We present a new deep determination of the spectroscopic LF within the virial radius of the nearby and massive Abell 85 (A85) cluster down to the dwarf regime (M*+6) using VLT/VIMOS spectra for ~2000 galaxies with mr ≤ 21 mag and <μe,r > ≤ 24 mag arcsec-2. The resulting LF from 438 cluster members is best modeled by a double Schechter function due to the presence of a statistically significant upturn at the faint-end. The amplitude of this upturn (αf = -1.58+0.19-0.15), however, is much smaller than that of the SDSS composite photometric cluster LF by Popesso et al. (2006, αf ~-2). The faint-end slope of the LF in A85 is consistent, within the uncertainties, with that of the field. The red galaxy population dominates the LF at low luminosities, and is the main responsible for the upturn. The fact that the slopes of the spectroscopic LFs in the field and in a cluster as massive as A85 are similar suggests that the cluster environment does not play a major role in determining the abundance of low-mass galaxies. At the same time, it is important because it changes the nature of the dwarf galaxies transforming blue ones in field into red ones in high density regions as can be observe comparing the LFs of these populations.
It may interest you
Red dwarfs are the most common stars in the galaxy. In recent years they have become key targets in the search for exoplanets. These stars are usually accompanied by rocky planets and due to their low brightness, their habitable zone is close to the star, making it easier to find planets that are within it. GJ 1002 is a red dwarf just one-eighth the mass of the Sun, located only 15.8 light-years away. Using radial velocity measurements from the ESPRESSO and CARMENES spectrographs, we have discovered the presence of two Earth-like and potentially habitable planets. The planets, GJ 1002 b andAdvertised on
Accretion disks around compact objects are expected to enter an unstable phase at high luminosity. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion and refilling of the inner disk on short timescales. Such a scenario, however, has only been quantitatively verified for a single stellar-mass black hole. Although there are hints of these cycles in a few isolated cases, their apparent absence in the variable emission of most bright accreting neutron stars and black holes has been a continuing puzzle. HereAdvertised on
H II regions are ionized nebulae associated with the formation of massive stars. They exhibit a wealth of emission lines in their spectra that form the basis for estimation of chemical composition. The amount of heavy chemical elements is essential to the understanding of important phenomena such as nucleosynthesis, star formation and chemical evolution of galaxies. For over 80 years, however, a discrepancy exists of a factor of around two between heavy-element abundances (the so-called metallicity) derived from the two main kinds of emission lines that can be measured in nebular spectraAdvertised on