Search Publications
The dust and gas properties of M83
Clements, D. L.; Boquien, M.; Roussel, H. +17 more
We examine the dust and gas properties of the nearby, barred galaxy M83, which is part of the Very Nearby Galaxy Survey. Using images from the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) instruments of Herschel, we examine the dust temperature and dust mass surface density distribution. …
Correlated X-ray/ultraviolet/optical variability in the very low mass AGN NGC 4395
McHardy, I.; Breedt, E.; Uttley, P. +4 more
We report the results of a 1-yr Swift X-ray/ultraviolet (UV)/optical programme monitoring the dwarf Seyfert nucleus in NGC 4395 in 2008-2009. The UV/optical flux from the nucleus was found to vary dramatically over the monitoring period, with a similar pattern of variation in each of the observed UV/optical bands (spanning 1900-5500 Å). In particu…
Discovery of the millisecond pulsar PSR J2043+1711 in a Fermi source with the Nançay Radio Telescope
Camilo, F.; Guillemot, L.; Harding, A. K. +18 more
We report the discovery of the millisecond pulsar PSR J2043+1711 in a search of a Fermi Large Area Telescope (LAT) source with no known associations, with the Nançay Radio Telescope. The new pulsar, confirmed with the Green Bank Telescope, has a spin period of 2.38 ms, is relatively nearby (? kpc) and is in a 1.48-d orbit around a low-mass compani…
Stars, dust, and the growth of ultraviolet-selected sub-L* galaxies at redshift z∼ 2
Sawicki, Marcin
This work concerns the physical properties of very faint (?= 28 AB mag; Mstars,lim∼ 108 M⊙), ultraviolet-selected (UV-selected) sub-L* BX galaxies at z∼ 2.3. Stellar masses, dust content and dust-corrected star formation rates are constrained using broad-band spectral energy distribution fitting, resulting in a num…
Testing cosmology with extreme galaxy clusters
Harrison, Ian; Coles, Peter
Motivated by recent suggestions that a number of observed galaxy clusters have masses which are too high for their given redshift to occur naturally in a standard model cosmology, we use extreme value statistics to construct confidence regions in the mass-redshift plane for the most extreme objects expected in the universe. We show how such a diag…
A Giant Metrewave Radio Telescope/Chandra view of IRAS 09104+4109: a type 2 QSO in a cooling flow
Donahue, Megan; Hoekstra, Henk; Babul, Arif +8 more
IRAS 09104+4109 is a rare example of a dust enshrouded type 2 quasi-stellar object (QSO) in the centre of a cool-core galaxy cluster. Previous observations of this z = 0.44 system showed that, as well as powering the hyperluminous infrared emission of the cluster-central galaxy, the QSO is associated with a double-lobed radio source. However, the …
Further X-ray observations of the galaxy cluster PKS 0745-191 to the virial radius and beyond
Fabian, A. C.; Sanders, J. S.; Walker, S. A. +1 more
We use new Suzaku observations of PKS 0745-191 to measure the thermodynamic properties of its intracluster medium (ICM) out to and beyond r200 (reaching 1.25r200) with better accuracy than previously achieved, owing to a more accurate and better understood background model. We investigate and resolve the tensions between the …
Photometric determination of the mass accretion rates of pre-mainsequence stars - III. Results in the Large Magellanic Cloud
Panagia, N.; De Marchi, G.; Sicilia-Aguilar, A. +2 more
We present a multi-wavelength study of three star forming regions, spanning the age range 1-14 Myr, located between the 30 Doradus complex and supernova SN1987A in the Large Magellanic Cloud (LMC). We reliably identify about 1000 pre-main sequence (PMS) star candidates actively undergoing mass accretion and estimate their stellar properties and ma…
The effect of frame dragging on the iron Kα line in X-ray binaries
Ingram, Adam; Done, Chris
The clear characteristic time-scale picked out by the low-frequency quasi-periodic oscillations (QPOs) seen in many black hole and neutron star binaries has the potential to provide a very powerful diagnostic of the inner regions of the accretion flow. However, this potential cannot be realized without a quantitative model for the QPO. We have rec…
Modelling the very high energy flare of 3C 279 using one-zone leptonic model
Godambe, S.; Sahayanathan, S.
We model the simultaneous observations of the flat-spectrum radio quasar 3C 279 at radio, optical, X-ray and very high energy (VHE) gamma-ray energies during 2006 flare using a simple one-zone leptonic model. We consider synchrotron emission due to cooling of a non-thermal electron distribution in an equipartition magnetic field and inverse Compto…