• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.75.3-75.3
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• 2019

The filament is an interesting structure in the Universe because clusters form at the nodes of filaments and grow through the continuous accretion of individual galaxies and groups from the surrounding filaments. We study the chemical properties of star-forming (SF) galaxies in the five large-scale filamentary structures (Leo II A, Leo II B, Leo Minor, Canes Venatici, and Virgo III) related with the Virgo cluster, with the spectroscopic data taken with the SDSS DR12, and compare them with those of the Virgo cluster and field galaxies. In mass-metallicity relation, most of the SF galaxies in Virgo-related filaments (except Virgo III filament) show lower metallicity on average than the Virgo cluster SF galaxies, but similar to field counterparts. These chemically less evolved feature of SF galaxies in the filaments and field are more pronounced for lower mass galaxies. This is probably because low mass galaxies have low potential wells and are therefore likely to be sensitive to cluster environmental effects. Interestingly, we find that the metallicity enhancement of SF galaxies in the Virgo III filament. In chemical and morphological perspectives, SF galaxies in the Virgo III thought to be transitional objects possibly transformed from SF late-type galaxies and are on the way to red early-type galaxies in the filament environment. This is the first discovery of systematic 'chemical pre-processing' signature for filament galaxies in Local Universe before they fall into the cluster.

• Proceedings of the Korean Magnestics Society Conference
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• 2011.06a
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• pp.121-121
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• 2011

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.92-92
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• 2009

• The Bulletin of The Korean Astronomical Society
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• v.30 no.2
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• pp.82.1-82.1
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• 2005

• The Bulletin of The Korean Astronomical Society
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• v.9
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• pp.6.3-7
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• 1984

• The Bulletin of The Korean Astronomical Society
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• v.11
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• pp.6.3-7
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• 1986

• Publications of The Korean Astronomical Society
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• v.1 no.1
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• pp.39-54
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• 1984

For F,G,K stars, their photometric data and metallicity, [Fe/H] are collected and their correlations between $\delta$(U-B) and [Fe/H] for each spectral group are examined, using a reference sequence which is defined by the stars in Woolley's catalogue and other reference sequences. Detailed examination shows that the reference sequence by Woolley's catalogue appears to be properly defined for the calculation of $\delta$(U-B) of population I stars in the solar neighborhood. It is suggested that accuracies of metallicities derived from $\delta$(U-B) can be improved if we derive the correlations between [Fe/H] and $\delta$(U-B) from the stars in each spectral group.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.46.2-46.2
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• 2013

We utilize Sloan Digital Sky Survey DR7 spectroscopic data of ~380 star forming galaxies in the Virgo cluster to investigate their chemical properties depending on the environments. The chemical evolution of galaxies is linked to their star formation histories as well as to the gas interchange in different environments. We derived star formation rate (SFR) and gaseous metallicity (e.g., oxygen abundance) of star forming galaxies. Combining with GALEX ultraviolet photometry and ALFALFA HI 21 cm data, we examine the relations between SFRs, metallicity, and HI deficiency of galaxies in various regions of the Virgo cluster. We also quantify the degree of ram pressure around galaxy using the ROSAT X-ray surface brightness map. We discuss environmental effects on the chemical properties and evolution of star forming galaxies.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.45.1-45.1
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• 2014

structure of matters of Lambda cold dark matter (CDM) cosmology on detailed numerical simulations. To accomplish our research goal, we have added the following baryonic physics on the existing cosmological hydrodynamic code, Gadget-2: 1) radiative heating and cooling, 2) reionization of the Universe and UV shielding, 3) star formation, 4) energy and metallicity feedback by supernova. In addition, we included cluster formation to distinguish clustered star formation inside the very high density gas clumps from the field star formation. Our simulations cover a cubic box of a side length 4Mpc/h with 130 million particles. The mass of each particles is $3.4{\times}104Msun$, thus the GCs can be resolved with more than hundreds particles. We discuss various properties of the GCs such as mass function, specific frequency, baryon-to-dark matter ratio, metallicity, spatial distribution, and orbit eccentricity distribution as functions of redshift. We also discuss how the formation and evolution of the GCs are affected by UV shielding.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.59.1-59.1
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• 2014

AGN feedback has been believed as playing an important role in the galaxy-super massive black hole (SMBH) co-evolution. AGN gas outflow can lead to AGN feedback. We investigate gas outflow of low-redshift AGNs by using blue shift/asymmetric index (BAI), and velocity offset of CIV line. By comparing these gas outflow indicators (BAI and velocity offset) to AGN properties (i.e., SMBH mass, bolometric luminosity, and Eddington ratio) and BLR gas metallicity, we find positive correlations among outflow, Eddington ratio, and metallicity. These relations are consistent with those observed at high-redshift. We discuss the possibility of the connection between previous star formation with current AGN accretion and outflow.