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相关论文: Mass estimators for flattened dispersion-supported…

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A basic property of objects, like galaxies and halos that form in cosmological structure formation simulations, is their shape. Here, we critically investigate shape determination methods that are commonly used in the literature. It is…

天体物理仪器与方法 · 物理学 2012-02-22 Marcel Zemp , Oleg Y. Gnedin , Nickolay Y. Gnedin , Andrey V. Kravtsov

How is mass distributed in the Universe? How does it compare with the distribution of light and stars? We address these questions by examining the distribution of mass, determined from weak lensing observations, and starlight, around…

宇宙学与河外天体物理 · 物理学 2014-04-29 Neta A. Bahcall , Andrea Kulier

Determining the dynamical mass profiles of dispersion-supported galaxies is particularly challenging due to projection effects and the unknown shape of their velocity anisotropy profile. Our goal is to develop a machine learning algorithm…

A powerful method to measure the mass profile of a galaxy is through the velocities of tracer particles distributed through its halo. Transforming this kind of data accurately to a mass profile M(r), however, is not a trivial problem. In…

星系天体物理 · 物理学 2016-05-03 Gwendolyn M. Eadie , William E. Harris , Lawrence M. Widrow

The mass and anisotropy of an elliptical galaxy can be simultaneously determined from velocity dispersion and line profile shape measurements. We describe the principles, techniques, and limitations of this approach, and the results…

天体物理学 · 物理学 2007-05-23 Ortwin Gerhard , Gunther Jeske , R. P. Saglia , Ralf Bender

Sheth-Tormen mass function has been widely used to quantify the abundance of dark matter halos. It is a significant improvement over the Press-Schechter mass function as it uses ellipsoidal collapse in place of spherical collapse. Both of…

宇宙学与河外天体物理 · 物理学 2023-04-05 Swati Gavas , J S Bagla , Nishikanta Khandai , Girish Kulkarni

Recent work has suggested that mid-IR wavelengths are optimal for estimating the mass-to-light ratios of stellar populations and hence the stellar masses of galaxies. We compare stellar masses deduced from spectral energy distribution (SED)…

Weak gravitational lensing provides a unique method to directly measure the distribution of mass in the universe. Because the distortions induced by lensing in the shape of background galaxies are small, the measurement of weak lensing…

天体物理学 · 物理学 2009-11-06 Alexandre Refregier , David Bacon

We derive probability density functions for the projected axial ratios of the real and mock 2PIGG galaxy groups, and use this data to investigate the intrinsic three dimensional shape of the dark matter ellipsoids that they trace. As well…

天体物理学 · 物理学 2007-10-02 A. Robotham , S. Phillipps , R. de Propris

Large galaxies may contain an "atmosphere" of hot interstellar X-ray gas, and the temperature and radial density profile of this gas can be used to measure the total mass of the galaxy contained within a given radius r. We use this…

星系天体物理 · 物理学 2020-12-16 William E. Harris , Rhea-Silvia Remus , Gretchen L. H. Harris , Iurii V. Babyk

Model fitting is frequently used to determine the shape of galaxies and the point spread function, for examples, in weak lensing analyses or morphology studies aiming at probing the evolution of galaxies. However, the number of parameters…

宇宙学与河外天体物理 · 物理学 2012-10-03 Guoliang Li , Bo Xin , Wei Cui

A better understanding of the formation of mass structures in the universe can be obtained by determining the amount and distribution of dark and luminous matter in spiral galaxies. To investigate such matters a sample of 12 galaxies, most…

星系天体物理 · 物理学 2015-06-23 Roelof Bottema , Jose Luis G. Pestana

Given the recently deduced relationship between X-ray temperatures and stellar velocity dispersions (the "T-sigma relation") in an optically complete sample of elliptical galaxies (Davis & White 1996), we demonstrate that L>L_* ellipticals…

天体物理学 · 物理学 2009-10-31 Michael Loewenstein , Raymond E. White

This paper is the first in a series in which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilise the positions, velocities and colours of galaxies. Our primary aim is to test the…

Stellar mass can enhance the ranking of potential hosts for compact binary coalescences identified by ground-based gravitational-wave detectors within large localisation areas containing even thousands of galaxies. Despite its benefits,…

星系天体物理 · 物理学 2025-03-27 M. Pálfi , G. Dálya , P. Raffai

The stellar density profile a galaxy is typically summarised with two numbers: total stellar mass and half-light radius. The total mass of a galaxy, however, is not a well-defined quantity, due to the finite depth of photometric…

星系天体物理 · 物理学 2020-09-23 Alessandro Sonnenfeld

We study the problem of computationally efficient robust estimation of the covariance/scatter matrix of elliptical distributions -- that is, affine transformations of spherically symmetric distributions -- under the strong contamination…

数据结构与算法 · 计算机科学 2025-04-15 Gleb Novikov

Fourier series solutions to the deflection and magnification by a family of three-dimensional cusped two power-law ellipsoidal mass distributions are presented. The cusped two power-law ellipsoidal mass distributions are characterized by…

天体物理学 · 物理学 2009-11-07 Kyu-Hyun Chae

This paper presents the dynamical simulations run in the potential derived from the light distribution of 5 late-type barred spiral galaxies. The aim is to determine whether the mass distribution together with the hydrodynamical simulations…

天体物理学 · 物理学 2009-11-10 I. Pérez , R. Fux , K. Freeman

The elliptical power-law (EPL) model of the mass in a galaxy is widely used in strong gravitational lensing analyses. However, the distribution of mass in real galaxies is more complex. We quantify the biases due to this model mismatch by…