Search Publications
SN 2009jf: a slow-evolving stripped-envelope core-collapse supernova
Fugazza, D.; Sollerman, J.; Reichart, D. E. +28 more
We present an extensive set of photometric and spectroscopic data for SN 2009jf, a nearby Type Ib supernova (SN), spanning from ∼20 d before B-band maximum to 1 yr after maximum. We show that SN 2009jf is a slowly evolving and energetic stripped-envelope SN and is likely from a massive progenitor (25-30 M⊙). The large progenitor's mass …
Determination of the X-ray reflection emissivity profile of 1H 0707-495
Fabian, A. C.; Wilkins, D. R.
When considering the X-ray spectrum resulting from the reflection off the surface of accretion discs of AGN, it is necessary to account for the variation in reflected flux over the disc, i.e. the emissivity profile. This will depend on factors including the location and geometry of the X-ray source and the disc characteristics. We directly obtain …
A new look at NICMOS transmission spectroscopy of HD 189733, GJ-436 and XO-1: no conclusive evidence for molecular features
Aigrain, S.; Pont, F.; Gibson, N. P.
We present a re-analysis of archival HST/NICMOS transmission spectroscopy of three exoplanet systems: HD 189733, GJ-436 and XO-1. Detections of several molecules, including H2O, CH4 and CO2, have been claimed for HD 189733 and XO-1, but similarly sized features are attributed to systematic noise for GJ-436. The dat…
Bayesian inference of stellar parameters and interstellar extinction using parallaxes and multiband photometry
Bailer-Jones, C. A. L.
Astrometric surveys provide the opportunity to measure the absolute magnitudes of large numbers of stars, but only if the individual line-of-sight extinctions are known. Unfortunately, extinction is highly degenerate with stellar effective temperature when estimated from broad-band optical/infrared photometry. To address this problem, I introduce …
Data reduction pipeline for the Hi-GAL survey
Natoli, P.; Piacentini, F.; Polenta, G. +13 more
We present the data reduction pipeline for the Herschel Infrared Galactic Plane survey (Hi-GAL). Hi-GAL is a key project of the Herschel satellite, which is mapping the inner part of the Galactic plane (|l| ≤ 70° and |b| ≤ 1°), using two Photodetector Array Camera and Spectrometer (PACS) and three Spectral and Photometric Imaging Receiver (SPIRE) …
The emission line properties of gravitationally lensed 1.5 < z < 5 galaxies
Richard, Johan; Ellis, Richard; Stark, Daniel P. +3 more
We present and analyse near-infrared spectroscopy for a sample of 28 gravitationally lensed star-forming galaxies in the redshift range 1.5 < z < 5, observed mostly with the Keck II telescope. With typical magnifications of ≃1.5-4 mag, our survey provides a valuable census of star formation rates, gas-phase metallicities and dynamical masses…
Multidimensional Bayesian membership analysis of the Sco OB2 moving group
Ireland, M. J.; Rizzuto, A. C.; Robertson, J. G.
We present a new high-mass membership of the nearby Sco OB2 association based on Hipparcos positions, proper motions and parallaxes, and radial velocities taken from the 2nd Catalogue of Radial Velocities with Astrometric Data (CRVAD-2). The Bayesian membership selection method developed makes no distinction between subgroups of Sco OB2 and utiliz…
Constraints on turbulent velocity broadening for a sample of clusters, groups and elliptical galaxies using XMM-Newton
Fabian, A. C.; Sanders, J. S.; Smith, R. K.
Using the width of emission lines in XMM-Newton Reflection Grating Spectrometer spectra, we place direct constraints on the turbulent velocities of the X-ray emitting medium in the cores of 62 galaxy clusters, groups and elliptical galaxies. We find five objects where we can place an upper limit on the line-of-sight broadening of 500 km s-1
A mid-infrared imaging catalogue of post-asymptotic giant branch stars
Gledhill, Tim; Matsuura, Mikako; Szczerba, Ryszard +11 more
Post-asymptotic giant branch (post-AGB) stars are key objects for the study of the dramatic morphological changes of low- to intermediate-mass stars on their evolution from the AGB towards the planetary nebula stage. There is growing evidence that binary interaction processes may very well have a determining role in the shaping process of many obj…
A coincidence of disturbed morphology and blue UV colour: minor-merger-driven star formation in early-type galaxies at z∼ 0.6
Ellis, Richard S.; Kaviraj, Sugata; Silk, Joseph +1 more
We exploit multiwavelength photometry of early-type galaxies (ETGs) in the Cosmological Evolution Survey (COSMOS) to demonstrate that the low-level star formation activity in the ETG population at intermediate redshift is likely to be driven by minor mergers. Splitting the ETGs into galaxies that show disturbed morphologies indicative of recent me…