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Related papers: A method to analyse velocity structure

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We present a technique to extract radial velocity measurements from echelle spectrograph observations of rapidly rotating stars ($V\sin{i} \gtrsim 50$ km s$^{-1}$). This type of measurement is difficult because the line widths of such stars…

Solar and Stellar Astrophysics · Physics 2015-06-24 Juliette C. Becker , John Asher Johnson , Andrew Vanderburg , Timothy D. Morton

For understanding the nature of gaseous flows in star-forming regions of nearby galaxies it is usually utilized the relation between surface brightness in H$\alpha$ line and velocity dispersion of ionized gas known as ''surface brightness…

Astrophysics of Galaxies · Physics 2024-04-02 Evgemii O. Vasiliev , Yuri A. Shchekinov

A detailed understanding of the physics of star and planet formation requires study of individual objects as well as statistical assessment of global properties and evolutionary trends. Observational investigations of circumstellar material…

Astrophysics · Physics 2007-05-23 Lynne A. Hillenbrand

The Friends of Friends algorithm identifies groups of objects with similar spatial and kinematic properties, and has recently been used extensively to quantify the distributions of gas and stars in young star-forming regions. We apply the…

Astrophysics of Galaxies · Physics 2018-09-12 Richard J. Parker , Nicholas J. Wright

We explore the heating of the velocity distribution in the solar neighbourhood by stochastic spiral waves. Our investigation is based on direct numerical integration of initially circular test-particle orbits in the sheared sheet. We…

Astrophysics · Physics 2009-11-10 Richard S. De Simone , Xiaoan Wu , Scott Tremaine

We have developed a method for fast and accurate stellar population parameters determination in order to apply it to high resolution galaxy spectra. The method is based on an optimization technique that combines active learning with an…

Astrophysics · Physics 2010-11-11 Thamar Solorio , Olac Fuentes , Roberto Terlevich , Elena Terlevich

Radial velocity measurements can be used to constrain the dynamical state of a stellar cluster. However, for clusters with velocity dispersions smaller than a few km/s the observed radial velocity distribution tends to be dominated by the…

Solar and Stellar Astrophysics · Physics 2015-06-11 Michiel Cottaar , Michael R. Meyer , Richard J. Parker

A procedure is described of construction of velocity fields and velocity dispersion of the stellar component in the central regions of galaxies on the basis of data obtained with the integral field spectrograph MPFS. Cross-correlation and…

Astrophysics · Physics 2007-05-23 A. V. Moiseev

The Gaia satellite will observe the positions and velocities of over a billion Milky Way stars. In the early data releases, the majority of observed stars do not have complete 6D phase-space information. In this Letter, we demonstrate the…

Astrophysics of Galaxies · Physics 2021-07-08 Adriana Dropulic , Bryan Ostdiek , Laura J. Chang , Hongwan Liu , Timothy Cohen , Mariangela Lisanti

By virtue of their high galaxy space densities and their large spatial separations, clusters are efficient and accurate tracers of the large-scale density and velocity fields. Substantial progress has been made over the past decade in the…

Astrophysics · Physics 2007-05-23 Marc Postman

The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…

Discovering community structure in complex networks is a mature field since a tremendous number of community detection methods have been introduced in the literature. Nevertheless, it is still very challenging for practioners to determine…

Social and Information Networks · Computer Science 2021-04-15 Vinh-Loc Dao , Cécile Bothorel , Philippe Lenca

Modelling isolated rotating stars at any rotation rate is a challenge for the next generation of stellar models. These models will couple dynamical aspects of rotating stars, like angular momentum and chemicals transport, with classical…

Solar and Stellar Astrophysics · Physics 2015-06-11 Michel Rieutord , Francisco Espinosa Lara

The study of molecular gas is crucial for understanding star formation, feedback, and the broader ecosystem of a galaxy as a whole. However, we have limited understanding of its physics and distribution in all but the nearest galaxies. We…

Astrophysics of Galaxies · Physics 2017-05-18 Patrick C. Breysse , Mubdi Rahman

Surveys of galaxy clusters provide a promising method of testing models of structure formation in the universe. Within the context of our standard structure formation scenario, surveys provide measurements of the geometry of the universe…

Astrophysics · Physics 2007-05-23 Joseph J. Mohr

This paper introduces a novel technique to track structures in time varying graphs. The method uses a maximum a posteriori approach for adjusting a three-dimensional co-clustering of the source vertices, the destination vertices and the…

Machine Learning · Statistics 2016-08-30 Romain Guigourès , Marc Boullé , Fabrice Rossi

We present a method for converting a time record of turbulent velocity measured at a point in a flow to a spatial velocity record consisting of consecutive convection elements. The spatial record allows computation of dynamic statistical…

Fluid Dynamics · Physics 2019-06-18 Preben Buchhave , Clara M. Velte

It is shown that the average magnitude - redshift diagram for a magnitude-limited sample of galaxies can be effectively used for mapping galaxy velocity field. This new approach is quantitatively introduced and applied to the CfA, ESO/LV…

Astrophysics · Physics 2016-06-08 Jacek Choloniewski

Analyses of peculiar velocity surveys face several challenges, including low signal--to--noise in individual velocity measurements and the presence of small--scale, nonlinear flows. This is the second in a series of papers in which we…

Astrophysics · Physics 2009-11-07 Hume A. Feldman , Richard Watkins , Adrian L. Melott , Scott W. Chambers

Acquiring information on spatial phenomena can be costly and time-consuming. In this context, to obtain reliable global knowledge, the choice of measurement location is a crucial issue. Space-lling designs are often used to control…

Applications · Statistics 2024-02-15 Sylvain Coly , Pierre Druilhet , Nourddine Azzaoui
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