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.
Advertised on
References
It may interest you
-
The standard cosmological model states that massive galaxies contain a large fraction of dark matter. Dark matter is a transparent substance that does not interact through regular baryonic matter and is only detected through its gravitational pull over the stars and the gas. NGC 1277 is known as the prototype of a relic galaxy, that is, a galaxy that has not accreted other galaxies since it formed. Relic galaxies are extremely rare and are the untouched remains of the giant galaxies that populated the early Universe. Since relic galaxies are very important to understand the conditions in theAdvertised on
-
The amount and complexity of data delivered by modern galaxy surveys has been steadily increasing over the past years. New facilities will soon provide imaging and spectra of hundreds of millions of galaxies. Extracting coherent scientific information from these large and multi-modal data sets remains an open issue for the community and data-driven approaches such as deep learning have rapidly emerged as a potentially powerful solution to some long lasting challenges. This enthusiasm is reflected in an unprecedented exponential growth of publications using neural networks, which have goneAdvertised on
-
Stellar ages are key to several fields of astrophysics such as exoplanet research, galactic-archeology, and of course stellar physics. Obtaining the ages of stars is however not straightforward and requires stellar modeling. The most widely used technique only requires stellar colors or temperature and surface gravity, but the uncertainties are quite large. This technique is most efficient for stars belonging to clusters, as they were born from the same molecular cloud and share the same ages. In the last decades, based on the study of stellar acoustic waves, asteroseismology became the mostAdvertised on