MASSIVE CLUMPS IN LOCAL GALAXIES: COMPARISONS WITH HIGH-REDSHIFT CLUMPS

Journal Article · Sun Sep 01 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/774/1/86· OSTI ID:22133937

Elmegreen, Bruce G. ^[1]; Elmegreen, Debra Meloy; Dewberry, J.; Putko, J.; Teich, Y.; Popinchalk, M. ^[2]; Sanchez Almeida, J.; Munoz-Tunon, C. ^[3]

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1. IBM Research Division, T. J. Watson Research Center, Yorktown Hts., NY 10598 (United States)
2. Vassar College, Dept. of Physics and Astronomy, Poughkeepsie, NY 12604 (United States)
3. Instituto de Astrof'sica de Canarias, C/via Lactea, s/n, E-38205, La Laguna, Tenerife (Spain)

Local UV-bright galaxies in the Kiso survey include clumpy systems with kiloparsec-size star complexes that resemble clumpy young galaxies in surveys at high redshift. We compare clump masses and underlying disks in several dozen galaxies from each of these surveys to the star complexes and disks of normal spirals. Photometry and spectroscopy for the Kiso and spiral sample come from the Sloan Digital Sky Survey. We find that the largest Kiso clumpy galaxies resemble Ultra Deep Field (UDF) clumpies in terms of the star formation rates, clump masses, and clump surface densities. Clump masses and surface densities in normal spirals are smaller. If the clump masses are proportional to the turbulent Jeans mass in the interstellar medium, then for the most luminous galaxies in the sequence of normal:Kiso:UDF, the turbulent speeds and surface densities increase in the proportions 1.0:4.7:5.0 and 1.0:4.0:5.1, respectively, for fixed restframe B-band absolute magnitude. For the least luminous galaxies in the overlapping magnitude range, the turbulent speed and surface density trends are 1.0:2.7:7.4 and 1.0:1.4:3.0, respectively. We also find that while all three types have radially decreasing disk intensities when measured with ellipse-fit azimuthal averages, the average profiles are more irregular for UDF clumpies (which are viewed in their restframe UV) than for Kiso galaxies (viewed at g-band), and major axis intensity scans are even more irregular for the UDF than Kiso galaxies. Local clumpy galaxies in the Kiso survey appear to be intermediate between UDF clumpies and normal spirals.

• OSTI ID: 22133937
• Journal Information: Astrophysical Journal, Vol. 774, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
MILKY WAY
PHOTOMETRY
RED SHIFT
SPECTROSCOPY
STARS