Speaker
Description
"I will describe two dedicated campaigns with the VST, which exploit its fast optics and high image quality, and will extend its survey capabilities in the spectroscopic and time-domain.
The first project consists in high-cadence monitoring of strongly lensed quasars, for time-delay cosmography. With the eCOSMOGRAIL collaboration, we are performing (almost) nightly-cadence campaigns on bright Southern lenses, aiming at 2% accuracy and precision on H0, and the VST will be the ideal telescope to extend these on a larger sample of lenses discovered before 2020, reaching sub-percent uncertainties on H0. By comparison, the three-night (foreseen) cadence of LSST is sufficient only for lenses with long delays.
The second project is a slitless-spectroscopic survey, which will provide accurate redshifts for the LSST-Euclid synergy, an accurate and wide-field object classification, and the discovery of intrinsically rare objects. Being optically ""fast"", the VST can survey very wide footprints to a target depth of i=21, and its excellent image quality guarantees an accurate separation of overlapping spectra. Medium-low resolution spectroscopy will yield an unbiased coverage of emission-line objects (e.g. quasars up to z=4), a large sample of extremely metal poor stars, and the external calibration needed in the LSST-Euclid synergy to break degeneracies (between E(B-V), spectral type, and redshift) in photo-z determination, beyond the forecasted ~0.01 accuracy limit from broad-band information only."
