Astronomical spectrograph calibration with broad-spectrum frequency combs D. A. Braje, M. S. Kirchner, S. Osterman, T. Fortier and S. A. Diddams Eur. Phys. J. D, 48 1 (2008) 57-66 Published online: 29 May 2008 DOI: 10.1140/epjd/e2008-00099-9