Public Seminar of PhD Candidate:- Galactic Planetary Nebulae with Emphasis on those that are Members of Open Star Clusters
The study of Planetary Nebulae(PNe) provides vital clues for understanding late stage stellar evolution and stellar mass loss. Despite their significance, various issues concerning these objects remain unsolved. Interstellar extinction by dust hampers the detection of many Galactic PNe at optical wavelengths while their largely unknown distances and progenitor masses are two key parameters that hamper deeper understanding.
Identification of dust obscured PNe can be partially solved with observations at longer wavelengths where extinction effects are less serious and by multi-wavelength techniques proposed for their detection. Here, the efficacy of these methods is evaluated for identification of new Galactic PN candidates.
PNe in Galactic star clusters have distances and progenitor masses determined independently from cluster color-magnitude diagrams. Here, we study the first confirmed PN-open cluster pair(PHR1315-6555 – AL 1) identifying its central star and measuring its physical properties. We also demonstrate in detail the physical association of PN BMP J1613-5406 with Galactic open cluster NGC 6067. The PN’s progenitor mass is 5.6 Mʘ. Finally, we provide preliminary details on several additional cases of possible PN-cluster associations we have uncovered.
Our new PN-open cluster associations contribute to the improvement of the initial-to-final mass relation and our multi-wavelength study suggests that a new era begins for the identification of Galactic PNe hidden by dust.
時間:2019.07.30(二) 15:30
地點:香港大學 莊月明物理樓518室
講者:Vasilik FRAGKOU(香港大學)
語言:英語
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此活動由香港大學物理系主辦。