The UV-Optical Color Magnitude Diagram II: Physical Properties and Morphological Evolution On and Off of a Star-Forming Sequence

Abstract

We use the UV-optical color magnitude diagram in combination with spectroscopic and photometric measurements derived from the SDSS spectroscopic sample to measure the distribution of galaxies in the local universe (z<0.25) and their physical properties as a function of specific star formation rate (SSFR) and stellar mass. Throughout this study our emphasis is on the properties of galaxies on and off of a local "star-forming sequence." We discuss how the physical characteristics of galaxies along this sequence are related to scaling relations typically derived for galaxies of different morphological types. We find, among other trends that our measure of the star formation rate surface density is nearly constant along this sequence. We discuss this result and implications for galaxies at higher redshift. For the first time, we report on measurements of the local UV luminosity function versus galaxy structural parameters as well as inclination. We also split our sample into disk-dominated and bulge-dominated subsamples using the i-band Sersic index and find that disk-dominated galaxies occupy a very tight locus in SSFR vs. stellar mass space while bulge-dominated galaxies display a much larger spread of SSFR at fixed stellar mass. A significant fraction of galaxies with SSFR and SF surface density above those on the "star-forming sequence" are bulge-dominated. We can use our derived distribution functions to ask whether a significant fraction of these galaxies may be experiencing a final episode of star formation (possibly induced by a merger or other burst), soon to be quenched, by determining whether this population can explain the growth rate of the non-star-forming galaxies on the "red sequence." (Abridged)

30 pages, 28 figures, scheduled to appear as part of the GALEX Special Ap.J.Suppl., December, 2007 (29 papers)

References in corpus (13)

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• UV Star Formation Rates in the Local Universe
• Star formation in AEGIS field galaxies since z=1.1 . Staged galaxy formation, and a model of mass-dependent gas exhaustion
• An Ultraviolet-to-Radio Broadband Spectral Atlas of Nearby Galaxies
• The Discovery of 1000 km/s Outflows in Massive Post-starburst Galaxies at z=0.6
• Star Formation and the Growth of Stellar Mass
• Evolution of the Luminosity Function, Star Formation Rate, Morphology and Size of Star-forming Galaxies Selected at Rest-frame 1500A and 2800A
• The Diverse Properties of the Most Ultraviolet Luminous Galaxies Discovered by the Galaxy Evolution Explorer
• Ongoing Formation of Bulges and Black Holes in the Local Universe: New Insights from GALEX
• Statistical Properties of the GALEX/SDSS matched source catalogs, and classification of the UV sources
• Ultraviolet, Optical, and Infrared Constraints on Models of Stellar Populations and Dust Attenuation
• Infrared Spectral Energy Distributions of z~0.7 Star-Forming Galaxies
• The Color Magnitude Distribution of Field Galaxies to z~3: the evolution and modeling of the blue sequence

Cited by in corpus (9)

• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• Absorption Properties and Evolution of Active Galactic Nuclei
• Fluctuations in the High-Redshift Lyman-Werner Background: Close Halo Pairs as the Origin of Supermassive Black Holes
• The STAGES view of red spirals and dusty red galaxies: Mass-dependent quenching of star-formation in cluster infall
• UV Dust Attenuation in Star-forming Galaxies: II Calibrating the A(UV) vs. L_TIR/L_UV relation
• Mid-IR Luminosities and UV/Optical Star Formation Rates at z<1.4
• Ultraviolet, Optical, and Infrared Constraints on Models of Stellar Populations and Dust Attenuation
• The optical spectra of 24 micron galaxies in the COSMOS field: I. Spitzer/MIPS bright sources in the zCOSMOS-bright 10k catalogue
• The Radio Luminosity Function and Galaxy Evolution in the Coma Cluster