Browsing University of Hertfordshire by Author "Davies, R. L."

Now showing items 1-10 of 10

    • The ATLAS 3D project - XI : Dense molecular gas properties of CO-luminous early-type galaxies 

      Crocker, A.; Krips, M.; Bureau, M.; Young, L.M.; Davis, T.A.; Bayet, E.; Alatalo, K.; Blitz, L.; Bois, M.; Bournaud, F.; Cappellari, M.; Davies, R. L.; de Zeeuw, P.T.; Duc, P.A.; Emsellem, E.; Khochfar, S.; Krajnović, D.; Kuntschner, H.; Lablanche, Pierre-Yves; McDermid, Richard M.; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, N.; Serra, P.; Weijmans, Anne-Marie (2012-04)
      Surveying 18 12CO-bright galaxies from the ATLAS 3D early-type galaxy sample with the Institut de Radio Astronomie Millimétrique (IRAM) 30-m telescope, we detect 13CO(1-0) and 13CO(2-1) in all 18 galaxies, HCN(1-0) in 12/18 ...

    • The ATLAS3D project - XXV : Two-dimensional kinematic analysis of simulated galaxies and the cosmological origin of fast and slow rotators 

      Naab, Thorsten; Oser, L.; Emsellem, E.; Cappellari, Michele; Krajnović, D.; McDermid, Richard M.; Alatalo, Katherine; Bayet, Estelle; Blitz, L.; Bois, M.; Bournaud, Frederic; Bureau, M.; Crocker, A.; Davies, R. L.; Davis, T. A.; de Zeeuw, P.T.; Duc, P.A.; Hirschmann, Michaela; Johansson, P. H.; Khochfar, S.; Kuntschner, H.; Morganti, R.; Oosterloo, T.; Sarzi, Marc; Scott, N.; Serra, P.; van de Ven, G.; Weijmans, A.; Young, Lisa M. (2014-11-11)
      We present a detailed two-dimensional stellar dynamical analysis of a sample of 44 cosmological hydrodynamical simulations of individual central galaxies with stellar masses of 2 × 1010 M⊙ ≲ M* ≲ 6 × 1011 M⊙. Kinematic ...

    • 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 ...

    • 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 ...

    • 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 ...

    • Transient Low-mass X-ray Binary Populations in Elliptical Galaxies NGC 3379 and NGC 4278 

      Fragos, T.; Kalogera, V.; Willems, B.; 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.; Zezas, A. (2009-09-01)
      We propose a physically motivated and self-consistent prescription for the modeling of transient neutron star low-mass X-ray binary (LMXB) properties, such as duty cycle (DC), outburst duration, and recurrence time. We ...

    • 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 ...