English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Lyman-alpha emitter (LAE) surveys have successfully used the excess in anarrow-band filter compared to a nearby broad-band image to find candidates.However, the odd spectral energy distribution (SED) of LAEs combined with theinstrumental profile have important effects on the properties of the candidatesamples extracted from these surveys. We investigate the effect of the bandpasswidth and the transmission profile of the narrow-band filters used forextracting LAE candidates at redshifts z ~ 6.5 through Monte Carlo simulations,and we present pilot observations to test the performance of tunable filters tofind LAEs and other emission-line candidates. We compare the samples obtainedusing a narrow ideal-rectangular-filter, the Subaru NB921 narrow-band filter,and sweeping across a wavelength range using the ultra-narrow-band tunablefilters of the instrument OSIRIS, installed at the 10.4m Gran TelescopioCanarias. We use this instrument for extracting LAE candidates from a small setof real observations. Broad-band data from the Subaru, HST and Spitzerdatabases were used for fiting SEDs to calculate photometric redshifts and toidentify interlopers. Narrow-band surveys are very efficient to find LAEs inlarge sky areas, but the samples obtained are not evenly distributed inredshift along the filter bandpass, and the number of LAEs with equivalentwidths < 60 angstroms can be underestimated. These biased results do not appearin samples obtained using ultra-narrow-band tunable filters. However, the fieldsize of tunable filters is restricted because of the variation of the effectivewavelength across the image. Thus narrow-band and ultra-narrow-band surveys arecomplementary strategies to investigate high-redshift LAEs.

Filter Induced Bias in Ly{\alpha} Emitter Surveys: A Comparison Between Standard and Tunable Filters. Gran Telescopio Canarias Preliminary Results