... survey

Figures 9 to 12 are only available in electronic form at http://www.edpsciences.org

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...

Present address: California Institute of Technology, MS 320-47, Pasadena, CA 91125, USA

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... power-law

There is, however, a transition region just inside the expansion wavefront where the density gradient is flatter and closer to $\rho(r) \propto r^{-1}$.

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... quasars

The effective resolution of the telescope improved slightly from 1993 to 1995 due to holographic adjustments of the dish panels.

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... sources''

Although NGC 1333-IRAS 4B is similarly unresolved by our 30 m observations, there is independent evidence pointing to the presence of a compact, massive envelope in this more distant (Perseus) Class 0 object (see, e.g. Sect. 3.2).

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... envelopes

For thirteen objects in our sample, better estimates of $\mbox{$M_{\mbox{\tiny env}}^{\mbox{\tiny 4200~AU}}$ }$ may be derived by subtracting the disk contribution measured at 1.4 mm with interferometers (e.g. Motte et al. 2001). We estimate the true envelope mass to be $\mbox{$M_{\mbox{\tiny env}}^{\mbox{\tiny 4200~AU}}$ }\sim 0.03\ \mbox{$M_\odot$ }$ for L1489, $\sim$0.4 $M_\odot$  for K04166, $\sim$0.35 $M_\odot$for K04169, $\sim$0.45 $M_\odot$  for IRAM 04191, $\sim$0.18 $M_\odot$  for T04191, $\sim$0.75 $M_\odot$  for L1551-IRS5, $\sim$0.2 $M_\odot$  for TMR1, $\sim$0.7 $M_\odot$  for L1527 and $\sim$1.5 $M_\odot$  for L1448-NW, $\sim$2.5 $M_\odot$  for L1448-N, $\sim$1.3 $M_\odot$  for L1448-C, $\sim$1.1 $M_\odot$  for IRAS 03282, $\sim$1.3 $M_\odot$  for HH211-MM.

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... northern

For unknown reasons, the L1527 envelope has a steeper intensity profile in the south-west part than along the outflow axis (cf. Fig. 1l).

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... case

Similarity solutions exist with larger values of w₀, up to $+\infty$ (see Fig. 2 of Whitworth & Summers 1985), which physically correspond to cloud cores strongly perturbed/compressed from the outside.

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...$\rho(r) \propto r^{-1.5}$power-law

There is, however, a transition region just inside the expansion wavefront where the density gradient is flatter and closer to $\rho(r) \propto r^{-0.5}$.

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...$\mbox{$M_{\mbox{\tiny env}}^{\mbox{\tiny 4200~AU}}$ }\simeq 0.9\ \mbox{$M_\odot$ }$]

The measured envelope mass also exceeds by a factor of > 3 that of the best-fit inside-out isothermal collapse model of Choi et al. (1995).

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... stars

As the precise position of the birthline depends on $\mbox{$\dot{M}_{\mbox{\tiny acc}}$ }$, both $\mbox{$R_\star$ }$ and $\mbox{$L_\star$ }$ were interpolated from the values given by Stahler (1988) for constant accretion rates of $2~10^{-6}~\mbox{$M_\odot\: \mbox{yr}^{-1}$ }$ and $10^{-5}~\mbox{$M_\odot\: \mbox{yr}^{-1}$ }$.

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