5.5 External Comparison of Global Photometric Parameters

We compared our global photometric parameters in Gunn r with those from JFK95a. We have 14 galaxies in common, cf. Sect.  (p. ). We calculate the differences as ``our''-``JFK95a''. The result is shown in Table , and in Fig.  and . The agreement is very good for 11 of the 14 galaxies. For R269, R338, and R343 the agreement is less good. These galaxies have been marked in some of the plots. Even for all 14 galaxies, no systematic differences are seen, and the derived typical external uncertainties (rms/$\sqrt{2}$) are low. In other words, our global photometric parameters are of very good quality. Note, however, that JFK95a used the same methods to derive global parameters as we did. We therefore expect a priori that the agreement with JFK95a is better than with authors that use completely different methods.

The correlation of the errors in ${\log{r_{\rm e}}}$ and ${{< \hspace{-3pt} \mu \hspace{-3pt}>}_{\rm e}}$ is shown in Fig. . The linear correlation coefficient is r = 0.94.

 

Table: External Comparison of Global Photometric Parameters, Gunn r

Source	Parameter	N	mean	rms
JFK95a	${\log{r_{\rm e}}}$	14	$0.006\pm0.010$	0.039
JFK95a	${{< \hspace{-3pt} \mu \hspace{-3pt}>}_{\rm e}}$	14	$0.027\pm0.037$	0.137
JFK95a	``FP''	14	$-0.003\pm0.004$	0.016
JFK95a	${m_{\rm T}}$	14	$-0.002\pm0.022$	0.083
JFK95a	${\varepsilon_{\rm e}}$	14	$0.008\pm0.006$	0.023
JFK95a	${\varepsilon_{21.85}}$	14	$0.003\pm0.004$	0.016
JFK95a	c4	14	$-0.001\pm0.002$	0.007
JFK95a	${< \hspace{-4pt} c_4 \hspace{-4pt}>}$	14	$-0.003\pm0.002$	0.008
JFK95a	${< \hspace{-4pt} c_6 \hspace{-4pt}>}$	14	$-0.001\pm0.000$	0.001

 

Notes: ``FP'' = ${\log{r_{\rm e}}}- 0.328 {{< \hspace{-3pt} \mu \hspace{-3pt}>}_{\rm e}}$.