How the diffuse Universe cools

被引:19
作者
Bertone, Serena [1 ,2 ]
Aguirre, Anthony [2 ]
Schaye, Joop [3 ]
机构
[1] Aviospace Srl, I-10138 Turin, Italy
[2] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA
[3] Leiden Univ, Leiden Observ, NL-2300 RA Leiden, Netherlands
基金
欧洲研究理事会; 美国国家科学基金会;
关键词
radiation mechanisms: thermal; methods: numerical; intergalactic medium; diffuse radiation; HOT INTERGALACTIC MEDIUM; METAL-LINE EMISSION; SIMULATION; DETECTABILITY; IONIZATION; ABSORPTION; ABUNDANCES; FEEDBACK; MASS;
D O I
10.1093/mnras/stt131
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
In this work, we investigate the cooling channels of diffuse gas (i.e. n(H) < 0.1 cm(-3)) in cosmology. We aim to identify the wavelengths where most of the energy is radiated in the form of emission lines or continuum radiation, and the main elements and ions responsible for the emission. We use a subset of cosmological, hydrodynamical runs from the Overwhelmingly Large Simulations project to calculate the emission of diffuse gas and its evolution with time. We find that at z = 0 (z = 2) about 70 (80) per cent of the energy emitted by diffuse gas is carried by emission lines, with the continuum radiation contributing the remainder. Hydrogen lines in the Lyman series are the primary contributors to the line emission, with a share of 16 (20) per cent. Oxygen lines are the main metal contributors at high redshift, while silicon, carbon and iron lines are strongest at low redshift, when the contributions of asymptotic giant branch stars and Type Ia supernova explosions to the metal budget become important and when there is more hot gas. The ionic species carrying the most energy are O III, C II, C III, Si II, Si III, FeII and S III. The great majority of energy is emitted in the ultraviolet (UV) band (lambda = 100-4000 angstrom), both as continuum radiation and line emission. With almost no exception, all the strongest lines fall in this band. At high energies, continuum radiation is dominant (e. g. 80 per cent in the X-ray band), while lines contribute progressively more at lower energies. While the results do depend on the details of the numerical implementation of the physical processes modelled in the simulations, the comparison of results from different simulations demonstrates that the variations are overall small, and that the conclusions are fairly robust. Given the overwhelming importance of UV emission for the cooling of diffuse gas, it is desirable to build instruments dedicated to the detection and characterization of diffuse UV emission.
引用
收藏
页码:3292 / 3313
页数:22
相关论文
共 50 条
[1]  
[Anonymous], 2004, COSMOCHEMISTRY MELTI
[2]  
Bertone S., 2011, MNRAS, V419, P780
[3]   Numerical simulations of the warm-hot intergalactic medium [J].
Bertone, Serena ;
Schaye, Joop ;
Dolag, Klaus .
SPACE SCIENCE REVIEWS, 2008, 134 (1-4) :295-310
[4]   Metal-line emission from the warm-hot intergalactic medium - II. Ultraviolet [J].
Bertone, Serena ;
Schaye, Joop ;
Booth, C. M. ;
Dalla Vecchia, Claudio ;
Theuns, Tom ;
Wiersma, Robert P. C. .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2010, 408 (02) :1120-1138
[5]   Metal-line emission from the warm-hot intergalactic medium - I. Soft X-rays [J].
Bertone, Serena ;
Schaye, Joop ;
Dalla Vecchia, Claudio ;
Booth, C. M. ;
Theuns, Tom ;
Wiersma, Robert P. C. .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2010, 407 (01) :544-566
[6]   Cosmological simulations of the growth of supermassive black holes and feedback from active galactic nuclei: method and tests [J].
Booth, C. M. ;
Schaye, Joop .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2009, 398 (01) :53-74
[7]   The missing metals problem -: III.: How many metals are expelled from galaxies? [J].
Bouche, Nicolas ;
Lehnert, Matthew D. ;
Aguirre, Anthony ;
Peroux, Celine ;
Bergeron, Jacqueline .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2007, 378 (02) :525-540
[8]   Where are the baryons? III. Nonequilibrium effects and observables [J].
Cen, Renyue ;
Fang, Taotao .
ASTROPHYSICAL JOURNAL, 2006, 650 (02) :573-591
[9]   Where are the baryons? [J].
Cen, RY ;
Ostriker, JP .
ASTROPHYSICAL JOURNAL, 1999, 514 (01) :1-6
[10]   Galactic stellar and substellar initial mass function [J].
Chabrier, G .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 2003, 115 (809) :763-795