Chemical analysis of prestellar cores in Ophiuchus yields short timescales and rapid collapse Stefano Bovino, Alessandro Lupi, Andrea Giannetti, Giovanni Sabatini, Dominik R. G. Schleicher, Friedrich Wyrowski and Karl M. Menten A&A, 654 (2021) A34 Published online: 07 October 2021 DOI: 10.1051/0004-6361/202141252