J/ApJ/695/259 Massive metal-poor galaxies from SDSS (Peeples+, 2009) ================================================================================ Outliers from the mass-metallicity relation. II. A sample of massive metal-poor galaxies from SDSS. Peeples M.S., Pogge R.W., Stanek K.Z. =2009ApJ...695..259P ================================================================================ ADC_Keywords: Galaxies, optical ; Redshifts ; Abundances Keywords: galaxies: abundances - galaxies: evolution Abstract: We present a sample of 42 high-mass low-metallicity outliers from the mass-metallicity relation of star-forming galaxies. These galaxies have stellar masses that span log(M_*_/M_{sun}_)~9.4 to 11.1 and are offset from the mass-metallicity relation by -0.3 to -0.85dex in 12+log(O/H). In general, they are extremely blue, have high star-formation rates for their masses, and are morphologically disturbed. Tidal interactions are expected to induce large-scale gas inflow to the galaxies' central regions, and we find that these galaxies' gas-phase oxygen abundances are consistent with large quantities of low-metallicity gas from large galactocentric radii diluting the central metal-rich gas. We conclude with implications for deducing gas-phase metallicities of individual galaxies based solely on their luminosities, specifically in the case of long gamma-ray burst host galaxies. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 37 42 Low-metallicity mass-metallicity outliers -------------------------------------------------------------------------------- See also: II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009) J/ApJ/685/904 : Metal-rich dwarf galaxies from SDSS-DR4 (Peeples+, 2008) J/A+A/459/85 : O/H and gas densities in star-forming galaxies (Nagao+, 2006) J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006) http://www.sdss.org/ : SDSS home page Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 8 F8.4 deg RAdeg Right ascension in decimal degrees (J2000) 10- 17 F8.5 deg DEdeg Declination in decimal degrees (J2000) 19- 22 F4.2 [-] eps(O) Oxygen abundance (12+log(O/H)) from Tremonti et al. 2004ApJ...613..898T 24- 28 F5.2 [-] logM* Stellar mass from Tremonti et al. 2004ApJ...613..898T (1) 30- 35 F6.4 --- z Redshift 37 A1 --- Note [s] "s" for spiral galaxy -------------------------------------------------------------------------------- Note (1): Sample of massive low-metallicity galaxies, reverse sorted by stellar mass. -------------------------------------------------------------------------------- Nomenclature notes: Galaxies are <[PPS2009] DDD.dddd+DD.ddddd> in Simbad. History: From electronic version of the journal References: Peeples et al. Paper I. 2008ApJ...685..904P Cat. J/ApJ/685/904 ================================================================================ (End) Emmanuelle Perret [CDS] 04-Apr-2011