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We measure the topology (genus) of isodensity contour surfaces in volume limited subsets of the 1.2 Jy IRAS redshift survey, for smoothing scales $\lambda=4\hmpc$, $7\hmpc$, and $12\hmpc$. At $12\hmpc$, the observed genus curve has a…

Astrophysics · Physics 2009-10-30 Zacharias A. M. Protogeros , David H. Weinberg

The "dark flow" dipole is a statistically significant dipole found at the position of galaxy clusters in filtered maps of Cosmic Microwave Background (CMB) temperature anisotropies. The dipole measured in WMAP 3, 5 and 7 yr data releases…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-23 Fernando Atrio-Barandela , Alexander Kashlinsky , Harald Ebeling , Dale J. Fixsen , Dale Kocevski

We generate the peculiar velocity field for the 2MASS Redshift Survey (2MRS) catalog using an orbit-reconstruction algorithm. The reconstructed velocities of individual objects in 2MRS are well-correlated with the peculiar velocities…

Astrophysics · Physics 2012-02-08 G. Lavaux , R. Brent Tully , R. Mohayaee , S. Colombi

The divergence of the momentum density field of the large scale structure generates a secondary anisotropy contribution to the Cosmic Microwave Background (CMB). While the effect is best described as a non-linear extension to the well-known…

Astrophysics · Physics 2009-11-13 Asantha Cooray , Naoki Seto

There have been recent reports of unexpectedly large velocity dipole in the NRAO VLA Sky Survey data. We investigate whether the excess in the NVSS dipole reported can be of cosmological origin. We assume a long wavelength inhomogeneous…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 Shamik Ghosh

We critically assess the impact of significant dipole and large-scale anisotropies on galaxy clustering signals, with a focus on radio continuum surveys. Our study reveals that these anisotropies -- resulting from intrinsic cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-15 Prabhakar Tiwari

We investigate dipole asymmetries in four large radio surveys, each spanning more than 80\% of the sky. Two of them, the Very Large Array Sky Survey (VLASS) and the Rapid ASKAP Continuum Survey (RACS), have recently yielded dipoles that…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Ashok K. Singal

A number of cosmic-ray observatories have measured a change in both phase and amplitude of the dipole component in the distribution of cosmic-ray arrival directions above a primary energy of 100 TeV. We focus on probing the cosmic-ray…

High Energy Astrophysical Phenomena · Physics 2021-08-23 A. M. Taylor , G. Giacinti , P. Desiati , J. C. Diaz Velez , A. Chiavassa , G. Di Sciascio , J. C. Arteaga Velazquez , S. Kunwar

We design a new observable, the expansion rate fluctuation $\eta$, to characterize deviations from the linear relation between redshift and distance in the local universe. We also show how to compress the resulting signal into spherical…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Basheer Kalbouneh , Christian Marinoni , Julien Bel

In the standard diffusive picture for transport of cosmic rays (CRs), a gradient in the CR density induces a typically small, dipolar anisotropy in their arrival directions. This has been widely advertised as a tool for finding nearby…

High Energy Astrophysical Phenomena · Physics 2015-01-15 Philipp Mertsch , Stefan Funk

We study the signal of anisotropy in AGNs/quasars of CatWISE2020 catalogue using different observables. It has been reported earlier that this data shows a strong signal of dipole anisotropy in the source number counts. We test this claim…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-06 Rahul Kothari , Mohit Panwar , Gurmeet Singh , Prabhakar Tiwari , Pankaj Jain

A key test of the isotropy of the Universe on large scales consists in comparing the dipole in the Cosmic Microwave Background (CMB) temperature with the dipole in the distribution of sources at low redshift. Current analyses find a dipole…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 N. Grimm , M. Pijnenburg , S. Mastrogiovanni , C. Bonvin , S. Foffa , G. Cusin

Our local motion with respect to the cosmic frame of rest is believed to be dominantly responsible for the observed dipole anisotropy in the Cosmic Microwave Background Radiation (CMBR). We study the effect of this motion on the sky…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Gopal Kashyap , Naveen K. Singh , Khun Sang Phukon , Sarah Caudill , Pankaj Jain

We propose a data-driven approach to reconstruct the all-sky distribution of the dispersion measure contribution from the Galactic halo ($\mathrm{DM_{halo}}$) through a spherical harmonic expansion, enabling an investigation of its possible…

Astrophysics of Galaxies · Physics 2026-01-07 Yang Liu , Bao Wang , Puxun Wu , Jun-Jie Wei , Xue-Feng Wu

In this paper we analyse the alignment of galaxy groups with the surrounding large scale structure traced by spectroscopic galaxies from the Sloan Digital Sky Survey Data Release 7. We characterise these alignments by means of an extension…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Dante J. Paz , Mario A. Sgró , Manuel Merchán , Nelson Padilla

We present a detailed analysis (including redshift tomography) of the cosmic dipoles in the Keck+VLT quasar absorber and in the Union2 SnIa samples. We show that the fine structure constant cosmic dipole obtained through the Keck+VLT quasar…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Antonio Mariano , Leandros Perivolaropoulos

We propose a novel representation of cosmic microwave anisotropy maps, where each multipole order l is represented by l unit vectors pointing in directions on the sky and an overall magnitude. These "multipole vectors and scalars" transform…

Astrophysics · Physics 2008-11-26 C. J. Copi , D. Huterer , G. D. Starkman

Motivated by the ~7 % dipole anisotropy in the distribution of ultra-high energy cosmic-rays (UHECRs) above 8 EeV, we explore the anisotropy induced by the large scale structure, using constrained simulations of the local Universe and…

High Energy Astrophysical Phenomena · Physics 2019-01-23 Noémie Globus , Tsvi Piran , Yehuda Hoffman , Edoardo Carlesi , Daniel Pomarède

The peculiar motion of the Earth causes a dipole anisotropy modulation in the distant galaxy distribution due to the aberration effect. However, the amplitude and angular direction of the effect is not necessarily the same as those of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Yousuke Itoh , Kazuhiro Yahata , Masahiro Takada

We report a possible dipole anisotropy on acceleration scale $g_{\dag}$ with 147 rotationally supported galaxies in local Universe. It is found that a monopole and dipole correction for the radial acceleration relation can better describe…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-16 Zhe Chang , Hai-Nan Lin , Zhi-Chao Zhao , Yong Zhou