A Large Sky Survey with MeerKAT

Abstract

We discuss the ground-breaking science that will be possible with a wide area survey, using the MeerKAT telescope, known as MeerKLASS (MeerKAT Large Area Synoptic Survey). The current specifications of MeerKAT make it a great fit for cosmological applications, which require large volumes. In particular, a large survey over ∼ 4, 000 deg 2 for ∼ 4, 000 hours will potentially provide the first ever measurements of the baryon acoustic oscillations using the 21cm intensity mapping technique, with enough accuracy to impose constraints on the nature of dark energy. The combination with multi-wavelength data will give unique additional information, such as the first constraints on primordial non-Gaussianity using the multi-tracer technique, as well as a better handle on foregrounds and systematics. The survey will also produce a large continuum galaxy sample down to a depth of 5 µJy in L-band, unmatched by any other concurrent telescope, which will allow to study the large-scale structure of the Universe out to high redshifts. Finally, the same survey will supply unique information for a range of other science applications, including a large statistical investigation of galaxy clusters, and the discovery of rare high-redshift AGN that can be used to probe the epoch of reionization as well as produce a rotation measure map across a huge swathe of the sky. The MeerKLASS survey will be a crucial step on the road to using SKA1-MID for cosmological applications, as described in the top priority SKA key science projects.

Line-Intensity Mapping: 2017 Status Report

“…Initial construction will likely prioritize Bands 2, 5, and 1, the most relevant for 21cm intensity mapping being Band 2 (covering 950 − 1760 MHz), and Band 1 Left: joint marginal error contours using the multi-tracer technique for primordial non-Gaussianity (fNL) and GR corrections (fGR) considering different scenarios for the bias and Euclid/LSST surveys [190]. Right: HI power spectrum detection with MeerKLASS, showing the expected signal (black solid) and measurement errors (cyan) [191]. (Courtesy of Mario Santos)…”

“…using the auto-correlations from each of its dishes). A wide area survey has therefore been proposed, known as MeerKLASS (MeerKAT Large Area Synoptic Survey [191,192]) which aims to start observations in 2018. Covering an area of ∼ 4000 deg 2 for ∼ 4000 hours, it will potentially provide the first ever measurements of the baryon acoustic oscillations using the 21cm intensity mapping technique [193], with enough accuracy to constrain the nature of dark energy (see Fig.…”

Radio-optical synergies at high redshift to constrain primordial non-Gaussianity

“…For T Hi , we use the parametrisation given in [5,57,58], which captures the dependence of the average Hi brightness temperature on the comoving Hi density fraction, Ω Hi , whose full expression is given in eq. (2.1) of [59].…”

FAST Drift Scan Survey for Hi Intensity Mapping: I. Preliminary Data Analysis

“…Several HI IM experiments are under construction, such as the Baryonic Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO, Battye et al 2013) and the Hydrogen Intensity and Real-Time Analysis experiment (HIRAX, Newburgh et al 2016). The HI IM technique is also proposed as the major cosmology project with the Square Kilometre Array (SKA; 14 Santos et al 2015; Square Kilometre Array Cosmology Science Working Group et al 2020) and MeerKAT (Bull et al 2015;Santos et al 2016;Li et al 2021;Paul et al 2021;Wang et al 2021;Chen et al 2023). Recently, the MeerKAT HI IM survey reported cross-correlation power spectrum detection with the optical galaxy survey (Cunnington et al 2023).…”