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Related papers: Effect of errors on arm asymmetry of doubles

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We establish a dynamical mechanism to explain the origin of the asymmetry between the arms observed in some barred disk galaxies, where one of the two arms emanating from the bar ends is very well defined, while the second one displays a…

Astrophysics of Galaxies · Physics 2023-01-31 P. Sánchez-Martín , C. García-Gómez , J. J. Masdemont , M. Romero-Gómez

The distributions of galaxies in the environments of 16 large radio sources have been examined using the Sloan Digital Sky Survey. In the giant radio galaxy J1552+2005 (3C326) which has the highest arm-length ratio, the shorter arm is found…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Pirya , D. J. Saikia , M. Singh , H. C. Chandola

Cosmic-ray antiprotons are a remarkable diagnostic tool for the study of astroparticle physics' processes in our Galaxy. While the bulk of measured antiprotons is consistent with a secondary origin, several studies have found evidence for a…

High Energy Astrophysical Phenomena · Physics 2021-08-02 Jan Heisig , Michael Korsmeier , Martin Wolfgang Winkler

The random error of radioastronomical measurements is usually computed in the weak-signal limit, which assumes that the system temperature is sensibly the same on and off source, or with and without a spectral line. This assumption is often…

Astrophysics · Physics 2009-11-07 H. Liszt

Galactic aberration (GA) is a small effect in proper motions of celestial objects with an amplitude of about 5 $\mu$as/yr already noticeable in highly accurate astrometric observations such as VLBI and Gaia. However accurate accounting for…

Instrumentation and Methods for Astrophysics · Physics 2023-08-29 Zinovy Malkin

Continuum fitting uncertainties are a major source of error in estimates of the temperature-density relation (usually parametrized as a power-law, $T \propto \Delta^{\gamma - 1} $) of the inter-galactic medium (IGM) through the flux…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-28 Khee-Gan Lee

Poisson distributed shot noise is normally considered in the Gaussian limit in cosmology. However, if the shot noise is large enough and the correlation function/power spectrum conspires, the Gaussian approximation mis-estimates the errors…

Astrophysics · Physics 2009-01-23 J. D. Cohn

The apparent position angle difference $\Delta$PA between parsec and kilo-parsec jets in blazars can be related to the bending properties of the jets. We present correlations between the misalignment $\Delta$PA and the ratio of radio to…

Astrophysics · Physics 2007-05-23 Xinwu Cao

A well constrained estimate of the distance remains one of the main factors to properly interpret the observations of accreting X-ray pulsars. Since these objects are typically well studied, multiple distance estimates obtained with…

High Energy Astrophysical Phenomena · Physics 2019-11-26 S. Treuz , V. Doroshenko , A. Santangelo , R. Staubert

An analysis of the position angles distribution of 10461 extended radio sources shows that the spatial orientation of the axes of these objects is anisotropic: they avoid the direction towards the Celestial Pole and are mostly oriented in…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 V. R. Amirkhanyan

Asymmetric statistical errors arise for experimental results obtained by Maximum Likelihood estimation, in cases where the number of results is finite and the log likelihood function is not a symmetric parabola. This note discusses how…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Roger Barlow

We have observed a small sample of powerful double radio sources (radio galaxies and quasars) at frequencies around 90 GHz with the BIMA millimetre array, with the intention of constraining the resolved high-frequency spectra of radio…

Astrophysics · Physics 2009-11-13 M. J. Hardcastle , L. W. Looney

We develop a general method to "self-calibrate" observations of galaxy clustering with respect to systematics associated with photometric calibration errors. We first point out the danger posed by the multiplicative effect of calibration…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-24 Daniel L. Shafer , Dragan Huterer

This paper analyses the effects of random noise in determining errors and confidence levels for galaxy redshifts obtained by cross-correlation techniques. The main finding is that confidence levels have previously been overestimated, and…

Astrophysics · Physics 2015-06-24 A. F. Heavens

We present a new method for detecting and correcting systematic errors in the distances to stars when both proper motions and line-of-sight velocities are available. The method, which is applicable for samples of 200 or more stars that have…

Astrophysics of Galaxies · Physics 2015-06-03 Ralph Schoenrich , James Binney , Martin Asplund

We address the nature of broad-lined radio galaxies, in particular their radio axis orientation, using new, matched resolution, dual frequency radio observations of a sample of twelve nearby broad-lined extragalactic 3C objects. Radio…

Astrophysics · Physics 2007-05-23 J. Dennett-Thorpe , P. D. Barthel , I. M. van Bemmel

The search for faint emission or absorption lines in astronomical spectra has received considerable attention in recent years, especially in the X-ray wavelength range. These features usually appear as a deficit or excess of counts in a…

High Energy Astrophysical Phenomena · Physics 2018-10-05 Massimiliano Bonamente

Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-05 Duncan Hanson , Antony Lewis , Anthony Challinor

Random hyperspherical harmonics are Gaussian Laplace eigenfunctions on the unit $d$-sphere ($d\ge 2$). We investigate the distribution of their defect i.e., the difference between the measure of positive and negative regions. Marinucci and…

Probability · Mathematics 2018-07-24 Maurizia Rossi

Parity-odd asymmetries in the electromagnetic decays of compound nuclei can sometimes be amplified above values expected from simple dimensional estimates by the complexity of compound nuclear states. In this work we use a statistical…