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Related papers: Unravelling stellar populations in the Andromeda G…

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We present $\sim300$ stellar metallicity measurements in two faint M31 dwarf galaxies, Andromeda XVI ($M_V = -7.5$) and Andromeda XXVIII ($M_V = -8.8$) derived using metallicity-sensitive Calcium H & K narrow-band Hubble Space Telescope…

We selected Bulge stars from APOGEE DR17 cross-matched with astrometric data from \textit{Gaia} DR3. Bulge stars were divided into sub-samples with line-of-sight velocity dispersion analyzed and the peaks of MDF were detected by both…

Astrophysics of Galaxies · Physics 2025-10-29 Haoyang Liu , Cuihua Du , Zhongcheng Li , Jian Zhang , Mingji Deng

Elemental abundance ratios as tracers of stellar populations are discussed with emphasis on F, G, and K stars providing a `fossil' record of the chemical evolution of the Galaxy. Most abundance studies have been based on homogeneous 1D…

Astrophysics of Galaxies · Physics 2011-09-20 Poul Erik Nissen

Based on high-resolution spectra obtained during gravitational microlensing events we present a detailed elemental abundance analysis of 32 dwarf and subgiant stars in the Galactic bulge. [ABRIDGED], we now have 58 microlensed bulge dwarfs…

(Abriged) We report results of a campaign to image the stellar populations in the halos of highly inclined spiral galaxies, with the fields roughly 10 kpc (projected) from the nuclei. We use the F814W (I) and F606W (V) filters in the Wide…

Astrophysics · Physics 2009-11-13 M. Mouhcine , R. M. Rich , H. C. Ferguson , T. M. Brown , T. E. Smith

It is well established that the chemical structure of the Milky Way exhibits a bimodality with respect to the $\alpha$-enhancement of stars at a given [Fe/H]. This has been studied largely based on a bulk $\alpha$ abundance, computed as a…

Astrophysics of Galaxies · Physics 2019-09-20 Kirsten Blancato , Melissa Ness , Kathryn V. Johnston , Jan Rybizki , Megan Bedell

In this paper we consider the implications of the distributions of dust and metals in the disc of M31. We derive mean radial dust distributions using a dust map created from Herschel images of M31 sampling the entire far-infrared (FIR)…

Astrophysics of Galaxies · Physics 2014-09-16 L. Mattsson , H. L. Gomez , A. C. Andersen , M. W. L. Smith , I. De Looze , M. Baes , S. Viaene , G. Gentile , J. Fritz , L. Spinoglio

We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The analyses of carbon-enhanced stars in our…

Astrophysics of Galaxies · Physics 2015-05-20 Takuma Suda , Shimako Yamada , Yutaka Katsuta , Yutaka Komiya , Chikako Ishizuka , Wako Aoki , Masayuki Y. Fujimoto

We present evidence for a metal-poor, [Fe/H]$\sim-1.4$ $\sigma$=0.2 dex, stellar halo component detectable at radii from 10 kpc to 70 kpc, in our nearest giant spiral neighbor, the Andromeda galaxy. This metal-poor sample underlies the…

Astrophysics · Physics 2008-11-26 S. C. Chapman , R. Ibata , G. F. Lewis , A. M. N. Ferguson , M. Irwin , A. McConnachie , N. Tanvir

We present a new determination of the metallicity distribution, age, and luminosity function of the Galactic bulge stellar population. By combining near-IR data from the 2MASS survey, from the SOFI imager at ESO NTT and the NICMOS camera on…

We investigate the inner regions of the Milky Way with a sample of unprecedented size and coverage thanks to APOGEE DR16 and Gaia EDR3 data. Our inner Galactic sample has more than 26,000 stars within $|X_{\rm Gal}| <5$ kpc, $|Y_{\rm Gal}|…

We develop a new method to account for the finite lifetimes of stars and trace individual abundances within a semi-analytic model of galaxy formation. At variance with previous methods, based on the storage of the (binned) past star…

Astrophysics of Galaxies · Physics 2015-06-22 Gabriella De Lucia , Luca Tornatore , Carlos S. Frenk , Amina Helmi , Julio F. Navarro , Simon D. M. White

The connection between some features of the metallicity gradient in the Galactic disk, best revealed by Open Clusters and Cepheids, and the spiral structure, is explored. The step-like abrupt decrease in metallicity at 8.5 kpc (with R_0=…

Astrophysics of Galaxies · Physics 2015-05-28 J. R. D. Lepine , P. Cruz , S. Scarano , D. A. Barros , W. S. Dias , L. Pompeia , S. M. Andrievsky , G. Carraro , B. Famaey

We investigate the metal enrichment of elliptical galaxies in the framework of hierarchical models of galaxy formation. The semi-analytical model we use in this Letter, which has been used to study the metal enrichment of the intracluster…

Rich and poor galaxy clusters have the same measured halo metallicity, 0.35-0.4 $Z_\odot$, even though they are an order of magnitude apart in stellar fraction, $M_*/M_{gas}$. The measured intracluster medium (ICM) metallicity in high-mass…

Astrophysics of Galaxies · Physics 2022-02-18 Anne E Blackwell , Joel N Bregman , Steven L Snowden

We derive central values and logarithmic gradients for the Hbeta, Mg and Fe indices of 35 early-type galaxies in the Coma cluster. We find that pure elliptical galaxies have on average slightly higher velocity dispersions, lower Hbeta, and…

Astrophysics · Physics 2008-11-26 D. Mehlert , D. Thomas , R. P. Saglia , R. Bender , G. Wegner

Accreted stellar populations are comprised of the remnants of destroyed galaxies, and often dominate the `stellar haloes' of galaxies such as the Milky Way (MW). This ensemble of external contributors is a key indicator of the past assembly…

Astrophysics of Galaxies · Physics 2023-03-01 Alis J. Deason , Sergey E. Koposov , Azadeh Fattahi , Robert J. J. Grand

We present alpha to iron abundance ratios for 226 individual red giant branch stars in nine dwarf galaxies of the Andromeda (M 31) satellite system. The abundances are measured from the combined signal of Mg, Si, Ca, and Ti lines in…

Astrophysics of Galaxies · Physics 2015-06-19 Luis C. Vargas , Marla C. Geha , Erik J. Tollerud

Context: The mass-metallicity relationship (MMR) of star-forming galaxies is well-established, however there is still some disagreement with respect to its exact shape and its possible dependence on other observables. Aims: We measure the…

The $([\alpha/{\rm Fe}],[{\rm Fe/H}])$ distribution of Milky Way stars shows at least two distinct sequences, which have traditionally been associated with the thin and thick disc components. The abundance distribution varies systematically…

Astrophysics of Galaxies · Physics 2021-08-04 Sanjib Sharma , Michael R. Hayden , Joss Bland-Hawthorn