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Related papers: Non-parametric estimation of morphological lopside…

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We present the first nonparametric morphological analysis of a set of spiral galaxies from UV to submm wavelengths. Our study is based on high-quality multi-wavelength imaging for nine well-resolved spiral galaxies from the DustPedia…

The velocity distributions of stellar tracers in general exhibit weak non-Gaussianity encoding information on the orbital composition of a galaxy and the underlying potential. The standard solution for measuring non-Gaussianity involves…

Astrophysics of Galaxies · Physics 2020-10-28 Jason L. Sanders , N. Wyn Evans

The luminosity functions of galaxies and quasars provide invaluable information about galaxy and quasar formation. Estimating the luminosity function from magnitude limited samples is relatively straightforward, provided that the distances…

Astrophysics · Physics 2008-11-26 Ravi K. Sheth

We investigate the time evolution of non-parametric morphological quantities and their relationship to major mergers between $4\geq z \geq 2$ in high-resolution cosmological zoom simulations of disk galaxies that implement kinetic wind…

Astrophysics of Galaxies · Physics 2015-08-11 Robert Thompson , Romeel Davé , Shuiyao Huang , Neal Katz

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

Astrophysics · Physics 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determine the shape of the correlation function, its possible evolution…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Francesco Sylos Labini , Daniil Tekhanovich , Yurij V. Baryshev

Context: Galaxy morphology is a fundamental property to describe galaxy evolution. However, the observed morphology of a particular galaxy may depend on the observed wavelength. Aims: Our aim is to investigate the wavelength dependence and…

We develop a novel method to explore the galaxy-halo connection using the galaxy imaging surveys by modeling the projected two-point correlation function measured from the galaxies with reasonable photometric redshift measurements. By…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Zhaoyu Wang , Haojie Xu , Xiaohu Yang , Y. P. Jing , Hong Guo , Zheng Zheng , Ying Zu , Zhigang Li , Chengze Liu

(Abridged) Weak gravitational lensing induces distortions on the images of background galaxies, and thus provides a direct measure of mass fluctuations in the universe. Since the distortions induced by lensing on the images of background…

Astrophysics · Physics 2009-10-31 David Bacon , Alexandre Refregier , Douglas Clowe , Richard Ellis

It is generally agreed that the rotational velocities of spiral galaxies indicate that a lot of matter is unseen. Hitherto, the majority of these mass models are all based on spherical symmetry, although this assumption is obviously not the…

Astrophysics · Physics 2007-05-23 Pieter Buyle , Herwig Dejonghe , Gianfranco Gentile

Lopsidedness is common in disk galaxies, yet its origin and evolution remain unclear. Previous studies typically examined stellar and gas asymmetries separately, but a combined analysis offers a stronger probe of the mechanisms driving…

We describe a new technique for measuring accurate galaxy colours from images taken under different seeing conditions. The method involves two ingredients. First we define the Gaussian-aperture-and-PSF flux, which is the Gaussian-weighted…

Astrophysics · Physics 2015-09-23 Konrad Kuijken

Halometry---mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo---can be realized via variable weak gravitational lensing of the apparent motions of stars and other luminous background…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 Ken Van Tilburg , Anna-Maria Taki , Neal Weiner

Due to their great flexibility, nonparametric Bayes methods have proven to be a valuable tool for discovering complicated patterns in data. The term "nonparametric Bayes" suggests that these methods inherit model-free operating…

Methodology · Statistics 2013-04-15 Peter D. Hoff

Several hypothesis testing methods have been proposed to validate the assumption of isotropy in spatial point patterns. A majority of these methods are characterised by an unknown distribution of the test statistic under the null hypothesis…

Methodology · Statistics 2025-04-09 Jakub J. Pypkowski , Adam M. Sykulski , James S. Martin

This paper continues a series in which we developed a non-parametric method to measure inhomogeneities in the gas distribution from X-ray observations of galaxy clusters. In this work, we apply our method to Chandra X-ray observations of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Andrea Morandi , Wei Cui

We introduce a new galaxy image decomposition tool, GALPHAT (GALaxy PHotometric ATtributes), to provide full posterior probability distributions and reliable confidence intervals for all model parameters. GALPHAT is designed to yield a high…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Ilsang Yoon , Martin Weinberg , Neal Katz

Surface brightness asymmetries are a very common feature of stars. Among other effects they cause a difference between the projected barycentre and photocentre. The evolution of those surface features makes this difference time-dependent.…

Solar and Stellar Astrophysics · Physics 2015-05-28 Ester Pasquato , Dimitri Pourbaix , Alain Jorissen

New HI synthesis data have been obtained for six face-on galaxies with the Very Large Array. These data and reanalyses of three additional data sets make up a sample of nine face-on galaxies analyzed for deviations from axisymmetry in…

Astrophysics · Physics 2009-10-31 David A. Kornreich , Martha P. Haynes , R. V. E. Lovelace , Liese van Zee

Advances in optical astrometry allow us to infer the non-radial kinematic structure of the Universe directly from observations. Here I use a supervised machine learning neural network method to predict 1.57 million redshifts based on…

Astrophysics of Galaxies · Physics 2025-07-03 Valeri V. Makarov