Abstract Details
| Name: samyaday choudhury Affiliation: yonsei university observatory, seoul, republic of korea Conference ID: ASI2017_1266 Title : First of its kind photometric metallicity map of the Small Magellanic Cloud Authors and Co-Authors : Samyaday Choudhury (1), Annapurni Subramaniam (2), Andrew A. Cole (3), Young-Jong Sohn(4) (1)Yonsei University Observatory, 120-749, Seoul, Republic of Korea (2) Indian Institute of Astrophysics, 2B Koramangala, Bangalore 560034, India (3)School of Physical Sciences, University of Tasmania, Private Bag 37, Hobart, Tasmania 7001, Australia (4) Department of Astronomy, Yonsei University, Seoul, Republic of Korea Abstract Type : Oral Abstract Category : Extragalactic astronomy Abstract : The Magellanic Clouds (MCs), comprising of the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are two nearby (∼ 57 kpc), interacting galaxies to our Milky Way. In a previous attempt to understand the metallicity variation within the LMC, we created a first of its kind high-spatial resolution metallcity map with Red Giant Branch (RGB) stars as the tool, using the Magellanic Cloud Photometric Survey (MCPS) and Optical Gravitational Lensing Experiment (OGLE III) photometric data. The RGB is identified in the V, (V - I) colour- magnitude diagrams of small subregions of varying sizes in both data sets. The slope of the RGB is used as an indicator of the mean metallicity of a subregion, and it is calibrated to metallicity using spectroscopic data for field and cluster RGB stars in selected subregions. We now extend our technique to the SMC with similar dataset. A high spatial resolution metallicity map showing the trend across the complete SMC is still unavailable. For the SMC, we have developed a technique similar to the LMC to first estimate the RGB slope, and calibrate the same to metallicity using spectroscopic results. The map can be used to estimate the mean metallicity within different regions of the SMC, the metallcity gradient, as well as help locate outliers, which are important in the context of understanding the chemical evolution of this galaxy. The nature of any metallicity gradient in the SMC, is a matter of great current controversy and requires a study such as ours using global, homogeneous datasets to make significant advances. The LMC and the SMC map can be compared to understand the chemical evolution history and the interaction history of the Clouds. The initial results based on our study will be discussed. |