• Title/Summary/Keyword: Galaxy: evolution

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EVOLUTIONARY MODELS OF ROTATING DENSE STELLAR SYSTEMS WITH EMBEDDED BLACK HOLES

  • FIESTAS, JOSE A.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.345-347
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    • 2015
  • We present evolutionary models of rotating self-gravitating systems (e.g. globular clusters, galaxy cores). These models are characterized by the presence of an initial axi-symmetry due to rotation. Central black hole seeds are included in our models, and black hole growth due to the consumption of stellar matter is simulated until the central potential dominates the kinematics of the core. Our goal is to study the long-term evolution (Gyr) of relaxed dense stellar systems which deviate from spherical symmetry, and their morphology and final kinematics. With this purpose in mind, we developed a 2D Fokker-Planck analytical code, and confirmed its results using detailed N-Body simulations, applying a high performance code developed for GPU machines. We conclude that the initial rotation significantly modifies the shape and lifetime of these systems, and cannot be neglected in the study of the evolution of globular clusters, and the galaxy itself. Our models give a constraint for the final intermediate black hole masses expected to be present in globular clusters.

WALLABY - the ASKAP HI All-Sky Survey

  • Oh, Se-Heon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.235-235
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    • 2012
  • The "Widefield ASKAP L-band Legacy All-sky Blind surveY" (WALLABY) is an extragalactic HI survey which aims to examine HI properties and large-scale distribution of ~500,000 galaxies out to z ~ 0.27, covering a wide range of science goals associated with galaxy formation and evolution (P.I.: B. Koribalski & L. Staveley-Smith). The combination of ASKAP's exquisite column density sensitivity and a large primary beam will make it possible to systematically investigate the rarely explored low column-density HI in the universe. Ultimately, the largest and most homogeneous data set from WALLABY will drastically improve and broaden our knowledge on galaxy formation and evolution. ASKAP will be on-line in 2013, so to ensure timely and efficient reduction and analysis of the large WALLABY data set, we have been developing and testing reliable source finding tools and data analysis pipelines. In this talk I present recent progress of WALLABY, especially on the kinematic parameterisation pipeline for the spatially resolved galaxies detected by WALLABY.

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Phas-space Analysis of Halos around Large-scale Filamentary Structures

  • Jhee, Hannah;Song, Hyunmi;Smith, Rory;Shin, Jihye;Park, Inkyu
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.64.3-65
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    • 2020
  • It has been studied that galaxies evolve following a typical trajectory on the phase space under the influence of deep gravitational potential of galaxy clusters. Similarly, the large-scale filaments could also affect the evolution of galaxies before falling into the clusters. In this study, using a dark matter-only cosmological simulation, N-Cluster Run, we explore the evolution of galaxies on the phase space drien by large-scale filaments. We find that galaxies around the filaments form a common trajectory on the phase space as well as cluster galaxies do. We also examine how these trajectories change depending on various physical parameters such as galaxy mass, initial distance of galaxies from large-scale filaments, and cluster mass.

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The Zoo of Early-type Dwarf Galaxies in Clusters

  • Rey, Soo-Chang
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.40.2-40.2
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    • 2012
  • Early-type dwarf galaxies are the most numerous galaxies in dense environments, making them ideal probes of the mechanisms that govern galaxy formation and evolution. Despite the common picture of an early-type dwarf galaxy as a quiescent one with no star formation and little gas, recent systematic investigations of early-type dwarf galaxies in the cluster revealed an unexpected variety among these apparently simple objects. In this talk, I review intriguing complexity of early-type dwarf galaxies in the cluster. I will also briefly introduce a new catalog of galaxies in the Virgo cluster using SDSS data, extended Virgo Cluster Catalog (EVCC).

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PROGRESS REPORT: INVESTIGATION OF THE MORPHOLOGY OF CLUSTER GALAXIES

  • OH, SEULHEE;YI, SUKYOUNG K.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.529-530
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    • 2015
  • We investigated the galaxy morphology of 6 Abell clusters at z = 0.0784 - 0.145 based on deep images obtained using MegaCam on the CFHT. For hundreds of galaxies in our data, we classified their morphology based on criteria related to secular or merger related evolution. We found that the morphological mixture of galaxies varies considerably from cluster to cluster. This article contains a general description of our deep imaging campaign and preliminary results for galaxy morphologies in cluster environments.