中文
相关论文

相关论文: An empirical calibration of Lick indices using Mil…

200 篇论文

We provide the whole set of Lick indices from CN1 to TiO2 of Simple Stellar Population models with, for the first time, variable element abundance ratios, [alpha/Fe]=0.0, 0.3, 0.5, [alpha/Ca]=-0.1, 0.0, 0.2, 0.5, and [alpha/N]=-0.5, 0.0.…

天体物理学 · 物理学 2009-11-07 Daniel Thomas , Claudia Maraston , Ralf Bender

We test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…

太阳与恒星天体物理 · 物理学 2017-05-10 S. S. Larsen , J. P. Brodie , J. Strader

We define a method for analysis of the integrated spectra of extra-galactic globular clusters that provides more reliable measures of age, metallicity and alpha-element abundance ratio than have so far been achieved. The method involves the…

天体物理学 · 物理学 2009-11-10 Robert N. Proctor , Duncan A. Forbes , Michael A. Beasley

We perform integrated spectroscopy of 24 Galactic globular clusters. Spectra are observed from one core radius for each cluster with a high wavelength resolution of ~2.0 A FWHM. In combination with two existing data sets from Puzia et al.…

星系天体物理 · 物理学 2016-12-14 Hak-Sub Kim , Jaeil Cho , Ray M. Sharples , Alexandre Vazdekis , Michael A. Beasley , Suk-Jin Yoon

All 25 Lick/IDS spectral indices have been computed for the integrated light of simple stellar populations over broad ranges of age and metallicity and with effects from horizontal-branch stars fully implemented. For Balmer indices a…

天体物理学 · 物理学 2009-11-11 Hyun-chul Lee , Guy Worthey

We present abundances of globular clusters in the Milky Way and Fornax from integrated light spectra. Our goal is to evaluate the consistency of the integrated light analysis relative to standard abundance analysis for individual stars in…

星系天体物理 · 物理学 2017-01-11 J. E. Colucci , R. A. Bernstein , A. McWilliam

We present a comprehensive spectroscopic study of the integrated light of metal-rich Galactic globular clusters and the stellar population in the Galactic bulge. We measure line indices which are defined by the Lick standard system and…

The Lick-index spectrophotometric system is investigated in its inherent statistical and operational properties to ease a more appropriate use for astrophysical studies. Non-Gaussian effects in the index standardization procedure suggest…

星系天体物理 · 物理学 2015-06-23 Alberto Buzzoni

Synthetic Lick indices (e.g. Mg_2, Fe, etc.) of Simple Stellar Population (SSP) models are calibrated for the first time up to solar metallicity with a sample of Milky Way globular clusters (GCs) which includes the metal rich GCs of the…

天体物理学 · 物理学 2009-11-07 C. Maraston , L. Greggio , A. Renzini , S. Ortolani , R. P. Saglia , T. H. Puzia , M. Kissler-Patig

The Lick Fe5015, Fe5270, Fe5335, Mgb and Mg2 indices are presented for 139 candidate SMR stars of different luminosity class studied in Malagnini et al. (2000). Evidence is found for a standard (i.e. [Mg/Fe]~0) Mg vs. Fe relative abundance.…

天体物理学 · 物理学 2009-11-07 A. Buzzoni , M. Chavez , M. L. Malagnini , C. Morossi

We present new stellar population models of Lick absorption-line indices with variable element abundance ratios. The models are based on our new calibrations of absorption-line indices with stellar parameters derived from the MILES stellar…

宇宙学与河外天体物理 · 物理学 2015-05-20 Daniel Thomas , Claudia Maraston , Jonas Johansson

We present detailed chemical abundances in 8 clusters in the Large Magellanic Cloud (LMC). We measure abundances of 22 elements for clusters spanning a range in age of 0.05 to 12 Gyr, providing a comprehensive picture of the chemical…

星系天体物理 · 物理学 2015-06-03 J. E. Colucci , R. A. Bernstein , S. A. Cameron , A. McWilliam

We present absorption line indices measured in the integrated spectra of globular clusters both from the Galaxy and from M 31. Our samples include 41 Galactic globular clusters, and more than 300 clusters in M 31. The conversion of…

An analysis of ages, metallicities, and [alpha/Fe] ratios of globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized in Puzia et al. (2004, Paper I of this series). In the light of…

We have extended our evolutionary synthesis code, GALEV, to include Lick/IDS absorption-line indices for both simple and composite stellar population models (star clusters and galaxies), using the polynomial fitting functions of Worthey et…

天体物理学 · 物理学 2009-11-11 Thomas Lilly , Uta Fritze-v. Alvensleben

Application of fitting techniques to obtain physical parameters---such as ages, metallicities, and $\alpha$-element to iron ratios---of stellar populations is an important approach to understand the nature of both galaxies and globular…

星系天体物理 · 物理学 2016-12-14 Zhou Fan , Richard de Grijs , Bingqiu Chen , Linhua Jiang , Fuyan Bian , Zhongmu Li

We report the first detailed chemical abundances for 5 globular clusters (GCs) in M31 from high-resolution (R ~ 25,000) spectroscopy of their integrated light. These GCs are the first in a larger set of clusters observed as part of an…

星系天体物理 · 物理学 2015-05-14 J. E. Colucci , R. A. Bernstein , S. Cameron , A. McWilliam , J. G. Cohen

We describe the detailed chemical abundance analysis of a high-resolution (R~35,000), integrated-light (IL), spectrum of the core of the Galactic globular cluster 47 Tuc, obtained using the du Pont echelle at Las Campanas. We develop an…

天体物理学 · 物理学 2009-11-13 Andrew McWilliam , Rebecca A. Bernstein

Assuming that in the atmospheres of low-mass, metal-poor red giant stars, 1-D models based on LTE accurately predict the abundance of iron from Fe II, we derive a globular cluster metallicity scale based on the equivalent widths of Fe II…

天体物理学 · 物理学 2009-07-28 Robert P. Kraft , Inese I. Ivans

Spectrophotometric indices for $18$ Galactic globular clusters, obtained from CCD observations and careful reductions, were used to determine reliable calibrations on metallicity $[Fe/H]$. The indices were measured in the bandpasses adopted…

天体物理学 · 物理学 2016-08-30 S. Covino , S. Galletti , L. E. Pasinetti
‹ 上一页 1 2 3 10 下一页 ›