no code implementations • 13 Jan 2021 • Kareem El-Badry, Hans-Walter Rix, Tyler M. Heintz
The underestimates are generally $\le 30\%$ for isolated sources with well-behaved astrometry, but are larger (up to 80%) for apparently well-behaved sources with a companion within $\lesssim 4$ arcsec, and much larger for sources with poor astrometric fits.
Solar and Stellar Astrophysics Astrophysics of Galaxies
no code implementations • 7 Jan 2021 • Jing Li, Xiang-Xiang Xue, Chao Liu, Bo Zhang, Hans-Walter Rix, Jeffrey L. Carlin, Chengqun Yang, Rene A. Mendez, Jing Zhong, Hao Tian, Lan Zhang, Yan Xu, Yaqian Wu, Gang Zhao, Ruixiang Chang
Their location in [$\alpha$/M] vs. [M/H] space is more metal poor than typical thin disk stars, with [$\alpha$/M] \textbf{lower} than the thick disk.
Astrophysics of Galaxies
2 code implementations • 23 Sep 2020 • Knud Jahnke, Christian Fendt, Morgan Fouesneau, Iskren Georgiev, Tom Herbst, Melanie Kaasinen, Diana Kossakowski, Jan Rybizki, Martin Schlecker, Gregor Seidel, Thomas Henning, Laura Kreidberg, Hans-Walter Rix
Analysing greenhouse gas emissions of an astronomical institute is a first step in reducing its environmental impact.
Instrumentation and Methods for Astrophysics Physics and Society
1 code implementation • 16 Jul 2018 • Kareem El-Badry, Hans-Walter Rix
We construct from Gaia DR2 an extensive and very pure ($\lesssim 0. 2\%$ contamination) catalog of wide binaries containing main-sequence (MS) and white dwarf (WD) components within 200 pc of the Sun.
Solar and Stellar Astrophysics Astrophysics of Galaxies
2 code implementations • 4 Apr 2018 • Yuan-Sen Ting, Charlie Conroy, Hans-Walter Rix, Phillip Cargile
We present The Payne, a general method for the precise and simultaneous determination of numerous stellar labels from observed spectra, based on fitting physical spectral models.
Solar and Stellar Astrophysics Astrophysics of Galaxies
1 code implementation • 20 Nov 2017 • Jacopo Chevallard, Emma Curtis-Lake, Stephane Charlot, Pierre Ferruit, Giovanna Giardino, Marijn Franx, Michael V. Maseda, Ricardo Amorin, Santiago Arribas, Andy Bunker, Stefano Carniani, Bernd Husemann, Peter Jakobsen, Roberto Maiolino, Janine Pforr, Timothy D. Rawle, Hans-Walter Rix, Renske Smit, Chris J. Willott
The James Webb Space Telescope (JWST) will enable the detection of optical emission lines in galaxies spanning a broad range of luminosities out to redshifts z > 10.
Astrophysics of Galaxies
3 code implementations • 28 Feb 2017 • Jan Rybizki, Andreas Just, Hans-Walter Rix
A Chempy model is specified by a set of 5-10 parameters that describe the effective galaxy evolution along with the stellar and star-formation physics: e. g. the star-formation history, the feedback efficiency, the stellar initial mass function (IMF) and the incidence of supernova type Ia (SN Ia).
Astrophysics of Galaxies Instrumentation and Methods for Astrophysics Solar and Stellar Astrophysics
2 code implementations • 24 Oct 2016 • Adrian M. Price-Whelan, David W. Hogg, Daniel Foreman-Mackey, Hans-Walter Rix
We capitalize on this by building a sampling method in which we densely sample the prior pdf in the non-linear parameters and perform rejection sampling using a likelihood function marginalized over the linear parameters.
Solar and Stellar Astrophysics Earth and Planetary Astrophysics
1 code implementation • 20 Jun 2016 • Karl D. Gordon, Morgan Fouesneau, Heddy Arab, Kirill Tchernyshyov, Daniel R. Weisz, Julianne J. Dalcanton, Benjamin F. Williams, Eric F. Bell, Luciana Bianchi, Martha Boyer, Yumi Choi, Andrew Dolphin, Leo Girardi, David W. Hogg, Jason S. Kalirai, Maria Kapala, Alexia R. Lewis, Hans-Walter Rix, Karin Sandstrom, Evan D. Skillman
We present the Bayesian Extinction And Stellar Tool (BEAST), a probabilistic approach to modeling the dust extinguished photometric spectral energy distribution of an individual star while accounting for observational uncertainties common to large resolved star surveys.
Astrophysics of Galaxies
1 code implementation • 25 Jan 2016 • Adrian M. Price-Whelan, Branimir Sesar, Kathryn V. Johnston, Hans-Walter Rix
The Ophiuchus stellar stream is peculiar: (1) its length is short given the age of its constituent stars, and (2) several probable member stars that lie close in both sky position and velocity have dispersions in these dimensions that far exceed those seen within the stream.
Astrophysics of Galaxies
3 code implementations • 22 Sep 2015 • Jo Bovy, Hans-Walter Rix, Gregory M. Green, Edward F. Schlafly, Douglas P. Finkbeiner
This formalism demonstrates that the spatially-complex effect of extinction on the selection function of a pencil-beam or contiguous sky survey is equivalent to a low-pass filtering of the extinction-affected selection function with the smooth density field.
Astrophysics of Galaxies
1 code implementation • 18 Sep 2015 • Jo Bovy, Hans-Walter Rix, Edward F. Schlafly, David L. Nidever, Jon A. Holtzman, Matthew Shetrone, Timothy C. Beers
We use data on 14, 699 red-clump stars from the APOGEE survey, covering 4 kpc <~ R <~ 15 kpc, to determine the structure of mono-abundance populations (MAPs)---stars in narrow bins in [a/Fe] and [Fe/H]---accounting for the complex effects of the APOGEE selection function and the spatially-variable dust obscuration.
Astrophysics of Galaxies
no code implementations • 29 Jan 2015 • Melissa Ness, David W. Hogg, Hans-Walter Rix, Anna Y. Q. Ho, Gail Zasowski
New spectroscopic surveys offer the promise of consistent stellar parameters and abundances ('stellar labels') for hundreds of thousands of stars in the Milky Way: this poses a formidable spectral modeling challenge.
Solar and Stellar Astrophysics Astrophysics of Galaxies Instrumentation and Methods for Astrophysics
1 code implementation • 11 Jan 2010 • Benjamin P. Moster, Rachel S. Somerville, Jeffrey A. Newman, Hans-Walter Rix
This implies that cosmic variance is a significant source of uncertainty at z=2 for small fields and massive galaxies, while for larger fields and intermediate mass galaxies cosmic variance is less serious.
Cosmology and Nongalactic Astrophysics
