NOAO >   Observing Info >   Approved Programs >   2014A-0523

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Proposal Information for 2014A-0523


PI: Robert Bassett, Swinburne University of Technology, rbassett.astro@gmail.com
Address: Swinburne Centre for Astrophysics and Supercomputing, Mail number 31, PO Box 218, Hawthorne, Victoria, 3122, Australia

CoI: Karl Glazebrook, Swinburne University of Technology
CoI: David Fisher, Swinburne University of Technology
CoI: Roberto Abraham, University of Toronto
CoI: Ivana Damjanov, Harvard-Smithsonian Center for Astrophysics

Title: Local Counterparts to High-Redshift Turbulent Galaxies: What are the Stellar Kinematics?

Abstract: We aim to measure the stellar kinematics of 4 low redshift turbulent, clumpy disks with the GMOS IFU. Recent observations of high redshift galaxies show that gaseous disks in high redshift (z 2) galaxies are turbulent. The source of this turbulence remains an open question. A possible scenario is that turbulent disks are fed by streams of cold gas, flowing along cosmic filaments, which drive the large H-alpha velocity dispersions and clumpy star formation observed (for example by the SINS survey). However, the recent discovery of low redshift disk galaxies with clumpy-high velocity dispersion disks shows that galaxies with similar properties to high-z clumpy disks can exists in absence of cold flows, therefore an alternate driver for turbulence seems likely to explain, at least these nearby galaxies. A contrasting scenario is that the turbulence is driven by feedback from extreme star formation originating from a thin stellar disk. These nearby star forming disks are very rare, yet they provide an oppurtunity to study clumpy disks with techniques which are impossible at high redshift (due to both resolution and surface brightness dimming). Here we propose one such study, to measure the stellar kinematics from Balmer absorption lines. If the stars and gas have similar velocity dispersion, this would favor externally driven turbulence by gas accretion (a rare thing in the low redshift Universe); conversely if the gas and stars have different dynamics then this would suggest that internally driven turbelence from feedback is a plausible scenario. We currently have GMOS IFU observations of two disk systems, and we propose here to extend our sample. To identify galaxies as disks we use lower resolution IFU emission line kinematics from AAO, surface photometry from UKIDSS and SDSS, and Halpha maps from Hubble Space Telescope.


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NOAO >   Observing Info >   Approved Programs >   2014A-0523

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