High-resolution spectroscopic atlas of M subdwarfs. Effective temperature and metallicity A. S. Rajpurohit, C. Reylé, F. Allard, R.-D. Scholz, D. Homeier, M. Schultheis and A. Bayo A&A, 564 (2014) A90 Published online: 11 April 2014 DOI: 10.1051/0004-6361/201322881