NIR spectroscopic study of young M dwarfs

The sample includes 53 dwarf stars (M0V-M7V) from new observations using the TIFR Near-Infrared Spectrometer and Imager instrument on the 2-m Himalayan Chandra Telescope. Using interferometrically measured effective temperature (T_eff_), radius and luminosity of nearby bright calibrator stars, we have created new empirical relationships among those fundamental parameters and spectral indices.

The equivalent widths of H-band spectral features like Mg (1.57{mu}m), Al (1.67{mu}m) and Mg (1.71{mu}m), and the H_2_O-H index are found to be good indicators of T_eff_, radius and luminosity and we establish linear functions using these features relating to those stellar parameters. The root-mean-squared error of our best fits are 102K, 0.027R_{sun}_ and 0.12dex respectively. Using spectral-type standards along with known parallaxes, we calibrate both H- and K-band H_2_O indices as a tracer of spectral type and absolute K_s_ magnitude.