The High Dispersion Lyman Limit (HD-LLS) Sample

Brought to you by:

J. Xavier Prochaska (UCO/Lick Observatory)
John M. O'Meara (St. Michael's College)
Michele Fumagalli (Durham University)

These pages give tables and spectra of the first data release (DR1) of LLS surveyed at high-dispersion with the HIRES, ESI, MIKE and MAGE spectrometers. We also provide the papers of reference for this material. Please reference these when appropriate.

Data Products


  • pyigm: Python package (to be affiliated to astropy) that includes routines for reading in HD-LLS.


  • The Keck + Magellan Survey for Lyman Limit Absorption. I. The Frequency Distribution of Super Lyman Limit Systems, O'Meara et al. ApJ, 2007, 656, 666 (astro-ph/0610726) ADS
  • The Keck + Magellan Survey for Lyman Limit Absorption. II. A Case Study on Metallicity Variations, Prochter et al. ApJ, 2010, 708, 1221 (astro-ph/0912.0293) ADS
  • The Keck + Magellan Survey for Lyman Limit Absorption III: Sample Definition and Column Density Measurements, Prochaska et al. 2015, ApJS, 221, 2 ADS
  • The physical properties of z > 2 Lyman limit systems: new constraints for feedback and accretion models; Fumagalli, O'Meara, & Prochaska 2016, MNRAS, 455, 4100 ADS
  • Supersolar Super-Lyman Limit Systems, Prochaska et al. 2006, ApJ, 648, L97 (astro-ph/0606573) ADS
  • The Deuterium-to-Hydrogen Abundance Ratio toward the QSO SDSS J155810.16-003120.0, O'Meara et al. 2006, ApJ, 649, L61 (astro-ph/0608302) ADS

This research is supported by grants from the National Science Foundation (AST 03-07824 and AST 05-48180), NASA (HST-GO-10878.05-A) and the Science and Technology Facilities Council [grant number ST/L00075X/1].
e-mail: xavier at
modified 21/December/2015