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
   Horizon 2020 Framework Programme
   740120

   Star formation quenching and feedback in galaxies throughout the cosmic epochs
   QUENCH
   European Commission
   Horizon 2020 Framework Programme
   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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