Search Publications
Distances to Cepheid open clusters via optical and K-band imaging
Tanvir, N. R.; Shanks, Tom; Hoyle, Fiona
We investigate the reddening and main-sequence-fitted distances to 11 young, Galactic open clusters that contain Cepheids. Each cluster contains or is associated with at least one Cepheid variable star. Reddening to the clusters is estimated using the U-B:B-V colours of the OB stars and the distance modulus to the cluster is estimated via B-V:V an…
Iron K-features in the hard X-ray XMM-Newton spectrum of NGC 4151
Schurch, N. J.; Warwick, R. S.; Griffiths, R. E. +1 more
Recent XMM-Newton observations have measured the hard (2.5-12 keV) X-ray spectrum of the well-known Seyfert galaxy NGC 4151 with a signal-to-noise unprecedented for this source. We find that a spectral model, developed to fit previous BeppoSAX and ASCA observations of NGC 4151, provides an excellent description of the XMM-Newton European Photon Im…
The discovery of a new non-thermal X-ray filament near the Galactic Centre
Decourchelle, A.; Warwick, R. S.; Predehl, P. +1 more
We report the discovery by XMM-Newton and Chandra of a hard extended X-ray source (XMM J174540-2904.5) associated with a compact non-thermal radio filament (the Sgr A-E `wisp'= 1LC 359.888-0.086 = G359.88-0.07), which is located within ~4 arcmin of the Galactic Centre. The source position is also coincident with the peak of the molecular cloud M-0…
The planetary nebula K 1-2 and its binary central star VW Pyx
Exter, K. M.; Pollacco, D. L.; Bell, S. A.
New data are presented of the post-common-envelope binary VW Pyx and its associated planetary nebula (PN), K 1-2. The central star is found to be a single-lined (and possibly double-lined) spectroscopic binary and is a good candidate for a system in which the main-sequence secondary star is more massive than the subdwarf primary star. The old PN h…
The XMM-Newton/2dF survey - I. X-ray properties of normal galaxies
Georgakakis, A.; Georgantopoulos, I.; Shanks, T. +2 more
This paper explores the X-ray properties of `normal' galaxies using a shallow (2-10 ks) XMM-Newton survey covering an area of ~1.5 deg2. The X-ray survey overlaps with the 2dF Galaxy Redshift Survey. Compared with previous studies this has the advantage that high-quality spectra and spectral classifications (early-, late-type) exist for…
XMM-Newton surveys of the Canada-France Redshift Survey fields - I. The submillimetre/X-ray relation
Eales, Stephen A.; Thuan, Trinh X.; Gear, Walter K. +7 more
First results from XMM-Newton observations of the Canada-France Redshift Survey (CFRS) 3-h, 10-h and 14-h fields are presented. Limited regions of two of the XMM surveys (3 and 14 h) are compared with the Canada-UK Deep Submillimetre Surveys (CUDSS) undertaken with SCUBA. None of the 27 SCUBA sources in the 3-h field is detected by XMM, while one …
An empirical test of the theoretical population corrections to the red clump absolute magnitude
Salaris, Maurizio; Percival, Susan M.
The mean absolute magnitude of the local red clump (RC), MRCλ, is a very well-determined quantity owing to the availability of accurate Hipparcos parallaxes for several hundred RC stars, potentially allowing it to be used as an accurate extragalactic distance indicator. Theoretical models predict that the RC mean magnitude is…
Inverse Compton X-rays from the radio galaxy 3C 219
Bondi, M.; Brunetti, G.; Comastri, A. +3 more
We report the results from a Chandra observation of the powerful nearby (z= 0.1744) radio galaxy 3C 219. We find evidence for non-thermal X-ray emission from the radio lobes which fits fairly well with a combination of inverse Compton scattering of Cosmic Microwave Background radiation and of nuclear photons with the relativistic electrons in the …
The redshift of the Einstein ring in MG 1549+305
Treu, T.; Koopmans, L. V. E.
A deep spectrum taken with the Echelle Spectrograph and Imager (ESI) at the Keck II Telescope as part of the Lenses Structure and Dynamics (LSD) Survey reveals the redshifts of the extremely red source of the radio Einstein ring in the gravitational lens system MG 1549+305 (zs= 1.170 +/- 0.001) and an intermediate-redshift lensed spiral…
A two-arm gaseous spiral in the inner 200 pc of the early-type galaxy NGC 2974: signature of an inner bar
Emsellem, Eric; Ferruit, Pierre; Goudfrooij, Paul
TIGER integral-field spectrography and Hubble Space Telescope Wide Field and Planetary Camera 2 (WFPC2) imaging of the E3 galaxy NGC 2974 are used to derive the kinematics of the stellar and ionized gas components in its central 500 pc. We derive a numerical two-integral distribution function from a multi-Gaussian expansion (MGE) mass model using …