  We compare the star forming main sequence (SFMS) -- both integrated and
resolved on 1kpc scales -- between the high-resolution TNG50 simulation of
IllustrisTNG and observations from the 3D-HST slitless spectroscopic survey at
z~1. Contrasting integrated star formation rates (SFRs), we find that the slope
and normalization of the star-forming main sequence in TNG50 are quantitatively
consistent with values derived by fitting observations from 3D-HST with the
Prospector Bayesian inference framework. The previous offsets of 0.2-1dex
between observed and simulated main sequence normalizations are resolved when
using the updated masses and SFRs from Prospector. The scatter is generically
smaller in TNG50 than in 3D-HST for more massive galaxies with M_*>10^10Msun,
even after accounting for observational uncertainties. When comparing resolved
star formation, we also find good agreement between TNG50 and 3D-HST: average
specific star formation rate (sSFR) radial profiles of galaxies at all masses
and radii below, on, and above the SFMS are similar in both normalization and
shape. Most noteworthy, massive galaxies with M_*>10^10.5Msun, which have
fallen below the SFMS due to ongoing quenching, exhibit a clear central SFR
suppression, in both TNG50 and 3D-HST. In TNG this inside-out quenching is due
to the supermassive black hole (SMBH) feedback model operating at low accretion
rates. In contrast, the original Illustris simulation, without this same
physical SMBH mechanism, does not reproduce the central SFR profile suppression
seen in data. The observed sSFR profiles provide support for the TNG quenching
mechanism and how it affects gas on kiloparsec scales in the centers of
galaxies.
