Properties of the diffuse X-ray background in a high-resolution hydrodynamical simulation

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	Properties of the diffuse X-ray background in a high-resolution hydrodynamical simulation
	Dolag, K; Roncarelli, M , Univ Bologna, Dipartimento Astron, Via Ranzani 1, I-40127 Bologna, Italy; Murante, G; Roncarelli, M; Moscardini, L; Tozzi, P; Borgani, S; Cheng, LM; Diaferio, A
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2006
卷号	368 期号:1 页码:74-84
关键词	Sunyaev-zeldovich Effect(s) Deep Field-south Intracluster Medium Galaxy Clusters Xmm-newton Surface Brightness Chandra Evolution Baryons Entropy
ISSN号	0035-8711
英文摘要	We study the properties of the diffuse X-ray background by using the results of a cosmological hydrodynamical simulation of the concordance Lambda cold dark matter (Lambda CDM) model. The simulation follows gravitational and gas dynamics and includes a treatment of physical processes, such as radiative cooling, star formation and supernova feedback. From the simulation outputs, we produce a set of two-dimensional maps of the intergalactic medium X-ray emission integrated over redshift. We find that the signal in the soft (0.5-2 keV) band is lognormally distributed with a mean intensity of about 4 x 10(-12) erg s(-1) cm(-2) deg(-2); approximately 40 per cent of the emission originates from warm-hot gas ( defined as baryons with 10(5) < T < 10(7) K), and 90 per cent comes from structures at z < 0.9. Since the spectrum is soft, being mostly provided by the intergalactic medium at low temperature, the total mean intensity in the hard (2-10 keV) X-ray band is smaller by a factor of about 4. In order to constrain the physical processes included in our simulation, we compare our results with the observed upper limit (1.2 +/- 0.3) x 10(-12) erg s(-1) cm(-2) deg(-2) of the soft X-ray emission due to diffuse gas. To this purpose, we remove the contributions of observable extended objects ( groups and clusters of galaxies) from the simulated maps by adopting different detectability criteria which are calibrated on the properties of systems at intermediate redshifts observed by Chandra. We show that the simulated diffuse soft X-ray emission is consistent with the present observed upper limit. However, if future measurements will decrease the level of the unresolved X-ray background by a factor of 2, a more efficient feedback mechanism should be required to suppress the soft emission of the gas residing within filaments and group-size haloes.
学科主题	Physics
URL标识	查看原文
WOS记录号	WOS:000236797600023
公开日期	2012-08-02
内容类型	期刊论文
源URL	[http://ir.itp.ac.cn/handle/311006/5996]
专题	理论物理研究所_理论物理所1978-2010年知识产出
通讯作者	Roncarelli, M , Univ Bologna, Dipartimento Astron, Via Ranzani 1, I-40127 Bologna, Italy
推荐引用方式 GB/T 7714	Dolag, K,Roncarelli, M , Univ Bologna, Dipartimento Astron, Via Ranzani 1, I-40127 Bologna, Italy,Murante, G,et al. Properties of the diffuse X-ray background in a high-resolution hydrodynamical simulation[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2006,368(1):74-84.
APA	Dolag, K.,Roncarelli, M , Univ Bologna, Dipartimento Astron, Via Ranzani 1, I-40127 Bologna, Italy.,Murante, G.,Roncarelli, M.,Moscardini, L.,...&Diaferio, A.(2006).Properties of the diffuse X-ray background in a high-resolution hydrodynamical simulation.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,368(1),74-84.
MLA	Dolag, K,et al."Properties of the diffuse X-ray background in a high-resolution hydrodynamical simulation".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 368.1(2006):74-84.