• 제목/요약/키워드: EVLA

검색결과 2건 처리시간 0.016초

The Vertical Disk Structure and Star Formation in Nearby Edge-On Galaxies

  • Yim, Kijeong;Wong, Tony;Rand, Richard;Rosolowsky, Erik
    • 천문학회보
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    • 제41권2호
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    • pp.31.3-32
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    • 2016
  • We present the radial variations of the scale heights and the vertical velocity dispersions in a sample of nearby edge-on galaxies using BIMA/CARMA $^{12}CO$ ($J=1{\rightarrow}0$), VLA/EVLA HI, and Spitzer $3.6{\mu}m$ data. Both the disk thicknesses and the velocity dispersions of gas and stars vary with radius, contrary to assumptions of previous studies. We investigate how the interstellar gas pressure and the gravitational instability parameter differ from values derived assuming constant velocity dispersions and scale heights. Using the measurement of the disk thicknesses and the derived radial profiles of gas and stars, we estimate the corresponding volume densities. The gravitational instability parameter Q follows a fairly uniform profile with radius and is ${\geq}1$ across the star-forming disk. The star formation law has a slope that is significantly different from those found in more face-on galaxy studies. The midplane gas pressure appears to roughly hold a power-law correlation with the midplane volume density ratio (${\rho}_{H2}/{\rho}_{HI}$).

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Photometry of dwarf galaxies in the Leo HI gas ring

  • 김묘진;정애리;이준협;임성순;김민진;이종철;고종완;양성철
    • 천문학회보
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    • 제38권1호
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    • pp.40.1-40.1
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    • 2013
  • The HI ring serendipitously found in the Leo I galaxy group is unique in size in the Local Universe. It is ~200kpc in diameter with MHI~$1.67{\times}109M{\odot}$, surrounding a pair of early type galaxies M105 and NGC 3384. Its origin is still under debate whether it is the remnant of formation of a galaxy group (primordial) or formed from stripped material during galaxy-galaxy interaction (tidal origin). Intriguingly a number of dwarf galaxies have been identified along the gas ring (with or without optical counterpart). Various properties of these dwarf galaxies such as dark matter content, color, and/or metallicity will allow us to pin down the origin of this large scale HI ring. We have obtained a mosaicked CFHT MegaCam image and the EVLA HI cube of the large scale gas ring. In this work we present optical and gas properties of dwarf galaxies identified in the CFHT data.

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