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Related papers: Bimodality in low luminosity E and S0 galaxies

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We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li…

Astrophysics of Galaxies · Physics 2015-06-05 P. E. Nissen , W. J. Schuster

We compute the chemical evolution of the Galactic bulge to explain the existence of two main stellar populations recently observed. After comparing model results and observational data we suggest that the old more metal poor stellar…

Astrophysics of Galaxies · Physics 2015-06-11 V. Grieco , F. Matteucci , A. Pipino , G. Cescutti

This is the first paper presenting our long-term project aimed at studying the nature of bulges through the analysis of their stellar population gradients. We present deep spectroscopic observations along the minor axis and the data…

Astrophysics · Physics 2009-11-13 J. Gorgas , P. Jablonka , P. Goudfrooij

Low-metallicity galaxies may provide key insights into the evolutionary history of galaxies. Galaxies with strong emission lines and high equivalent widths (rest-frame EW(H-beta) > 30 A) are ideal candidates for the lowest metallicity…

Astrophysics of Galaxies · Physics 2022-09-13 Isaac H. Laseter , Amy J. Barger , Lennox L. Cowie , Anthony J. Taylor

We compute the properties of a sample of 221 local early-type galaxies with a spectral energy distribution (SED) modeling software, CIGALEMC. Concentrating on the star forming activity and dust contents, we derive parameters such as the…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-02 A. Amblard , L. Riguccini , P. Temi , S. Im , M. Fanelli , P. Serra

A search for lithium is performed on seven metal poor dwarfs with metallicities ranging from [Fe/H]=-1.5 down to [Fe/H]=-3.0 but showing disk-like kinematics. These stars belong to the metal poor tail of the Galactic thick disk and they may…

Astrophysics · Physics 2016-01-13 P. Molaro , P. Bonifacio , L. Pasquini

Ultra strong emission-line galaxies (USELs) with extremely high equivalent widths (EW(H beta) > 30A) can be used to pick out galaxies of extremely low metallicity in the z=0-1 redshift range. Large numbers of these objects are easily…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Esther M. Hu , Lennox L. Cowie , Yuko Kakazu , Amy J. Barger

[ABRIDGED] Based on high-resolution (R~42000 to 48000) and high signal-to-noise (S/N~50 to 150) spectra obtained with UVES/VLT, we present detailed elemental abundances (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, and Ba) and stellar ages…

We present UV and optical observations from the Cosmic Origins Spectrograph on the Hubble Space Telescope and Keck of a z= 0.27395 Lyman limit system (LLS) seen in absorption against the QSO PG1630+377. We detect H I absorption with log…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Joseph Ribaudo , Nicolas Lehner , J. Christopher Howk , Jessica K. Werk , Todd M. Tripp , J. Xavier Prochaska , Joseph D. Meiring , Jason Tumlinson

We have obtained low resolution spectra of nineteen red and blue low surface brightness galaxies, using the Marcario Low Resolution Spectrograph on the 9.2m Hobby-Eberly Telescope. These galaxies form a very heterogeneous class, whose…

Astrophysics · Physics 2009-11-07 Marcel Bergmann , Inger Jorgensen , Gary J. Hill

Spectra from MDM Observatory are used to assess Lick/IDS feature strength gradients inside the half-light radius of the compact Local Group elliptical galaxy M32. All but a few (of 24 measured) indices show a statistically significant…

Astrophysics · Physics 2009-11-10 Guy Worthey

We derive metal abundance estimates for a large sample of starbursting emission-line galaxies (ELGs). Our sample is drawn from the KPNO International Spectroscopic Survey (KISS) which has discovered over 2000 ELG candidates to date.…

Astrophysics · Physics 2009-10-12 Jason Melbourne , John J. Salzer

We present a newly observed relation between galaxy mass and radial metallicity gradients of early-type galaxies. Our sample of 51 early-type galaxies encompasses a comprehensive mass range from dwarf to brightest cluster galaxies. The…

Astrophysics of Galaxies · Physics 2009-11-13 Max Spolaor , Robert N. Proctor , Duncan A. Forbes , Warrick J. Couch

ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…

Astrophysics of Galaxies · Physics 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

We present new measurements of central line-strength indices (namely Mg2, <Fe>, and Hbeta and gradients for a sample of 6 bright spheroidal galaxies (Sph's) in the Virgo cluster. Comparison with similar measurements for elliptical galaxies…

Astrophysics · Physics 2009-10-30 J. Gorgas , S. Pedraz , R. Guzman , N. Cardiel , J. J. Gonzalez

We present stellar population age and metallicity trends for a sample of 59 S0 galaxies based on optical SDSS and NIR J & H photometry. When combined with optical g and r passband imaging data from the SDSS archive and stellar population…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 L. C. Prochaska Chamberlain , Stephane Courteau , Michael McDonald , James A. Rose

Lithium (Li) abundance is an age indicator for G, K, and M stellar types, as its abundance decreases over time for these spectral types. However, despite the observational efforts made over the past few decades, the role of rotation,…

Solar and Stellar Astrophysics · Physics 2024-05-15 D. Cuenda-Muñoz , D. Barrado , M. A. Agüeros , J. L. Curtis , H. Bouy

(Abridged) As part of an ongoing effort to study the stellar nuclei of very late-type, bulge-less spirals, we present results from a high-resolution spectroscopic survey of nine such nuclear star clusters, undertaken with VLT/UVES. We fit…

We present follow-up spectra of 39 emission-line galaxies (ELGs) from the KPNO International Spectroscopic Survey (KISS). Many targets were selected as potentially low metallicity systems based on their absolute B magnitudes and the…

Astrophysics · Physics 2009-11-10 J. Melbourne , A. Phillips , J. Salzer , C. Gronwall , V. Sarajedini

We have carried out a high resolution spectroscopic survey of the 220-250 Myr old cluster NGC 6475: our main purpose is to investigate Li evolution during the early stages of the Main Sequence. We have determined Li abundances for 33 late F…

Astrophysics · Physics 2009-11-07 Paola Sestito , Sofia Randich , Jean-Claude Mermilliod , Roberto Pallavicini