Search Publications
Three-dimensional photoionization modelling of the planetary nebula NGC 3918
Morisset, C.; Barlow, M. J.; Liu, X. -W. +2 more
The three-dimensional Monte Carlo photoionization code MOCASSIN has been applied to construct a realistic model of the planetary nebula NGC 3918. Three different geometric models were tried, the first being the biconical density distribution already used some years ago by Clegg et al. In this model the nebula is approximated by a biconical structu…
Cyclical period changes in the dwarf novae V2051 Oph and V4140 Sgr
Baptista, R.; Steiner, J. E.; Bond, H. E. +3 more
We report on the identification of cyclical changes in the orbital period of the eclipsing dwarf novae V2051 Ophiuchi and V4140 Sagittarii. We used sets of white dwarf mid-eclipse timings to construct observed-minus-calculated diagrams covering, respectively, 25 and 16 yr of observations. The V2051 Oph data present cyclical variations that can be …
A softer look at MCG-6-30-15 with XMM-Newton
Vaughan, S.; Fabian, A. C.; Lee, J. C. +1 more
We present the analysis and first results from the Reflection Grating Spectrometer (RGS) during the 320-ks XMM-Newton observation of the Seyfert 1 galaxy MCG-6-30-15. The spectrum is marked by a sharp drop in flux at 0.7 keV which has been interpreted by Branduardi-Raymont et al. using RGS spectra from an earlier and shorter observation as the blu…
X-ray and ultraviolet observations of the dwarf nova VW Hyi in quiescence
Pandel, Dirk; Howell, Steve B.; Córdova, France A.
We present an analysis of X-ray and ultraviolet (UV) data of the dwarf nova VW Hyi that were obtained with XMM-Newton during the quiescent state. The X-ray spectrum indicates the presence of an optically thin plasma in the boundary layer that cools as it settles on to the white dwarf. The plasma has a continuous temperature distribution that is we…
Statistical re-examination of reported emission lines in the X-ray afterglow of GRB 011211
Sako, Masao; Rutledge, Robert E.
A 0.2-12 keV spectrum obtained with the XMM-Newton EPIC/pn instrument of GRB 011211, taken in the first 5 ks of a 27-ks observation, was found by Reeves et al. in 2002 to contain emission lines that were interpreted to be from MgXI, SiXIV, SXVI, ArXVIII and CaXX, at a lower redshift (zobs= 1.88) than that of the host galaxy (zhost<…
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…