Search Publications
Positron annihilation spectrum from the Galactic Centre region observed by SPI/INTEGRAL
Sunyaev, R.; Revnivtsev, M.; Sazonov, S. +2 more
The electron-positron annihilation spectrum observed by SPI/INTEGRAL during deep Galactic Centre region exposure is reported. The line energy (510.954+/-0.075 keV) is consistent with the unshifted annihilation line. The width of the annihilation line is 2.37 +/- 0.25 keV (full width at half-maximum), while the strength of the ortho-positronium con…
Spitzer imaging of i'-drop galaxies: old stars at z~ 6
Bunker, Andrew J.; Ellis, Richard S.; Stanway, Elizabeth R. +3 more
We present new evidence for mature stellar populations with ages >100Myr in massive galaxies (Mstellar > 1010Msolar) seen at a time when the Universe was less than 1Gyr old. We analyse the prominent detections of two z~ 6 star-forming galaxies (SBM03#1 and #3) made at wavelengths corresponding to the rest-fra…
Polar shapelets
Refregier, Alexandre; Massey, Richard
The shapelets method for image analysis is based upon the decomposition of localized objects into a series of orthogonal components with convenient mathematical properties. We extend the `Cartesian shapelet' formalism from earlier work, and construct `polar shapelet' basis functions that separate an image into components with explicit rotational s…
The progenitor of SN 2005cs in the Whirlpool Galaxy
Smartt, Stephen J.; Maund, Justyn R.; Danziger, I. John
The progenitor of SN 2005cs, in the galaxy M51, is identified in pre-explosion Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) imaging. Differential astrometry, with post-explosion ACS High Resolution Channel (HRC) F555W images, permitted the identification of the progenitor with an accuracy of 0.006 arcsec.…
XMM-Newton spectroscopy of high-redshift quasars
O'Brien, P. T.; Reeves, J. N.; Page, K. L. +1 more
XMM-Newton observations of 29 high-redshift (z > 2) quasars, including seven radio-quiet, 16 radio-loud and six broad absorption line (BAL) objects, are presented; due to the high redshifts, the rest-frame energy bands extend up to ~30-70 keV. Over 2-10 keV, the quasars can be well fitted in each case by a simple power law, with no strong evide…
Absolute dimensions of detached eclipsing binaries - I. The metallic-lined system WW Aurigae
Maxted, P. F. L.; Southworth, J.; Claret, A. +2 more
WW Aurigae is a detached eclipsing binary composed of two metallic-lined A-type stars orbiting each other every 2.5 d. We have determined the masses and radii of both components to accuracies of 0.4 and 0.6 per cent, respectively. From a cross-correlation analysis of high-resolution spectra we find masses of 1.964 +/- 0.007 Msolar for t…
Near-infrared properties of i-drop galaxies in the Hubble Ultra Deep Field
Bunker, Andrew J.; McMahon, Richard G.; Stanway, Elizabeth R.
We analyse near-infrared Hubble Space Telescope (HST)/Near-Infrared Camera and Multi-Object Spectrometer F110W (J) and F160W (H) band photometry of a sample of 27 i'-drop candidate z~= 6 galaxies in the central region of the HST/Advanced Camera for Surveys Ultra Deep Field. The infrared colours of the 20 objects not affected by near neighbours are…
A study of the Type II-P supernova 2003gd in M74
Smartt, S. J.; Peletier, R. F.; Kotak, R. +18 more
We present photometric and spectroscopic data of the Type II-P supernova (SN II-P) 2003gd, which was discovered in M74 close to the end of its plateau phase. SN 2003gd is the first Type II supernova (SN) to have a directly confirmed red supergiant (RSG) progenitor. We compare SN 2003gd to SN 1999em, a similar SN II-P, and estimate an explosion dat…
High-resolution studies of radio sources in the Hubble Deep and Flanking Fields
Muxlow, T. W. B.; Richards, A. M. S.; Wilkinson, P. N. +8 more
18 days of MERLIN data and 42 h of A-array VLA data at 1.4 GHz have been combined to image a 10-arcmin field centred on the Hubble Deep Field (HDF). This area also includes the Hubble Flanking Fields (HFF). A complete sample of 92 radio sources with S1.4 > 40 µJy was detected using the VLA data alone and then imaged with the ME…
The abundance discrepancy - recombination line versus forbidden line abundances for a northern sample of galactic planetary nebulae
Barlow, M. J.; Liu, X. -W.; Wesson, R.
We present deep optical spectra of 23 galactic planetary nebulae, which are analysed in conjunction with archival infrared and ultraviolet spectra. We derive nebular electron temperatures based on standard collisionally excited line (CEL) diagnostics as well as the hydrogen Balmer jump and find that, as expected, the Balmer jump almost always yiel…