On the Transition of the Galaxy Quenching Mode at 0.5<z<1 in CANDELS
  We investigate the galaxy quenching process at intermediate redshift using a
sample of $\sim4400$ galaxies with $M_{\ast} > 10^{9}M_{\odot}$ between
redshift 0.5 and 1.0 in all five CANDELS fields. We divide this sample, using
the integrated specific star formation rate (sSFR), into four sub-groups:
star-forming galaxies (SFGs) above and below the ridge of the star-forming main
sequence (SFMS), transition galaxies and quiescent galaxies. We study their
$UVI$ ($U-V$ versus $V-I$) color gradients to infer their sSFR gradients out to
twice effective radii. We show that on average both star-forming and transition
galaxies at all masses are not fully quenched at any radii, whereas quiescent
galaxies are fully quenched at all radii. We find that at low masses ($M_{\ast}
= 10^{9}-10^{10}M_{\odot}$) SFGs both above and below the SFMS ridge generally
have flat sSFR profiles, whereas the transition galaxies at the same masses
generally have sSFRs that are more suppressed in their outskirts. In contrast,
at high masses ($M_{\ast} > 10^{10.5}M_{\odot}$), SFGs above and below the SFMS
ridge and transition galaxies generally have varying degrees of more
centrally-suppressed sSFRs relative to their outskirts. These findings indicate
that at $z\sim~0.5-1.0$ the main galaxy quenching mode depends on its already
formed stellar mass, exhibiting a transition from "the outside-in" at $M_{\ast}
\leq 10^{10}M_{\odot}$ to "the inside-out" at $M_{\ast} > 10^{10.5}M_{\odot}$.
In other words, our findings support that internal processes dominate the
quenching of massive galaxies, whereas external processes dominate the
quenching of low-mass galaxies.
