Search Publications
Cosmological constraints from baryon acoustic oscillations and clustering of large-scale structure
Halpern, M.; Hinshaw, G.; Addison, G. E.
We constrain cosmological parameters using combined measurements of the baryon acoustic oscillation (BAO) feature in the correlation function of galaxies and Lyα absorbers that together cover 0.1 < z < 2.4. The BAO position measurements alone - without fixing the absolute sound horizon `standard ruler' length with cosmic microwave background…
Hard-X-ray spectra of active galactic nuclei in the INTEGRAL complete sample
Bird, A. J.; Ubertini, P.; Malizia, A. +4 more
In this paper, we present the hard-X-ray spectral analysis of a complete sample of active galactic nuclei (AGNs) detected by INTEGRAL/IBIS. In conjunction with IBIS spectra, we make use of Swift/BAT data, with the aim of cross-calibrating the two instruments, studying source variability and constraining some important spectral parameters. We find …
Fast and slow rotators in the densest environments: a FLAMES/GIRAFFE integral field spectroscopy study of galaxies in A1689 at z = 0.183
Dalla Bontà, E.; Davies, R. L.; D'Eugenio, F. +1 more
We present FLAMES/GIRAFFE integral field spectroscopy of 30 galaxies in the massive cluster A1689 at z = 0.183. Conducting an analysis similar to that of ATLAS3D, we extend the baseline of the kinematic morphology-density relation by an order of magnitude in projected density and show that it is possible to use existing instruments to i…
The accretion flow to the intermittent accreting millisecond pulsar, HETE J1900.1-2455, as observed by XMM-Newton and RXTE
Egron, E.; Papitto, A.; Di Salvo, T. +6 more
We present a study of the accretion flow to the intermittent accreting millisecond pulsar, HETE J1900.1-2455, based on observations made simultaneously by XMM-Newton and RXTE. The 0.33-50 keV energy spectrum is described by the sum of a hard Comptonized component produced in an optically thin τ ≃ 1 corona, a soft thermal kTin ≃ 0.2 keV …
XMM-Newton observations of the merging galaxy cluster CIZA J2242.8+5301
Simionescu, A.; Croston, J. H.; Brüggen, M. +4 more
We studied the intracluster medium (ICM) of the galaxy cluster CIZA J2242.8+5301 using deep XMM-Newton observations. The cluster hosts a remarkable 2 Mpc long, ∼50 kpc wide radio relic that has been nicknamed the `Sausage'. A smaller, more irregular counter relic is also present, along with a faint giant radio halo. We analysed the distribution of…
The merger rates and sizes of galaxies across the peak epoch of star formation from the HiZELS survey
Smail, Ian; Sobral, David; Stott, John P. +3 more
We use the HiZELS narrow-band Hα survey in combination with CANDELS, UKIDSS and WIRDS near-infrared imaging, to investigate the morphologies, merger rates and sizes of a sample of Hα emitting galaxies in the redshift range z = 0.40-2.23, an epoch encompassing the rise to the peak of the star formation rate density. Merger rates are estimated from …
Symbiotic stars and other Hα emission-line stars towards the Galactic bulge
Udalski, Andrzej; Miszalski, Brent; Mikołajewska, Joanna
Symbiotic stars are interacting binaries with the longest orbital periods, and their multicomponent structure makes them rich astrophysical laboratories. The accretion of a high-mass-loss-rate red giant wind on to a white dwarf (WD) makes them promising Type Ia supernova (SN Ia) progenitors. Systematic surveys for new Galactic symbiotic stars are …
The Chandra-COSMOS survey - IV. X-ray spectra of the bright sample
Salvato, M.; Merloni, A.; Fiore, F. +14 more
We present the X-ray spectral analysis of the 390 brightest extragalactic sources in the Chandra-Cosmic Evolution Survey catalogue, showing at least 70 net counts in the 0.5-7 keV band. This sample has a 100 per cent completeness in optical-infrared identification, with ∼75 per cent of the sample having a spectroscopic redshift and ∼25 per cent a …
Herschel-ATLAS/GAMA: a difference between star formation rates in strong-line and weak-line radio galaxies
Cooray, A.; Hardcastle, M. J.; De Zotti, G. +25 more
We have constructed a sample of radio-loud objects with optical spectroscopy from the Galaxy and Mass Assembly (GAMA) project over the Herschel Astrophysical Terahertz Large Area Survey (Herschel-ATLAS) Phase 1 fields. Classifying the radio sources in terms of their optical spectra, we find that strong-emission-line sources (`high-excitation radio…
Finding rare AGN: XMM-Newton and Chandra observations of SDSS Stripe 82
Nandra, Kirpal; Schawinski, Kevin; Comastri, Andrea +15 more
We have analysed the XMM-Newton and Chandra data overlapping ∼16.5 deg2 of Sloan Digital Sky Survey Stripe 82, including ∼4.6 deg2 of proprietary XMM-Newton data that we present here. In total, 3362 unique X-ray sources are detected at high significance. We derive the XMM-Newton number counts and compare them with our previou…