Candidate cosmic filament in the GJ526 field, mapped with the NIKA2 camera

Abstract

Distinctive large-scale structures have been identified in the spatial distribution of optical galaxies up to redshift z ~ 1. In the more distant universe, the relationship between the dust-obscured population of star-forming galaxies observed at millimetre wavelengths and the network of cosmic filaments of dark matter apparent in all cosmological hydrodynamical simulations is still under study. Using the NIKA2 dual-band millimetre camera, we mapped a field of ~ 90 arcminutes^2 in the direction of the star GJ526 simultaneously in its 1.15-mm and 2.0-mm continuum wavebands to investigate the nature of the quasi-alignment of five sources found ten years earlier with the MAMBO camera at 1.2 mm. We find that these sources are not clumps of a circumstellar debris disc around this star as initially hypothesized. Rather, they must be dust-obscured star-forming galaxies, or sub-millimetre galaxies (SMGs), in the distant background. The new NIKA2 map at 1.15 mm reveals a total of seven SMGs distributed in projection on the sky along a filament-like structure crossing the whole observed field. Furthermore, we show that the NIKA2 and supplemental Herschel photometric data are compatible with a model of the spectral energy distributions (SEDs) of these sources when a common redshift of 2.5 and typical values of the dust parameters for SMGs are adopted. Hence, we speculate that these SMGs might be located in a filament of the distant `cosmic web'. The length of this candidate cosmic filament crossing the whole map is at least 4 cMpc (comoving), and the separations between sources are between 0.25 cMpc and 1.25 cMpc at this redshift, in line with expectations from cosmological simulations. Nonetheless, further observations to determine the precise spectroscopic redshifts of these sources are required to definitively support this hypothesis of SMGs embedded in a cosmic filament of dark matter.

Article accepted in Astronomy and Astrophysics ; 9 pages, 6 figures

References in corpus (18)

• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Simba: Cosmological Simulations with Black Hole Growth and Feedback
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: High resolution 870um source counts
• The Uchuu Simulations: Data Release 1 and Dark Matter Halo Concentrations
• Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant Universe
• Introducing the NewHorizon simulation: Galaxy properties with resolved internal dynamics across cosmic time
• AzTEC Millimetre Survey of the COSMOS Field: I. Data Reduction and Source Catalogue
• High-redshift star formation in the ALMA era
• Gas filaments of the cosmic web located around active galaxies in a proto-cluster
• The NIKA2 large field-of-view millimeter continuum camera for the 30-m IRAM telescope
• An ALMA/NOEMA survey of the molecular gas properties of high-redshift star-forming galaxies
• Three Lyman-alpha emitting filaments converging to a massive galaxy group at z=2.91: discussing the case for cold gas infall
• The MUSE Extremely Deep Field: the Cosmic Web in Emission at High Redshift
• Reproducing sub-millimetre galaxy number counts with cosmological hydrodynamic simulations
• The influence of wavelength, flux, and lensing selection effects on the redshift distribution of dusty, star-forming galaxies
• A Deep 1.2 mm Map of the Lockman Hole North Field
• Search for Cold Debris Disks around M-dwarfs
• Molecular gas budget and characterization of intermediate-mass star-forming galaxies at $z\approx 2-3$

Cited by in corpus (1)

• Overdense fireworks in GOODS-N: Unveiling a record number of massive dusty star forming galaxies at z$\sim$5.2 with the N2CLS