Bibcode
Gonçalves, D. R.; Corradi, R. L. M.; Mampaso, A.; Quireza, C.
Bibliographical reference
XII Latin American IAU Regional Meeting (Eds. G. Magris, G. Bruzual, & L. Carigi) Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) Vol. 35, pp. 64-65 (2009) (http://www.astroscu.unam.mx/~rmaa/)
Advertised on:
5
2009
Citations
0
Refereed citations
0
Description
Years ago we have compiled all the available optical data in the
literature to build a comprehensive classification of the low-ionization
structures (LIS), as knots, jets and jet-like structures in planetary
nebulae (PNe). This classification highlighted a number of questions
that 6 years later still remain open, such as, what is the role of
magnetic fields and of the binary systems on the formation of collimated
LIS, or, how do collimated low-velocity LIS survive throughout the PNe
evolution? Other very puzzling properties were found in a few cases and
need to be explained: i.e., the fact that highly supersonic LIS are
mainly photoionized (e.g., in NGC 7662 and NGC 7009) or the lack of
significant density contrasts found in collimated and isolated knots. In
an attempt to provide an answer to the questions above we have
undertaken a systematical exploration of the physical properties of the
LIS. By using our own optical long-slit spectra for 20 PNe, we have
estimated the electronic temperature and density of the LIS and compared
them with those of the their surrounding nebula. Here we discuss our
newly found correlations between the type of the LIS and its physical
properties for NGC 7662.