Details

Autor(en) / Beteiligte

• Kamble, Vikrant
• Dawson, Kyle
• Bourboux, Hélion du Mas des
• Bautista, Julian
• Scheinder, Donald P.

Titel

Measurements of Effective Optical Depth in the Lyα Forest from the BOSS DR12 Quasar Sample

Ist Teil von

• The Astrophysical journal, 2020-03, Vol.892 (1), p.70

Ort / Verlag

Philadelphia: IOP Publishing

Erscheinungsjahr

2020

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Abstract We measure the effective optical depth in the Ly α forest using 40,035 quasar spectra from the Twelfth Data Release (DR12) of the Baryon Oscillation Spectroscopic Survey of Sloan Digital Sky Survey IV. A rigorous selection based on spectral index and the equivalent width of the C iv emission line is applied to choose seven uniform samples with minimal intrinsic variations across redshifts. Modeling the redshift evolution of the effective optical depth with a power law, produces and . The 2.2% precision estimate on γ is dominated by systematic errors, likely arising from the bias and uncertainties in spectral index estimates. Even after incorporating the systematic errors, this work provides the most precise estimates of optical depth parameters to date. Finally, using the reconstructed Ly α forest continuum to directly measure the transmitted flux ratio as a function of redshift, we find deviations of less than 2.5% from the predictions from the global model and no convincing evidence for signal associated with He ii reionization.