• Title/Summary/Keyword: 분광 관측

Search Result 421, Processing Time 0.03 seconds

Spectroscopy of Local Starburst Galaxies (가까운 폭발적 항성생성은하의 분광 관측)

  • Lee, Cheolhui;Shim, Hyunjin
    • Journal of the Korean earth science society
    • /
    • v.38 no.3
    • /
    • pp.209-221
    • /
    • 2017

  • We investigate the star formation rate, stellar mass, and gas-phase metallicity of local starburst galaxies with different star formation time scales based on their optical spectra. The observation is made using the longslit spectrograph attached to the 4K CCD on the Bohyunsan Optical Astronomy Observatory 1.8m telescope, targeting 21 Wolf-Rayet galaxies as young starbursts and 13 UV excess galaxies as slightly older starbursts. A Baldwin-Phillips-Terlevich diagram analysis shows that 50% of the observed targets are pure star-forming galaxies while only 15% are classified as Active Galactic Nuclei. Fraction of galaxies that reside in composite region is higher in UV excess galaxies than in Wolf-Rayet galaxies, suggesting that the AGN development requires extra time after the onset of the star formation. Most of the observed starburst galaxies have stellar masses of $10^{9-11}M_{\odot}$ and stellar formation rates of $0.01-100M_{\odot}yr^{-1}$, and their star formation rates are consistent with that of the SDSS star forming main sequence galaxies of similar stellar mass. There is no significant difference between Wolf-Rayet galaxies and UV excess galaxies in terms of the stellar mass and star formation rate. We also see a mass-metallicity relation for local starbursts with slightly lower metallicity for a given stellar mass, which implies the existence of a strong feedback activity due to the star formation in these galaxies.

  • https://doi.org/10.5467/JKESS.2017.38.3.209 인용 PDF KSCI

Analysis Methods of Visible and Near-Infrared (VNIR) Spectrum Data in Space Exploration (우주탐사에서의 가시광-근적외선 분광 자료 분석 기법)

  • Eung Seok Yi;Kyeong Ja Kim;Ik-Seon Hong;Suyeon Kim
    • Journal of Space Technology and Applications
    • /
    • v.3 no.2
    • /
    • pp.154-164
    • /
    • 2023

  • In space exploration, spectroscopic observation is useful for understanding objects' composition and physical properties. There are various methods for analyzing spectral data, and there are differences depending on the object and the wavelength. This paper introduces a method for analyzing visible & nearinfrared (VNIR) spectral data, which is mainly applied in lunar exploration. The main analysis methods include false color ratio image processing, reflectance pattern analysis, integrated band depth (IBD) processing, and continuum removal as preprocessing before analysis. These spectroscopic analysis methods help to understand the mineral properties of the lunar surface in the VNIR region and can be applied to other celestial bodies such as Mars.

  • https://doi.org/10.52912/jsta.2023.3.2.154 인용 PDF