메뉴 건너뛰기

제목 :  Study of sparse star clusters and metallicity distribution in the Large Magellanic Cloud

연사 :  Samyaday Choudhury 박사님 (연세대학교)

언어 :  English


요약

          The Large Magellanic Cloud (LMC), located in the southern sky, is by far the most liveliest and lustrous satellite of the Milky Way (d ~ 50 kpc)! I shall present our study of sparse star clusters and metallicity distribution in this nearby galaxy. The study of sparse star clusters in the LMC aims 
to increase our understanding of such objects, using deep Washington photometric data of 45 star clusters obtained from 4-m Blanco Telescope, CTIO. A systematic study was performed to estimate their parameters (radius, reddening, and age) using the main-sequence turn-off, as well as
the evolved portion of the color-magnitude diagram. We grouped the clusters into two categories based on their genuineness, namely true clusters and possible clusters/asterisms. The sizes (~2-10 pc) and masses (~a few 100 - 1000 M⊙) of these 45 inconspicuous clusters emphasizes that
the LMC has a significant population of clusters, which are similar to the open clusters in our Galaxy. To understand the metallicity distribution and
gradient of the LMC, we estimated a metallicity map using the red giant branch (RGB) stars, from the MCPS and OGLE III photometric data.
This is a first of its kind map of metallicity up to a radius of 4˚ - 5˚, with good sampling of the bar region. The slope of the RGB is used as an indicator of the average metallicity of a subregion, and it is calibrated to metallicity using spectroscopic data for field and cluster red giants in selected
subregions. We estimated the mean metallicities of different regions within the LMC using both data sets. The bar is found to have an uniform and higher metallicity compared to the disk, and is indicative of an active bar in the past. Both the data sets suggest a shallow radial metallicity gradient up to a radius of 4 kpc for the LMC disk (−0.049 ± 0.002 dex/kpc to −0.066 ± 0.006 dex/kpc ), which resembles the gradient seen in spiral galaxies, and is also similar to that found in our Galaxy.

번호 제목 글쓴이 날짜 조회 수
공지 [5/26] 근지구환경 관측을 위한 나노위성, SNIPE mission [2] webmaster 2017.05.24 86
공지 [5/19] Neutrinos and Cosmic Web with Large-Volume Surveys webmaster 2017.05.17 156
공지 [5/12] The Plasma-Physics of AGN on (Sub)Parsec Scales webmaster 2017.05.11 78
공지 [4/28] Nuclear Rings, Nuclear Spirals, and Mass Accretion to Supermassive Black Holes in Disk Galaxies. webmaster 2017.04.27 136
공지 [4/14] Challenging Space Smart, 쎄트렉아이의 우주 미션 소개 webmaster 2017.04.13 461
공지 [4/7] Observational Evidence for the Coevolution between Supermassive Black Holes and Host Galaxies webmaster 2017.04.04 434
공지 [4/3] The gas cycle of galaxies across environments webmaster 2017.03.28 359
공지 [3/24] National Space Situational Awareness Initiative webmaster 2017.03.20 2226
공지 [3/17] A New Paradigm for Star Formation: Episodic Accretion webmaster 2017.03.15 1043
공지 [3/10] Neutrino Oscillation Measurement webmaster 2017.03.08 1127
36 [12/16] Herschel and Millimeter Observations of Supernova Remnants webmaster 2016.12.05 675
35 [12/13] Galaxy Transformation in the local Universe webmaster 2016.12.05 676
34 [12/2] Intensive Monitoring of Nearby Galaxies and Early light curve of Supernovae webmaster 2016.11.29 986
33 [11/25] 활동성 블랙홀의 가스분출과 별생성 webmaster 2016.11.22 1061
» [11/18] Study of sparse star clusters and metallicity distribution in the Large Magellanic Cloud webmaster 2016.11.15 687
31 [10/28] 힉스 입자와 우주 webmaster 2016.10.24 836
30 [10/21] Small nascent galaxies in the debris of interacting systems webmaster 2016.10.18 767
29 [10/14] Relativistic Geodesy - Numerical simulation of the Post-Newtonian Equations of Motion webmaster 2016.10.07 763
28 [10/04] LSST and the physics of the dark universe webmaster 2016.10.04 1020
27 [9/30] Testing the statistical isotropy using dipolar modulation in galaxy number counts webmaster 2016.09.30 1352