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Related papers: The Metallicity Distribution Function of Omega Cen…

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We present a low metallicity map of the Milky Way consisting of $\sim$111,000 giants with $-3.5 \lesssim$ [Fe/H] $\lesssim -$0.75, based on public photometry from the second data release of the SkyMapper survey. These stars extend out to…

Astrophysics of Galaxies · Physics 2021-04-28 Anirudh Chiti , Mohammad K. Mardini , Anna Frebel , Tatsuya Daniel

Stellar metallicity distribution functions (MDF) have been measured for resolved stellar populations in the outer halos of many galaxies in nearby groups. Among them, the MDF of NGC 5128, the central giant elliptical in the Centaurus group,…

Astrophysics of Galaxies · Physics 2022-04-27 Ena Choi , Jeremiah P. Ostriker , Michaela Hirschmann , Rachel S. Somerville , Thorsten Naab

We present radial velocities, Fe, and Al abundances for 180 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri ($\omega$ Cen). The majority of our data lie in the range 11.0$<$V$<$13.5, which covers the RGB from…

In this contribution, results from CCD vby Stroemgren photometry of a statistically complete sample of red giants and stars in the main sequence turn-off region in omega Centauri are presented. From the location of stars in the (b-y),m_1…

Astrophysics · Physics 2007-05-23 Michael Hilker , Tom Richtler

We study the age and metallicity distribution function (MDF) of metal-poor stars in the Milky Way halo as a function of galactocentric radius by combining N-body simulations and semi-analytical methods. We find that the oldest stars…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 S. Salvadori , A. Ferrara , R. Schneider , E. Scannapieco , D. Kawata

We use deep narrowband Ca H&K ($F395N$) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group (LG) ultra-faint dwarf (UFD) galaxy Eridanus II (Eri II). When combined with…

We present multi-wavelength observations of the northern population of Omega Cen from the main-sequence turn-off to high on the red giant branch. We show that the best information about the metallicity and age of the stars can be gained…

Astrophysics · Physics 2016-08-30 Joanne Hughes , George Wallerstein , Floor van Leeuwen

We describe the methodology required for estimation of photometric estimates of metallicity based on the SDSS gri passbands, which can be used to probe the properties of main-sequence stars beyond ~ 10 kpc, complementing studies of nearby…

Omega Centauri is a peculiar Globular Cluster formed by a complex stellar population. To shed light on this, we studied 172 stars belonging to the 5 SGBs that we can identify in our photometry, in order to measure their [Fe/H] content as…

Astrophysics of Galaxies · Physics 2015-06-22 S. Villanova , D. Geisler , R. G. Gratton , S. Cassisi

$\omega$ Cen is a rare example of a globular cluster where the iron abundance of the stars spans more than one order of magnitude. Many spectroscopic investigations of its red-giant- and sub-giant- branches have revealed multiple peaks in…

Solar and Stellar Astrophysics · Physics 2021-09-29 M. Latour , A. Calamida , T. -O. Husser , S. Kamann , S. Dreizler , J. Brinchmann

We present chemical abundance measurements for 7,302 red giant branch stars within the half-light radius (~5') of $\omega$ Centauri ($\omega$ Cen), derived from MUSE spectra using the neural network model DD-Payne. DD-Payne effectively…

We present wide-field and high-precision BV and Ca & Stromgren by photometry of omega Centauri, which represents one of the most extensive photometric surveys to date for this cluster. The member stars of omega Cen are well discriminated…

Astrophysics · Physics 2009-11-10 S. -C. Rey , Y. -W. Lee , C. Ree , J. -M. Joo , Y. -J. Sohn , A. Walker

We present results of an extensive spectroscopic survey of Subgiant stars in the stellar system omega Centauri. Using infrared CaII triplet lines, we derived metallicities and radial velocities for more than 250 stars belonging to different…

Astrophysics · Physics 2009-11-13 A. Sollima , E. Pancino , F. R. Ferraro , M. Bellazzini , O. Straniero , L. Pasquini

CCD vby Stroemgren photometry of a statistically complete sample of red giants and stars in the main sequence turn-off region in omega Centauri has been used to analyse the apparently complex star formation history of this cluster. From the…

Astrophysics · Physics 2009-10-05 Michael Hilker , Tom Richtler

We report metallicities and radial velocities derived from spectra at the near-infrared calcium triplet for 373 red giants in a 200 square arcminute area at the optical center of the LMC bar. These are the first spectroscopic abundance…

Astrophysics · Physics 2009-11-10 Andrew A. Cole , E. Tolstoy , J. S. Gallagher , T. A. Smecker-Hane

We present the metallicity distribution function (MDF) for 24,270 G and 16,847 K dwarfs at distances from 0.2 to 2.3 kpc from the Galactic plane, based on spectroscopy from the Sloan Extension for Galactic Understanding and Exploration…

We present a technique that applies spectral synthesis to medium resolution spectroscopy (MRS, R ~ 6000) in the red (6300 A < lambda < 9100 A) to measure [Fe/H] and [alpha/Fe] of individual red giant stars over a wide metallicity range. We…

Astrophysics · Physics 2008-08-09 Evan N. Kirby , Puragra Guhathakurta , Christopher Sneden

The photometric study of the Sagittarius dwarf galaxy by Marconi et al (1998) has suggested the presence of a spread in metallicity (-0.7< [Fe/H] < -1.6), which may result from different bursts of star formation. We present the results from…

Astrophysics · Physics 2019-08-17 G. Marconi , P. Bonifacio , L. Pasquini , P. Molaro

We present elemental abundances for 855 red giant branch (RGB) stars in the globular cluster Omega Centauri (w Cen) from spectra obtained with the Blanco 4m telescope and Hydra multifiber spectrograph. The sample includes nearly all RGB…

Solar and Stellar Astrophysics · Physics 2015-05-19 Christian I. Johnson , Catherine A. Pilachowski

We interpret the de-reddened UBV data for the field SA 133 to deduce the stellar density and metallicity distributions function. The logarithmic local space density for giants, $D^{*}(0)=6.40$, and the agreement of the luminosity function…

Astrophysics · Physics 2015-06-24 Y. Karatas , S. Bilir , S. Karaali , S. G. Ak