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Related papers: The M Dwarf Problem in the Galaxy

200 papers

We construct three extreme different scenarios of the star formation histories applicable to a sample of dwarf galaxies, based either on their present metallicity or their luminosity. The three possible scenarios imply different mechanical…

In this work we present and discuss the observations of the Mn abundances for 247 FGK dwarfs, located in the Galactic disc with metallicity -1<Fe/H]<+0.3. The observed stars belong to the substructures of the Galaxy thick and thin discs,…

Astrophysics of Galaxies · Physics 2015-10-14 T. Mishenina , T. Gorbaneva , M. Pignatari , F. -K. Thielemann , S. A. Korotin

We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from (lambda…

Astrophysics · Physics 2009-11-10 Vincent M. Woolf , George Wallerstein

A few dozen dwarf satellite galaxies of the Milky Way have been discovered, which are often viewed as the remaining building blocks of our Galaxy. The follow-up spectroscopy showed that dwarf galaxies have a sizeable spread in their…

Astrophysics of Galaxies · Physics 2020-02-24 Sang-Il Han , Hak-Sub Kim , Suk-Jin Yoon , Young-Wook Lee , Nobuo Arimoto , Sakurako Okamoto , Chang H. Ree

We present a study of a large, statistically complete sample of star-forming dwarf galaxies using mid-infrared observations from the {\it Spitzer Space Telescope}. The relationships between metallicity, star formation rate (SFR) and…

Astrophysics of Galaxies · Physics 2010-07-01 Sukbum A. Hong , Jessica L. Rosenberg , Matthew L. N. Ashby , John J. Salzer

We present stellar metallicities in Leo I, Leo II, IC 1613, and Phoenix dwarf galaxies derived from medium (F390M) and broad (F555W, F814W) band photometry using the Wide Field Camera 3 (WFC3) instrument aboard the Hubble Space Telescope.…

Astrophysics of Galaxies · Physics 2015-06-03 Teresa L. Ross , Jon A. Holtzman , Abhijit Saha , Barbara J. Anthony-Twarog

Dwarf galaxies are found to have lost most of their metals via feedback processes; however, there still lacks consistent assessment on the retention rate of metals in their circumgalactic medium (CGM). Here we investigate the metal content…

We present stellar parameters and metallicities for 29 planet-host stars, as well as for a large volume-limited sample of 53 stars not known to be orbited by any planetary-mass companion. These stars add to the results presented in our…

Astrophysics · Physics 2009-11-10 N. C. Santos , G. Israelian , M. Mayor , J. P. Bento , P. C. Almeida , S. G. Sousa , A. Ecuvillon

We study the metallicity properties of galaxies in the zCOSMOS sample between 0.2<z<0.8. At z<0.46, where Ha and [NII] are detected, we find the same dependence of metallicity on stellar mass and Star Formation Rate (SFR), the Fundamental…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Giovanni Cresci , Filippo Mannucci , Veronica Sommariva , Roberto Maiolino , Alessandro Marconi , Marcella Brusa

While the number of stars in the Galactic bulge with detailed chemical abundance measurements is increasingly rapidly, the inner Galactic bulge ( |b| < 2$^\circ$) remains poorly studied, due to heavy interstellar absorption and photometric…

Astrophysics of Galaxies · Physics 2018-05-23 G. Nandakumar , N. Ryde , M. Schultheis , B. Thorsbro , H. Jönsson , P. S. Barklem , R. M. Rich , F. Fragkoudi

Star clusters are known to have smaller intrinsic metallicity spreads than dwarf galaxies due to their shorter star formation timescales. Here we use individual spectroscopic [Fe/H] measurements of stars in 19 Local Group dwarf galaxies, 13…

Astrophysics of Galaxies · Physics 2015-06-11 Ryan Leaman

To account for the observed differential metallicity distribution (DMD) of the Milky Way halo, a semi-analytical model is presented in the framework of the hierarchical merging paradigm for structure formation. It is assumed that the Milky…

Astrophysics · Physics 2009-11-13 Nikos Prantzos

Recent work suggests that galaxy evolution, and the build-up of stellar mass (M*) over cosmic time, is characterized by changes with redshift of star formation rate (SFR) and oxygen abundance (O/H). In a companion paper, we have compiled a…

Astrophysics of Galaxies · Physics 2016-08-31 Leslie Hunt , Pratika Dayal , Laura Magrini , Andrea Ferrara

Strongly Mg-enhanced stars with [Mg/Fe] $>$ 1.0 show peculiar abundance patterns and hence are of great interest for our understanding of stellar formation and chemical evolution of the Galaxy. A systematical search for strongly Mg-enhanced…

Solar and Stellar Astrophysics · Physics 2015-06-19 Xiang Li , Gang Zhao , Yu-Qin Chen , Hai-Ning Li

Baryonic cycling is reflected in the spatial distribution of metallicity within galaxies, yet gas-phase metallicity distribution and its connection with other properties of dwarf galaxies are largely unexplored. We present the first…

We study the dwarf spheroidal galaxies in the nearby M81 group in order to construct their photometric metallicity distributions and to investigate the potential presence of population gradients. We select all the dwarf spheroidals with…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-26 Sophia Lianou , Eva K. Grebel , Andreas Koch

A possible relation between the high dispersion in metallicity of metal-poor halo stars and the minor merger processes in the history of the Galaxy is presented. The foreign populations of stars in the satellites through minor merger…

Astrophysics · Physics 2007-05-23 Y. Lu , K. S. Cheng , L. C. Deng

The stellar metallicity and its gradient pose constraints to the formation and evolution of galaxies. This is a study of the metallicity gradient of the LMC, SMC and M33 galaxies derived from their asymptotic giant branch (AGB) stars. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Maria-Rosa L. Cioni

Based on the Beijing-Arizona-Taiwan-Connecticut (BATC) and Sloan Digital Sky Survey (SDSS) photometric data, we adopt SEDs fitting Method to evaluate the metallicity distribution for \sim40,000 main-sequence stars in the Galaxy. According…

Astrophysics of Galaxies · Physics 2015-06-03 Xiyan Peng , Cuihua Du , Zhenyu Wu

We are studying the effects of submm observations on the total dust mass and thus dust-to-gas mass ratio measurements. We gather a wide sample of galaxies that have been observed at submm wavelengths to model their Spectral Energy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Maud Galametz , Suzanne C. Madden , Frederic Galliano , Sacha Hony , George J. Bendo , Marc Sauvage