We study the formation of galaxy cluster-size dark matter halos (M > 1014.0 Msun) formed within a set of cosmological Lambda CDM N-body simulations, and track the accretion histories of cluster subhalos. We use the merger trees of these halos to trace their assembly and examine the populations of clusters/protoclusters in several different redshift

We present an asteroseismic study of the solar-like stars KIC 11395018, KIC 10273246, KIC 10920273, KIC 10339342, and KIC 11234888 using short-cadence time series of more than eight months from the Kepler satellite. For four of these stars, we derive atmospheric parameters from spectra acquired with the Nordic Optical Telescope. The global seismic

Context. Fossil systems are galaxy associations dominated by a relatively isolated, bright elliptical galaxy, surrounded by a group of smaller galaxies lacking L∗ objects. Because of this extreme environment, fossil groups (FGs) are ideal laboratories for studying the mass assembly of brightest group galaxies (BGGs). Aims: We analyzed the near

The SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE) will obtain high resolution (R 22,500) and high S/N ( 100 per pixel) H-band spectra of 100,000 giant stars in the Milky Way disk, bulge and halo to study the chemical and kinematical evolution of the Milky Way Galaxy. APOGEE will be able to probe deep into regions of our

The Apache Point Observatory Galactic Evolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III, is exploring the stellar populations of the Milky Way using the Sloan 2.5-m telescope linked to a high resolution (R 22,500), near-infrared (1.51-1.68 microns) spectrograph with 300 optical fibers. For about 100,000, predominantly red

The stellar content of the bulge of the Galaxy is not well characterized yet, in part due to the high extinction and, therefore, limited access at optical wavelengths. The SDSS-III Apache Point Observatory Galaxy Evolution Experiment (APOGEE) is an on-going near-infrared survey acquiring very high quality spectra (S/N > 100 per pixel, R 22,500) of