Table 7: Physical parameters at the observed positions M 83 and M 51, derived from fitting the observed intensity ratios to PDR models of Kaufman et al. (1999). Column (2) gives the galacto-centric distance. Columns (3) and (4) list the fitted local densities and FUV fields together with the corresponding surface temperature (Col. (5)) and the minimum chi squared (Col. (6)). The filling factor $\phi _{\rm UV}=G_{0,\rm obs}/G_0$ reflects the ratio of TIR $_{\rm c}$ to the best fitting FUV field G₀. $\phi _{\rm A}^{\rm CI}$ is the area filling factor of the [C I] emitting regions, i.e. the ratio of observed [C I] intensity vs. that of the best fit model, corrected for beam and velocity filling (see text).
( $\Delta\alpha$ , $\Delta\delta$ ) $R_{\rm gal}$ n log(G₀) T $_{\rm s}$ $\chi ^2$ log(G $_{0,\rm obs}$ ) $\phi_{\rm UV}$ $\phi _{\rm A}^{\rm CI}$

['', ''] [kpc] [10⁴cm^-3] [K]

(1) (2) (3) (4) (5) (6) (7) (8) (9)

M 83:

(0, 0) 0.00 4.0 1.50 76. 2.8 2.16 4.57 0.019

(-80,-72) 1.93 4.0 1.50 76. 12.9 1.51 1.03 0.011

(89, 38) 1.76 4.0 1.50 76. 15.3 1.47 0.94 0.010

M 51:

(0, 0) 0.00 4.0 1.25 66. 3.2 1.88 4.31 0.013

(72, 84) 5.40 4.0 1.25 66. 5.2 1.32 1.17 0.016

(-84,-84) 5.77 4.0 1.25 66. 14.1 1.19 0.88 0.009

**Table 7:** Physical parameters at the observed positions M 83 and M 51, derived from fitting the observed intensity ratios to PDR models of Kaufman et al. (1999). Column (2) gives the galacto-centric distance. Columns (3) and (4) list the fitted local densities and FUV fields together with the corresponding surface temperature (Col. (5)) and the minimum chi squared (Col. (6)). The filling factor $\phi _{\rm UV}=G_{0,\rm obs}/G_0$ reflects the ratio of TIR $_{\rm c}$ to the best fitting FUV field G₀. $\phi _{\rm A}^{\rm CI}$ is the area filling factor of the [C I] emitting regions, i.e. the ratio of observed [C I] intensity vs. that of the best fit model, corrected for beam and velocity filling (see text).
( $\Delta\alpha$ , $\Delta\delta$ )	$R_{\rm gal}$	n	log(G₀)	T $_{\rm s}$	$\chi ^2$	log(G $_{0,\rm obs}$ )	$\phi_{\rm UV}$	$\phi _{\rm A}^{\rm CI}$
['', '']	[kpc]	[10⁴cm^-3]		[K]
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)
M 83:
(0, 0)	0.00	4.0	1.50	76.	2.8	2.16	4.57	0.019
(-80,-72)	1.93	4.0	1.50	76.	12.9	1.51	1.03	0.011
(89, 38)	1.76	4.0	1.50	76.	15.3	1.47	0.94	0.010
M 51:
(0, 0)	0.00	4.0	1.25	66.	3.2	1.88	4.31	0.013
(72, 84)	5.40	4.0	1.25	66.	5.2	1.32	1.17	0.016
(-84,-84)	5.77	4.0	1.25	66.	14.1	1.19	0.88	0.009

Source LaTeX | All tables | In the text

	1 Introduction
	2 Data sets
	3 Spectra and line ratios
	4 Physical conditions
	5 Summary
	References
	Online Material