Speaker: Charitarth Vyas (chair: David Aguilera Dena)
Title: The study of the fuel for the Milky Way star formation
To form stars for many Gyrs, the Milky Way is considered to accrete pristine gas from the halo it resides in. This feeding ensures that the required mass and metallicity is replenished addressing the star formation rate and the G-dwarf problem. Among many accretion modes considered in the literature, the Galactic fountain is the most favorable.
In this talk, I will present the study we have conducted towards two prototypical, high Galactic latitude translucent clouds, Draco and Spider. Apparent from their radial velocities, they are currently approaching the Galactic disk and will probably provide the fuel for the future star formation. We use the two most important tracers of the interstellar medium – dust, and gas to study their physical properties. Multiwavelength single dish and radio interferometric data allow us to probe sub-parsec scales disclosing the compact cold gas clumps which are already forming molecular hydrogen. We estimate their dust temperature, v_lsr, volume density, linear size, and other relevant physical parameters. I will also briefly talk about the first results of the Pico-Veleta CO observations of these clouds that we’ve conducted with the IMPRS group.
Speaker: Jan Luca van den Busch (chair: Charitarth Vyas)
Title: Calibrating Redshifts Using Galaxy Cross-correlations
Current and future cosmological probes based on the large scale structure distribution are sensitive to biases in the redshift distributions of galaxies down to the percent level. Meeting such demands with secondary redshift estimates requires a precise calibration with reference samples.
One of the strategies deployed by the KiDS-VIKING cosmic shear survey is determining galaxy redshifts from the angular cross-correlation with spectroscopic data from 2dFLenS, zCOSMOS, DEEP2, GAMA, SDSS, VVDS and WiggleZ. Using such a large reference sample and carefully correcting for galaxy biases and selection effects allows to obtain high precision redshift distributions.