An HI intensity mapping survey with a Phased Array Feed

• Published in: Research in astronomy and astrophysics Vol. 21; no. 2; pp. 30 - 51
• Main Authors: Li, Lin-Cheng, Staveley-Smith, Lister, Rhee, Jonghwan
• Format: Journal Article
• Language: English
• Published: Beijing IOP Publishing 01.03.2021; School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China; ARC Centre of Excellence for All-sky Astrophysics (CAASTRO),Perth,6009,Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D),Perth,6009,Australia; National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China; ARC Centre of Excellence for All-sky Astrophysics (CAASTRO),Perth,6009,Australia%International Centre for Radio Astronomy Research (ICRAR),The University of Western Australia,35 Stirling Hwy,Crawley,WA,6009,Australia; International Centre for Radio Astronomy Research (ICRAR),The University of Western Australia,35 Stirling Hwy,Crawley,WA,6009,Australia
• Subjects: Correlation; Cross correlation; Dark energy; Data reduction; Hydrogen; Mapping; Phased arrays; Polls & surveys; Radio frequency interference; Red shift; Signal processing; Sky surveys (astronomy); Subtraction; methods:statistical; cosmology:observation; radio lines:galaxy
• ISSN: 1674-4527
• DOI: 10.1088/1674-4527/21/2/30

We report results from a neutral hydrogen (H i ) intensity mapping survey conducted with a Phased Array Feed (PAF) on the Parkes telescope. The survey was designed to cover ∼ 380 deg 2 over the redshift range 0.3 < z < 1 (a volume of ∼ 1.5 Gpc 3 ) in four fields covered by the WiggleZ Dark Energy Survey. The results presented here target a narrow redshift range of 0.73 < z < 0.78 where the effect of radio frequency interference (RFI) was less problematic. The data reduction and simulation pipeline was described, with an emphasis on flagging of RFI and correction for signal loss in the data reduction process, particularly due to the foreground subtraction methodology. A cross-correlation signal was detected between the H i intensity maps and the WiggleZ redshift data, with a mean amplitude of ⟨Δ T b δ opt ⟩ = 1.32 ± 0.42 mK (statistical errors only). A future Parkes cryogenic PAF is expected to detect the cross-correlation signal with higher accuracy than previously possible and allow measurement of the cosmic H i density at redshifts up to unity.