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The extraction of a 'haze' from the WMAP microwave skymaps is based on subtraction of known foregrounds, viz. free-free (bremsstrahlung), thermal dust and synchrotron, each traced by other skymaps. While the 408 MHz all-sky survey is used…

High Energy Astrophysical Phenomena · Physics 2010-10-19 Philipp Mertsch , Subir Sarkar

Accurate Hessian spectra of foundation models have remained out of reach, leading most prior work to rely on small models or strong structural approximations. We show that faithful spectral analysis of the true Hessian is tractable at…

Machine Learning · Statistics 2026-02-03 Diego Granziol , Khurshid Juarev

Polarized Galactic synchrotron emission is an undesirable foreground for cosmic microwave background (CMB) experiments observing at frequencies $< 150$ GHz. We perform a combined analysis of observational data at 1.4, 2.3, 23, 30 and 33 GHz…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Janet L. Weiland , Graeme E. Addison , Charles L. Bennett , Mark Halpern , Gary Hinshaw

We follow up on a report by Vacca et al. (2018) of 28 candidate large-scale diffuse synchrotron sources in an 8{\deg}$\times$8{\deg} area of the sky (centred at RA 5h0m0s Dec 5{\deg}48'0''). These sources were originally observed at 1.4 GHz…

Astrophysics of Galaxies · Physics 2022-05-27 Torrance Hodgson , Melanie Johnston-Hollitt , Benajmin McKinley , Tessa Vernstrom , Valentina Vacca

We present a search for the synchrotron emission from the synchrotron cosmic web by cross correlating 180MHz radio images from the Murchison Widefield Array with tracers of large scale structure (LSS). We use two versions of the radio image…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Tessa Vernstrom , Bryan M. Gaensler , Shea Brown , Emil Lenc , Ray P. Norris

Fluctuations in the Galactic synchrotron emission can be traced by the angular power spectrum of radio maps at low multipoles. At frequencies below few GHz, large-scale anisotropies are mainly induced by magnetic field turbulence. By…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Marco Regis

There have recently been several claims of an asymmetric distribution of large scale fluctuations in the WMAP data. I review some recent results from a test of isotropy of the power spectrum at all scales and show how the power is…

Astrophysics · Physics 2007-05-23 F. K. Hansen

We quantify the level of foreground contamination in the QMAP Cosmic Microwave Background (CMB) data with two objectives: (a) measuring the level to which the QMAP power spectrum measurements need to be corrected for foregrounds and (b)…

We present multi-frequency maps of a portion of the Galactic Plane centered on a declination of -60 degrees with resolutions ranging from 0.2 to 0.9 degrees. The maps are optimized to detect unresolved source emission and are…

The main goals of this study is to use the information from both WMAP intensity and polarization data to do a separation of the Galactic components, with a focus on the synchrotron and anomalous emissions. Our analysis is made at 23 GHz…

Photometric instruments operating at far infrared to millimetre wavelengths often have broad spectral passbands (central wavelength/bandwidth ~ 3 or less), especially those operating in space. A broad passband can result in significant…

We cross-correlate a 19 GHz full sky Cosmic Microwave Background (CMB) survey with other maps to quantify the foreground contribution. Correlations are detected with the Diffuse Infrared Background Experiment (DIRBE) 240, 140 and 100 micron…

Astrophysics · Physics 2009-10-30 Angelica de Oliveira-Costa , Max Tegmark , Lyman Page , Steven Boughn

We present a new model of the diffuse Galactic synchrotron radiation, concentrating on its angular anisotropies. While previous studies have focussed on either the variation of the emissivity on large (kpc) scales, or on fluctuations due to…

Astrophysics of Galaxies · Physics 2013-06-26 Philipp Mertsch , Subir Sarkar

Estimators for $n$-point clustering statistics in Fourier-space demand that modern surveys of large-scale structure be transformed to Cartesian coordinates to perform Fast Fourier Transforms (FFTs). In this work, we explore this…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-05 Steven Cunnington , Laura Wolz

We investigate the existence and meaning of a preferred length in the large-scale distribution of 60-micron IRAS sources applying three tests to the 2-dimensional distribution on the celestial sphere, involving respectively the rms…

Astrophysics · Physics 2011-05-23 R. Fabbri , V. Natale

We compute the angular power spectrum C_l from the BATSE 3B catalog of 1122 gamma-ray bursts, and find no evidence for clustering on any scale. These constraints bridge the entire range from small scales (which probe source clustering and…

Astrophysics · Physics 2009-10-07 Max Tegmark , Dieter Hartmann , Michael Briggs , Charles Meegan

We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1-year cosmic microwave background sky maps. A non-linear coupling parameter, f_NL, characterizes the amplitude of a quadratic term in the primordial…

We present a partial-sky survey of the radio continuum at 2.3 GHz within the scope of the Galactic Emission Mapping (GEM) project, an observational program conceived and developed to reveal the large-scale properties of Galactic synchrotron…

Understanding the properties of the galactic emission at millimetre wavelengths is important for studies of the cosmic microwave background (CMB). In this work we explore the bispectrum, the harmonic equivalent of the three point function,…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 William R. Coulton , David N. Spergel

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