The Pristine survey uses narrow-band photometry to derive precise metallicities down to the extremely metal-poor regime ( [Fe/H] < -3), and currently consists of over 4 million FGK-type stars over a sky area of ̃ 2500 deg^2. We focus our analysis on a subsample of ̃80 000 main-sequence turn-off stars with heliocentric distances between 6 and 20 kpc

A chemo-dynamical analysis of 115 metal-poor candidate stars selected from the narrow-band Pristine photometric survey is presented based on CFHT high-resolution ESPaDOnS spectroscopy. We have discovered 28 new bright (V < 15) stars with [Fe/H] < -2.5 and 5 with [Fe/H] < -3.0 for success rates of 40 (28/70) and 19 per cent (5/27), respectively. A

Context. The OSIRIS Tunable Filter Emission Line Object (OTELO) survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain

An excellent laboratory for studying large scale magnetic fields is the grand design face-on spiral galaxy M51. Due to wavelength-dependent Faraday depolarization, linearly polarized synchrotron emission at different radio frequencies gives a picture of the galaxy at different depths: Observations at L-band (1 - 2 GHz) probe the halo region while

We carry out a theoretical study of the polarization of the solar Mg II h-k doublet (including its extended wings) and the subordinate ultraviolet (UV) triplet around 280 nm. These lines are of great diagnostic interest, as they encode information on the physical properties of the solar atmosphere from the upper photosphere to the chromosphere

In the present work we analyzed seven globular clusters (GCs) selected from their location in the Galactic bulge and with metallicity values in the range -1.30 ≲ [Fe/H] ≲ -0.50. The aim of this work is first to derive cluster ages assuming single stellar populations and second to identify the stars from first (1G) and second generations (2G) from