HST Grism Observations of a z~1.8 Cluster Candidate from the Clusters Occupied by Bent Radio AGN (COBRA) Survey

Abstract

We present new Hubble Space Telescope/Wide Field Camera 3 G141 grism observations for COBRA1411+3415, originally identified as a high-redshift cluster candidate in the Clusters Occupied by Bent Radio AGN (COBRA) survey using radio, infrared, and optical data. We spectroscopically identify seven cluster members within a 0.5 Mpc radius with grism redshifts in the range $1.8006\le z_{grism}\le 1.8175$, consistent with COBRA1411+3415 being a high-redshift cluster with a mean redshift of $⟨z_{grism}⟩=1.8106\pm 0.0006$. The detection of seven galaxies within this small redshift range is significant above the background distribution of galaxies at the level of 5$\sigma$. The line-of-sight velocity dispersion of the cluster is found to be ${\sigma }_{\parallel }=701_{-138}^{+347}$ km/s with a virial mass of $M_{200}\approx 2.2_{-1.3}^{+3.3}\times 10^{14}$ M${}_{\odot }$. However, the mass may be lower if the cluster is still in formation. In projected phase-space, we also identify two possible infalling members of COBRA1411+3415 and two additional structures at $z\sim 1.73$ and $z\sim 1.88$. The similar spatial distributions and small projected separation from the main cluster suggest they could be a part of the same large-scale filament and together may form a protocluster system that could eventually merge to form a single, massive cluster. COBRA1411+3415 is the highest redshift cluster to be spectroscopically confirmed using a bent, double-lobed radio source as a cluster tracer.

References in corpus (61)

• The Sloan Digital Sky Survey: Technical Summary
• Galactic Stellar and Substellar Initial Mass Function
• The Structure of Cold Dark Matter Halos
• The Gaia mission
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• The Seventh Data Release of the Sloan Digital Sky Survey
• Cosmic Star Formation History
• Correcting for the Effects of Interstellar Extinction
• The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies
• EAZY: A Fast, Public Photometric Redshift Code
• Multiwavelength study of massive galaxies at z~2. I. Star formation and galaxy growth
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• The propagation of uncertainties in stellar population synthesis modeling III: model calibration, comparison, and evaluation
• A Study of the Gas-Star Formation Relation over Cosmic Time
• The lesser role of starbursts for star formation at z=2
• Galaxy Clusters Discovered via the Sunyaev-Zel'dovich Effect in the 2500-square-degree SPT-SZ survey
• A New Method For Galaxy Cluster Detection I: The Algorithm
• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• [OII] as a Star Formation Rate Indicator
• Distant Radio Galaxies and their Environments
• Galaxy clusters discovered with a Sunyaev-Zel'dovich effect survey
• A Spitzer-Selected Galaxy Cluster at z=1.62
• Clusters of Galaxies in the First Half of the Universe from the IRAC Shallow Survey
• BUDHIES II: A phase-space view of HI gas stripping and star-formation quenching in cluster galaxies
• Galaxy Clusters around radio-loud AGN at 1.3 < z < 3.2 as seen by Spitzer
• The SPTpol Extended Cluster Survey
• Spectroscopic Confirmation of the Rich z=1.80 Galaxy Cluster JKCS 041 Using the WFC3 Grism: Environmental Trends in the Ages and Structure of Quiescent Galaxies
• IDCS J1426+3508: Discovery of a Massive, IR-Selected Galaxy Cluster at z = 1.75
• Halpha-Derived Star-Formation Rates For Three z ~ 0.75 EDisCS Galaxy Clusters
• Discovery of a Rich Cluster at z = 1.63 using the Rest-Frame 1.6um "Stellar Bump Sequence" Method
• The Angular Clustering of Distant Galaxy Clusters
• The Mid-Infrared Environments of High-Redshift Radio Galaxies
• MHD Simulations of AGN Jets in a Dynamic Galaxy Cluster Medium
• Galaxy Cluster Environments of Radio Sources
• The Galaxy Cluster Mid-Infrared Luminosity Function at 1.3<z<3.2
• Deep Chandra Observations of the Extended Gas Sloshing Spiral in A2029
• A mature galaxy cluster at z=1.58 around the radio galaxy 7C1753+6311
• IDCS J1433.2+3306: An IR-Selected Galaxy Cluster at z = 1.89
• $HST$ Grism Confirmation of $16$ Structures at $1.4<z<2.8$ from the Clusters Around Radio-Loud AGN (CARLA) Survey
• The Environments of a Complete, Moderate-Redshift Sample of FIRST Bent-Double Radio Sources
• ZFIRE: Galaxy Cluster Kinematics, H$\alpha$ Star Formation Rates, and Gas-Phase Metallicities of XMM-LSS J02182-05102 at z=1.6233
• FIRST Bent-Double Radio Sources: Tracers of High-Redshift Clusters
• An Extreme Starburst in Close Proximity to the Central Galaxy of a Rich Galaxy Cluster at z=1.7
• Discovery of a High-Redshift (z=0.96) Cluster of Galaxies Using a FIRST Wide-Angle Tailed Radio Source
• BUDHIES I: characterizing the environments in and around two clusters at z~0.2
• Photometric redshifts for galaxies in the Subaru Hyper Suprime-Cam and unWISE and a catalogue of identified clusters of galaxies
• HST Grism Confirmation of Two $z\sim 2$ Structures from the Clusters Around Radio-Loud AGN (CARLA) Survey
• Cluster candidates around low power radio-galaxies at z~1-2 in COSMOS
• The formation history of massive cluster galaxies as revealed by CARLA
• Galaxy Merger Fractions in Two Clusters at $z\sim 2$ Using the Hubble Space Telescope
• The High-Redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: The \spitzer Catalog
• Candidate Clusters of Galaxies at $z>1.3$ Identified in the Spitzer SPT Deep Field Survey
• The Merger Environment of the WAT Hosting Cluster Abell 562
• The Megaparsec-scale Gas-sloshing Spiral in the Remnant Cool Core Cluster Abell 1763
• SFR estimations from z=0 to z=0.9 -- A comparison of SFR calibrators for star-forming galaxies
• Three candidate clusters of galaxies at redshift ~1.8: the "missing link" between protoclusters and local clusters?
• Chandra Observation of the Cluster Environment of a WAT Radio Source in Abell 1446
• The High-Redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: Follow-Up Optical Imaging
• An Examination of the Optical Substructure of Galaxy Clusters Hosting Radio Sources
• The High-Redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: Radio Source Properties
• The Grism Lens-Amplified Survey from Space (GLASS). XIII. G800L optical spectra from the parallel fields

Cited by in corpus (1)

• Probing the influence of the protocluster environment on galaxy morphology at z = 2.23