Abstract Details

Conference ID: ASI2017_1357
Title : Understanding Physical Properties of Young M-dwarfs : Optical and Near-IR spectroscopic studies.
Authors and Co-Authors : Dr. Soumen Mondal, Dr. Ramkrishna Das, S.N.Bose National Centre For Basic Sciences; Salt Lake; Kolkata- 700106
Abstract Type : Oral
Abstract Category : Stars,ISM and the Galaxy
Abstract : Large population of M-dwarfs (more than 70% of all stars) are becoming attractive targets as a representative of archaeological record of the chemical evolution, star formation history of the Milky Way and as potential exoplanet host stars. Based on the age distribution of M dwarfs, we have taken a sample of young M-dwarfs from young moving groups and old population from the galactic field for medium spectral resolution spectrophotometric studies in the optical and near-infrared region. Using optical HFOSC and Near-IR TIRSPEC instruments on 2m Himalayan Chandra Telescope (HCT) at Hanle, Ladhak, we are characterizing a sample of M dwarfs on basis of several atomic and molecular indices. The main goal is to quantify the changes in the strength of these absorption features with spectral types and to find the correlation with different fundamental parameters like effective temperature (Teff ), surface gravity (logg), metallicity ([M/H]) etc. of M dwarfs. To complement with observations, the synthetic spectra from PHOENIX (BT-Settl) model grid and moderate resolution archival observed spectra (1-2.5 μm) from several library like IRTF SPEX-spectral library for different spectral types (M0V-M9V) is taken to support a qualitative validation of our approach. These will help us to find the best-fit of these parameters as well as to determine radii, ages and masses etc., which will provide a road map for future target selection of transit search around young and old population of M dwarfs.