  The pressure of hot gas in groups and clusters of galaxies is a key physical
quantity, which is directly linked to the total mass of the halo and several
other thermodynamical properties. In the wake of previous observational works
on the hot gas pressure distribution in massive halos, we have investigated a
sample of 31 clusters detected in both the Planck and Atacama Cosmology
Telescope (ACT), MBAC surveys. We made use of an optimised Sunyaev-Zeldovich
(SZ) map reconstructed from the two data sets and tailored for the detection of
the SZ effect, taking advantage of both Planck coverage of large scales and the
ACT higher spatial resolution. Our average pressure profile covers a radial
range going from 0.04xR_500 in the central parts to 2.5xR_500 in the outskirts.
In this way, it improves upon previous pressure-profile reconstruction based on
SZ measurements. It is compatible, as well as competitive, with constraints
derived from joint X-ray and SZ analysis. This work demonstrates the
possibilities offered by large sky surveys of the SZ effect with multiple
experiments with different spatial resolutions and spectral coverages, such as
ACT and Planck.
