Semi-empirical analysis of Sloan Digital Sky Survey galaxies – II. The bimodality of the galaxy population revisited

By A. Mateus, L. Sodré, R. C. Fernandes, G. Stasińska, William Schoenell, Jean M. Gomes IAG-USP, Brazil Ufsc, B. Luth, O. Meudon, France.. 2005

178 citations recorded by the source corpus.

We revisit the bimodal distribution of the galaxy population commonly seen in the local universe. Here, we address the bimodality observed in galaxy properties in terms of spectral synthesis products, such as mean stellar ages and stellar masses, derived from the application of this powerful method to a volume-limited sample, with magnitude limit cut-off M(r ) =− 20.5, containing about 50 000 luminous galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 2 (DR2). In addition, galaxies are classified according to their emission-line properties in three distinct spectral classes: star-forming galaxies, with young stellar populations; passive galaxies, dominated by old stellar populations; and hosts of active nuclei, which comprise a mix of young and old stellar populations. We show that the extremes of the distribution of some galaxy properties, essentially galaxy colours, 4000 A break index and mean stellar ages, are associated to star-forming galaxies at one side, and passive galaxies at another. We find that the mean light-weighted stellar age of galaxies is directly responsible for the bimodality seen in the galaxy population. The stellar mass, in this view, has an additional role since most of the star-forming galaxies present in the local universe are low-mass galaxies. Our results also give support to the existence of a ‘downsizing’ in galaxy formation, where massive galaxies seen nowadays have stellar populations formed at early times.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/a0cfa6e6b4067fee02e19c64d88e887d1a9fcb10

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Citations in the corpus

A comprehensive classification of galaxies in the SDSS: How to tell true from fake AGN? (2010, methodology): “In the literature one often finds PGs and ELGs defined in terms of limits on the signal to noise ratio (S Nλ) of emission lines (e.g. Miller et al. 2003; Brinchmann et al. 2004; Mateus et al. 2006).”
DO HOT HALOS AROUND GALAXIES CONTAIN THE MISSING BARYONS? (2010, methodology): “We classify each galaxy as early type or late type using its SDSS u − r color, with early-type galaxies having u − r > 2.2 and late-type galaxies having u − r < 2.2 (Strateva et al. 2001; Mateus et al. 2006).”
Alternative diagnostic diagrams and the 'forgotten' population of weak line galaxies in the SDSS (2009, methodology): “This transformation is achieved with an adaptation of the optimal class separation technique of Strateva et al. (2001, see also Mateus et al. 2006).”
A fundamental plane for field star-forming galaxies (2010, methodology): “Moreover, the obtained masses must be corrected for aperture eff cts based on the differences between the total galaxy magnitude in ther band, and the magnitude inside the fiber, assuming that the mass–to–light ratio does not depend on the radius (see Mateus et al. 2006 for details).”
The star formation history of CALIFA galaxies: Radial structures (2013, background): “This location correlates with stellar population properties (Kauffmann et al. 2003a,b; Baldry et al. 2004; Bell et al. 2004; Brinchmann et al. 2004; Gallazzi et al. 2005; Mateus et al. 2006, 2007; Blanton & Moustakas 2009).”
The history of star-forming galaxies in the Sloan Digital Sky Survey (2007, methodology): “In SEAGal II (Mateus et al. 2006) we have revisited the bimodality of the galaxy population in terms of spectral synthesis products.”