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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

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Dartmouth Scholarship

2005

Galaxy evolution

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Noao Fundamental Plane Survey. Ii. Age And Metallicity Along The Red Sequence From Line‐Strength Data, Jenica E. Nelan, Russell J. Smith, Michael J. Hudson, Gary A. Wegner Oct 2005

Noao Fundamental Plane Survey. Ii. Age And Metallicity Along The Red Sequence From Line‐Strength Data, Jenica E. Nelan, Russell J. Smith, Michael J. Hudson, Gary A. Wegner

Dartmouth Scholarship

We present spectroscopic line-strength data for 4097 red-sequence galaxies in 93 low-redshift galaxy clusters and use these to investigate variations in average stellar populations as a function of galaxy mass. Our analysis includes an improved treatment of nebular emission contamination, which affects ~10% of the sample galaxies. Using the stellar population models of D. Thomas and collaborators, we simultaneously fit 12 observed line-strength-σ relations in terms of common underlying trends of age, [Z/H] (total metallicity), and [α/Fe] (α-element enhancement). We find that the observed line-strength-σ relations can be explained only if higher mass red-sequence galaxies are, on average, …


The Oxford-Dartmouth Thirty Degree Survey - Ii. Clustering Of Bright Lyman Break Galaxies: Strong Luminosity-Dependent Bias At Z = 4, Paul D. Allen, Leonidas A. Moustakas, Gavin Dalton, Emily Macdonald, Chris Blake, Lee Clewley, Catherine Heymans, Gary Wegner Apr 2005

The Oxford-Dartmouth Thirty Degree Survey - Ii. Clustering Of Bright Lyman Break Galaxies: Strong Luminosity-Dependent Bias At Z = 4, Paul D. Allen, Leonidas A. Moustakas, Gavin Dalton, Emily Macdonald, Chris Blake, Lee Clewley, Catherine Heymans, Gary Wegner

Dartmouth Scholarship

We present measurements of the clustering properties of bright (L > L*) z~4 Lyman break galaxies (LBGs) selected from the Oxford-Dartmouth Thirty Degree Survey (ODT). We describe techniques used to select and evaluate our candidates and calculate the angular correlation function, which we find best fitted by a power law, ω(θ) =Awθ−β with Aw= 15.4 (with θ in arcsec), using a constrained slope of β= 0.8. Using a redshift distribution consistent with photometric models, we deproject this correlation function and find a comoving Mpc in a Ωm= 0.3 flat λ cosmology for iAB≤ 24.5. This corresponds to a linear bias value …