The MeerKAT Absorption Line Survey (MALS)

Gupta, N.; Srianand, R.; Baan, W. A.; Baker, A. J.; Beswick, R.; Bhatnagar, S.; Bhattacharya, Dipankar; Bosma, A.; Carilli, C. L.; Cluver, Michelle; Combes, F.; Cress, C. M.; Dutta, Rajeshwari; Fynbo, J. P. U.; Heald, G.; Hilton, Matt; Hussain, Tanvir; Jarvis, Matt J.; Józsa, G. I. G.; Kamphuis, P.; Kembhavi, Ajit; Kerp, J.; Kloeckner, H. R.; Krogager, J.-K.; Kulkarni, Varsha P.; Ledoux, C.; Mahabal, A.; Mauch, T.; Moodley, Kavilan; Momjian, Emmanuel; Morganti, Raffaella; Noterdaeme, P.; Oosterloo, Tom; Petitjean, P.; Schroeder, Anja; Serra, P.; Sievers, Jonathan; Spekkens, Kristine; Vaïsänen, P.; Hulst, Thijs van der; Vivek, M.; Wang, J; Wong, O. Ivy; Zungu, A. R.

doi:10.22323/1.277.0014

Cited by 10 publications

(3 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SPT sample overlaps with ours at higher redshifts; however, it does not cover lower redshifts (z < 0.33). This study is a precursor to studies of larger samples exploring lower mass and higher redshift cluster sample studies such as the MeerKAT Extended Relics, Giant Halos, and Extragalactic Radio Sources (MERGHERS) survey [63] and the MeerKAT Absorption Line Survey (MALS; [64]).…”

Section: The Actpol Samplementioning

confidence: 99%

A GMRT Narrowband vs. Wideband Analysis of the ACT−CL J0034.4+0225 Field Selected from the ACTPol Cluster Sample

et al. 2021

View full text Add to dashboard Cite

Low frequency radio observations of galaxy clusters are a useful probe of the non-thermal intracluster medium (ICM), through observations of diffuse radio emission such as radio halos and relics. Current formation theories cannot fully account for some of the observed properties of this emission. In this study, we focus on the development of interferometric techniques for extracting extended, faint diffuse emissions in the presence of bright, compact sources in wide-field and broadband continuum imaging data. We aim to apply these techniques to the study of radio halos, relics and radio mini-halos using a uniformly selected and complete sample of galaxy clusters selected via the Sunyaev-Zel’dovich (SZ) effect by the Atacama Cosmology Telescope (ACT) project, and its polarimetric extension (ACTPol). We use the upgraded Giant Metrewave Radio Telescope (uGMRT) for targeted radio observations of a sample of 40 clusters. We present an overview of our sample, confirm the detection of a radio halo in ACT−CL J0034.4+0225, and compare the narrowband and wideband analysis results for this cluster. Due to the complexity of the ACT−CL J0034.4+0225 field, we use three pipelines to process the wideband data. We conclude that the experimental spam wideband pipeline produces the best results for this particular field. However, due to the severe artefacts in the field, further analysis is required to improve the image quality.

show abstract

Section: The Actpol Samplementioning

confidence: 99%

A GMRT Narrowband vs. Wideband Analysis of the ACT−CL J0034.4+0225 Field Selected from the ACTPol Cluster Sample

et al. 2021

View full text Add to dashboard Cite

show abstract

“…For example, the combined MeerKLASS 32 and HIRAX intensity mapping surveys will have the potential to produce a cosmological analysis over a redshift range of 0 z 2.5, with contrasting systematic challenges from the differing observing modes and instruments. The blind HI absorber surveys with HIRAX will extend observations beyond the redshift limits of ongoing surveys, such as the MeerKAT Absorption Line Survey (MALS 33 ), to investigate the relationship between cold atomic gas and the evolution of star formation and AGN activity.…”

Section: Introductionmentioning

confidence: 99%

The Hydrogen Intensity and Real-time Analysis eXperiment: 256-Element Array Status and Overview

Crichton,

Aich,

Amara

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory (SARAO) Square Kilometer Array (SKA) site in South Africa. Each of the 6 m, f /0.23 dishes will be instrumented with dual-polarisation feeds operating over a frequency range of 400-800 MHz. Through intensity mapping of the 21 cm emission line of neutral hydrogen, HIRAX will provide a cosmological survey of the distribution of large-scale structure over the redshift range of 0.775 < z < 2.55 over ∼15,000 square degrees of the southern sky. The statistical power of such a survey is sufficient to produce ∼7 percent constraints on the dark energy equation of state parameter when combined with measurements from the Planck satellite. Additionally, HIRAX will provide a highly competitive platform for radio transient and HI absorber science while enabling a multitude of cross-correlation studies. In these proceedings, we describe the science goals of the experiment, overview of the design and status of the sub-components of the telescope system, and describe the expected performance of the initial 256-element array as well as the planned future expansion to the final, 1024-element array.

show abstract

“…This will complement the MeerKAT Absorption Line Survey (MALS; 0 < z < 1.4) by extending the exploration of cold atomic gas in the circum-galactic and inter-galactic medium to higher redshifts. 17 Detecting the BAO in the presence of significant astronomical foregrounds, most notably synchrotron radiation from the Milky Way galaxy, is a significant challenge. The high level requirements for the array to achieve its science goals are sensitivity, redundancy, and control of systematics.…”

Section: Introductionmentioning

confidence: 99%

Mechanical and Optical Design of the HIRAX Radio Telescope

Saliwanchik¹,

Ewall‐Wice²,

Crichton³

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a planned interferometric radio telescope array that will ultimately consist of 1024 close packed 6 m dishes that will be deployed at the SKA South Africa site. HIRAX will survey the majority of the southern sky to measure baryon acoustic oscillations (BAO) using the 21 cm hyperfine transition of neutral hydrogen. It will operate between 400-800 MHz with 391 kHz resolution, corresponding to a redshift range of 0.8 < z < 2.5 and a minimum ∆z/z of ∼0.003 (frequency resolution 500 < R < 1000). One of the primary science goals of HIRAX is to constrain the dark energy equation of state by measuring the BAO scale as a function of redshift over a cosmologically significant range. Achieving this goal places stringent requirements on the mechanical and optical design of the HIRAX instrument which are described in this paper. This includes the simulations used to optimize the mechanical and electromagnetic characteristics of the instrument, including the dish focal ratio, receiver support mechanism, and instrument cabling. As a result of these simulations, the dish focal ratio has been reduced to 0.23 to reduce inter-dish crosstalk, the feed support mechanism has been redesigned as a wide (35 cm diam.) central column, and the feed design has been modified to allow the cabling for the receiver to pass directly along the symmetry axis of the feed and dish in order to eliminate beam asymmetries and reduce sidelobe amplitudes. The beams from these full-instrument simulations are also used in an astrophysical m-mode analysis pipeline which is used to evaluate cosmological constraints and determine potential systematic contamination due to physical non-redundancies of the array elements. This

show abstract

The MeerKAT Absorption Line Survey (MALS)

Cited by 10 publications

References 40 publications

A GMRT Narrowband vs. Wideband Analysis of the ACT−CL J0034.4+0225 Field Selected from the ACTPol Cluster Sample

A GMRT Narrowband vs. Wideband Analysis of the ACT−CL J0034.4+0225 Field Selected from the ACTPol Cluster Sample

The Hydrogen Intensity and Real-time Analysis eXperiment: 256-Element Array Status and Overview

Mechanical and Optical Design of the HIRAX Radio Telescope

Contact Info

Product

Resources

About