| Description |
We propose to exploit Herschels unprecedented sensitivity to obtain
100-500 micron photometry for a statistical, flux-limited (in the IRAS
60 micron band) sample of Galactic bulge planetary nebulae (GBPNe),
using PACS and SPIRE. The Galactic Bulge volume, offers a unique,
nearby environment where a statistical population of PNe, all at
roughly the same well-established distance, can be studied in order to
understand these objects, test theoretical models for their formation
and evolution, and address the mystery of the constancy of the PN
luminosity function (an important cosmological distance indicator).
Much of the mass ejected during the preceding AGB phase is expected to
lie outside the ionised shells in these objects, and can only be
detected via the thermal emission from cold dust.
Herschel provides us the only platform to measure the mass budgets of a
statistical sample of GBPNe, and thus help us address one of the
longest standing astrophysical problem: the relationship between the
birth mass of solar mass stars and the mass left at the end when they
die. PNe are an important contributor to the total mass return to the
ISM for the old Bulge population, and the proposed observations will
allow us to infer the PN contribution to the total rate of mass loss in
the Bulge, a crucial input to evolutionary models. The robust
constraints to the progenitor masses of PNe from our study will allow
elemental enrichments to be determined as a function of initial stellar
mass, providing key information for models of AGB nucleosynthesis.
The proposed observations are a critical component of a broader study
comprising existing and future ground- and space-based observations
that will produce a combination of nebular masses, mass-loss rates,
luminosities, physical sizes, morphologies, radial velocities, ages,
and chemical abundances for a statistical sample of planetary nebulae,
resulting in a unique dataset describing the final stages of stellar
evolution in unprecedented detail. |
