Simulating MOS science on the ELT: Ly$\alpha$ forest tomography

Abstract

Mapping of the large-scale structure through cosmic time has numerous applications in the studies of cosmology and galaxy evolution. At $z>2$, the structure can be traced by the neutral intergalactic medium (IGM) by way of observing the Ly$\alpha$, forest towards densely-sampled lines-of-sight of bright background sources, such as quasars and star forming galaxies. We investigate the scientific potential of MOSAIC, a planned multi-object spectrograph on the European Extremely Large Telescope (ELT), for the 3D mapping of the IGM at $z\gtrsim 3$. We simulate a survey of $3\lesssim z\lesssim 4$ galaxies down to a limiting magnitude of $m_r\sim 25.5$ mag in an area of 1 degree${}^2$ in the sky. Galaxies and their spectra (including the line-of-sight Ly$\alpha$ absorption) are taken from the lightcone extracted from the Horizon-AGN cosmological hydrodynamical simulation. The quality of the reconstruction of the original density field is studied for different spectral resolutions and signal-to-noise ratios of the spectra. We demonstrate that the minimum $S/N$ (per resolution element) of the faintest galaxies that such survey has to reach is $S/N=4$. We show that a survey with such sensitivity enables a robust extraction of cosmic filaments and the detection of the theoretically-predicted galaxy stellar mass and star-formation rate gradients towards filaments. By simulating the realistic performance of MOSAIC we obtain $S/N(T_{\mathrm{obs}},R,m_r)$ scaling relations. We estimate that $\lesssim 35(65)$ nights of observation time are required to carry out the survey with the instrument's high multiplex mode and with the spectral resolution of $R=1000(2000)$. A survey with a MOSAIC-concept instrument on the ELT is found to enable the mapping of the IGM at $z>3$ on Mpc scales, and as such will be complementary to and competitive with other planned IGM tomography surveys. [abridged]

28 pages, accepted to A&A; language edited

References in corpus (19)

• The Cosmic Evolution Survey (COSMOS) -- Overview
• The James Webb Space Telescope
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• Spin alignment of dark matter haloes in filaments and walls
• The COS-Dwarfs Survey: The Carbon Reservoir Around sub-L* Galaxies
• Metal-line absorption around $z\approx$2.4 star-forming galaxies in the Keck Baryonic Structure Survey
• The VIMOS Public Extragalactic Redshift Survey (VIPERS): Galaxy segregation inside filaments at $z\simeq 0.7$
• Observations and modelling of a clumpy galaxy at z=1.6: Spectroscopic clues to the origin and evolution of chain galaxies
• From voids to filaments: environmental transformations of galaxies in the SDSS
• Spin alignments of spiral galaxies within the large-scale structure from SDSS DR7
• Lyman-alpha Forest Tomography from Background Galaxies: The First Megaparsec-Resolution Large-Scale Structure Map at z>2
• Scientific Synergy Between LSST and Euclid
• Horizon-AGN virtual observatory - 1. SED-fitting performance and forecasts for future imaging surveys
• Alignment of galaxies relative to their local environment in SDSS-DR8
• The large-scale environment from cosmological simulations I: The baryonic cosmic web
• Metals in the z~3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrum
• Using the Topology of Large Scale Structure to constrain Dark Energy
• On the Search for Quasar Light Echoes

Cited by in corpus (5)

• Rivers of Gas I.: Unveiling The Properties of High Redshift Filaments
• The relationship between gas and galaxies at z<1 using the Q0107 quasar triplet
• LyMAS reloaded: improving the predictions of the large-scale Lyman-α forest statistics from dark matter density and velocity fields
• An Optimized Ly$\alpha$ Forest Inversion Tool Based on a Quantitative Comparison of Existing Reconstruction Methods
• The CUBES Science Case