scholarly journals Thermal Sunyaev–Zel’dovich Effect in the IGM due to Primordial Magnetic Fields

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 143 ◽  
Author(s):  
Teppei Minoda ◽  
Kenji Hasegawa ◽  
Hiroyuki Tashiro ◽  
Kiyotomo Ichiki ◽  
Naoshi Sugiyama
Keyword(s):  
Magnetic Fields ◽  
Power Spectrum ◽  
Mass Density ◽  
Temperature Anisotropy ◽  
Angular Power Spectrum ◽  
Stringent Constraint ◽  
Small Scales ◽  
Sunyaev Zel'dovich Effect ◽  
Primordial Magnetic Fields ◽  
Initial Power

In the present universe, magnetic fields exist with various strengths and on various scales. One possible origin of these cosmic magnetic fields is the primordial magnetic fields (PMFs) generated in the early universe. PMFs are considered to contribute to matter density evolution via Lorentz force and the thermal history of intergalactic medium (IGM) gas due to ambipolar diffusion. Therefore, information about PMFs should be included in the temperature anisotropy of the Cosmic Microwave Background through the thermal Sunyaev–Zel’dovich (tSZ) effect in IGM. In this article, given an initial power spectrum of PMFs, we show the spatial fluctuation of mass density and temperature of the IGM and tSZ angular power spectrum created by the PMFs. Finally, we find that the tSZ angular power spectrum induced by PMFs becomes significant on small scales, even with PMFs below the observational upper limit. Therefore, we conclude that the measurement of tSZ anisotropy on small scales will provide the most stringent constraint on PMFs.

scholarly journals An Accurate Reconstruction of CMB E Mode Signal over Large Angular Scales using Prior Information of CMB Covariance Matrix in ILC Algorithm

2020 ◽  
Author(s):  
Ujjal Purkayastha ◽  
Vipin Sudevan ◽  
Rajib Saha
Keyword(s):  
Power Spectrum ◽  
Linear Combination ◽  
Covariance Matrix ◽  
Large Scale ◽  
Prior Information ◽  
Future Generation ◽  
Temperature Anisotropy ◽  
Satellite Mission ◽  
Angular Power Spectrum ◽  
Accurate Reconstruction

Abstract Recently, the internal-linear-combination (ILC) method was investigated extensively in the context of reconstruction of Cosmic Microwave Background (CMB) temperature anisotropy signal using observations obtained by WMAP and Planck satellite missions. In this article, we, for the first time, apply the ILC method to reconstruct the large scale CMB E mode polarization signal, which could probe the ionization history, using simulated observations of 15 frequency CMB polarization maps of future generation Cosmic Origin Explorer (COrE) satellite mission. We find that the clean power spectra, from the usual ILC, are strongly biased due to non zero CMB-foregrounds chance correlations. In order to address the issues of bias and errors we extend and improve the usual ILC method for CMB E mode reconstruction by incorporating prior information of theoretical E mode angular power spectrum while estimating the weights for linear combination of input maps (Sudevan & Saha 2018b). Using the E mode covariance matrix effectively suppresses the CMB-foreground chance correlation power leading to an accurate reconstruction of cleaned CMB E mode map and its angular power spectrum. We compare the performance of the usual ILC and the new method over large angular scales and show that the later produces significantly statistically improved results than the former. The new E mode CMB angular power spectrum contains neither any significant negative bias at the low multipoles nor any positive foreground bias at relatively higher mutlipoles. The error estimates of the cleaned spectrum agree very well with the cosmic variance induced error.

scholarly journals Primordial magnetism in CMB B modes

2013 ◽  
Vol 91 (6) ◽  
pp. 451-454 ◽  
Author(s):  
Levon Pogosian ◽  
Tanmay Vachaspati ◽  
Amit Yadav
Keyword(s):  
Magnetic Fields ◽  
Cosmic Microwave Background ◽  
Frequency Dependence ◽  
Faraday Rotation ◽  
Characteristic Frequency ◽  
Mode Coupling ◽  
Microwave Background ◽  
Small Scales ◽  
Cmb Polarization ◽  
Primordial Magnetic Fields

Cosmic microwave background (CMB) polarization B modes induced by Faraday rotation (FR) can provide a distinctive signature of primordial magnetic fields because of their characteristic frequency dependence and because they are only weakly damped on small scales. FR also leads to mode-coupling correlations between the E- and B-type polarizations and between the temperature and the B mode. These additional correlations can further help distinguish magnetic fields from other sources of B modes. We review the FR-induced CMB signatures and present the constraints on primordial magnetism that can be expected from upcoming CMB experiments. Our results suggest that FR of CMB will be a promising probe of primordial magnetic fields.

scholarly journals Thermal Sunyaev-Zel’dovich effect in the intergalactic medium with primordial magnetic fields

2017 ◽  
Vol 96 (12) ◽  
Author(s):  
Teppei Minoda ◽  
Kenji Hasegawa ◽  
Hiroyuki Tashiro ◽  
Kiyotomo Ichiki ◽  
Naoshi Sugiyama
Keyword(s):  
Magnetic Fields ◽  
Intergalactic Medium ◽  
Sunyaev Zel'dovich Effect ◽  
Primordial Magnetic Fields

scholarly journals A Measurement of the Angular Power Spectrum of the CMB Temperature Anisotropy from the 2003 Flight of BOOMERANG

2006 ◽  
Vol 647 (2) ◽  
pp. 823-832 ◽  
Author(s):  
W. C. Jones ◽  
P. A. R. Ade ◽  
J. J. Bock ◽  
J. R. Bond ◽  
J. Borrill ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Temperature Anisotropy ◽  
Angular Power Spectrum ◽  
Cmb Temperature

scholarly journals The CMB angular power spectrum via component separation: a study on Planck data

2019 ◽  
Vol 624 ◽  
pp. A67
Author(s):  
C. Umiltà ◽  
J. F. Cardoso ◽  
K. Benabed ◽  
M. Le Jeune
Keyword(s):  
Power Spectrum ◽  
Point Source ◽  
Cosmological Parameters ◽  
Point Sources ◽  
Blind Separation ◽  
Microwave Background ◽  
Angular Power Spectrum ◽  
Planck Data ◽  
Small Scales ◽  
Source Emission

Aims. We investigate the extent to which foreground-cleaned cosmic microwave background (CMB) maps can be used to estimate cosmological parameters at small scales. Methods. We use the SMICA method, a blind separation technique that works directly at the spectral level. In this work we focus on the small scales of the CMB angular power spectrum, which are chiefly affected by noise and extragalactic foregrounds, such as point sources. We adapt SMICA to use only cross-spectra between data maps, thus avoiding the noise bias. In this study, performed using both simulations and Planck 2015 data, we fit for extragalactic point sources by modelling them as shot noise of two independent populations. Results. In simulations, we correctly recover the point-source emission law, and obtain a CMB angular power spectrum that has an average foreground residual of one fifth of the CMB power at ℓ ≥ 2200. With Planck data, the recovered point-source emission law corresponds to external estimates, with some offsets at the highest and lowest frequencies, possibly due to frequency decoherence of point sources. The CMB angular power spectrum residuals are consistent with what we find in simulations. The cosmological parameters obtained from the simulations and the data show offsets up to 1σ on average from their expected values. Biases on cosmological parameters in simulations represent the expected level of bias in Planck data. Conclusions. The results on cosmological parameters depend on the detail of the foreground residual contamination in the spectrum, and therefore a tailored modelling of the likelihood foreground model is required.

scholarly journals Constraining the primordial magnetic field with dwarf galaxy simulations

2020 ◽  
Vol 643 ◽  
pp. A54 ◽  
Author(s):  
Mahsa Sanati ◽  
Yves Revaz ◽  
Jennifer Schober ◽  
Kerstin E. Kunze ◽  
Pascale Jablonka
Keyword(s):  
Dark Matter ◽  
Magnetic Fields ◽  
Power Spectrum ◽  
Dwarf Galaxies ◽  
Magnetic Energy ◽  
Dwarf Galaxy ◽  
High Amplitude ◽  
Density Fluctuations ◽  
Large Set ◽  
Primordial Magnetic Fields

Using a set of cosmological hydro-dynamical simulations, we constrained the properties of primordial magnetic fields by studying their impact on the formation and evolution of dwarf galaxies. We performed a large set of simulations (8 dark matter only and 72 chemo-hydrodynamical) including primordial magnetic fields through the extra density fluctuations they induce at small length scales (k ≥ 10 h Mpc−1) in the matter power spectrum. Our sample of dwarfs includes nine systems selected out of the initial (3.4 Mpc h−1)3 parent box, resimulated from z = 200 to z = 0 using a zoom-in technique and including the physics of baryons. We explored a wide variety of primordial magnetic fields with strength Bλ ranging from 0.05 to 0.50 nG and magnetic energy spectrum slopes nB from −2.9 to −2.1. Strong magnetic fields characterized by a high amplitude (Bλ = 0.50,  0.20 nG with nB = −2.9) or by a steep initial power spectrum slope (nB = −2.1, −2.4, with Bλ = 0.05 nG) induce perturbations on mass scales from 107 to 109 M⊙. In this context emerging galaxies see their star formation rates strongly boosted. They become more luminous and metal rich than their counterparts without primordial magnetic fields. Such strong fields are ruled out by their inability to reproduce the observed scaling relations of dwarf galaxies. They predict that dwarf galaxies are at the origin of an unrealistically early reionization of the Universe and that they also overproduce luminous satellites in the Local Group. Weaker magnetic fields impacting the primordial density field at corresponding masses ≲106 M⊙, produce a large number of mini dark matter halos orbiting the dwarfs, however out of reach for current lensing observations. This study allows us, for the first time, to constrain the properties of primordial magnetic fields based on realistic cosmological simulations of dwarf galaxies.

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