Search Publications
Bridging model and observed stellar spectra
Allende Prieto, C.
Accurate model stellar fluxes are key for the analysis of observations of individual stars or stellar populations. Model spectra differ from real stellar spectra due to limitations of the input physical data and adopted simplifications, but can be empirically calibrated to maximize their resemblance to actual stellar spectra. We describe a least-s…
Oxford SWIFT integral field spectrograph and multiwavelength observations of the Eagle galaxy at z= 0.77
Weiner, Benjamin J.; Koekemoer, A. M.; Salim, Samir +17 more
The ‘Eagle' galaxy at a redshift of 0.77 is studied with the Oxford Short Wavelength Integral Field Spectrograph (SWIFT) and multiwavelength data from the All-wavelength Extended Groth strip International Survey (AEGIS). It was chosen from AEGIS because of the bright and extended emission in its slit spectrum. 3D kinematic maps of the Eagle reveal…
Updated Phoebe's orbit
Zhang, H. Y.; Qiao, R. C.; Shen, K. X. +4 more
In recent years, many new CCD observations of Phoebe, the ninth Saturnian satellite, were published. In this paper, we have used all the observations of Phoebe available until 2009 to update Phoebe's orbit. These observations represent a total number of 2994 positions, spread over a time-interval of 105 years, from 1904 to 2009. The accuracy of th…
A study of the gas-star formation relation over cosmic time
Lutz, D.; Förster Schreiber, N. M.; Genzel, R. +19 more
We use the first systematic data sets of CO molecular line emission in z ~ 1-3 normal star-forming galaxies (SFGs) for a comparison of the dependence of galaxy-averaged star formation rates on molecular gas masses at low and high redshifts, and in different galactic environments. Although the current high-z samples are still small and biased towar…
The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150Msolar stellar mass limit
Parker, Richard J.; Crowther, Paul A.; Goodwin, Simon P. +4 more
Spectroscopic analyses of hydrogen-rich WN5-6 stars within the young star clusters NGC3603 and R136 are presented, using archival Hubble Space Telescope and Very Large Telescope spectroscopy, and high spatial resolution near-IR photometry, including Multi-Conjugate Adaptive Optics Demonstrator (MAD) imaging of R136. We derive high stellar temperat…
The WiggleZ Dark Energy Survey: survey design and first data release
Glazebrook, Karl; Pimbblet, Kevin A.; Drinkwater, Michael J. +24 more
The WiggleZ Dark Energy Survey is a survey of 240000 emission-line galaxies in the distant Universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The primary aim of the survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at l…
The dependence of Type Ia Supernovae luminosities on their host galaxies
Sullivan, M.; Lidman, C.; Astier, P. +22 more
Precision cosmology with Type Ia supernovae (SNe Ia) makes use of the fact that SN Ia luminosities depend on their light-curve shapes and colours. Using Supernova Legacy Survey (SNLS) and other data, we show that there is an additional dependence on the global characteristics of their host galaxies: events of the same light-curve shape and colour …
Detection of a dark substructure through gravitational imaging
Vegetti, S.; Treu, T.; Gavazzi, R. +2 more
We report the detection of a dark substructure - undetected in the Hubble Space Telescope HST ACS F814W image - in the gravitational lens galaxy SDSSJ0946+1006 (the `double Einstein ring'), through direct gravitational imaging. The detection of a small mass concentration in the surface density maps, at 4.3 kpc from the galaxy centre, has a strong …
Star formation rates and masses of z ~ 2 galaxies from multicolour photometry
Dickinson, Mark; Daddi, Emanuele; Maraston, Claudia +4 more
Fitting synthetic spectral energy distributions (SEDs) to the multiband photometry of galaxies to derive their star formation rates (SFRs), stellar masses, ages, etc. requires making a priori assumptions about their star formation histories (SFHs). A widely adopted parametrization of the SFH, the so-called τ models where SFR ~ e-t/τ is …
Accurate fundamental parameters for 23 bright solar-type stars
Butler, R. P.; Carrier, F.; Lo Curto, G. +7 more
We combine results from interferometry, asteroseismology and spectroscopy to determine accurate fundamental parameters of 23 bright solar-type stars, from spectral type F5 to K2 and luminosity classes III-V. For some stars we can use direct techniques to determine the mass, radius, luminosity and effective temperature, and we compare with indirect…