NOAO >   Observing Info >   Approved Programs >   2011A-0118

# Proposal Information for 2011A-0118

PI: Daniel H. McIntosh, University of Missouri-Kansas City, mcintoshdh@umkc.edu
Address: Physics Department, 5110 Rockhill Rd., Kansas City, MO 64110, USA

CoI: Cory Walker, University of Missouri-Kansas City
CoI: Justin Mann, University of Missouri-Kansas City

Title: Spectroscopy of Gas-rich Major Mergers from the SDSS

Abstract: Gas-rich major galaxy mergers, leading to starbursts and then to quiescent massive spheroidal galaxies, are postulated to be a central mechanism in explaining the growth of the red-sequence' population since z=1. Yet, merger rate constraints are severely limited by the merger visibility timescale, which depends critically on the complex space of merger properties. Improving our understanding of merger timescales requires careful data-simulation comparisons using large numbers of ongoing interactions. With the SDSS, we have identified statistical samples of gas-rich interaction snapshots from the nearby universe. Unfortunately, 40% of these mergers have no spectrum for one (or both) of the interacting galaxies, and \it this incompleteness increases with decreasing angular separation producing a potential bias in the subset with existing SDSS spectra. Here we propose 4760- 7240Aspectroscopy of 30 blue merger progenitors, and 3760-6240\AA\ spectroscopy of 15 red galaxies (in mixed' mergers), using the GoldCam Spectrometer on the 2.1-meter. This data will efficiently improve the statistics of gas-rich mergers at low-redshift, and provide better constraints of their dependence on host environment and nuclear activity.

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 NOAO >   Observing Info >   Approved Programs >   2011A-0118