Predictions for the abundance and clustering of Hα emitting galaxies

Madar, Makun S; Baugh, Carlton M; Shi, Difu

Abstract

We predict the surface density and clustering bias of Hα emitting galaxies for the Euclid and Nancy Grace Roman Space Telescope redshift surveys using a new calibration of the GALFORM galaxy formation model. We generate 3000 GALFORM models to train an ensemble of deep learning algorithms to create an emulator. We then use this emulator in a Markov Chain Monte Carlo (MCMC) parameter search of an eleven-dimensional parameter space, to find a best-fitting model to a calibration dataset that includes local luminosity function data, and, for the first time, higher redshift data, namely the number counts of Hα emitters. We discover tensions when exploring fits for the observational data when applying a heuristic weighting scheme in the MCMC framework. We find improved fits to the Hα number counts while maintaining appropriate predictions for the local universe luminosity function. For a flux limited Euclid-like survey to a depth of 2 × 10−16 erg−1 s−1 cm−2 for sources in the redshift range 0.9 < z < 1.8, we estimate 2962-4331 Hα emission-line sources deg−2. For a Nancy Grace Roman survey, with a flux limit of 1 × 10−16 erg−1 s−1 cm−2 and a redshift range 1.0 < z < 2.0, we predict 6786-10322 Hα emission-line sources deg−2.

Citation

Madar, M. S., Baugh, C. M., & Shi, D. (2024). Predictions for the abundance and clustering of Hα emitting galaxies. Monthly Notices of the Royal Astronomical Society, 535(4), 3324-3341. https://doi.org/10.1093/mnras/stae2560

• Journal Article Type: Article
• Acceptance Date: Nov 7, 2024
• Online Publication Date: Nov 14, 2024
• Publication Date: 2024-12
• Deposit Date: Nov 18, 2024
• Publicly Available Date: Nov 19, 2024
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 535
• Issue: 4
• Pages: 3324-3341
• DOI: https://doi.org/10.1093/mnras/stae2560
• Public URL: https://durham-repository.worktribe.com/output/3100085