Search Publications
Principal component analysis of International Ultraviolet Explorer galaxy spectra
Brosch, Noah; Formiggini, Liliana
We analyse the UV spectral energy distribution of a sample of normal galaxies listed in the International Ultraviolet Explorer (IUE) Newly Extracted Spectra (INES) Guide No. 2 - Normal Galaxies using a principal component analysis. The sample consists of the IUE short-wavelength (SW) spectra of the central regions of 118 galaxies, where the IUE ap…
A search for X-ray flashes with XMM-Newton
Law, Nicholas M.; Kulkarni, Shrinivas R.; Rutledge, Robert E.
We searched for X-ray flashes (XRFs) - which we defined as ~10-s duration transient X-ray events observable in the 0.4-15 keV passband - in fields observed using XMM-Newton with the EPIC/pn detector. While we find two non-Poissonian events, the astrophysical nature of the events is not confirmed in fully simultaneous observations with the EPIC/MOS…
Properties of serendipitous X-ray flares discovered in XMM-Newton observations
Ramsay, Gavin; Trenholme, Duncan; Foley, Carl
We present the results of a search of the XMM-Newton public data archive for stellar X-ray flares. We find eight flaring sources for which we identify seven optical counterparts. Three of these sources have distance estimates which allow us to determine their luminosities. Based on the decay time of the flares and their luminosity, we derive loop …
Erratum: Probable intermediate-mass black holes in NGC 4559: XMM-Newton spectral and timing constraints
Cropper, Mark; Soria, Roberto; Wu, Kinwah +3 more
The XMM-Newton/2dF survey - V. The radio properties of the X-ray population
Georgakakis, A.; Georgantopoulos, I.; Akylas, A. +3 more
In this paper, we cross-correlate the FIRST (Faint Images of the Radio Sky at Twenty centimeters) 1.4-GHz radio survey with a wide-field (1.6 deg2) shallow [fX(0.5 - 8keV) ~ 10-14erg s-1]XMM-Newton survey. We find 12 X-ray/radio matches representing 4 per cent of the X-ray-selected sample. Most of them a…
On characterizing the variability properties of X-ray light curves from active galaxies
Vaughan, S.; Uttley, P.; Warwick, R. S. +1 more
We review some practical aspects of measuring the amplitude of variability in `red noise' light curves typical of those from active galactic nuclei (AGN). The quantities commonly used to estimate the variability amplitude in AGN light curves, such as the fractional rms variability amplitude, Fvar, and excess variance, σ2…
The chemical compositions of Galactic disc F and G dwarfs
Lambert, David L.; Allende Prieto, Carlos; Reddy, Bacham E. +1 more
Photospheric abundances are presented for 27 elements from carbon to europium in 181 F and G dwarfs from a differential local thermodynamic equilibrium (LTE) analysis of high-resolution and high signal-to-noise ratio spectra. Stellar effective temperatures (Teff) were adopted from an infrared flux method calibration of Strömgren photome…
Quasars, their host galaxies and their central black holes
McLure, R. J.; Dunlop, J. S.; Hughes, D. H. +3 more
We present the final results from our deep Hubble Space Telescope (HST) imaging study of the host galaxies of radio-quiet quasars (RQQs), radio-loud quasars (RLQs) and radio galaxies (RGs). We describe and analyse new Wide Field & Planetary Camera 2 (WFPC2) R-band observations for 14 objects, which when combined with the first tranche of HST i…
A high-velocity ionized outflow and XUV photosphere in the narrow emission line quasar PG1211+143
O'Brien, P. T.; King, A. R.; Reeves, J. N. +3 more
We report on the analysis of a ~60-ks XMM-Newton observation of the bright, narrow emission line quasar PG1211+143. Absorption lines are seen in both European Photon Imaging Camera and Reflection Grating Spectrometer spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C. The observed line energies indicate an ionized outflow ve…
The Cosmic Lens All-Sky Survey - II. Gravitational lens candidate selection and follow-up
Pearson, T. J.; McKean, J. P.; Blandford, R. D. +19 more
We report the final results of the search for gravitationally lensed flat-spectrum radio sources found in the combination of CLASS (Cosmic Lens All-Sky Survey) and JVAS (Jodrell Bank VLA Astrometric Survey). VLA (Very Large Array) observations of 16503 sources have been made, resulting in the largest sample of arcsec-scale lens systems available. …