Browsing Research publications by Author "Brassington, Nicola"

Now showing items 1-20 of 26

    • AGN activity and the misaligned hot ISM in the compact radio elliptical NGC4278 

      Pellegrini, S.; Wang, J.; Fabbiano, G.; Kim, D.-W.; Brassington, Nicola; Gallagher, J.S.; Trinchieri, G.; Zezas, A. (2012-10-20)
      The analysis of a deep (579ks) Chandra ACIS pointing of the elliptical galaxy NGC4278, which hosts a low-luminosity active galactic nucleus (AGN) and compact radio emission, allowed us to detect extended emission from hot ...

    • Chandra observations of the interacting galaxies NGC 3395/3396 (Arp 270) 

      Brassington, Nicola; Read, Andrew M.; Ponman, T.J. (2005-07-01)
      In this paper we present the results of a 20-ks high-resolution Chandra X-ray observation of the peculiar galaxy pair NGC 3395/3396, a system at a very early stage of merging, and less evolved than the famous Antennae and ...

    • The Chandra view of galaxy mergers 

      Brassington, Nicola; Ponman, T.J.; Read, Andrew M. (2007-06-01)
      From a Chandra survey of nine interacting galaxy systems the evolution of X-ray emission during the merger process has been investigated. It is found that the X-ray luminosity peaks ~300Myr before nuclear coalescence, and ...

    • Comparing GC and Field LMXBs in elliptical galaxies with Deep Chandra and Hubble Data 

      Kim, D.-W.; Fabbiano, G.; Brassington, Nicola; Fragos, T.; Kalogera, V.; Zezas, A.; Jordán, A.; Sivakoff, G.R.; Kundu, A.; Zepf, S.E.; Angelini, L.; Davies, R. L.; Gallagher, J.S.; Juett, A.M.; King, A.R.; Pellegrini, S.; Sarazin, C.L.; Trinchieri, G. (2009-09-01)
      We present a statistical study of the low-mass X-ray binary (LMXB) populations of three nearby, old elliptical galaxies: NGC 3379, NGC 4278, and NGC 4697. With a cumulative ~1 Ms Chandra ACIS observing time, we detect ...

    • Deep Chandra Monitoring Observations of NGC 3379 : Catalog of Source Properties 

      Brassington, Nicola; Fabbiano, G.; Kim, D.-W.; Zezas, A.; Zepf, S.; Kundu, A.; Angelini, L.; Davies, R. L.; Gallagher, J.; Kalogera, V.; Fragos, T.; King, A.R.; Pellegrini, S.; Trinchieri, G. (2008-11-01)
      We present the properties of the discrete X-ray sources detected in our monitoring program of the `typical' elliptical galaxy, NGC 3379, observed with Chandra ACIS-S in five separate pointings, resulting in a co-added ...

    • Deep Chandra Monitoring Observations of NGC 4278 : Catalog of Source Properties 

      Brassington, Nicola; Fabbiano, G.; Kim, D.-W.; Zezas, A.; Zepf, S.; Kundu, A.; Angelini, L.; Davies, R. L.; Gallagher, J.; Kalogera, V.; Fragos, T.; King, A.R.; Pellegrini, S.; Trinchieri, G. (2009-04-01)
      We present the properties of the discrete X-ray sources detected in our monitoring program of the globular cluster (GC) rich elliptical galaxy, NGC 4278, observed with Chandra ACIS-S in six separate pointings, resulting ...

    • Discovery of Hot Gas in Outflow in NGC 3379 

      Trinchieri, G.; Pellegrini, S.; Fabbiano, G.; Fu, R.; Brassington, Nicola; Zezas, A.; Kim, D.-W.; Gallagher, J.; Angelini, L.; Davies, R. L.; Kalogera, V.; King, A.R.; Zepf, S. (2008-12-01)
      We report the discovery of a faint (LX~4+/-1.5×1037 ergs s-1, 0.5-2 keV), outflowing gaseous hot interstellar medium (ISM) in NGC 3379. This represents the lowest X-ray luminosity ever measured from a hot phase of the ISM ...

    • 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 ...

    • FIELD AND GLOBULAR CLUSTER LOW-MASS X-RAY BINARIES IN NGC 4278 

      Fabbiano, G.; Brassington, Nicola; Lentati, L.; Angelini, L.; Davies, R. L.; Gallagher, J.; Kalogera, V.; Kim, D. -W.; King, A. R.; Kundu, A.; Pellegrini, S.; Richings, A. J.; Trinchieri, G.; Zezas, A.; Zepf, S. (2010-12)
      We report a detailed spectral analysis of the population of low-mass X-ray binaries (LMXBs) detected in the elliptical galaxy NGC 4278 with Chandra. Seven luminous sources were studied individually, four in globular clusters ...

    • 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 ...

    • 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 ...

    • Low-mass X-ray binaries and globular clusters streamers and ARCS in NGC 4278 

      D'Abrusco, R.; Fabbiano, G.; Brassington, Nicola (2014-03-01)
      We report significant inhomogeneities in the projected two-dimensional spatial distributions of low-mass X-ray binaries (LMXBs) and globular clusters (GCs) of the intermediate mass elliptical galaxy NGC 4278. In the inner ...

    • 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 ...

    • Luminosity functions of LMXBs in different stellar environments 

      Zhang, Z.; Gilfanov, M.; Voss, R.; Sivakoff, G. R.; Kraft, R. P.; Brassington, Nicola; Kundu, A.; Jordan, A.; Sarazin, C. (2011-09)
      Aims. Based on the archival data from the Chandra observations of nearby galaxies, we study different sub populations of low-mass X-ray binaries (LMXBs) - dynamically formed systems in globular clusters (GCs) and in the ...

    • Models for Low-Mass X-Ray Binaries in the Elliptical Galaxies NGC 3379 and NGC 4278 : Comparison with Observations 

      Fragos, T.; Kalogera, V.; Belczynski, K.; Fabbiano, G.; Kim, D.-W.; Brassington, Nicola; Angelini, L.; Davies, R. L.; Gallagher, J.S.; King, A.R.; Pellegrini, S.; Trinchieri, G.; Zepf, S.E.; Kundu, A.; Zezas, A. (2008-08-01)
      We present theoretical models for the formation and evolution of populations of low-mass X-ray binaries (LMXBs) in the two elliptical galaxies NGC 3379 and NGC 4278. The models are calculated with the recently updated ...

    • 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 ...

    • Probing the X-ray binary populations of the ring galaxy NGC 1291 

      Luo, B.; Fabbiano, G.; Fragos, T.; Kim, D. -W.; Belczynski, K.; Brassington, Nicola; Pellegrini, S.; Tzanavaris, P.; Wang, Junfeng; Zezas, A. (2012-04)
      We present Chandra studies of the X-ray binary (XRB) populations in the bulge and ring regions of the ring galaxy NGC 1291. We detect 169 X-ray point sources in the galaxy, 75 in the bulge and 71 in the ring, utilizing the ...

    • The Spectral and Temporal Properties of Transient Sources in Early-type Galaxies 

      Brassington, Nicola; Fabbiano, G.; Zezas, A.; Kim, D.-W.; Fragos, T.; Kundu, A.; King, A.R.; Pellegrini, S.; Trinchieri, G.; Zepf, S.; Wright, N.J. (2012-08-20)
      We report the spectral and temporal variability properties of 18 candidate transient (TC) and potential transient (PTC) sources detected in deep multi-epoch Chandra observation of the nearby elliptical galaxies, NGC3379, ...