  We present high resolution large scale observations of the molecular and
atomic gas in the Local Group Galaxy M33. The observations were carried out
using the HERA at the 30m IRAM telescope in the CO(2-1) line achieving a
resolution of 12"x2.6 km/s, enabling individual GMCs to be resolved. The
observed region mainly along the major axis out to a radius of 8.5 kpc, and
covers the strip observed with HIFI/PACS Spectrometers as part of the HERM33ES
Herschel key program. The achieved sensitivity in main beam temperature is
20-50 mK at 2.6 km/s velocity resolution. The CO(2-1) luminosity of the
observed region is 1.7\pm0.1x10^7 Kkm/s pc^2, corresponding to H2 masses of
1.9x10^8 Msun (including He), calculated with a NH2/ICO twice the Galactic
value due to the half-solar metallicity of M33. HI 21 cm VLA archive
observations were reduced and the mosaic was imaged and cleaned using the
multi-scale task in CASA, yielding a series of datacubes with resolutions
ranging from 5" to 25". The HI mass within a radius of 8.5 kpc is estimated to
be 1.4x10^9 Msun. The azimuthally averaged CO surface brightness decreases
exponentially with a scale length of 1.9\pm0.1 kpc whereas the atomic gas
surface density is constant at Sigma_HI=6\pm2 Msun/pc^2 deprojected to face-on.
The central kiloparsec H_2 surface density is Sigma_H2=8.5\pm0.2 Msun/pc^2. The
star formation rate per unit molecular gas (SF Efficiency, the rate of
transformation of molecular gas into stars), as traced by the ratio of CO to
Halpha and FIR brightness, is constant with radius. The SFE appears 2-4 times
greater than of large spiral galaxies. A morphological comparison of molecular
and atomic gas with tracers of star formation shows good agreement between
these maps both in terms of peaks and holes. A few exceptions are noted.
Several spectra, including those of a molecular cloud situated more than 8 kpc
from the galaxy center, are presented.
