The Orientation of the Collimated Outflows of Planetary Nebula: Independence Day

The discovery of collimated outflows in planetary nebulae (PNe) has changed the paradigm of PN formation. They actively participate in the nebular shaping immediately before or while fast stellar winds and D-type ionization fronts shock and swept the nebular envelope. The general properties of collimated outflows of PNe cannot be studied because projection effects do not allow us to determine their space velocities and linear sizes. The large number of collimated outflows already detected in PNe can be used to derive orientation independent properties of this sample of outflows. We find they can be assigned to two different populations: about 85% collimated outflows have space velocities below 100 kms/ and only 15% have larger velocities. Collimated outflows are mostly coeval with their PNe and their ages imply time spans before they dissolve shorter than a few thousand years. A significant fraction of collimated outflows experience notable interactions with the nebular envelope and get trapped into it, traveling away at velocities similar to the that of their parent PNe.

09/07/2019 - 12:30
Jackeline Suzett Rechy Garcia & Martin A. Guerrero