Linear evolution of cosmic baryonic medium on large scales

Fang, Li‐Zhi; Bi, Hongguang; Shen, Xiang; Boerner, G.

doi:10.1086/173017

Cited by 44 publications

(38 citation statements)

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“…x (z ) is the matter power spectrum, and is the Jeans length P (k) x b at each redshift, which relates the matter power spectrum to that of baryons (Fang et al 1993)…”

Section: Contribution To Cmb Anisotropiesmentioning

confidence: 99%

Kinematic Sunyaev-Zel'dovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures

Atrio-Barandela

Mücket

Génova-Santos

2008

ApJ

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If the gas in filaments and halos shares the same velocity field as the luminous matter, it will generate measurable temperature anisotropies due to the kinematic Sunyaev-Zel'dovich effect. We compute the distribution function of the KSZ signal produced by a typical filament and show it is highly non-Gaussian. The combined contribution of the thermal and kinematic SZ effects of a filament of size Mpc and electron density m Ϫ3 could 3

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“…x (z ) is the matter power spectrum, and is the Jeans length P (k) x b at each redshift, which relates the matter power spectrum to that of baryons (Fang et al 1993)…”

Section: Contribution To Cmb Anisotropiesmentioning

confidence: 99%

Kinematic Sunyaev-Zel'dovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures

Atrio-Barandela

Mücket

Génova-Santos

2008

ApJ

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“…In the linear growth regime, the IGM velocity follows the dark matter velocity point by point, i.e., v(x; t) ¼ v dm (x; t) Fang et al 1993;Bi 1993;Nusser 2000). Burgers turbulence will lead to a deviation of v(x; t) from v dm (x; t).…”

Section: Relation Between the Igm And Dark Matter Velocity Fieldsmentioning

confidence: 99%

The Velocity Field of Baryonic Gas in the Universe

Kim¹,

He²,

Pando³

et al. 2005

ApJ

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The dynamic evolution of the baryonic intergalactic medium ( IGM) caused by the underlying dark matter gravity is governed by the Navier-Stokes equations in which many cooling and heating processes are involved. However, it has long been recognized that the growth mode dynamics of cosmic matter clustering can be sketched by a random force driven Burgers equation if cooling and heating are ignored. Just how well the dynamics of the IGM can be described as a Burgers fluid has not been fully investigated, probably because cooling and heating are essential for a detailed understanding of the IGM. Using IGM samples produced by a cosmological hydrodynamic simulation in which heating and cooling processes are properly accounted for, we show that the IGM velocity field in the nonlinear regime shows the features of a Burgers fluid, that is, when the Reynolds number is high, the velocity field consists of an ensemble of shocks. Consequently, (1) the IGM velocity v is generally smaller than that of dark matter; (2) for the smoothed field, the IGM velocity shows tight correlation with dark matter given by v ' sv dm , with s < 1, such that the lower the redshift, the smaller the s; (3) the velocity probability density functions ( pdf's) are asymmetric between acceleration and deceleration events; (4) the pdf of velocity difference Áv ¼ v(x þ r) À v(x) satisfies the scaling relation for a Burgers fluid, i.e., P(Áv) ¼ (1/r y )F(Áv/r y ). We find the scaling function and parameters for the IGM that are applicable to the entire scale range of the samples (0.26-8 h À1 Mpc). These properties show that the similarity mapping between the IGM and dark matter is violated on scales much larger than the Jeans length of the IGM. Subject headingg s: cosmology: theory -intergalactic medium -large-scale structure of universe

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“…It is believed that on small scales (below the Jean’s length), the bias is a scale‐dependent function. However, it is reasonably scale‐independent on large scales (Fang et al 1993). Further, the bias depends on the redshift.…”

Section: Introductionmentioning

confidence: 99%

Constraining large-scale H i bias using redshifted 21-cm signal from the post-reionization epoch

Sarkar

Mitra

Majumdar

et al. 2012

Monthly Notices of the Royal Astronomical Society

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In the absence of complex astrophysical processes that characterize the reionization era, the 21‐cm emission from neutral hydrogen (H i) in the post‐reionization epoch is believed to be an excellent tracer of the underlying dark matter distribution. Assuming a background cosmology, it is modelled through (i) a bias function b(k, z), which relates H i to the dark matter distribution and (ii) a mean neutral fraction () which sets its amplitude. In this paper, we investigate the nature of large‐scale H i bias. The post‐reionization H i is modelled using gravity only N‐body simulations and a suitable prescription for assigning gas to the dark matter haloes. Using the simulated bias as the fiducial model for H i distribution at z≤ 4, we have generated a hypothetical data set for the 21‐cm angular power spectrum (Cℓ) using a noise model based on parameters of an extended version of the Giant Metrewave Radio Telescope (GMRT). The binned Cℓ is assumed to be measured with S/N ≳ 4 in the range 400 ≤ℓ≤ 8000 at a fiducial redshift z= 2.5. We explore the possibility of constraining b(k) using the principal component analysis on these simulated data. Our analysis shows that in the range 0.2 < k < 2 Mpc−1, the simulated data set cannot distinguish between models exhibiting different k‐dependences, provided 1 ≲b(k) ≲ 2 which sets the 2σ limits. This justifies the use of linear bias model on large scales. The largely uncertain is treated as a free parameter resulting in degradation of the bias reconstruction. The given simulated data are found to constrain the fiducial with an accuracy of ∼4 per cent (2σ error). The method outlined here could be successfully implemented on future observational data sets to constrain b(k, z) and and thereby enhance our understanding of the low‐redshift Universe.

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Linear evolution of cosmic baryonic medium on large scales

Cited by 44 publications

References 0 publications

Kinematic Sunyaev-Zel'dovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures

Kinematic Sunyaev-Zel'dovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures

The Velocity Field of Baryonic Gas in the Universe

Constraining large-scale H i bias using redshifted 21-cm signal from the post-reionization epoch

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