Evolution of spatially resolved star formation main sequence and surface density profiles in massive disc galaxies at $0\lesssim z \lesssim 1$: inside-out stellar mass buildup and quenching [GA]


We investigate a relation between surface densities (at a $\sim 1$kpc scale) of star formation rate (SFR) and stellar mass ($M_{}$) namely spatially resolved star formation main sequence (SFMS) at $z\sim 0$ and $z\sim 1$ of massive ($\log(M_{}/M_{\odot})>10.5$) face-on disc galaxies and examine the evolution of the relation with cosmic time. The spatially resolved SFMS of $z\sim 0$ galaxies is discussed in a companion paper. For $z\sim 1$ sample, we use 8 bands imaging dataset from CANDELS and 3D-HST which provides a rest-frame FUV-NIR SED for galaxies at $0.8\lesssim z \lesssim 1.8$. We perform a pixel-to-pixel SED fitting to derive the spatially resolved SFR and $M_{}$ distributions in a galaxy. We find a linear spatially resolved SFMS in the $z\sim 1$ galaxies that lie within $\pm 0.3$ dex from the global SFMS, while a “flattening” at high $\Sigma_{}$ end is found in the spatially resolved SFMS of the galaxies that lie below $-0.3$ dex from the global SFMS. The “flattening” trend is consistent with a decline of the sSFR radial profile (sSFR$(r)$) in the central region of the corresponding galaxies. Comparison with the spatially resolved SFMS in the $z\sim 0$ galaxies shows smaller difference in the sSFR at low $\Sigma_{}$ ($\sim 0.4$ dex at $\log(\Sigma_{}[M_{\odot} \text{kpc}^{-2}])=7.0$) than that at high $\Sigma_{}$ ($\sim 1.5$ dex at $\log(\Sigma_{}[M_{\odot} \text{kpc}^{-2}])=8.5$). This trend is consistent with the evolution of the sSFR$(r)$ radial profile, which shows a faster decrease in the central region than in the outskirt, agrees with the inside-out quenching scenario. We then derive an empirical model for the evolution of the $\Sigma_{*}(r)$, $\Sigma_{\rm SFR}(r)$ and sSFR$(r)$ radial profiles. Based on the empirical model, we estimate the radial profile of the quenching timescale and reproduce the observed spatially resolved SFMS at $z\sim 1$ and $z\sim 0$.

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Abdurro%27uf. and M. Akiyama
Tue, 13 Feb 18

Comments: 17 pages, 16 figures, submitted to MNRAS