W. J. Maciel -
Abstract #124
EVOLUTION OF PLANETARY NEBULAE IN THE MID-INFRARED
R. Ortiz, M. V. F. Copetti, W. J. Maciel, S. Lorenz-Martins,
Why galaxies care about AGB stars, ASP Conference Series, Vol. 378,
ed. F. Kerschbaum, C. Charbonnel, R. F. Wing, 329-330 (2007),
The evolution of planetary nebulae is studied using MSX data on
a sample of 214 objects situated near the galactic plane. The observed MSX
magnitudes are compared with synthetic magnitudes obtained by convolving
synthetic spectra generated by CLOUDY with MSX filter curves. Color-color
diagrams show that the evolutionary tracks are similar as the star begins its post-
AGB phase. Young PNe can be identified using the [14.7]-[21.3] color index,
because of the significant contribution of dust to the continuum at this phase.
On the other hand, dust-poor nebulae are also located in a characteristic region
of the ([14.7]-[21.3]) x ([8.3]-[14.7]) diagram. There is also some segregation
with respect to the mass of the central star in this diagram that might help the
diagnosis of objects severely affected by extinction.
