Search Publications
An unbiased study of debris discs around A-type stars with Herschel
Duchêne, G.; Wyatt, M. C.; Phillips, N. +8 more
The Herschel DEBRIS (Disc Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre) survey brings us a unique perspective on the study of debris discs around main-sequence A-type stars. Bias-free by design, the survey offers a remarkable data set with which to investigate the cold disc properties. The statistical analysis of the 100 a…
The L-σ relation for massive bursts of star formation
Terlevich, E.; Terlevich, R.; Bresolin, F. +4 more
The validity of the emission-line luminosity versus ionized gas velocity dispersion (L-σ) correlation for H II galaxies (HIIGx) and its potential as an accurate distance estimator are assessed. For a sample of 128 local (0.02 ≲ z ≲ 0.2) compact HIIGx with high equivalent widths of their Balmer emission lines, we obtained the ionized gas velocity d…
The ALHAMBRA Survey: Bayesian photometric redshifts with 23 bands for 3 deg
Cepa, J.; Infante, L.; Molino, A. +32 more
The Advance Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey has observed eight different regions of the sky, including sections of the Cosmic Evolution Survey (COSMOS), DEEP2, European Large-Area Infrared Space Observatory Survey (ELAIS), Great Observatories Origins Deep Survey North (GOODS-N), Sloan Digital Sky Survey (…
Broad absorption features in wind-dominated ultraluminous X-ray sources?
Middleton, Matthew J.; Roberts, Timothy P.; Walton, Dominic J. +1 more
The luminosities of ultraluminous X-ray sources (ULXs) require an exotic solution with either supercritical accretion modes on to stellar-mass black holes or subcritical accretion on to intermediate-mass black holes (IMBHs) being invoked. Discriminating between the two is non-trivial due to the present lack of a direct mass measurement. A key expe…
Azimuthally resolved X-ray spectroscopy to the edge of the Perseus Cluster
Simionescu, A.; Fabian, A. C.; Allen, S. W. +9 more
We present the results from extensive, new observations of the Perseus Cluster of galaxies, obtained as a Suzaku Key Project. The 85 pointings analysed span eight azimuthal directions out to 2° = 2.6 Mpc, to and beyond the virial radius r200 ∼ 1.8 Mpc, offering the most detailed X-ray measurements of the intracluster medium (ICM) at lar…
The effect of accretion on the measurement of neutron star mass and radius in the low-mass X-ray binary 4U 1608-52
Suleimanov, Valery F.; Poutanen, Juri; Nättilä, Joonas +4 more
Spectral measurements of thermonuclear (type I) X-ray bursts from low-mass X-ray binaries have been used to measure neutron star (NS) masses and radii. A number of systematic issues affect such measurements and have raised concerns as to the robustness of the methods. We present analysis of the X-ray emission from bursts observed from 4U 1608-52 a…
Simultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the narrow-line Seyfert 1 galaxy SWIFT J2127.4+5654
Harrison, F. A.; Cappi, M.; Fabian, A. C. +20 more
We present a broad-band spectral analysis of the joint XMM-Newton and Nuclear Spectroscopic Telescope Array observational campaign of the narrow-line Seyfert 1 SWIFT J2127.4+5654, consisting of 300 ks performed during three XMM-Newton orbits. We detect a relativistic broadened iron Kα line originating from the innermost regions of the accretion di…
Galaxy Zoo: CANDELS barred discs and bar fractions
Finkelstein, Steven L.; Bell, Eric F.; Ferguson, Henry C. +39 more
The formation of bars in disc galaxies is a tracer of the dynamical maturity of the population. Previous studies have found that the incidence of bars in discs decreases from the local Universe to z ∼ 1, and by z > 1 simulations predict that bar features in dynamically mature discs should be extremely rare. Here, we report the discovery of stro…
Astrometric detection of giant planets around nearby M dwarfs: the Gaia potential
Sozzetti, A.; Giacobbe, P.; Lattanzi, M. G. +3 more
Cool M dwarfs within a few tens of parsecs from the Sun are becoming the focus of dedicated observational programs in the realm of exoplanet astrophysics. Gaia, in its all-sky survey of >109 objects, will deliver precision astrometry for a magnitude-limited (V = 20) sample of M dwarfs. We investigate some aspects of the synergy betwe…
The soft-X-ray emission of Ark 120. XMM-Newton, NuSTAR, and the importance of taking the broad view
Harrison, F. A.; Stern, D.; Zhang, W. W. +17 more
We present simultaneous XMM-Newton and NuSTAR observations of the `bare' Seyfert 1 galaxy, Ark 120, a system in which ionized absorption is absent. The NuSTAR hard-X-ray spectral coverage allows us to constrain different models for the excess soft-X-ray emission. Among phenomenological models, a cutoff power law best explains the soft-X-ray emissi…