• 제목/요약/키워드: blue compact dwarf galaxy

검색결과 12건 처리시간 0.015초

Nitrogen self-enrichment in the starburst galaxies under the metal poor environments

  • Chung, Ji-Won;Sung, Eon-Chang;Rey, Soo-Chang;Kyeong, Jae-mann
    • 천문학회보
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    • 제35권2호
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    • pp.29.2-29.2
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    • 2010
  • We present elemental abundances of 412 blue compact dwarf galaxies (BCDs) at z=0.2~0.5 using the Sloan Digital Sky Survey (SDSS) DR7. The gas-phase nitrogen to oxygen abundance ratios (N/O) of sample galaxies increase as the oxygen to hydrogen abundance ratios (O/H) decrease. This indicates that the nitrogen is more enriched than the oxygen. We found that there is a noticeable distinction between the merger candidates and the isolated galaxies. Merging candidates show more enrichment of nitrogen abundance compared to isolated galaxies. On the other hand, neon and oxygen abundances for merging candidates are slightly lower than the isolated systems. We discuss the main cause of these trends with internal mixing and mass loss by fast rotation of young massive stars. We also discuss the environmental effect to the relation between specific star formation rate and galaxy mass.

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IGRINS Observations of Star Forming Clouds in NGC 6822 Hubble V

  • Pak, Soojong;Lee, Hye-In;Le, Huynh Anh N.;Lee, Sungho;Chung, Aeree;Kaplan, Kyle;Jaffe, Daniel T.
    • 천문학회보
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    • 제39권2호
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    • pp.92.2-92.2
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    • 2014
  • NGC 6822 is a dwarf irregular galaxy in the Local Group. Unlike clouds in the Large Magellanic Cloud and the Small Magellanic Cloud, molecular clouds in NGC 6822 are not influenced by the Galactic tidal force. Therefore the star forming processes are only dictated by local conditions. Hubble V is the brightest of the several bright H II region complexes in NGC 6822. The core of Hubble V, surrounded by a molecular cloud complex, contains compact clusters of bright blue stars. During the commissioning runs of the new high-resolution near-infrared spectrometer, IGRINS (Immersion GRating near-INfrared Spectrometer), we observed Hubble V and detected many emission lines from the H II regions and from the photodissociation region at the interface between the ionized gas and the molecular cloud. In this presentation, we report preliminary results of the IGRINS observations. We discuss the implications of the observed lines ratios and kinematics for our understanding of the evolution of star forming molecular clouds.

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