Tracers of chromospheric structure. I. CaII H$\&$K emission distribution of 13000 F, G and K stars in SDSS DR7 spectroscopic sample

J. K. Zhao, T. D. Oswalt, G. Zhao +3

We present chromospheric activity index $S{}_{\mathrm{HK}}$ measurements for over 13,000 F, G and K disk stars with high signal-to-noise ratio ($>$ 60) spectra in the Sloan Digital Sky Sur…