Search Publications
The nature of SS433 and the ultraluminous X-ray sources
King, A. R.; Pringle, J. E.; Begelman, M. C.
The periodic precession (162-d) and nodding (6.3-d) motions of the jets in SS433 are driven in the outer regions of the disc, whereas the jets themselves, being relativistic, are launched near the black hole at the disc centre. Given that the nutation period is comparable to the dynamical time-scale in the outer regions of the disc, it seems unlik…
Evidence for the strong effect of gas removal on the internal dynamics of young stellar clusters
Bastian, N.; Goodwin, S. P.
We present detailed luminosity profiles of the young massive clusters M82-F, NGC 1569-A and NGC 1705-1 which show significant departures from equilibrium (King and Elson, Fall & Freeman) profiles. We compare these profiles with those from N-body simulations of clusters that have undergone the rapid removal of a significant fraction of their ma…
Constraints on sterile neutrinos as dark matter candidates from the diffuse X-ray background
Neronov, A.; Boyarsky, A.; Ruchayskiy, O. +1 more
Sterile neutrinos with masses in the kilo-electronvolt range are viable candidates for the warm dark matter. We analyse existing data for the extragalactic diffuse X-ray background for signatures of sterile neutrino decay. The absence of a detectable signal within current uncertainties of background measurements puts model-independent constraints …
The SAURON project - VII. Integral-field absorption and emission-line kinematics of 24 spiral galaxy bulges
Bacon, Roland; Krajnović, Davor; Emsellem, Eric +10 more
We present observations of the stellar and gas kinematics for a representative sample of 24 Sa galaxies obtained with our custom-built integral-field spectrograph SAURON operating on the William Herschel Telescope. The data have been homogeneously reduced and analysed by means of a dedicated pipeline. All resulting data cubes were spatially binned…
Adaptive binning of X-ray data with weighted Voronoi tessellations
Statler, Thomas S.; Diehl, Steven
We present a technique to adaptively bin sparse data using weighted Voronoi tessellations (WVTs). WVT binning is a generalization of the Voronoi binning algorithm by Cappellari & Copin, developed for integral field spectroscopy. WVT binning is applicable to many types of data and creates unbiased binning structures with compact bins that do no…
The link between submillimetre galaxies and luminous ellipticals: near-infrared IFU spectroscopy of submillimetre galaxies
Ivison, R. J.; Smail, Ian; Swinbank, A. M. +5 more
We present two-dimensional spectroscopy covering the rest-frame wavelengths of strong optical emission lines in six luminous submillimetre galaxies (SMGs) at z = 1.3-2.5. Using this near-infrared integral field spectroscopy together with Hubble Space Telescope ACS and NICMOS imaging, we map the dynamics and morphologies of these systems on scales …
The colours of the Sun
Flynn, Chris; Holmberg, Johan; Portinari, Laura
We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the ultraviolet to the near-infrared). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stella…
The X-ray nuclei of intermediate-redshift radio sources
Hardcastle, M. J.; Croston, J. H.; Evans, D. A.
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 objects, mostly Fanaroff-Riley type IIs (FR IIs), it has been clear for some time that a population of radio galaxies [low…
Supernova remnant energetics and magnetars: no evidence in favour of millisecond proto-neutron stars
Vink, Jacco; Kuiper, Lucien
It is generally accepted that anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are magnetars, i.e. neutron stars with extremely high surface magnetic fields (B > 1014 G). The origin of these high magnetic fields is uncertain, but a popular hypothesis is that magnetars are born with an initial spin period not much ex…
V0332+53 in the outburst of 2004-2005: luminosity dependence of the cyclotron line and pulse profile
Sunyaev, R. A.; Tsygankov, S. S.; Lutovinov, A. A. +1 more
We present the results of observations of the transient X-ray pulsar V0332+53 performed during a very powerful outburst, from 2004 December to 2005 February, with the INTEGRAL and RXTE observatories in a wide (3-100 keV) energy band. A cyclotron resonance scattering line at an energy of ~26 keV has been detected in the source spectrum together wit…