Galaxy and Mass Assembly (GAMA): Extended intragroup light in a group at z = 0.2 from deep Hyper Suprime-Cam images

Pimbblet, Kevin A.; Martínez-Lombilla, Cristina; Brough, Sarah; Montes, Mireia; Baena-Gallé, Roberto; Akhlaghi, Mohammad; Infante-Sainz, Raúl; Driver, Simon P.; Holwerda, Benne W.; Robotham, Aaron S.G.

Abstract

We present a pilot study to assess the potential of Hyper Suprime-Cam Public Data Release 2 (HSC-PDR2) images for the analysis of extended faint structures within groups of galaxies. We examine the intragroup light (IGL) of the group 400138 (Mdyn = 1.3 ± 0.5 × 1013 M⊙, z ∼0.2) from the Galaxy And Mass Assembly (GAMA) survey using Hyper Suprime-Cam Subaru Strategic Program Public Data Release 2 (HSC-SSP PDR2) images in g, r, and i bands. We present the most extended IGL measurement to date, reaching down to μglim =30.76 mag arcsec-2 (3σ; 10 × 10 arcsec2) at a semimajor axis of 275 kpc. The IGL shows mean colour values of g - i = 0.92, g - r = 0.60, and r - i = 0.32 (±0.01). The IGL stellar populations are younger (2-2.5 Gyr) and less metal rich ([Fe/H] ∼-0.4) than those of the host group galaxies. We find a range of IGL fractions as a function of total group luminosity of ∼ 2-36 per cent depending on the definition of IGL, with larger fractions the bluer the observation wavelength. The early-type to late-type galaxy ratio suggests that 400138 is a more evolved group, dominated by early-type galaxies, and the IGL fraction agrees with that of other similarly evolved groups. These results are consistent with tidal stripping of the outer parts of Milky Way-like galaxies as the main driver of the IGL build-up. This is supported by the detection of substructure in the IGL towards the galaxy member 1660615 suggesting a recent interaction (<1 Gyr ago) of that galaxy with the core of the group.

Citation

Pimbblet, K. A., Martínez-Lombilla, C., Brough, S., Montes, M., Baena-Gallé, R., Akhlaghi, M., …Robotham, A. S. (2023). Galaxy and Mass Assembly (GAMA): Extended intragroup light in a group at z = 0.2 from deep Hyper Suprime-Cam images. Monthly notices of the Royal Astronomical Society, 518(1), 1195-1213. https://doi.org/10.1093/mnras/stac3119

• Journal Article Type: Article
• Acceptance Date: Oct 21, 2022
• Online Publication Date: Nov 24, 2022
• Publication Date: 2023
• Deposit Date: Dec 8, 2022
• Publicly Available Date: Dec 9, 2022
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 518
• Issue: 1
• Pages: 1195-1213
• DOI: https://doi.org/10.1093/mnras/stac3119
• Keywords: Galaxies: clusters: intracluster medium; Galaxies: groups: general; Galaxies: groups: individual: 400138; Galaxies: haloes; Galaxies: photometry; Galaxies: evolution
• Public URL: https://hull-repository.worktribe.com/output/4139749