The Arecibo Galaxy Environment Survey (AGES)

XI. The expanded Abell 1367 field: Data catalogue and H I census over the surveyed volume^⋆,⋆⋆

¹ Astronomical Institute, Czech Academy of Sciences, Boní II 1401, 14131 Prague, Czech Republic
e-mail: deshev@asu.cas.cz
² Stratospheric Observatory for Infrared Astronomy/USRA, NASA Ames Research Center, 232-12, Moffett Field, CA 94035, USA
³ Institute of Astrophysics and Space Sciences (IA), Rua das Estrelas, 4150-762 Porto, Portugal
⁴ Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK

Received: 13 January 2022
Accepted: 16 June 2022

Abstract

Context. Many galaxy properties are known to correlate with the environment in which the galaxies are embedded. Their cold, neutral gas content, which is usually assessed through 21 cm H I observations, is related to many other galaxy properties as it is the underlying fuel for star formation. With its high sensitivity and broad sky coverage the blind Arecibo Galaxy Environment Survey (AGES) brings significant improvement to the census of H I properties of galaxies in a wide range of environments, from voids to the core of a massive cluster. Here we present an H I census over a volume of ∼44 000 Mpc³ towards the merging cluster Abell 1367 and extending well beyond.

Aims. We measure the effects that different environments have on the H I content of their constituent galaxies.

Methods. We use AGES- a deep, blind, H I survey carried out with the Arecibo radio telescope, which covers 20 square degrees on the sky centred on the merging cluster Abell 1367, mapping the large-scale structure (LSS) surrounding the cluster out to cz = 20 000 km s⁻¹. The survey is sensitive down to a column density of N_H I = 1.5 × 10¹⁷ cm⁻² for emission filling the beam and a line width of 10 km s⁻¹. As an approximate mass sensitivity limit, a member of A1367 (at a distance of 92 Mpc), containing M_H I = 2.7 × 10⁸ M_⊙ distributed over a top-hat profile of 50 km s⁻¹ width would be detected at 4σ. The results are analysed in combination with optical spectroscopy data from SDSS which we use to estimate the local galaxy density based on the Voronoi-Delaunay method.

Results. We present the results of the complete AGES survey of the A1367 field. In total, we detect 457 H I sources, 213 of which are detected for the first time by the AGES survey, and 134 of which are presented in this article for the first time. Of the 457 detections, 225 are in the cluster and 232 are in the remaining volume surveyed. Here we present the full catalogue of H I detections and their basic properties, including optical ones. We concentrate on the difference between the cluster and the foreground and background LSS, revealing a continuous correlation of H I-detected fraction (and H I deficiency) with local galaxy density, independent of global environment.