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Related papers: Photometric Metallicities in Bootes I

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We present metallicities and ages for 52 red giants in the remote Galactic dwarf spheroidal (dSph) galaxy Leo II. These stars cover the entire surface area of Leo II and are radial velocity members. We obtained medium-resolution multi-fiber…

We present chemical abundance measurements of two metal-poor red giant stars in the ultra-faint dwarf galaxy Bootes I, based on Magellan/MIKE high-resolution spectra. For Boo I-980, with [Fe/H]=-3.1, we present the first elemental abundance…

Astrophysics of Galaxies · Physics 2016-08-03 Anna Frebel , John E. Norris , Gerard Gilmore , Rosemary F. G. Wyse

Photometric metallicity formulae of fundamental-mode RR Lyr (RRab) stars are presented using globular-cluster data exclusively. The aim is to check whether this selection may help increasing the overall accuracy of the fits and eliminating…

Solar and Stellar Astrophysics · Physics 2023-08-21 Johanna Jurcsik , Gergely Hajdu

To enlarge our growing sample of well-studied star clusters in the Large Magellanic Cloud (LMC), we present CCD Washington CT1 photometry to T1 ~ 23 in the fields of twenty-three mostly unstudied clusters located in the inner disc and outer…

Astrophysics of Galaxies · Physics 2015-06-16 Tali Palma , Juan J. Clariá , Doug Geisler , Andrés E. Piatti , Andrea V. Ahumada

The age-metallicity relation of the solar neighbourhood is studied using a sample of 552 late-type dwarfs. This sample was built from the intersection of photometric catalogues with chromospheric activity surveys of the Mount Wilson group.…

Astrophysics · Physics 2007-05-23 H. J. Rocha-Pinto , W. J. Maciel , John Scalo , Chris Flynn

Hubble Space Telescope (HST) fine guidance sensor observations were used to obtain parallaxes of eight metal-poor ([Fe/H] < -1.4) stars. The parallaxes of these stars determined by the revised Hipparcos reduction average 17% accuracy, in…

We use data for 6048 early-type galaxies (ETGs) from Galaxy Zoo 1 that have been cross-matched with the catalog of the MPA-JHU emission-line measurements for the Sloan Digital Sky Survey Data Release 7. We measure the metallicity of these…

Astrophysics of Galaxies · Physics 2021-12-20 Wu Yuzhong

We combine photometric data from GALEX GR6+7 AIS and Gaia EDR3 with stellar parameters from the SAGA and PASTEL catalogs to construct high-quality training samples for dwarfs ($\rm 0.4< BP-RP<1.6$) and giants ($\rm 0.6< BP-RP <1.6$). We…

Solar and Stellar Astrophysics · Physics 2024-01-12 Xue Lu , Haibo Yuan , Shuai Xu , Ruoyi Zhang , Kai Xiao , Yang Huang , Timothy C. Beers , Jihye Hong

Accurate determinations of stellar parameters and distances for large complete samples of stars are keys for conducting detailed studies of the formation and evolution of our Galaxy. Here we present stellar atmospheric parameters ($T_{\rm…

Based on SDSS g, r and SCUSS (South Galactic Cap of u-band Sky Survey) $u$ photometry, we develop a photometric calibration for estimating the stellar metallicity from $u-g$ and $g-r$ colors by using the SDSS spectra of 32,542 F- and G-type…

A new metallicity distribution and an age-metallicity relation are presented for 437 nearby F and G turn-off and sub-giant stars selected from radial velocity data of Nidever et al. Photometric metallicities are derived from uvby-H\beta…

Astrophysics · Physics 2009-11-11 Y. Karatas , S. Bilir , W. J. Schuster

We derive stellar ages, from evolutionary tracks, and metallicities, from Stromgren photometry, for a sample of 5828 dwarf and sub-dwarf stars from the Hipparcos Catalogue. This stellar disk sample is used to investigate the age-metallicity…

Astrophysics · Physics 2009-11-07 Sofia Feltzing , Johan Holmberg , Jarrod R. Hurley

The estimation of stellar atmospheric parameters for large-scale samples, particularly metal-poor stars, is a cornerstone of Galactic archaeology. In this work, we optimized a photometric filter design tailored to measuring stellar…

Solar and Stellar Astrophysics · Physics 2026-04-24 Ruifeng Shi , Yang Huang , Kai Xiao , Chuanjie Zheng , Bowen Zhang , Hongrui Gu , Xinyi Li , Huiling Chen

We present imaging results from a high Galactic latitude survey designed to examine the structure of the Galactic halo. The objective of the survey is to identify candidate halo stars which can be observed spectroscopically to obtain radial…

We use rest-frame Stromgren photometry to observe clusters of galaxies in a self-consistent manner from z=0 to z=0.8. Stromgren photometry of galaxies is an efficient compromise between standard broad-band photometry and spectroscopy, in…

Astrophysics · Physics 2009-10-31 Susanna Steindling , Noah Brosch , Karl Rakos

We present a new calibration of the Stroemgren metallicity index m1 using red giant (RG) stars in 4 globular clusters (GCs:M92,M13,NGC1851,47Tuc) with metallicity ranging from [Fe/H]=-2.2 to -0.7, marginally affected by reddening…

We investigated the age-metallicity relation using a sample of 5691 F and G type dwarfs from RAVE DR3 by applying several constraints: i) We selected stars with surface gravities log g < 3.8 and effective temperatures in the…

Astrophysics of Galaxies · Physics 2015-06-16 S. Duran , S. Ak , S. Bilir , S. Karaali , T. Ak , Z. F. Bostanci , B. Coskunoglu

We demonstrate that the combination of GALEX UV photometry in the FUV (~1530 angstroms) and NUV (~2310 angstroms) passbands with optical photometry in the standard U,B,V,R,I filters can efficiently break the age-metallicity degeneracy. We…

Astrophysics · Physics 2009-11-11 S. Kaviraj , S. -C. Rey , R. M. Rich , Y. -W. Lee , S. -J. Yoon , S. K. Yi

Aims. We explore machine learning techniques to forecast star formation rate, stellar mass, and metallicity across galaxies with redshifts ranging from 0.01 to 0.3. Methods. Leveraging CatBoost and deep learning architectures, we utilize…

Astrophysics of Galaxies · Physics 2024-05-27 F. Z. Zeraatgari , F. Hafezianzadeh , Y. -X. Zhang , A. Mosallanezhad , J. -Y. Zhang

We present a homogeneous metallicity analysis of old stellar populations in Local Volume (LV) galaxies using data from the CMDs/TRGB catalog of the Extragalactic Distance Database (EDD; http://edd.ifa.hawaii.edu), which provides uniformly…

Astrophysics of Galaxies · Physics 2026-04-21 Lidia N. Makarova , Denis G. Purytin , R. Brent Tully , Gagandeep S. Anand