NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-03-25 T11:53:49 PDT
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For refcode 2005MNRAS.358..813D:
Retrieve 83 NED objects in this reference.
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Copyright by Royal Astronomical Society. 2005MNRAS.358..813D Group, field and isolated early-type galaxies - II. Global trends from nuclear data Denicolo, G.; Terlevich, Roberto; Terlevich, Elena; Forbes, Duncan A.; Terlevich, Alejandro Abstract. We have derived ages, metallicities and enhanced-element ratios [{alpha}/Fe] for a sample of 83 early-type galaxies essentially in groups, the field or isolated objects. The stellar-population properties derived for each galaxy correspond to the nuclear r_e_/8 aperture extraction. The median age found for Es is 5.8+/-0.6 Gyr and the average metallicity is +0.37+/-0.03 dex. For S0s, the median age is 3.0+/-0.6 Gyr and [Z/H]= 0.53+/-0.04 dex. We compare the distribution of our galaxies in the H{beta}-[MgFe] diagram with Fornax galaxies. Our elliptical galaxies are 3-4 Gyr younger than Es in the Fornax cluster. We find that the galaxies lie in a plane defined by [Z/H]= 0.99 log{sigma}_0_- 0.46 log(age) - 1.60, or in linear terms Z is proportional to {sigma}_0_ x (age)^-0.5^. More massive (larger {sigma}_0_) and older galaxies present, on average, large [{alpha}/Fe] values, and therefore must have undergone shorter star-formation time-scales. Comparing group against field/isolated galaxies, it is not clear that environment plays an important role in determining their stellar-population history. In particular, our isolated galaxies show ages differing by more than 8 Gyr. Finally we explore our large spectral coverage to derive log(O/H) metallicity from the H{alpha} and NII{lambda}6584 and compare it with model-dependent [Z/H]. We find that the O/H abundances are similar for all galaxies, and we can interpret it as if most chemical evolution has already finished in these galaxies.
Retrieve 83 NED objects in this reference.
Please click here for ADS abstract

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