期刊
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
卷 132, 期 1012, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/1538-3873/ab7d1d
关键词
Analytical mathematics; Astronomy data analysis; Galaxy kinematics; Galaxy dynamics
资金
- Telescope Data Center at Smithsonian Astrophysical Observatory
- Russian Science Foundation [19-12-00281]
- Russian Science Foundation [19-12-00281] Funding Source: Russian Science Foundation
Pixel-space full spectrum fitting exploiting nonlinear chi(2) minimization became a de facto standard way of deriving internal kinematics from absorption line spectra of galaxies and star clusters. However, reliable estimation of uncertainties for kinematic parameters remains a challenge and is usually addressed by running computationally expensive Monte-Carlo simulations. Here we derive simple formulae for the radial velocity and velocity dispersion uncertainties based solely on the shape of a template spectrum used in the fitting procedure and signal-to-noise information. Comparison with Monte-Carlo simulations provides agreement within a few per cent for different templates, signal-to-noise ratios and input velocity dispersions between 0.5 and 10 times the instrumental spectral resolution. For moderate template mismatch our technique returns uncertainties consistent within 20%-30% with those reported by Monte-Carlo simulations. We provide IDL and python implementations of our approach. The main applications are: (i) exposure time calculators; (ii) design of observational programs and estimates on expected uncertainties for spectral surveys of galaxies and star clusters; (iii) a cheap and accurate substitute for Monte-Carlo simulations when running them for large samples of thousands of spectra is unfeasible.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据