Cosmology

Research group

Sub department

About

A comprehensive view of a strongly lensed planck-associated submillimeter galaxy

Astrophysical Journal 753:2 (2012)

Authors:

H Fu, E Jullo, A Cooray, RS Bussmann, RJ Ivison, I Pérez-Fournon, SG Djorgovski, N Scoville, L Yan, DA Riechers, J Aguirre, R Auld, M Baes, AJ Baker, M Bradford, A Cava, DL Clements, H Dannerbauer, A Dariush, G De Zotti, H Dole, L Dunne, S Dye, S Eales, D Frayer, R Gavazzi, M Gurwell, AI Harris, D Herranz, R Hopwood, C Hoyos, E Ibar, MJ Jarvis, S Kim, L Leeuw, R Lupu, S Maddox, P Martínez-Navajas, MJ Michałowski, M Negrello, A Omont, M Rosenman, D Scott, S Serjeant, I Smail, AM Swinbank, E Valiante, A Verma, J Vieira, JL Wardlow, P Van Der Werf

Abstract:

We present high-resolution maps of stars, dust, and molecular gas in a strongly lensed submillimeter galaxy (SMG) at z = 3.259. HATLAS J114637.9-001132 is selected from the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) as a strong lens candidate mainly based on its unusually high 500 μm flux density (300mJy). It is the only high-redshift Planck detection in the 130deg2 H-ATLAS Phase-I area. Keck Adaptive Optics images reveal a quadruply imaged galaxy in the K band while the Submillimeter Array and the Jansky Very Large Array show doubly imaged 880 μm and CO(1→0) sources, indicating differentiated distributions of the various components in the galaxy. In the source plane, the stars reside in three major kpc-scale clumps extended over 1.6kpc, the dust in a compact (∼1 kpc) region ∼3kpc north of the stars, and the cold molecular gas in an extended (∼7kpc) disk ∼5kpc northeast of the stars. The emissions from the stars, dust, and gas are magnified by ∼17, ∼8, and ∼7times, respectively, by four lensing galaxies at z ∼1. Intrinsically, the lensed galaxy is a warm (T dust ∼40-65 K), hyper-luminous (L IR ∼ 1.7 × 1013 L star formation rate (SFR) ∼2000 M yr-1), gas-rich (M gas/M baryon 70%), young (M stellar/SFR 20Myr), and short-lived (M gas/SFR 40Myr) starburst. With physical properties similar to unlensed z > 2 SMGs, HATLAS J114637.9-001132 offers a detailed view of a typical SMG through a powerful cosmic microscope. © 2012. The American Astronomical Society. All rights reserved..
More details from the publisher
More details
Details from ArXiV

Supernova simulations and strategies for the dark energy survey

Astrophysical Journal 753:2 (2012)

Authors:

JP Bernstein, R Kessler, S Kuhlmann, R Biswas, E Kovacs, G Aldering, I Crane, CB D'Andrea, DA Finley, JA Frieman, T Hufford, MJ Jarvis, AG Kim, J Marriner, P Mukherjee, RC Nichol, P Nugent, D Parkinson, RRR Reis, M Sako, H Spinka, M Sullivan

Abstract:

We present an analysis of supernova light curves simulated for the upcoming Dark Energy Survey (DES) supernova search. The simulations employ a code suite that generates and fits realistic light curves in order to obtain distance modulus/redshift pairs that are passed to a cosmology fitter. We investigated several different survey strategies including field selection, supernova selection biases, and photometric redshift measurements. Using the results of this study, we chose a 30deg2 search area in the griz filter set. We forecast (1) that this survey will provide a homogeneous sample of up to 4000 TypeIa supernovae in the redshift range 0.05
More details from the publisher
More details
Details from ArXiV

Herschel-ATLAS: VISTA VIKING near-infrared counterparts in the Phase 1 GAMA 9-h data

\mnras 423 (2012) 2407-2424-2407-2424

Authors:

S Fleuren, W Sutherland, L Dunne, DJB Smith, SJ Maddox, J González-Nuevo, J Findlay, R Auld, M Baes, NA Bond, DG Bonfield, N Bourne, A Cooray, S Buttiglione, A Cava, A Dariush, G De Zotti, SP Driver, S Dye, S Eales, J Fritz, MLP Gunawardhana, R Hopwood, E Ibar, RJ Ivison, MJ Jarvis, L Kelvin, A Lapi, J Liske, MJ Micha lowski, M Negrello, E Pascale, M Pohlen, M Prescott, EE Rigby, A Robotham, D Scott, P Temi, MA Thompson, E Valiante, PVD Werf
More details from the publisher
More details
Details from ArXiV

Blowing cold flows away: the impact of early AGN activity on the formation of a brightest cluster galaxy progenitor

(2012)

Authors:

Yohan Dubois, Christophe Pichon, Julien Devriendt, Joseph Silk, Martin Haehnelt, Taysun Kimm, Adrianne Slyz
More details from the publisher

Blowing cold flows away: the impact of early AGN activity on the formation of a brightest cluster galaxy progenitor

ArXiv 1206.5838 (2012)

Authors:

Yohan Dubois, Christophe Pichon, Julien Devriendt, Joseph Silk, Martin Haehnelt, Taysun Kimm, Adrianne Slyz

Abstract:

Supermassive black holes (BH) are powerful sources of energy that are already in place at very early epochs of the Universe (by z=6). Using hydrodynamical simulations of the formation of a massive M_vir=5 10^11 M_sun halo by z=6 (the most massive progenitor of a cluster of M_vir=2 10^15 M_sun at z=0), we evaluate the impact of Active Galactic Nuclei (AGN) on galaxy mass content, BH self-regulation, and gas distribution inside this massive halo. We find that SN feedback has a marginal influence on the stellar structure, and no influence on the mass distribution on large scales. In contrast, AGN feedback alone is able to significantly alter the stellar-bulge mass content by quenching star formation when the BH is self-regulating, and by depleting the cold gas reservoir in the centre of the galaxy. The growth of the BH proceeds first by a rapid Eddington-limited period fed by direct cold filamentary infall. When the energy delivered by the AGN is sufficiently large to unbind the cold gas of the bulge, the accretion of gas onto the BH is maintained both by smooth gas inflow and clump migration through the galactic disc triggered by merger-induced torques. The feedback from the AGN has also a severe consequence on the baryon mass content within the halo, producing large-scale hot superwinds, able to blow away some of the cold filamentary material from the centre and reduce the baryon fraction by more than 30 per cent within the halo's virial radius. Thus in the very young universe, AGN feedback is likely to be a key process, shaping the properties of the most massive galaxies.
Details from ArXiV
More details from the publisher
Details from ORA
More details