Narrow-band surveys for very high redshift Lyman-alpha emitters

Abstract

Context: Many current and future surveys aim to detect the highest redshift (z >~ 7) sources through their Lyman-alpha (Ly-alpha) emission, using the narrow-band imaging method. However, to date the surveys have only yielded non-detections and upper limits as no survey has reached the necessary combination of depth and area to detect these very young star forming galaxies. Aims: We aim to calculate model luminosity functions and mock surveys of Ly-alpha emitters at z >~ 7 based on a variety of approaches. Methods: We calculate model luminosity functions at different redshifts based on three different approaches: a semi-analytical model based on CDM, a simple phenomenological model, and an extrapolation of observed Schechter functions at lower redshifts. The results of the first two models are compared with observations made at redshifts z ~ 5.7 and z ~ 6.5, and they are then extrapolated to higher redshift. Results: We present model luminosity functions for redshifts between z = 7 - 12.5 and give specific number predictions for future planned or possible narrow-band surveys for Ly-alpha emitters. We also investigate what constraints future observations will be able to place on the Ly-alpha luminosity function at very high redshift. Conclusion: It should be possible to observe z = 7 - 10 Ly-alpha emitters with present or near-future instruments if enough observing time is allocated. In particular, large area surveys such as ELVIS (Emission Line galaxies with VISTA Survey) will be useful in collecting a large sample. However, to get a large enough sample to constrain well the z >= 10 Ly-alpha luminosity function, instruments further in the future, such as an ELT, will be necessary.

8 pages, 4 figures, 3 tables, Accepted in A&A, best printed in colour

References in corpus (10)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• The James Webb Space Telescope
• 3D Lyman-alpha radiation transfer. I. Understanding Lyman-alpha line profile morphologies
• The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field
• A galaxy at a redshift z = 6.96
• The Impact of The IGM on High-Redshift Lyman Alpha Emission Lines
• Lyman alpha Resonant Scattering in Young Galaxies - Predictions from Cosmological Simulations
• Luminosity Functions of Lyman Alpha Emitting Galaxies and Cosmic Reionization of Hydrogen
• A narrow-band search for Ly alpha emitting galaxies at z = 8.8
• Lyman-alpha emission galaxies at a redshift of z = 5.7 in the FORS Deep Field

Cited by in corpus (5)

• The Polarization of Scattered Lyman Alpha Radiation Around High-Redshift Galaxies
• The clustering of Ly-alpha emitters in a LambdaCDM Universe
• Probing the first galaxies with the SKA
• Continuum Emission by Cooling Clouds
• Near-IR narrow-band imaging with CIRCE at the Gran Telescopio Canarias: Searching for Ly$\alpha$-emitters at $z\sim 9.3$