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Related papers: Photometric Abundances for G-Dwarfs: A Cautionary …

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We discuss the detailed composition of 28 extremely metal-poor dwarfs, 22 of which are from the Hamburg/ESO Survey, based on Keck Echelle spectra. Our sample has a median [Fe/H] of -2.7 dex, extends to -3.5 dex, and is somewhat less…

We present empirical metallicity-dependent calibrations of effective temperature against colours for dwarfs of luminosity classes IV and V and for giants of luminosity classes II and III, based on a collection from the literature of about…

Solar and Stellar Astrophysics · Physics 2015-10-28 Yang Huang , Xiao-Wei Liu , Hai-Bo Yuan , Mao-sheng Xiang , Bing-Qiu Chen , Hua-Wei Zhang

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

An apparent Ca underabundance for cool metal rich disk dwarfs was derived by Feltzing & Gustafsson (1998, A&AS, 129, 237). This was suggested to be a NLTE effect, following the prediction by Drake (1991, MNRAS, 251, 369). New NLTE…

Astrophysics · Physics 2007-05-23 Patrik Thoren

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

We present K band spectra for 133 nearby (d < 33 parsecs) M dwarfs, including 18 M dwarfs with reliable metallicity estimates (as inferred from an FGK type companion), 11 M dwarf planet hosts, more than 2/3 of the M dwarfs in the Northern 8…

Solar and Stellar Astrophysics · Physics 2012-03-15 Bárbara Rojas-Ayala , Kevin R. Covey , Philip S. Muirhead , James P. Lloyd

We present wide field JHKs photometry of 16 Galactic globular clusters located towards the Galactic bulge, calibrated on the 2MASS photometric system. Differential reddening corrections and statistical field star decontamination are…

Solar and Stellar Astrophysics · Physics 2016-11-15 Roger E. Cohen , Christian Moni Bidin , Francesco Mauro , Charles Bonatto , Douglas Geisler

We present the first spectroscopic metallicities of three M dwarfs with known or candidate planetary mass companions. We have analyzed high resolution, high signal-to-noise spectra of these stars which we obtained at McDonald Observatory.…

Astrophysics · Physics 2009-11-11 Jacob L. Bean , G. Fritz Benedict , Michael Endl

We present a high-resolution spectrum of a microlensed G dwarf in the Galactic bulge with spectroscopic temperature T_eff = 5600 +/- 180 K. This I~21 mag star was magnified by a factor ranging from 1160 to 1300 at the time of observation.…

Solar and Stellar Astrophysics · Physics 2014-11-20 Courtney R. Epstein , Jennifer A. Johnson , Subo Dong , Andrzej Udalski , Andrew Gould , George Becker

A collection of Johnson/Cousins photometry for stars with known [Fe/H] is used to generate color-color relations that include the abundance dependence. Literature temperature and bolometric correction dependences are attached to the color…

Astrophysics · Physics 2011-01-27 G. Worthey , H. -c. Lee

We examine the biases inherent to chemical abundance distributions when targets are selected from the red giant branch (RGB), using simulated giant branches created from isochrones. We find that even when stars are chosen from the entire…

Astrophysics of Galaxies · Physics 2017-08-30 Ellen M. Manning , Andrew A. Cole

We investigate the environmental effect on the metal enrichment of star-forming galaxies (SFGs) in the farthest spectroscopically confirmed and X-ray detected cluster, CL~J1449+0856 at $z=1.99$. We combined HST/WFC3~G141 slitless…

Astrophysics of Galaxies · Physics 2015-06-23 F. Valentino , E. Daddi , V. Strazzullo , R. Gobat , M. Onodera , F. Bournaud , S. Juneau , A. Renzini , N. Arimoto , M. Carollo , A. Zanella

Studies of the early chemical evolution of some larger dwarf galaxies ( $>10^7$ solar masses) are limited by the small number of stars known at low metallicities in these systems. Here we present metallicities and carbon abundances for…

Astrophysics of Galaxies · Physics 2020-10-14 Anirudh Chiti , Kylie Y. Hansen , Anna Frebel

In a series of three papers, we investigate the current status of published metallicities for open clusters that were derived from a variety of photometric and spectroscopic methods. The current article focuses on spectroscopic methods. The…

Astrophysics of Galaxies · Physics 2014-01-10 U. Heiter , C. Soubiran , M. Netopil , E. Paunzen

We present surface photometry and metallicity measurements for 104 nearby dwarf galaxies imaged with the Advanced Camera for Surveys and Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. In addition, we carried out…

We report the statistical properties of stars and brown dwarfs obtained from four radiation hydrodynamical simulations of star cluster formation that resolve masses down to the opacity limit for fragmentation. The calculations are identical…

Solar and Stellar Astrophysics · Physics 2014-05-23 Matthew R. Bate

Current galaxy observations suggest that a roughly linear correlation exists between the [CII] emission and the star formation rate, either as spatially-resolved or integrated quantities. Observationally, this correlation seems to be…

Astrophysics of Galaxies · Physics 2020-01-22 Alessandro Lupi , Stefano Bovino

As an investigation of the origin of ``$\alpha$-poor'' halo stars, we analyze kinematic and abundance data for 73 intermediate metallicity stars ($-1 >$ [Fe/H] $\geq -2$) selected from Paper I of this series. We find evidence for a…

Astrophysics · Physics 2009-12-08 Jon P. Fulbright

uvby(--$\beta$) photometry has been obtained for an additional 411 very metal-poor stars selected from the HK survey, and used to derive basic parameters such as interstellar reddenings, metallicities, photometric classifications,…

Astrophysics · Physics 2009-11-10 W. J. Schuster , T. C. Beers , R. Michel , P. E. Nissen , G. Garcia

CCD photometry on the intermediate-band vbyCaHbeta system is presented for the metal-deficient open cluster, NGC 2420. Restricting the data to probable single members of the cluster using the CMD and the photometric indices alone generates…

Astrophysics · Physics 2016-08-30 Barbara J. Anthony-Twarog , Delora Tanner , Misty Cracraft , Bruce A. Twarog