray observations to study the cores and extended structures of radio-loud AGN, to determine their structure, accretion properties and the impact they have on their surroundings. I use new Chandra ...

    • An X-Ray Study of Magnetic Field Strengths and Particle Content in the Lobes of FR II Radio Sources 

      Croston, J.H.; Hardcastle, M.J.; Harris, D.E.; Belsole, E.; Birkinshaw, M.; Worrall, D.M. (2005-05)

    • An X-ray survey of the 2 Jy sample - II. X-ray emission from extended structures 

      Mingo, B.; Hardcastle, M. J.; Ineson, J.; Mahatma, V.; Croston, J. H.; Dicken, D.; Evans, D. A.; Morganti, R.; Tadhunter, C.N. (2017-09-21)
      The 2 Jy sample is a survey of radio galaxies with flux densities above 2 Jy at 2.7 GHz. As part of our ongoing work on the southern subset of 2 Jy sources, in paper I of this series we analysed the X-ray cores of the ...

    • An X-ray survey of the 2 Jy sample-I : Is there an accretion mode dichotomy in radio-loud AGN? 

      Mingo, B.; Hardcastle, M.J.; Croston, J.H.; Dicken, D.; Evans, D. A.; Morganti, R.; Tadhunter, C. (2014-05-01)
      We carry out a systematic study of the X-ray emission from the active nuclei of the 0.02 < z< 0.7 2 Jy sample, using Chandra and XMM-Newton observations.We combine our results with those from mid-infrared, optical emission-line ...