A spatially resolved study of ionized regions in galaxies at different ...

3.4. Results 85
◦A−1
)
s−1
Flux (erg cm−2
1e−14
2.8
2.4
2.0
1.6
1.2
0.8
0.4
[OII]3727
PPak-field
4000 4500 5000 5500 6000 6500
1e−14
HδHγ
Hβ[OIII]4959
[OIII]5007
HeI 5876
[SII] 6717,6731
Hα
◦A−1
)
s−1
Flux (erg cm−2
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
7000 7500 8000 8500 9000
Wavelength (◦A)
[ArIII] 7136
[OII] 7319,7330
[SIII]9069
Figure 3.25: Blue and red spectra for the whole PPak-field.
pointing of the knots A and B, and C and D, respectively. Their ratios, as compared with
the ones obtained from the mosaic exposure are, again, in good agreement. Thus, we only
show the measured line intensities coming from the first pointing exposure. In Tables 3.5
and 3.6 the total reddening-corrected Hβ intensity (I tot (Hβ)) measured in the mosaic is also
given. As it can be appreciated, the total flux is between a factor of 2 or 3 higher than the
value measured in the one single pointing.
The Hβ flux of the emission knots amounts to about 50% of the total PPak field-ofview
flux, with knot A, B, C, and D contributing 38%, 2%, 7%, and 3% to the total flux,
respectively. Knot A is the brightest of them and provides 75% of the combined flux from
the four knots.
Electron densities and temperatures
The physical conditions of the ionized gas, including electron temperature and electron
density, have been derived using the five-level statistical equilibrium atom approximation in
the task temden of the STSDAS package of the software IRAF. For details of the equations
involved, the reader is referred to Appendix B. We have taken as sources of error the uncertainties
associated with the measurement of the emission-line fluxes and the reddening