Search Publications
X-ray and strong lensing mass estimate of MS2137.3-2353
Ettori, S.; Donnarumma, A.; Meneghetti, M. +1 more
We present new mass estimates of the cluster of galaxies MS2137.3-2353, inferred from X-ray and strong lensing analyses. This cluster exhibits an outstanding strong lensing configuration and indicates a well-relaxed dynamical state, being most suitable for a mass reconstruction which combines both techniques. Despite this, several previous studies…
IRTF observations of white dwarfs with possible near-infrared excess
Farihi, J.
Near-infrared photometry and spectroscopy are obtained for a heterogeneous sample of nearby white dwarfs with possible excess flux as identified primarily in the Two Micron All Sky Survey. Among the sample of 43 stars are a number of white dwarfs that are either metal-rich, magnetic or binary suspects. With a few notable exceptions in four (or pos…
Evidence of a link between the evolution of clusters and their AGN fraction
Simpson, Chris; Rawlings, Steve; Jarvis, Matt J. +9 more
We discuss the optical properties, X-ray detections and active galactic nucleus (AGN) populations of four clusters at z ~ 1 in the Subaru-XMM Deep Field (SXDF). The velocity distribution and plausible extended X-ray detections are examined, as well as the number of X-ray point sources and radio sources associated with the clusters. We find that th…
Constraining star formation and AGN in z ~ 2 massive galaxies using high-resolution MERLIN radio observations
Muxlow, T. W. B.; Alexander, D. M.; Conselice, C. J. +3 more
We present high spatial resolution Multi-Element Radio-Linked Interferometer Network (MERLIN) 1.4-GHz radio observations of two high-redshift (z ~ 2) sources, RGJ123623 (HDF147) and RGJ123617 (HDF130), selected as the brightest radio sources from a sample of submillimetre-faint radio galaxies. They have starburst classifications from their rest-fr…
The accretion powered spin-up of GRO J1750-27
Hill, A. B.; Kretschmar, P.; Kuulkers, E. +3 more
The timing properties of the 4.45 s pulsar in the Be X-ray binary system GRO J1750-27 are examined using hard X-ray data from INTEGRAL and Swift during a type II outburst observed during 2008. The orbital parameters of the system are measured and agree well with those found during the last known outburst of the system in 1995. Correcting the effec…
The initial mass function of the rich young cluster NGC 1818 in the Large Magellanic Cloud
de Grijs, R.; Hu, Y.; Baraffe, I. +3 more
We use deep Hubble Space Telescope photometry of the rich, young (~20- to 45-Myr old) star cluster NGC 1818 in the Large Magellanic Cloud to derive its stellar mass function (MF) down to ~0.15Msolar. This represents the deepest robust MF thus far obtained for a stellar system in an extragalactic, low-metallicity ([Fe/H] ~= -0.4dex) envi…
2XMMiJ225036.9+573154 - a new eclipsing AMHer binary discovered using XMM-Newton
Barclay, Thomas; Ramsay, Gavin; Hakala, Pasi +1 more
We report the discovery of an eclipsing polar, 2XMMiJ225036.9+573154, using XMM-Newton. It was discovered by searching the light curves in the 2XMMi catalogue for objects showing X-ray variability. Its X-ray light curve shows a total eclipse of the white dwarf by the secondary star every 174min. An extended pre-eclipse absorption dip is observed i…
Photometric redshift accuracy in AKARI deep surveys
Im, M.; Lee, H. M.; Burgarella, D. +11 more
We investigate the photometric redshift accuracy achievable with the AKARI infrared data in deep multiband surveys, such as in the North Ecliptic Pole field. We demonstrate that the passage of redshifted polycyclic aromatic hydrocarbons (PAH) and silicate features into the mid-infrared wavelength window covered by AKARI is a valuable means to reco…
Probing re-ionization with quasar spectra: the impact of the intrinsic Lyman α emission line shape uncertainty
Haiman, Z.; Kramer, R. H.
Arguably the best hope of understanding the tail end of the re-ionization of the intergalactic medium (IGM) at redshift z > 6 is through the detection and characterization of the Gunn-Peterson damping wing absorption of the IGM in bright quasar spectra. However, the use of quasar spectra to measure the IGM damping wing requires a model of the q…
A new perspective on the irregular satellites of Saturn - II. Dynamical and physical origin
Marzari, F.; Tosi, F.; Turrini, D.
The origin of the irregular satellites of the giant planets has been long debated since their discovery. Their dynamical features argue against an in situ formation suggesting that they are captured bodies, yet there is no global consensus on the physical process at the basis of their capture. In this paper, we explore the collisional capture scen…