Browsing Research publications by Author "Forman, W.R."
Now showing items 1-20 of 27
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An active galactic nucleus driven shock in the intracluster medium around the radio galaxy 3C310
Kraft, R.P.; Nulsen, P.E.J.; Forman, W.R.; Jones, C.; Murray, S.S.; Birkinshaw, M.; Worrall, D.M.; Croston, J.H.; Hardcastle, M.J. (2012-04-10)We present results from a 57.6 ks Chandra observation of the cluster gas associated with the fat-double radio galaxy 3C 310. We find a surface brightness discontinuity in the gas outside the southern radio lobe that we ... -
Cen A and its Interaction with the X-ray Emitting Interstellar Medium
Worrall, D.M.; Kraft, R.P.; Birkinshaw, M.; Hardcastle, M.J.; Forman, W.R.; Jones, C.; Murray, S.S. (2004)As the closest radio galaxy, Centaurus A is a powerful laboratory for the X-ray study of radio-emitting structures and their interactions with the hot interstellar medium (ISM). This paper details our interpretation of the ... -
Chandra and XMM-Newton Observations of the Nucleus of Centaurus A
Evans, D.A.; Kraft, R.P.; Worrall, D.M.; Hardcastle, M.J.; Jones, C.; Forman, W.R.; Murray, S.S. (2004-09)We present X-ray spectra of the nucleus of the nearby radio galaxy Centaurus A from observations with the XMM-Newton EPIC CCD cameras (two exposures separated by 12 months) and the Chandra HETGS. For the first time in an ... -
A Chandra observation of 3C 288 - reheating the cool core of a 3 keV cluster from a nuclear outburst at z=0.246
Lal, D.V.; Kraft, R.P.; Forman, W.R.; Hardcastle, M.J.; Jones, C.; Nulsen, P.E.J.; Evans, D.A.; Croston, J.H.; Lee, J.C. (2010)We present results from a 42 ks Chandra/ACIS-S observation of the transitional FR I/FR II radio galaxy 3C 288 at z = 0.246. We detect ~3 keV gas extending to a radius of ~0.5 Mpc with a 0.5-2.0 keV luminosity of 6.6 × 1043 ... -
Chandra Observations of the X-Ray Jet in Centaurus A
Kraft, R.P.; Forman, W.R.; Jones, C.; Murray, S.S.; Hardcastle, M.J.; Worrall, D.M. (2002-04)We present high angular resolution X-ray images and spectra from two Chandra AXAF CCD Imaging Spectrometer (ACIS-I) observations of the X-ray jet in the nearby radio galaxy Cen A. We find that the X-ray emission from the ... -
Evidence for Non-Hydrostatic Gas Motions in the Hot Interstellar Medium of Centaurus A
Kraft, R.P.; Hardcastle, M.J.; Sivakoff, G.R.; Jordan, A.; Nulsen, P.E.J.; Birkinshaw, M.; Forman, W.R.; Jones, C.; Worrall, D.M.; Croston, J.H.; Evans, D.A.; Raychaudhury, S.; Murray, S.S.; Brassington, Nicola; Goodger, Joanna; Harris, W.E.; Juett, A.M.; Sarazin, C.L.; Woodley, K.A. (2008)We present preliminary results from a deep (600 ks) Chandra observation of the hot interstellar medium of the nearby early-type galaxy Centaurus A. We find a surface brightness discontinuity in the gas ~3.5 kpc from the ... -
The fading of two transient ultraluminous x-ray sources to below the stellar mass Eddington limit
Burke, M.J.; Kraft, R.P.; Soria, R.; Maccarone, T. J.; Raychaudhury, S.; Sivakoff, G.R.; Birkinshaw, M.; Brassington, Nicola; Forman, W.R.; Hardcastle, M.J.; Jones, C.; Murray, S.S.; Worrall, D.M. (2013-09-20)We report new detections of the two transient ultraluminous X-ray sources (ULXs) in NGC 5128 from an ongoing series of Chandra observations. Both sources have previously been observed L (2-3) × ∼10 erg s, at the lower end ... -
The gas dynamics of NGC 4472 revealed by XMM-Newton
Kraft, R.P.; Forman, W.R.; Jones, C.; Nulsen, P.E.J.; Hardcastle, M.J.; Raychaudhury, S.; Evans, D.A.; Sivakoff, G.R.; Sarazin, C.L. (2011)We present results from a 100 ks XMM-Newton observation of the hot gas in the Virgo cluster elliptical galaxy NGC 4472. We find a surface brightness discontinuity ∼21 kpc north of the nucleus, consistent with being a contact ... -
Gas sloshing and radio galaxy dynamics in the core of the 3C 449 group
Lal, D.V.; Kraft, R.P.; Randall, S.W.; Forman, W.R.; Nulsen, P.E.J.; Jones, C.; Roediger, E.; Zuhone, J.A.; Hardcastle, M.J.; Croston, J.H. (2013-02-10)We present results from a 140 ks Chandra/ACIS-S observation of the hot gas around the canonical FR I radio galaxy 3C 449. An earlier, shorter 30 ks Chandra observation of the group gas showed an unusual entropy distribution ... -
High resolution X-ray observation and monitoring of the x-ray jet and radio lobes of Centaurus A
Kraft, R.P.; Hardcastle, M.J.; Forman, W.R.; Jones, C.; Murray, S.S.; Worrall, D.M. (2003)We summarize the results of our Chandra AO-1 observations of the X-ray jet in the nearby radio galaxy Centaurus A, and discuss preliminary results from our ongoing monitoring campaign, the first observation of which was ... -
High-energy particle acceleration at the radio-lobe shock of Centaurus A
Croston, J.H.; Kraft, R.P.; Hardcastle, M.J.; Birkinshaw, M.; Worrall, D.M.; Nulsen, P.E.J.; Penna, R.F.; Sivakoff, G.R.; Jordan, R.; Brassington, Nicola; Evans, D.A.; Forman, W.R.; Gilfanov, M.; Goodger, Joanna; Harris, W.E.; Jones, C.; Juett, A.M.; Murray, S.S.; Raychaudhury, S.; Sarazin, C.L.; Voss, R.; Woodley, K.A. (2009)We present new results on the shock around the south-west radio lobe of Centaurus A using data from the Chandra Very Large Programme observations (740 ks total observing time). The X-ray spectrum of the emission around the ... -
The jet heated x-ray filament in the Centaurus A northern middle radio lobe
Kraft, R.P.; Forman, W.R.; Hardcastle, M.J.; Birkinshaw, M.; Croston, J.H.; Jones, C.; Nulsen, P.E.J.; Worrall, D.M.; Murray, S.S. (2009)We present results from a 40 ks XMM-Newton observation of the X-ray filament coincident with the southeast edge of the Centaurus A Northern Middle Radio Lobe (NML). We find that the X-ray filament consists of five spatially ... -
The Jet/ISM Interaction in Three Nearby Radio Galaxies as Seen with Chandra.
Kraft, R.P.; Forman, W.R.; Churazov, E.; Eilek, J.; Hardcastle, M.J.; Heinz, S.; Jones, C.; Markevitch, M.; Murray, S.S.; Nulsen, P.E.J.; Owen, F.; Vikhlinin, V.; Worrall, D.M. (2004)Chandra observations of radio galaxies have demonstrated a wide range of complex interactions between their jets and the ambient interstellar/intracluster medium (ISM/ICM). In this paper, we discuss results from Chandra ... -
LOFAR facet calibration
Van Weeren, R. J.; Williams, W. L.; Hardcastle, M.J.; Shimwell, T. W.; Rafferty, D. A.; Sabater, J.; Heald, G.; Sridhar, S. S.; Dijkema, T. J.; Brunetti, G.; Brüggen, M.; Andrade-Santos, F.; Ogrean, G. A.; Röttgering, H. J. A.; Dawson, W. A.; Forman, W.R.; Gasperin, F. de; Jones, C.; Miley, G.K.; Rudnick, L.; Sarazin, C.L.; Bonafede, A.; Best, P. N.; Bîrzan, L.; Cassano, R.; Chyży, K. T.; Croston, J. H.; Ensslin, T.; Ferrari, C.; Hoeft, M.; Horellou, C.; Jarvis, M.J.; Kraft, R.P.; Mevius, M.; Intema, H. T.; Murray, S. S.; Orrú, E.; Pizzo, R.; Simionescu, A.; Stroe, A.; Tol, S. van der; White, G.J. (2016-03-07)LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides ... -
LOFAR, VLA, and Chandra observations of the Toothbrush galaxy cluster
Van Weeren, R. J.; Brunetti, G.; Brüggen, M.; Andrade-Santos, F.; Ogrean, G. A.; Williams, W. L.; Röttgering, H. J. A.; Dawson, W. A.; Forman, W.R.; Gasperin, F. de; Hardcastle, M.J.; Jones, C.; Miley, G.K.; Rafferty, D. A.; Rudnick, L.; Sabater, J.; Sarazin, C.L.; Shimwell, T. W.; Bonafede, A.; Best, P. N.; Bîrzan, L.; Cassano, R.; Chyży, K. T.; Croston, J. H.; Dijkema, T. J.; Ensslin, T.; Ferrari, C.; Heald, G.; Hoeft, M.; Horellou, C.; Jarvis, M.J.; Kraft, R.P.; Mevius, M.; Intema, H. T.; Murray, S. S.; Orrú, E.; Pizzo, R.; Sridhar, S. S.; Simionescu, A.; Stroe, A.; Tol, S. van der; White, G.J. (2016-02-22)We present deep LOFAR observations between 120-181 MHz of the "Toothbrush" (RX J0603.3+4214), a cluster that contains one of the brightest radio relic sources known. Our LOFAR observations exploit a new and novel calibration ... -
Long-term monitoring of the dynamics and particle acceleration of knots in the jet of Centaurus A
Goodger, Joanna; Hardcastle, M.J.; Croston, J.H.; Kraft, R.P.; Birkinshaw, M.; Evans, D.A.; Jordan, A.; Nulsen, P.E.J.; Sivakoff, G.R.; Worrall, D.M.; Brassington, Nicola; Forman, W.R.; Gilfanov, M.; Jones, C.; Murray, S.S.; Raychaudhury, S.; Sarazin, C.L.; Voss, R.; Woodley, K.A. (2010)We present new and archival multi-frequency radio and X-ray data for Centaurus A obtained over almost 20 years at the Very Large Array and with Chandra, with which we measure the X-ray and radio spectral indices of jet ... -
Low-Mass X-ray Binaries and Globular Clusters in Centaurus A
Jordan, A.; Sivakoff, G.R.; McLaughlin, D.E.; Blakeslee, J.P.; Evans, D.A.; Kraft, R.P.; Hardcastle, M.J.; Peng, E.W.; Cote, P.; Croston, J.H.; Juett, A.M.; Minniti, D.; Raychaudhury, S.; Sarazin, C.L.; Worrall, S.M.; Harris, W.E.; Woodley, K.A.; Birkinshaw, M.; Brassington, Nicola; Forman, W.R.; Jones, C.; Murray, S.S. (2007)We present results of Hubble Space Telescope and Chandra X-Ray Observatory observations of globular clusters (GCs) and low-mass X-ray binaries (LMXBs) in the central regions of Centaurus A. Out of 440 GC candidates, we ... -
Luminosity functions of LMXBs in Centaurus A: globular clusters versus the field
Voss, R.; Gilfanov, M.; Sivakoff, G.R.; Kraft, R.P.; Jordan, A.; Raychaudhury, S.; Birkinshaw, M.; Brassington, Nicola; Croston, J.H.; Evans, D.A.; Forman, W.R.; Hardcastle, M.J.; Harris, W.E.; Jones, C.; Juett, A.M.; Murray, S.S.; Sarazin, C.L.; Woodley, K.A.; Worrall, D.M. (2009)We study the X-ray luminosity function (XLF) of low-mass X-ray binaries (LMXB) in the nearby early-type galaxy Centaurus A, concentrating primarily on two aspects of binary populations: the XLF behavior at the low-luminosity ... -
New results on particle acceleration in the Centaurus A jet and counterjet from a deep Chandra observation
Hardcastle, M.J.; Kraft, R.P.; Sivakoff, G.R.; Goodger, Joanna; Croston, J.H.; Jordan, A.; Evans, D.A.; Worrall, D.M.; Birkinshaw, M.; Raychaudhury, S.; Brassington, Nicola; Forman, W.R.; Harris, W.E.; Jones, C.; Juett, A.M.; Murray, S.S.; Nulsen, P.E.J.; Sarazin, C.L.; Woodley, K.A. (2007)We present new deep Chandra observations of the Centaurus A jet, with a combined on-source exposure time of 719 ks. These data allow detailed X-ray spectral measurements to be made along the jet out to its disappearance ... -
Particle acceleration and jet dynamics in Centaurus A
Hardcastle, M.J.; Worrall, D.M.; Kraft, R.P.; Forman, W.R.; Jones, C.; Murray, S.S. (2004-06)New multi-epoch Chandra observations, combined with multi-epoch, high-dynamic range VLA data, have allowed us to relate the radio and X-ray structure of the jet in Cen A to the jet dynamics. We present evidence that a ...