• Title/Summary/Keyword: plasma and nebular physics

Search Result 2, Processing Time 0.019 seconds

PHYSICAL AND CHEMICAL PROPERTIES OF PLANETARY NEBULAE WITH WR-TYPE NUCLEI

  • DANEHKAR, ASHKBIZ;WESSON, ROGER;KARAKAS, AMANDA I.;PARKER, QUENTIN A.
    • Publications of The Korean Astronomical Society
    • /
    • v.30 no.2
    • /
    • pp.159-161
    • /
    • 2015
  • We have carried out optical spectroscopic measurements of emission lines for a sample of Galactic planetary nebulae with Wolf-Rayet (WR) stars and weak emission-line stars (wels). The plasma diagnostics and elemental abundance analysis have been done using both collisionally excited lines (CELs) and optical recombination lines (ORLs). It was found that the abundance discrepancy factors ($ADF{\equiv}ORL/CEL$) are closely correlated with the difference between temperatures derived from forbidden lines and those from $He\;{\small{I}}$ recombination lines, implying the existence of H-deficient materials embedded in the nebula. The $H{\beta}$ surface brightness correlations suggest that they might be also related to the nebular evolution.

EMISSION LINE SPECTROSCOPY WITH THE 1.8M OPTICAL TELESCOPE (1.8m 망원경을 이용한 방출선 천체 연구)

  • HYUNG SIEK;ALLER LAWRENCE H.;KIM KANG-MIN
    • Publications of The Korean Astronomical Society
    • /
    • v.15 no.spc1
    • /
    • pp.61-71
    • /
    • 2000
  • The emission line objects such as planetary nebulae, symbiotics, gaseous nebulae, HII regions, novae, supernovae, SNRs, nearby spiral galaxies, dIrr, dE, and nearby active galactic nuclei, would be goldmines for us to dig with the 1.8m bohyunsan optical (BOAO) telescope. We discussed the importance of strategically important diagnostic lines and atomic constant calculation for a study of Galactic and extragalactic emission objects. The scientific background on a spectrometer development history is briefly presented and spectroscopic research areas other than the emission objects are also summarized.

  • PDF