\begin{table}%t1 \par \caption{\label{tab:obs}\label{tab1}Physical parameters for well observed massive-star forming regions in the Galaxy and in the LMC.} \small%\centering \par \begin{tabular}{l|llll|lll|llll} \hline\hline &&&&&&&&&&&\\[-3mm]%\noalign{\smallskip} & &\multicolumn{3}{c|}{Cluster} && \multicolumn{2}{c|}{Superbubble} & \multicolumn{4}{c}{$\theta_{\star}$\tablefootmark{d}} \\%\cline{3-5}\cline{7-8} % \hline Name & $N_{\star}$\tablefootmark{a} & Age & Distance & Size\tablefootmark{b} & & Size\tablefootmark{b} & Density\tablefootmark{c} & $B=1~\mu\rm{G}$ & $B=1~\mu\rm{G}$ & $B=10~\mu\rm{G}$ & $B=10~\mu\rm{G}$ \\ &&(Myr)&(kpc)&(pc)&&(pc)&($\rm cm^{-3}$) & $q=5/3$&$q=3/2$&$q=5/3$&$q=3/2$ \\ \hline &&&&&&&&&&&\\[-3mm]%\noalign{\smallskip} Cygnus OB1/3 & 38$^{(16)}$ & 2$-$6$^{(12)}$ & 1.8$^{(19)}$ & 24 & & 80$-$100$^{(14)}$ & $0.01?$ & $5\times 10^4$ & $4\times 10^2$ & $4\times 10^{0}$ & $2\times 10^{-2}$ \\ &&&&&&&& $5\times 10^5$&$3\times 10^3$&$4\times 10^{1}$&$1\times 10^{-1}$\\ Cygnus OB2 & 750$^{(5)}$ & 3--4$^{(12)}$ & 1.4--1.7$^{(10)}$ & 60$^{(11)}$ & & 450?$^{(5)}$ & 0.02$^{(5)}$ & $2\times 10^4$ & $9\times 10^1$ & $1\times 10^0$ & $4\times 10^{-3}$ \\ &&&&&&&& $2\times 10^5$& $7\times 10^2$& $2\times 10^1$& $3\times 10^{-2}$\\ Orion OB1 & 30--100$^{(3)}$ & 12$^{(2)}$ & 0.45$^{(2)}$ & 10$^{(2)}$ & & $140\times 300$$^{(3)}$ & 0.02--0.03$^{(4)}$ & $3\times 10^3$ & $4\times 10^1$ & $3\times 10^{-1}$ & $1\times 10^{-3}$ \\ &&&&&&&& $2\times 10^6$ & $7\times 10^3$& $2\times 10^2$& $3\times 10^{-1}$\\ Carina nebula & ? & 3$^{(23)}$ & 2.3$^{(8)}$ & 20& & 110$^{(23)}$ & $0.01?$ & $2\times 10^4$ & $1\times 10^2$ & $1\times 10^0$ & $5\times 10^{-3}$ \\ &&&&&&&& $2\times 10^6$& $7\times 10^3$& $1\times 10^2$& $3\times 10^{-1}$\\ Westerlund 1 & 450$^{(1)}$ & 3.3$^{(1)}$ & 3.9$^{(13)}$ &1$^{(1)}$& & 40?$^{(13)}$ & $0.01?$ & $2\times 10^3$ & $5\times 10^1$ & $2\times 10^{-1}$ & $2\times 10^{-3}$ \\ &&&&&&& $3\times 10^6$& $2\times 10^4$& $3\times 10^2$ & $8\times 10^{-1}$\\ Westerlund 2 &14$^{(21)}$ & 2$^{(21)}$ & 8$^{(21)}$ &1$^{(6)}$ & & 100$^{(21,6)}$ & 0.0015$^{(24)}$ & $1\times 10^2$ & $2\times 10^0$ & $9\times 10^{-3}$ & $1\times 10^{-4}$ \\ &&&&&&&& $5\times 10^4$& $2\times 10^2$& $4\times 10^0$& $1\times 10^{-2}$\\ DEM L192 & 135 & 3$^{(20)}$ & 50 & 60$^{(20)}$& & $120 \times135$$^{(9)}$ & 0.03$^{(7)}$ & $3\times 10^5$ & $2\times 10^3$ & $2\times 10^1$ & $6\times 10^{-2}$ \\ &&&&&&&& $1\times 10^6$& $4\times 10^3$ & $9\times 10^1$& $2\times 10^{-1}$\\ 30 Doradus & $>$400$^{(22)}$ & 2$^{(17)}$ & 50 & 40$^{(25)}$& & 200$^{(25)}$ & 0.09$^{(27)}$ & $2\times 10^5$ & $1\times 10^3$& $2\times 10^1$ & $6\times 10^{-2}$\\ &&&&&&&& $2\times 10^6$ & $7\times 10^3$& $2\times 10^2$& $3\times 10^{-1}$ \\ N11 & 130 & 5$^{(26)}$ & 50 & $15\times 30$$^{(18)}$ && $100\times 150^{(9)}$ & 0.08$^{(15)}$ & $9\times 10^4$ & $9\times 10^2$& $8\times 10^0$ & $3\times 10^{-2}$ \\ &&&&&&&& $4\times 10^6$& $2\times 10^4$& $4\times 10^2$& $8\times 10^{-1}$\\ \hline \end{tabular} \tablefoot{\tablefoottext{a}{$N_{\star}$ is the number of stars with mass $\ge$$8~M_{\odot}$ (a Salpeter IMF has been assumed, expected for N11 where an index of 2.4 has been used).} \tablefoottext{b}{Sizes are either the diameter if the region is spherical, or the large and small semi-axis if the region is ellipsoidal.} \tablefoottext{c}{The density is the Hydrogen nuclei density.} \tablefoottext{d}{Estimates of $\theta_{\star}$ are calculated from Eq.~(\ref{eq:Theta_ref}), as explained in Sect.~\ref{sec:selection}. The range of values of $\theta_{\star}$ given for each object and for each magnetic configuration reflects uncertainties in the actual values of bubble density, accelerator size and turbulence scale.}} \vspace*{-3mm} \tablebib{(1)~\cite{Brandner2008a}; (2)~\cite{Brown1994a}; (3)~\cite{Brown1995a}; (4)~\cite{Burrows1993a}; (5)~\cite{Cash1980a}; (6)~\cite{Conti2004a}; (7)~\cite{Cooper2004a}; (8)~\cite{Davidson1997a}; (9)~\cite{Dunne2001a}; (10)~\cite{Hanson2003a}; (11)~\cite{Knodlseder2000a}; (12)~\cite{Knodlseder2002a}; (13)~\cite{Kothes2007a}; (14)~\cite{Lozinskaya1998a}; (15)~\cite{Maddox2009a}; (16)~\cite{Massey1995a}; (17)~\cite{Massey1998a}; (18)~\cite{Naze2004a}; (19)~\cite{Nichols-Bohlin1993a}; (20)~\cite{Oey1998a}; (21)~\cite{Rauw2007a}; (22)~\cite{Selman1999a}; (23)~\cite{Smith2000a}; (24)~\cite{Tsujimoto2007a}; (25)~\cite{Walborn1991a}; (26)~\cite{Walborn1992a}; (27)~\cite{Wang1991a}.} \vspace*{5mm} \end{table}