Mon. Not. R. Astron. Soc., 399, 1191-1205 (2009/November-1)
Galaxy Zoo green peas: discovery of a class of compact extremely star-forming galaxies.
CARDAMONE C., SCHAWINSKI K., SARZI M., BAMFORD S.P., BENNERT N., URRY C.M., LINTOTT C., KEEL W.C., PAREJKO J., NICHOL R.C., THOMAS D., ANDREESCU D., MURRAY P., RADDICK M.J., SLOSAR A., SZALAY A. and VANDENBERG J.
Abstract (from CDS):
We investigate a class of rapidly growing emission line galaxies, known as `Green Peas', first noted by volunteers in the Galaxy Zoo project because of their peculiar bright green colour and small size, unresolved in Sloan Digital Sky Survey imaging. Their appearance is due to very strong optical emission lines, namely [Oiii] λ5007Å, with an unusually large equivalent width of up to ∼1000Å. We discuss a well-defined sample of 251 colour-selected objects, most of which are strongly star forming, although there are some active galactic nuclei interlopers including eight newly discovered narrow-line Seyfert 1 galaxies. The star-forming Peas are low-mass galaxies (M ∼ 108.5-1010M☉) with high star formation rates (∼10M☉/yr), low metallicities (log[O/H] + 12 ∼ 8.7) and low reddening [E(B - V) ≤ 0.25] and they reside in low-density environments. They have some of the highest specific star formation rates (up to ∼10–8/yr) seen in the local Universe, yielding doubling times for their stellar mass of hundreds of Myr. The few star-forming Peas with Hubble Space Telescope imaging appear to have several clumps of bright star-forming regions and low surface density features that may indicate recent or ongoing mergers. The Peas are similar in size, mass, luminosity and metallicity to luminous blue compact galaxies. They are also similar to high-redshift ultraviolet-luminous galaxies, e.g. Lyman-break galaxies and Lyα emitters, and therefore provide a local laboratory with which to study the extreme star formation processes that occur in high-redshift galaxies. Studying starbursting galaxies as a function of redshift is essential to understanding the build up of stellar mass in the Universe.
© 2009 The Authors. Journal compilation © 2009 RAS
galaxies: dwarf - galaxies: evolution - galaxies: formation - galaxies: high-redshift - galaxies: Seyfert - galaxies: starburst
View the references in ADS
To bookmark this query, right click on this link: simbad:2009MNRAS.399.1191C and select 'bookmark this link' or equivalent in the popup menu