Cosmology

Research group

Sub department

About

GalICS II: the [alpha/Fe]-mass relation in elliptical galaxies

(2008)

Authors:

A Pipino, JEG Devriendt, D Thomas, J Silk, S Kaviraj
More details from the publisher

GalICS II: the [alpha/Fe]-mass relation in elliptical galaxies

ArXiv 0810.5753 (2008)

Authors:

A Pipino, JEG Devriendt, D Thomas, J Silk, S Kaviraj

Abstract:

We aim at reproducing the mass- and sigma-[alpha/Fe] relations in the stellar populations of early-type galaxies by means of a cosmologically motivated assembly history for the spheroids. We implement a detailed treatment for the chemical evolution of H, He, O and Fe in GalICS, a semi-analytical model for galaxy formation which successfully reproduces basic low- and high-redshift galaxy properties. The contribution of supernovae (both type Ia and II) as well as low- and intermediate-mass stars to chemical feedback are taken into account. We find that this chemically improved GalICS does not produce the observed mass- and sigma-[alpha/Fe] relations. The slope is too shallow and scatter too large, in particular in the low and intermediate mass range. The model shows significant improvement at the highest masses and velocity dispersions, where the predicted [alpha/Fe] ratios are now marginally consistent with observed values. We show that this result comes from the implementation of AGN (plus halo) quenching of the star formation in massive haloes. A thorough exploration of the parameter space shows that the failure of reproducing the mass- and sigma-[alpha/Fe] relations can partly be attributed to the way in which star formation and feedback are currently modelled. The merger process is responsible for a part of the scatter. We suggest that the next generation of semi-analytical model should feature feedback (either stellar of from AGN) mechanisms linked to single galaxies and not only to the halo, especially in the low and intermediate mass range. The integral star formation history of a single galaxy determines its final stellar [alpha/Fe] as it might be expected from the results of closed box chemical evolution models. (abridged)
Details from ArXiV
More details from the publisher
More details

The 2dF-SDSS LRG and QSO Survey: The spectroscopic QSO catalogue

ArXiv 0810.4955 (2008)

Authors:

Scott M Croom, Gordon T Richards, Tom Shanks, Brian J Boyle, Robert G Sharp, Joss Bland-Hawthorn, Terry Bridges, Robert J Brunner, Russell Cannon, Daniel Carson, Kuenley Chiu, Matthew Colless, Warrick Couch, Roberto De Propris, Michael J Drinkwater, Alastair Edge, Stephen Fine, Jon Loveday, Lance Miller, Adam D Myers, Robert C Nichol, Phil Outram, Kevin Pimbblet, Isaac Roseboom, Nicholas Ross, Donald P Schneider, Allyn Smith, Chris Stoughton, Michael A Strauss, David Wake

Abstract:

We present the final spectroscopic QSO catalogue from the 2dF-SDSS LRG and QSO (2SLAQ) Survey. This is a deep, 18
More details from the publisher
More details
Details from ArXiV

The Cℓover experiment

Proceedings of SPIE the International Society for Optical Engineering 7020 (2008)

Authors:

L Piccirillo, P Ade, MD Audley, C Baines, R Battye, M Brown, P Calisse, A Challinor, WD Duncan, P Ferreira, W Gear, DM Glowacka, D Goldie, PK Grimes, M Halpern, V Haynes, GC Hilton, KD Irwin, B Johnson, M Jones, A Lasenby, P Leahy, J Leech, S Lewis, B Maffei, L Martinis, PD Mauskopf, SJ Melhuish, CE North, D O'Dea, S Parsley, G Pisano, CD Reintsema, G Savini, RV Sudiwala, D Sutton, A Taylor, G Teleberg, D Titterington, VN Tsaneva, C Tucker, R Watson, S Withington, G Yassin, J Zhang

Abstract:

CℓOVER is a multi-frequency experiment optimised to measure the Cosmic Microwave Background (CMB) polarization, in particular the B-mode component. CℓOVER comprises two instruments observing respectively at 97 GHz and 150/225 GHz. The focal plane of both instruments consists of an array of corrugated feed-horns coupled to TES detectors cooled at 100 mK. The primary science goal of CℓOVER is to be sensitive to gravitational waves down to r ∼ 0.03 (at 3σ) in two years of operations.
More details from the publisher

A young, dusty, compact radio source within a Lyα halo

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 389:2 (2008) 792-798

Authors:

F Eugenio Barrio, Matt J Jarvis, Steve Rawlings, Amanda Bauer, Steve Croft, Gary J Hill, Arturo Manchado, Ross J McLure, Daniel JB Smith, Thomas A Targett
More details from the publisher
Details from ORA
Details from ArXiV