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Quentin Parker |
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"The Macquarie/AAO/Strasbourg
H-alpha Planetary Nebula Project: M*A*S*H" |
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Planetary nebulae (PNe) are a common end-point of stellar
evolution and among the most complex, varied and fascinating of
celestial phenomena. Because of their strong emission lines, they are also excellent kinematical and chemical probes, visible to large distances. Their shapes provide clues to PNe formation, mass loss processes, evolution and the role of binary stars. Their luminosity behavior in galaxies also permits their use as excellent standard candles in the cosmic distance ladder. PNe are thus extremely potent astrophysical probes. Here I describe the results and potential of the Macquarie/AAO/Strabsourg H-alpha PN project: MASH, which has uncovered an unprecedented new population of Galactic PNe across the Southern Galactic plane from the SuperCOSMOS AAO/UKST H-alpha survey (SHS). The SHS has a faint sensitivity limit of ~2–5 Rayleighs at H-alpha enabling detection of large numbers of new PNe. Furthermore, the discoveries are not simply more of what was previously known. MASH PNe are typically more evolved, of lower surface brightness, and more obscured than those in most previous surveys. These form a potent resource for tackling several outstanding problems in late stage stellar evolution and unraveling the space density, scale height and PNe population in our Galaxy. |