Radial Distribution Of ISM Gas-phase Metallicity In CLASH Clusters at z~0.35: A New Outlook On Environmental Impact On Galaxy Evolution

Abstract

We present the first observation of cluster-scale radial metallicity gradients from star-forming galaxies. We use the DEIMOS spectrograph on the Keck II telescope to observe two CLASH clusters at z~0.35: MACS1115+0129 and RXJ1532+3021. Based on our measured interstellar medium (ISM) properties of star-forming galaxies out to a radius of 2.5 Mpc from the cluster centre, we find that the galaxy metallicity decreases as a function of projected cluster-centric distance (-0.15+/-0.08 dex/Mpc) in MACS1115+01. On the mass-metallicity relation (MZR), star-forming galaxies in MACS1115+01 are offset to higher metallicity (~0.2 dex) than the local SDSS galaxies at a fixed mass range. In contrast, the MZR of RXJ1532+30 is consistent with the local comparison sample. RXJ1532+30 exhibits a bimodal radial metallicity distribution, with one branch showing a similar negative gradient as MACS1115+01 (-0.14+/-0.05 dex/Mpc) and the other branch showing a positive radial gradient. The positive gradient branch in RXJ1532+30 is likely caused by either interloper galaxies or an in-plane merger, indicating that cluster-scale abundance gradients probe cluster substructures and thus the dynamical state of a cluster. Most strikingly, we discover that neither the radial metallicity gradient nor the offset from the MZR is driven by the stellar mass. We compare our observations with Rhapsody-G cosmological hydrodynamical zoom-in simulations of relaxed galaxy clusters and find that the simulated galaxy cluster also exhibits a negative abundance gradient, albeit with a shallower slope (-0.04+/-0.03 dex/Mpc). Our observations suggest that the negative radial gradient originates from ram-pressure stripping and/or strangulation processes in the cluster environments.

17 pages, 11 Figures; Accepted for publication in ApJ

References in corpus (15)

• The Host Galaxies and Classification of Active Galactic Nuclei
• The hierarchical formation of the brightest cluster galaxies
• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• Strangulation as the primary mechanism for shutting down star formation in galaxies
• The Universal Relation of Galactic Chemical Evolution: The Origin of the Mass-Metallicity Relation
• CLASH: The Concentration-Mass Relation of Galaxy Clusters
• The Role of Environment in the Mass-Metallicity Relation
• The environmental dependence of the chemical properties of star-forming galaxies
• The Absence of an Environmental Dependence in the Mass-Metallicity Relation at z=2
• Metal deficiency in cluster star-forming galaxies at z=2
• The Effects of AGN Feedback on Present-Day Galaxy Properties in Cosmological Simulations
• On the occurrence of galaxy harassment
• Metal enrichment of the intra-cluster medium over a Hubble time for merging and relaxed galaxy clusters
• On the Dynamical Origin of the ICM Metallicity Evolution
• On the relationship between environment and galaxy properties in clusters of galaxies

Cited by in corpus (8)

• The Dawes Review 9: The role of cold gas stripping on the star formation quenching of satellite galaxies
• CLEAR: The Gas-Phase Metallicity Gradients of Star-Forming Galaxies at 0.6 < z < 2.6
• Cluster induced quenching of galaxies in the massive cluster XMMXCSJ2215.9-1738 at z~1.5 traced by enhanced metallicities inside half R200
• On the influence of the environment on galactic chemical abundances
• The Fornax3D project: The environmental impact on gas metallicity gradients in Fornax cluster galaxies
• K-CLASH: Strangulation and Ram Pressure Stripping in Galaxy Cluster Members at 0.3 < z < 0.6
• A Multiwavelength Study of the Massive Cool Core Cluster MACS J1447.4+0827
• Survival of Massive Star-forming Galaxies in Cluster Cores Drives Gas-Phase Metallicity Gradients : The Effects of Ram Pressure Stripping