Maps of λ (top panel), Alfvén Mach number (middle panel), and plasma β parameter (bottom panel) in ρ Oph-A using the $B_{\mathrm{pos}}^{\mathrm{DCF}}$ in band D. In each map, yellow square and cyan diamond symbols indicate the positions of prestellar and protostellar cores, respectively. Green circles indicate the positions of YSOs (Enoch et al. 2009; Evans et al. 2009; Connelley & Greene 2010). The star and “×” symbols mark the positions of the Oph-S1 star and the SM1 core, respectively. Black contours show $N_{{\mathrm{H}}_2}$, similar as in Fig. 1.