Astronomy & Astrophysics

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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f1a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f1b.eps} \end{figure}$ Figure 1: Spectra of C¹⁸O J=3-2 ( left) and CS J=7-6 ( right) from JCMT observations. In this figure, and Figs. 2-4, the classes of the individual objects are indicated in the upper right corner of each plot by "0'' for the class 0 objects (envelope mass > $0.5~ M_\odot$ ), "I'' for the class I objects (envelope mass < $0.5~ M_\odot$ ) and "P'' for the pre-stellar cores.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f2a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f2b.eps} \end{figure}$ Figure 2: Spectra of H¹³CO⁺ ( left) and DCO⁺ J=3-2 ( right) from JCMT observations.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f3a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f3b.eps} \end{figure}$ Figure 3: Spectra of HCN ( left) and HNC ( right) J=4-3 from JCMT observations.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f4a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f4b.eps} \end{figure}$ Figure 4: Spectra of CN J=1-0 ( left) and J=3-2 ( right). The J=1-0observations are from the Onsala 20 m telescope and the SEST (marked with ***), the J=3-2 observations are from the JCMT.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0440f5a.eps}\par\vspace*{3mm} \includegraphics[width=8.2cm,clip]{0440f5b.eps} \end{figure}$ Figure 5: Density as function of temperature for the envelopes around TMR1 and N1333-I2 (solid line) compared to the critical densities of the observed transitions of CS, CO, HCO⁺ and HCN. The critical densities are indicated in order of increasing excitation by the dashed-dotted, dotted and dashed lines, respectively, i.e., showing the 2-1, 5-4 and 7-6 transitions for CS, the 1-0, 2-1 and 3-2 transitions for CO, and the 1-0, 3-2 and 4-3 transitions for HCO⁺ and HCN.
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In the text

$\begin{figure} \par\includegraphics[angle=90,width=8cm,clip]{0440f6.eps} \end{figure}$ Figure 6: Simulated abundance profile in "drop'' models.
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In the text

$\begin{figure} \par\includegraphics[angle=90,width=7.6cm,clip]{0440f7.eps} \end{figure}$ Figure 7: Fitted C¹⁸O line-profiles for L723. Upper panels: constant fractional abundance of 3.9 $\times 10^{-9}$ from Paper I. Lower panels: drop model with abundances of $X_0=2.0\times 10^{-7}$ for the undepleted material (with either temperatures higher than 30 K or densities lower than $3\times 10^{-4}$ ) and an abundance of $X_{\rm D}=1.5\times 10^{-8}$ for material with CO frozen out.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0440f8.eps} \end{figure}$ Figure 8: Modeling of the velocity field in the envelope around N1333-I2: in the upper panel C³⁴S model lines are compared with observations for a constant broadening of 0.8 km s^-1, as in jorgensen02. In the lower panel, a model with no turbulent broadening, but a power-law velocity field with v₀=2.5 km s^-1 at the inner radius, r₀=23.4 AU, is adopted. In both plots a constant abundance of $1.4\times 10^{-10}$ was assumed.
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In the text

$\begin{figure} \par\includegraphics[width=7.6cm,clip]{0440f9.eps} \end{figure}$ Figure 9: Dependence of the C³⁴S abundance on velocity field for an infalling envelope around N1333-I2. The grey region indicates 1 $\sigma$ confidence and the almost vertical lines indicate the 2 $\sigma$ , 3 $\sigma$ and 4 $\sigma$ confidence levels. It is seen that the derived abundances do not depend on the assumed velocity field for this optically thin species.
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In the text

$\begin{figure} \par\includegraphics[width=14cm,clip]{0440f10.eps} \end{figure}$ Figure 10: Comparison between average abundances for class 0 and I objects and pre-stellar cores (this paper), IRAS 16293-2422 outer envelope (Schöier et al. 2002), average abundances for W3(IRS4), W3(IRS5) and W3(H2O) (all high-mass YSOs; Helmich & van Dishoeck 1997) and abundances in the dark cloud L134N (Dickens et al. 2000). Note that the L134N abundances have been rescaled assuming a CO abundance of $2.7\times 10^{-4}$ (Lacy et al. 1994), as was also assumed by Helmich & van Dishoeck (1997) for the high-mass YSOs. The L134N abundances thereby become: [CS] = $2.7\times 10^{-9}$ , [SO] = $1.5\times 10^{-8}$ , [HCO⁺] = $2.1\times 10^{-8}$ , [HCN] = $~2.0\times 10^{-8}$ , [HNC] = $7.0\times 10^{-8}$ , [CN] = $1.3\times 10^{-9}$ , and [HC₃N] = $1.2\times 10^{-9}$ .
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In the text

$\begin{figure} \par\includegraphics[width=5.8cm,clip]{0440f11.eps} \end{figure}$ Figure 11: Relations between different molecules as judged from the Pearson correlation coefficients. The dashed line between HCN and HNC indicates the strongest correlation for HCN with any of the other molecules studied. The correlation coefficient for this relation is, however, lower than the cut of 0.7 adopted for good correlations.
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In the text

$\begin{figure} \par\includegraphics[width=8.1cm,clip]{0440f12a.eps}\par\vspace{3mm} \includegraphics[width=8.1cm,clip]{0440f12b.eps} \end{figure}$ Figure 12: Abundances of CS from optically thin C³⁴S isotopic lines (where detected) and CS lines ( upper panel) and of SO ( lower panel) vs. mass. In this figure and in following figures in this paper, the class 0 objects are indicated by " $\blacklozenge$ '', the class I objects by " $\lozenge$ '' and the pre-stellar cores by " $\blacksquare$ ''. The class 0 objects VLA1623 and IRAS 16293-2422 have been singled out by " $\square$ '' and " $\bigstar$ '', respectively.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f13a.eps}\vspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f13b.eps} \end{figure}$ Figure 13: CS vs. SO abundance. The dashed line indicates a linear relation between the CS and SO abundances, the solid line is the best-fit correlation. In the lower panel the abundances have been normalized to a CO abundance of 10^-4, mimicking the assumption in Buckle & Fuller (2003). Symbols are defined in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0440f14a.eps}\par\vspace*{3mm} \includegraphics[width=8.2cm,clip]{0440f14b.eps} \end{figure}$ Figure 14: HCO⁺ abundance vs. mass ( upper panel) and vs. CO abundance ( lower panel). In the lower panel has the linear correlation between the HCO⁺ and CO abundances been overplotted. Symbols defined as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0440f15a.eps}\par\vspace*{3mm} \includegraphics[width=8.2cm,clip]{0440f15b.eps} \end{figure}$ Figure 15: N₂H⁺ abundance vs. mass ( upper panel) and vs. CO abundance ( lower panel). Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f16a.eps}\par\vspace*{5mm} \includegraphics[width=8cm,clip]{0440f16b.eps} \end{figure}$ Figure 16: Upper panel: the chemical networks for low CO abundances (i.e., depletion) and standard CO abundance ( $\rm [CO]\sim 10^{-4}$ ). The dominant reactions are indicated by solid arrows, secondary reactions by dashed arrows. Where dissociative recombination is the main destruction for a molecule (i.e., N₂H⁺ or HCO⁺) this has been indicated by a dotted arrow. Lower panel: the electron, N₂H⁺, H₃⁺, and HCO⁺ abundances as functions of CO abundance in a cell with density $n({\rm H_2})=1\times 10^6~{\rm cm}^{-3}$ and temperature T=20 K.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0440f17a.eps}\vspace*{3mm}... ....eps}\vspace*{3mm} \includegraphics[width=7.5cm,clip]{0440f17c.eps} \end{figure}$ Figure 17: The ratio of the CS and C³⁴S abundances plotted vs. HCN and H¹³CN ratio. The big cross mark the predictions from the standard isotopic ratio of ¹²C:¹³C of 70 and ³²S:³⁴S of 22. Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{0440f18a.eps}\hspace*{3mm}... ....eps}\hspace*{3mm} \includegraphics[width=8.4cm,clip]{0440f18d.eps} \end{figure}$ Figure 18: HCN abundances derived on the basis of main isotopic species and H¹³CN ( upper panels, left and right) and CN and HNC abundances ( lower panels) vs. mass. As in previous figures, the class 0 objects are indicated by " $\blacklozenge$ '', the class I objects by " $\lozenge$ '' and the pre-stellar cores by " $\blacksquare$ '' with the class 0 objects VLA1623 and IRAS 16293-2422 singled out by " $\square$ '' and " $\bigstar$ '', respectively.
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In the text

$\begin{figure} \par\includegraphics[width=8.6cm,clip]{0440f19a.eps}\vspace*{3mm}... ...3mm} \hspace*{2.6mm}\includegraphics[width=7.6cm,clip]{0440f19c.eps}\end{figure}$ Figure 19: [CN] vs. [HCN] ( upper panel) and vs. [HNC] ( lower panel). Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f20a.eps}\par\vspace*{3mm} \hspace*{3.4mm}\includegraphics[width=7.8cm,clip]{0440f20b.eps} \end{figure}$ Figure 20: [HC₃N] vs. mass and [CO] ( upper panel) and vs. [CS]/[SO] ratio ( lower panel). Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0440f21a.eps}\vspace*{3mm} \includegraphics[width=7.8cm,clip]{0440f21b.eps} \end{figure}$ Figure 21: CS/SO abundance ratio vs. abundance of CN constrained by the 1-0 lines ( upper) and 3-2 lines ( lower) probing the outer and inner regions of the envelope, respectively. Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f22a.eps}\vspace*{3mm} \includegraphics[width=8cm,clip]{0440f22b.eps} \end{figure}$ Figure 22: [DCO⁺]/[HCO⁺] ratio vs. mass ( upper panel) vs. and [CO] ( lower panel). Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f23a.eps}\vspace*{3mm} \hspace*{3mm}\includegraphics[width=8cm,clip]{0440f23b.eps} \end{figure}$ Figure 23: [DCN]/[HCN] abundance vs. mass ( upper panel) and [DCO⁺]/[HCO⁺] ratio ( lower panel). Symbols as in Fig. 12.
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In the text

$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f1a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f1b.eps} \end{figure}$	Figure 1: Spectra of C¹⁸O J=3-2 ( left) and CS J=7-6 ( right) from JCMT observations. In this figure, and Figs. 2-4, the classes of the individual objects are indicated in the upper right corner of each plot by "0'' for the class 0 objects (envelope mass > $0.5~ M_\odot$ ), "I'' for the class I objects (envelope mass < $0.5~ M_\odot$ ) and "P'' for the pre-stellar cores.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f2a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f2b.eps} \end{figure}$	Figure 2: Spectra of H¹³CO⁺ ( left) and DCO⁺ J=3-2 ( right) from JCMT observations.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f3a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f3b.eps} \end{figure}$	Figure 3: Spectra of HCN ( left) and HNC ( right) J=4-3 from JCMT observations.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f4a.eps}\hspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f4b.eps} \end{figure}$	Figure 4: Spectra of CN J=1-0 ( left) and J=3-2 ( right). The J=1-0observations are from the Onsala 20 m telescope and the SEST (marked with ***), the J=3-2 observations are from the JCMT.
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$\begin{figure} \par\includegraphics[angle=90,width=8cm,clip]{0440f6.eps} \end{figure}$	Figure 6: Simulated abundance profile in "drop'' models.
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$\begin{figure} \par\includegraphics[width=7.6cm,clip]{0440f9.eps} \end{figure}$	Figure 9: Dependence of the C³⁴S abundance on velocity field for an infalling envelope around N1333-I2. The grey region indicates 1 $\sigma$ confidence and the almost vertical lines indicate the 2 $\sigma$ , 3 $\sigma$ and 4 $\sigma$ confidence levels. It is seen that the derived abundances do not depend on the assumed velocity field for this optically thin species.
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$\begin{figure} \par\includegraphics[width=5.8cm,clip]{0440f11.eps} \end{figure}$	Figure 11: Relations between different molecules as judged from the Pearson correlation coefficients. The dashed line between HCN and HNC indicates the strongest correlation for HCN with any of the other molecules studied. The correlation coefficient for this relation is, however, lower than the cut of 0.7 adopted for good correlations.
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$\begin{figure} \par\includegraphics[width=8.5cm,clip]{0440f13a.eps}\vspace*{3mm} \includegraphics[width=8.5cm,clip]{0440f13b.eps} \end{figure}$	Figure 13: CS vs. SO abundance. The dashed line indicates a linear relation between the CS and SO abundances, the solid line is the best-fit correlation. In the lower panel the abundances have been normalized to a CO abundance of 10^-4, mimicking the assumption in Buckle & Fuller (2003). Symbols are defined in Fig. 12.
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$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0440f14a.eps}\par\vspace*{3mm} \includegraphics[width=8.2cm,clip]{0440f14b.eps} \end{figure}$	Figure 14: HCO⁺ abundance vs. mass ( upper panel) and vs. CO abundance ( lower panel). In the lower panel has the linear correlation between the HCO⁺ and CO abundances been overplotted. Symbols defined as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=8.2cm,clip]{0440f15a.eps}\par\vspace*{3mm} \includegraphics[width=8.2cm,clip]{0440f15b.eps} \end{figure}$	Figure 15: N₂H⁺ abundance vs. mass ( upper panel) and vs. CO abundance ( lower panel). Symbols as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{0440f17a.eps}\vspace{3mm}... ....eps}\vspace{3mm} \includegraphics[width=7.5cm,clip]{0440f17c.eps} \end{figure}$	Figure 17: The ratio of the CS and C³⁴S abundances plotted vs. HCN and H¹³CN ratio. The big cross mark the predictions from the standard isotopic ratio of ¹²C:¹³C of 70 and ³²S:³⁴S of 22. Symbols as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=8.6cm,clip]{0440f19a.eps}\vspace{3mm}... ...3mm} \hspace{2.6mm}\includegraphics[width=7.6cm,clip]{0440f19c.eps}\end{figure}$	Figure 19: [CN] vs. [HCN] ( upper panel) and vs. [HNC] ( lower panel). Symbols as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f20a.eps}\par\vspace{3mm} \hspace{3.4mm}\includegraphics[width=7.8cm,clip]{0440f20b.eps} \end{figure}$	Figure 20: [HC₃N] vs. mass and [CO] ( upper panel) and vs. [CS]/[SO] ratio ( lower panel). Symbols as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=7.8cm,clip]{0440f21a.eps}\vspace*{3mm} \includegraphics[width=7.8cm,clip]{0440f21b.eps} \end{figure}$	Figure 21: CS/SO abundance ratio vs. abundance of CN constrained by the 1-0 lines ( upper) and 3-2 lines ( lower) probing the outer and inner regions of the envelope, respectively. Symbols as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f22a.eps}\vspace*{3mm} \includegraphics[width=8cm,clip]{0440f22b.eps} \end{figure}$	Figure 22: [DCO⁺]/[HCO⁺] ratio vs. mass ( upper panel) vs. and [CO] ( lower panel). Symbols as in Fig. 12.
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$\begin{figure} \par\includegraphics[width=8cm,clip]{0440f23a.eps}\vspace{3mm} \hspace{3mm}\includegraphics[width=8cm,clip]{0440f23b.eps} \end{figure}$	Figure 23: [DCN]/[HCN] abundance vs. mass ( upper panel) and [DCO⁺]/[HCO⁺] ratio ( lower panel). Symbols as in Fig. 12.
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