Pilot-WINGS: An extended MUSE view of the structure of Abell 370

Abstract

We investigate the strong-lensing cluster Abell 370 (A370) using a wide Integral Field Unit (IFU) spectroscopic mosaic from the Multi-Unit Spectroscopic Explorer (MUSE). IFU spectroscopy provides significant insight into the structure and mass content of galaxy clusters, yet IFU-based cluster studies focus almost exclusively on the central Einstein-radius region. Covering over 14 arcmin 2 , the new MUSE mosaic extends significantly beyond the A370 Einstein radius, providing, for the first time, a detailed look at the cluster outskirts. Combining these data with wide-field, multi-band Hubble Space Telescope (HST) imaging from the BUFFALO project, we analyse the distribution of objects within the cluster and along the line of sight. Identifying 416 cluster galaxies, we use kinematics to trace the radial mass profile of the halo, providing a mass estimate independent from the lens model. We also measure radially-averaged properties of the cluster members, tracking their evolution as a function of infall. Thanks to the high spatial resolution of our data, we identify six cluster members acting as galaxy-galaxy lenses, which constrain localized mass distributions beyond the Einstein radius. Finally, taking advantage of MUSE's 3D capabilities, we detect and analyse multiple spatially extended overdensities outside of the cluster that influence lensing-derived halo mass estimates. We stress that much of this work is only possible thanks to the robust, extended IFU coverage, highlighting its importance even in less optically dense cluster regions. Overall, this work showcases the power of combining HST+MUSE, and serves as the initial step towards a larger and wider program targeting several clusters.

The ALMA Frontier Fields Survey. VI. Lensing-corrected 1.1mm number counts in Abell 2744, MACSJ0416.1-2403, MACSJ1149.5+2223, Abell 370 and Abell S1063

“…We search for counterparts to our ALMA detections in the last two FFs considering several public catalogs that report photometric and/or spectroscopic redshift estimates. These include: photometric redshifts estimated by Monna et al (2014), the CLASH team (Postman et al 2012;Molino et al 2017, the HFF-DeepSpace project, the KLASS survey, the ASTRODEEP survey (Bradač et al 2019), the SHARDS FF survey, and Pagul et al (2021); catalogs of spectroscopic redshifts by Richard et al (2010), Gómez et al (2012), Boone et al (2013), Johnson et al (2014), Richard et al (2014), Diego et al (2016), Lagattuta et al (2017), Vanzella et al (2017), Diego et al (2018), Strait et al (2018, Lagattuta et al (2019), Vega-Ferrero et al (2019), Walth et al (2019), Richard et al (2021), Lagattuta et al (2022), the GLASS survey, and the CLASH survey using VIMOS (Balestra et al 2013) and MUSE (Karman et al 2015;Caminha et al 2016;Karman et al 2017;Mercurio et al 2021) at VLT; and redshift estimates for Herschel detections (Rawle et al 2016).…”

“…A370-ID03 has a z spec = 1.258 (secure) counterpart within ≈ 0 . 2 from Lagattuta et al (2022) using MUSE at VLT. They give a redshift confidence flag of 3 to this source, indicating high reliability; this means that the redshift is either based on multiple clear spectral features, or on a single high-significance emission line with additional information.…”

“…(g) Photometric redshift from HFF-DeepSpace. (h) Spectroscopic redshift from Lagattuta et al (2022). (i) Spectroscopic redshift from CLASH.…”