Discovery of a protocluster core associated with an enormous Ly$\alpha$ Nebula at $z=2.3$

Abstract

The MAMMOTH-1 nebula at $z=2.317$ is an enormous Ly$\alpha$ nebula (ELAN) extending to a $\sim$440 kpc scale at the center of the extreme galaxy overdensity BOSS 1441. In this paper, we present observations of the $\mathrm{CO}(3-2)$ and 250 GHz dust-continuum emission from the MAMMOTH-1 using the IRAM NOrthern Extended Millimeter Array. Our observations show that $\mathrm{CO}(3-2)$ emission in this ELAN has not extended widespread emission into the circum- and inter-galactic media. We also find a remarkable concentration of six massive galaxies in $\mathrm{CO}(3-2)$ emission in the central $\sim$100 kpc region of the ELAN. Their velocity dispersions suggest a total halo mass of $M_{200c}\sim 10^{13.1}{M}_{\odot }$, marking a possible protocluster core associated with the ELAN. The peak position of the $\mathrm{CO}(3-2)$ line emission from the obscured AGN is consistent with the location of the intensity peak of MAMMOTH-1 in the rest-frame UV band. Its luminosity line ratio between the $\mathrm{CO}(3-2)$ and $\mathrm{CO}(1-0)$ $r_{3,1}$ is 0.61$\pm$0.17. The other five galaxies have $\mathrm{CO}(3-2)$ luminosities in the range of (2.1-7.1)$\times 10^9$ K $\mathrm{km}{\mathrm{s}}^{-1}$ pc${}^2$, with the star-formation rates derived from the 250GHz continuum of ($<$36)-224 $M_{\odot }$yr${}^{-1}$. Follow-up spectroscopic observations will further confirm more member galaxies and improve the accuracy of the halo mass estimation.

14 pages, 5 figures, 2 tables, accepted for publication in ApJ

References in corpus (22)

• Virial Scaling of Massive Dark Matter Halos: Why Clusters Prefer a High Normalization Cosmology
• 350 Micron Dust Emission from High Redshift Quasars
• Extreme gas kinematics in the z=2.2 powerful radio galaxy MRC1138-262: Evidence for efficient AGN feedback in the early Universe?
• CO excitation of normal star forming galaxies out to z=1.5 as regulated by the properties of their interstellar medium
• The relation between velocity dispersion and mass in simulated clusters of galaxies: dependence on the tracer and the baryonic physics
• Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant Universe
• The Spiderweb galaxy: a forming massive cluster galaxy at z~2
• ISM properties of a Massive Dusty Star-Forming Galaxy discovered at z ~ 7
• Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z~2-4 as probed by multi-J CO lines
• Cold Molecular Gas in Merger Remnants: I. Formation of Molecular Gas Disks
• Evolution of the Cool Gas in the Circumgalactic Medium (CGM) of Massive Halos -- A Keck Cosmic Web Imager (KCWI) Survey of Ly$\alpha$ Emission around QSOs at $z\approx 2$
• Inspiraling Halo Accretion Mapped in Lyman-$\alpha$ Emission around a $z\sim 3$ Quasar
• Molecular Gas in the Halo Fuels the Growth of a Massive Cluster Galaxy at High Redshift
• A Far-Infrared Spectroscopic Survey of Intermediate Redshift (Ultra) Luminous Infrared Galaxies
• VLA-ALMA Spectroscopic Survey in the Hubble Ultra Deep Field (VLASPECS): Total Cold Gas Masses and CO Line Ratios for z=2-3 "Main Sequence" Galaxies
• Confirming Herschel candidate protoclusters from ALMA/VLA CO observations
• CO Emission in Infrared-Selected Active Galactic Nuclei
• Mass and metallicity scaling relations of high redshift star-forming galaxies selected by GRBs
• The cold circumgalactic environment of MAMMOTH-I: dynamically cold gas in the core of an Enormous Ly-alpha Nebula
• Discovery of a Lya emitting dark-cloud within z ~ 2.8 SMMJ02399-0136 system
• CO luminosity - line width correlation of sub-millimeter galaxies and a possible cosmological application
• A search for dust and molecular gas in enormous Ly$\alpha$ nebulae at $z\approx 2$

Cited by in corpus (8)

• Inspiraling streams of enriched gas observed around a massive galaxy 11 billion years ago
• Molecular gas properties of Planck-selected protocluster candidates at z~1.3-3
• Starbursts with suppressed velocity dispersion revealed in a forming cluster at z=2.51
• The SUPERCOLD-CGM survey: \\ I. Probing the extended CO(4-3) Emission of the Circumglactic medium in a sample of 10 Enormous Ly$\alpha$ Nebulae at $z\sim 2$
• The Ly$\alpha$, CIV, and HeII nebulae around J1000+0234: a galaxy pair at the center of a galaxy overdensity at $z=4.5$
• JCMT/SCUBA-2 uncovers an excess of $850\mu$m counts on megaparsec scales around high-redshift quasars. Characterization of the overdensities and their alignment with the quasars' Ly$\alpha$ nebulae
• Probing the Mpc-scale environment of hyperluminous infrared galaxies at 2<z<4
• Direct high-resolution observation of feedback and chemical enrichment in the circumgalactic medium at redshift z ~ 2.8