Volume 559, November 2013
|Number of page(s)||4|
|Published online||29 October 2013|
Measuring galaxy [O ii] emission line doublet with future ground-based wide-field spectroscopic surveys
Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de
Marseille) UMR 7326,
2 Laboratoire d’astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland
3 CRAL, Observatoire de Lyon, Université Lyon 1, 9 avenue Ch. André, 69561 Saint-Genis-Laval Cedex, France
4 Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
5 Department of Physics and Astronomy, University of Pittsburgh and PITT-PACC, 3941 O’Hara St., Pittsburgh, PA 15260, USA
6 CEA, Centre de Saclay, IRFU, 91191 Gif-sur-Yvette, France
Accepted: 20 September 2013
The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7 ≤ z ≤ 2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [Oii] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [Oii] (λλ 3727, 3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies for the choice of the resolution for future spectrographs for BAO surveys. For bright [Oii] emitter surveys ([Oii] flux ~30 × 10-17 erg cm-2 s-1 like SDSS-IV/eBOSS), a resolution of R ~ 3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [Oii] emitter surveys ([Oii] flux ~10 × 10-17 erg cm-2 s-1 like DESi), the detection improves continuously with resolution, so we recommend the highest possible resolution, the limit being given by the number of pixels (4k by 4k) on the detector and the number of spectroscopic channels (2 or 3).
Key words: instrumentation: spectrographs / techniques: spectroscopic / cosmology: observations / galaxies: statistics
© ESO, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.