Extracting the spectral index of the intergalactic magnetic field from radio polarizations

Tiwari, Prabhakar; Jain, Pankaj

doi:10.1093/mnras/stw1108

Cited by 14 publications

(22 citation statements)

References 31 publications

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“…A similar phenomenon has also been observed in the case of radio polarizations from distant sources. In this case the correlation was seen on a smaller scale of about 100 Mpc (Tiwari & Jain 2013;Pelgrims & Hutsemékers 2015;Tiwari & Jain 2016). Furthermore radio jets from distant galaxies were found to be aligned on a distance scales greater than 20 Mpc (Taylor & Jagannathan 2016).…”

Section: Introductionmentioning

confidence: 70%

Alignment of Radio Galaxy Axes using FIRST Catalogue

Panwar,

Sandhu,

Wadadekar

et al. 2020

Preprint

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We study the alignment of radio galaxies axes using the FIRST catalogue. we impose several cuts in order to select the candidates which are most likely to be free of systematic bias. In our study we primarily focus on testing for alignment among sources within a certain angular separation from one another since for most sources redshift information is not available. We find a very significant effect for angular distances less than 1 degrees. The distance scale of alignment is found to be roughly 28 Mpc, in agreement with earlier estimates, assuming that these sources are dominantly at redshift of 0.8. However we are not able to entirely rule out the possibility of systematic bias in data. We also perform a full three dimensional analysis using a smaller data sample for which redshift information is available. In this case we only find a very weak signal at much larger distances.

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Section: Introductionmentioning

confidence: 70%

Alignment of Radio Galaxy Axes using FIRST Catalogue

Panwar,

Sandhu,

Wadadekar

et al. 2020

Preprint

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“…The Square Kilometer Array has the capability to convincingly test several of these effects. These include the dipole anisotropy in radio polarization angles (Jain and Ralston 1999), the dipole in the number counts and sky brightness (Blake and Wall 2002, Singal 2011, Gibelyou and Huterer 2012, Tiwari and Jain 2015a, Rubart and Schwarz 2013 and in the polarized number counts and polarized flux (Tiwari and Jain 2015b). These observations may indicate that we need to go beyond the standard Big Bang cosmology.…”

Section: Discussionmentioning

confidence: 99%

A Practical Model of Godel–Planck–Hubble–Birch Universe

U.V¹,

Lakshminarayana²

2019

AJS

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By considering 'Planck mass' as a characteristic massive seed and by replacing big bang with a growing Planck ball, an evolving model of quantum cosmology can be developed. With reference to increasing support for large scale cosmic anisotropy, preferred directions, quantum mechanical demand of cosmic spin and by considering a decreasing trend of angular velocity, from the beginning of Planck scale, we have developed a procedure for estimating the trend of all cosmic physical parameters. From and about the baby universe, in all directions, cosmic acceleration can be understood with increasing expansion velocity and decreasing total matter density ratio. We would like suggest that, from the beginning of Planck scale, 1) Dark matter can be considered as a kind of cosmic foam responsible for formation of galaxies. 2) Cosmic angular velocity decreases with square of the decreasing cosmic temperature. 3) Increasing ratio of Hubble parameter to angular velocity plays a crucial role in estimating increasing cosmic expansion velocity and decreasing total matter density ratio. 4) There is no need to consider dark energy for understanding cosmic acceleration. With further study, cosmological nucleosynthesis and dark matter synthesis along with mass generation mechanism can be reviewed in a quantum cosmological approach.

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“…Furthermore the SKA redshift survey would allow a 3 dimensional analysis which will provide an unambiguous test of this phenomenon, both at the supercluster scale Jain, 2013, 2015b) and on larger cosmological distance scales (Pelgrims and Hutsemékers, 2015). Within the framework of the theoretical model of Tiwari and Jain (2015b), it will allow a clean extraction of the spectral index of the supercluster magnetic field at distance scales of order 100 Mpc. On cluster scales of order few Mpc, cosmological magneto-hydrodynamic simulations lead to a spectral index of 2.7 for the corresponding magnetic field.…”

Section: Ska Technical Details and Capabilitiesmentioning

confidence: 99%

“…On cluster scales of order few Mpc, cosmological magneto-hydrodynamic simulations lead to a spectral index of 2.7 for the corresponding magnetic field. It may be interesting to apply the formalism proposed in Tiwari and Jain (2015b) and extract the magnetic field spectral index by studying correlations between the radio linear polarizations at this distance scale. This will require large amount of data on linear polarizations of galaxies separated by distances of order Mpc.…”

Section: Ska Technical Details and Capabilitiesmentioning

confidence: 99%

Probing Statistical Isotropy of Cosmological Radio Sources using Square Kilometre Array

et al. 2016

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There currently exist many observations which are not consistent with the cosmological principle. We review these observations with a particular emphasis on those relevant for Square Kilometre Array (SKA). In particular, several different data sets indicate a preferred direction pointing approximately towards the Virgo cluster. We also observe a hemispherical anisotropy in the Cosmic Microwave Background Radiation (CMBR) temperature fluctuations. Although these inconsistencies may be attributed to systematic effects, there remains the possibility that they indicate new physics and various theories have been proposed to explain them. One possibility, which we discuss in this review, is the generation of perturbation modes during the early pre-inflationary epoch, when the Universe may not obey the cosmological principle. Better measurements will provide better constraints on these theories. In particular, we propose measurement of the dipole in number counts, sky brightness, polarized flux and polarization orientations of radio sources. We also suggest test of alignment of linear polarizations of sources as a function of their relative separation. Finally we propose measurement of hemispherical anisotropy or equivalently dipole modulation in radio sources.

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Extracting the spectral index of the intergalactic magnetic field from radio polarizations

Cited by 14 publications

References 31 publications

Alignment of Radio Galaxy Axes using FIRST Catalogue

Alignment of Radio Galaxy Axes using FIRST Catalogue

A Practical Model of Godel–Planck–Hubble–Birch Universe

Probing Statistical Isotropy of Cosmological Radio Sources using Square Kilometre Array

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