We exploit moderately resolved [O III ], [C II ] and dust continuum ALMA observations to derive the gas density (n), the gas-phase metallicity (Z) and the deviation from the Kennicutt-Schmidt (KS) relation (κs) on ≈sub−kpc scales in the interstellar medium (ISM) of five bright Lyman Break Galaxies at the Epoch of Reionization (z ≈ 7). To do so, we use GLAM, a state-of-art, physically motivated Bayesian model that links the [C II ]and [O III ]surface brightness (Σ[CII], Σ[OIII]) and the SFR surface density (ΣSFR) to n, κs, and Z. All five sources are characterized by a central starbursting region, where the Σgas vs ΣSFR align ≈10 × above the KS relation (κs ≈ 10). This translates into gas depletion times in the range tdep ≈ 80 − 250 Myr. The inner starbursting centers are characterized by higher gas density (log (n/cm−3) ≈ 2.5 − 3.0) and higher metallicity (log (Z/Z⊙) ≈ −0.5) than the galaxy outskirts. We derive marginally negative radial metallicity gradients (∇log Z ≈ −0.03 ± 0.07 dex/kpc), and a dust temperature (Td ≈ 32 − 38 K) that anticorrelates with the gas depletion time.

Spatially resolved Kennicutt-Schmidt relation at z ≈ 7 and its connection with the interstellar medium properties

Vallini, Livia
;
Sommovigo, Laura;Pallottini, Andrea;Ferrara, Andrea;Carniani, Stefano;Kohandel, Mahsa;Gallerani, Simona;
2023

Abstract

We exploit moderately resolved [O III ], [C II ] and dust continuum ALMA observations to derive the gas density (n), the gas-phase metallicity (Z) and the deviation from the Kennicutt-Schmidt (KS) relation (κs) on ≈sub−kpc scales in the interstellar medium (ISM) of five bright Lyman Break Galaxies at the Epoch of Reionization (z ≈ 7). To do so, we use GLAM, a state-of-art, physically motivated Bayesian model that links the [C II ]and [O III ]surface brightness (Σ[CII], Σ[OIII]) and the SFR surface density (ΣSFR) to n, κs, and Z. All five sources are characterized by a central starbursting region, where the Σgas vs ΣSFR align ≈10 × above the KS relation (κs ≈ 10). This translates into gas depletion times in the range tdep ≈ 80 − 250 Myr. The inner starbursting centers are characterized by higher gas density (log (n/cm−3) ≈ 2.5 − 3.0) and higher metallicity (log (Z/Z⊙) ≈ −0.5) than the galaxy outskirts. We derive marginally negative radial metallicity gradients (∇log Z ≈ −0.03 ± 0.07 dex/kpc), and a dust temperature (Td ≈ 32 − 38 K) that anticorrelates with the gas depletion time.
2023
Settore FIS/05 - Astronomia e Astrofisica
galaxies: high-redshift; galaxies: ISM;0 galaxies: evolution, dark ages; reionization; first stars
   The Interstellar Medium of High Redshift Galaxies
   INTERSTELLAR
   European Commission
   740120

   Star formation quenching and feedback in galaxies throughout the cosmic epochs
   QUENCH
   European Commission
   695671

   RISEandFALL - The rise and fall of galaxies in the early Universe
   UK Research and Innovation
   UKRI
   EP/X038262/1

   Winds in galaxies
   WINGS
   European Commission
   101040227

   Dissecting galaxies at the cosmic dawn
   UK Research and Innovation
   STFC
   ST/S004831/1
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/135222
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