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相关论文: Is the Gini coefficient a stable measure of galaxy…

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Characterization of the morphology of strongly lensed galaxies is challenging because images of such galaxies are typically highly distorted. Lens modeling and source plane reconstruction is one approach that can provide reasonably…

星系天体物理 · 物理学 2016-12-14 Michael K. Florian , Nan Li , Michael D. Gladders

The sample of cosmological strong lensing systems has been steadily growing in recent years and with the advent of the next generation of space-based survey telescopes, the sample will reach into the thousands. The accuracy of strong lens…

星系天体物理 · 物理学 2016-01-20 Michael K. Florian , Michael D. Gladders , Nan Li , Keren Sharon

In this paper we present a new statistic for quantifying galaxy morphology based on measurements of the Gini coefficient of galaxy light distributions. This statistic is easy to measure and is commonly used in econometrics to measure how…

天体物理学 · 物理学 2009-11-07 Roberto Abraham , Sidney van den Bergh , Preethi Nair

We present two new non-parametric methods for quantifying galaxy morphology: the relative distribution of the galaxy pixel flux values (the Gini coefficient or G) and the second-order moment of the brightest 20% of the galaxy's flux (M20).…

天体物理学 · 物理学 2010-04-06 Jennifer M. Lotz , Joel Primack , Piero Madau

In recent years multi-wavelength observations have shown the presence of substructures related to merging events in a high fraction of galaxy clusters. Clusters can be roughly grouped into two categories -- relaxed and non-relaxed -- and a…

宇宙学与河外天体物理 · 物理学 2015-03-11 Viral Parekh , Kurt van der Heyden , Chiara Ferrari , Garry Angus , Benne Holwerda

The majority of galaxy mergers are expected to be minor mergers. The observational signatures of minor mergers are not well understood, thus there exist few constraints on the minor merger rate. This paper seeks to address this gap in our…

宇宙学与河外天体物理 · 物理学 2015-05-14 Jennifer M. Lotz , Patrik Jonsson , T. J. Cox , Joel R. Primack

[abridged] New near-infrared surveys, using the HST, offer an unprecedented opportunity to study rest-frame optical galaxy morphologies at z>1 and to calibrate automated morphological parameters that will play a key role in classifying…

We investigate the effect of observational constraints such as signal-to-noise, resolution and column density level on the HI morphological asymmetry ($\mathrm{A}_\mathrm{mod}$) and the effect of noise on the HI global profile…

星系天体物理 · 物理学 2022-06-08 P. V. Bilimogga , K. A. Oman , M. A. W. Verheijen , J. M. van der Hulst

The morphology of galaxies can be quantified to some degree using a set of scale-invariant parameters. Concentration (C), Asymmetry (A), Smoothness (S), the Gini index (G), relative contribution of the brightest pixels to the second order…

The distribution of errors is a central object in the assesment and benchmarking of computational chemistry methods. The popular and often blind use of the mean unsigned error as a benchmarking statistic leads to ignore distributions…

化学物理 · 物理学 2021-02-19 Pascal Pernot , Andreas Savin

Identifying statistical dependence between the features and the label is a fundamental problem in supervised learning. This paper presents a framework for estimating dependence between numerical features and a categorical label using…

机器学习 · 计算机科学 2021-10-01 Silu Zhang , Xin Dang , Dao Nguyen , Dawn Wilkins , Yixin Chen

Non-parametric morphology measures are a powerful tool for identifying galaxy mergers at low redshifts. We employ cosmological zoom simulations using Gizmo with the Mufasa feedback scheme, post-processed using 3D dust radiative transfer…

星系天体物理 · 物理学 2018-03-08 Matthew W. Abruzzo , Desika Narayanan , Romeel Davé , Robert Thompson

We study the optical morphology of galaxies in a large-scale hydrodynamic cosmological simulation, the EAGLE simulation. Galaxy morphologies were characterized using non-parametric statistics (Gini, $M_{20}$, Concentration and Asymmetry)…

The presence of Active Galaxy Nuclei (AGN) can affect the morphological classification of galaxies. This work aims to determine how the contribution of AGN affects the most used morphological parameters down to the redshift of z~2 in…

Gas-rich galaxy mergers are more easily identified by their disturbed morphologies than mergers with less gas. Because the typical gas fraction of galaxy mergers is expected to increase with redshift, the under-counting of low gas-fraction…

宇宙学与河外天体物理 · 物理学 2015-05-14 Jennifer M. Lotz , Patrik Jonsson , T. J. Cox , Joel R. Primack

Galaxy evolution is driven to a large extent by interactions and mergers with other galaxies and the gas in galaxies is extremely sensitive to the interactions. One method to measure such interactions uses the quantified morphology of…

宇宙学与河外天体物理 · 物理学 2015-05-27 B. W. Holwerda , N. Pirzkal , W. J. G. de Blok , A. Bouchard , S-L. Blyth , K. J. van der Heyden , E. C. Elson

The global 21 cm HI emission-line profile of a galaxy encodes valuable information on the spatial distribution and kinematics of the neutral atomic gas. Galaxy interactions significantly influence the HI disk and imprint observable features…

星系天体物理 · 物理学 2022-04-20 Pei Zuo , Luis C. Ho , Jing Wang , Niankun Yu , Jinyi Shangguan

The two interferometric LIGO gravitational-wave observatories provide the most sensitive data to date to study the gravitational-wave Universe. As part of a global network, they have just completed their third observing run in which they…

广义相对论与量子宇宙学 · 物理学 2022-08-24 Gregory Ashton , Sarah Thiele , Yannick Lecoeuche , Jess McIver , Laura K Nuttall

The Gini index does not give a strictly consistent scoring rule in general. Therefore, maximizing the Gini index may lead to wrong decisions. The main issue is that the Gini index is a rank-based score that is not calibration-sensitive. We…

机器学习 · 计算机科学 2022-08-11 Mario V. Wüthrich

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…

星系天体物理 · 物理学 2015-08-11 Robert Thompson , Romeel Davé , Shuiyao Huang , Neal Katz
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