Introducing the FLAMINGOS-2 Split-K Medium-band Filters: The Impact on Photometric Selection of High-z Galaxies in the FENIKS-pilot survey

Esdaile, James; Labbé, Ivo; Glazebrook, Karl; Antwi-Danso, Jacqueline; Papovich, Casey; Taylor, Edward; Marsan, Z. Cemile; Muzzin, Adam; Straatman, Caroline M.S.; Marchesini, Danilo; Diaz, Ruben; Spitler, Lee; Tran, Kim-Vy H.; Goodsell, Stephen

Abstract

Deep near-infrared photometric surveys are efficient in identifying high-redshift galaxies, however, they can be prone to systematic errors in photometric redshift. This is particularly salient when there is limited sampling of key spectral features of a galaxy's spectral energy distribution (SED), such as for quiescent galaxies where the expected age-sensitive Balmer/4000 Å break enters the K-band at z > 4. With single-filter sampling of this spectral feature, degeneracies between SED models and redshift emerge. A potential solution to this comes from splitting the K band into multiple filters. We use simulations to show an optimal solution is to add two medium-band filters, Kblue (λcen = 2.06 μm, Δλ = 0.25 μm) and Kred (λcen = 2.31 μm, Δλ = 0.27 μm), that are complementary to the existing Ks filter. We test the impact of the K-band filters with simulated catalogs comprised of galaxies with varying ages and signal-to-noise. The results suggest that the K-band filters do improve photometric redshift constraints on z > 4 quiescent galaxies, increasing precision and reducing outliers by up to 90%. We find that the impact from the K-band filters depends on the signal-to-noise, the redshift, and the SED of the galaxy. The filters we designed were built and used to conduct a pilot of the FLAMINGOS-2 Extragalactic Near-Infrared K-band Split survey. While no new z > 4 quiescent galaxies are identified in the limited area pilot, the Kblue and Kred filters indicate strong Balmer/4000 Å breaks in existing candidates. Additionally, we identify galaxies with strong nebular emission lines, for which the K-band filters increase photometric redshift precision and in some cases indicate extreme star formation.

Citation

Esdaile, J., Labbé, I., Glazebrook, K., Antwi-Danso, J., Papovich, C., Taylor, E., Marsan, Z. C., Muzzin, A., Straatman, C. M., Marchesini, D., Diaz, R., Spitler, L., Tran, K.-V. H., & Goodsell, S. (2021). Introducing the FLAMINGOS-2 Split-K Medium-band Filters: The Impact on Photometric Selection of High-z Galaxies in the FENIKS-pilot survey. Astronomical Journal, 162(6), Article 225. https://doi.org/10.3847/1538-3881/ac2148

• Journal Article Type: Article
• Acceptance Date: Aug 24, 2021
• Online Publication Date: Nov 3, 2021
• Publication Date: Dec 1, 2021
• Deposit Date: Nov 23, 2021
• Publicly Available Date: Nov 23, 2021
• Journal: The Astronomical Journal
• Print ISSN: 0004-6256
• Electronic ISSN: 1538-3881
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 162
• Issue: 6
• Article Number: 225
• DOI: https://doi.org/10.3847/1538-3881/ac2148
• Public URL: https://durham-repository.worktribe.com/output/1221178