Search Publications
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…
Six millisecond pulsars detected by the Fermi Large Area Telescope and the radio/gamma-ray connection of millisecond pulsars
Camilo, F.; Çelik, Ö.; Guillemot, L. +23 more
We report on the discovery of gamma-ray pulsations from five millisecond pulsars (MSPs) using the Fermi Large Area Telescope (LAT) and timing ephemerides provided by various radio observatories. We also present confirmation of the gamma-ray pulsations from a sixth source, PSR J2051-0827. Five of these six MSPs are in binary systems: PSRs J1713+074…
Optical polarimetry of the inner Crab nebula and pulsar
De Luca, A.; Mignani, R. P.; Laurent, P. +4 more
Time-resolved polarization measurements of pulsars offer a unique insight into the geometry of their emission regions. Such measurements provide observational constraints on the different models proposed for the pulsar emission mechanisms. Optical polarization data of the Crab nebula were obtained from the Hubble Space Telescope (HST) archive. The…
Inferring the mass of submillimetre galaxies by exploiting their gravitational magnification of background galaxies
Pérez-Fournon, I.; Valtchanov, I.; Ivison, R. J. +25 more
Dust emission at submillimetre wavelengths allows us to trace the early phases of star formation in the Universe. In order to understand the physical processes involved in this mode of star formation, it is essential to gain knowledge about the dark matter structures - most importantly their masses - that submillimetre galaxies live in. Here we us…
A tidal flare candidate in Abell 1795
Ho, L. C.; Maksym, W. P.; Ulmer, M. P. +2 more
As part of our ongoing archival X-ray survey of galaxy clusters for tidal flares, we present evidence of an X-ray transient source within 1 arcmin of the core of Abell 1795. The extreme variability (a factor of nearly 50), luminosity (>2 × 1042 erg s-1), long duration (>5 yr) and supersoft X-ray spectrum (<0.1 keV) a…