  The radio galaxy NGC 1275, recently identified as a very high energy (VHE,
>100 GeV) gamma-ray emitter by MAGIC, is one of the few non-blazar AGN detected
in the VHE regime. In order to better understand the origin of the gamma-ray
emission and locate it within the galaxy, we studied contemporaneous
multi-frequency observations of NGC 1275 and modeled the overall spectral
energy distribution (SED). We analyzed unpublished MAGIC observations carried
out between Oct. 2009 and Feb. 2010, and the previously published ones taken
between Aug. 2010 and Feb. 2011. We studied the multi-band variability and
correlations by analyzing data of Fermi-LAT (0.1-100 GeV), as well as Chandra
(X-ray), KVA (optical) and MOJAVE (radio) data taken during the same period.
Using customized Monte Carlo simulations corresponding to early MAGIC stereo
data, we detect NGC 1275 also in the earlier campaign. The flux level and
energy spectra are similar to the results of the second campaign. The monthly
light curve >100 GeV shows a hint of variability at the 3.6 sigma level. In the
Fermi-LAT band, both flux and spectral shape variabilities are reported. The
optical light curve is variable and shows a clear correlation with the
gamma-ray flux >100 MeV. In radio, 3 compact components are resolved in the
innermost part of the jet. One of them shows a similar trend as the LAT and KVA
light curves. The 0.1-650 GeV spectra measured simultaneously with MAGIC and
Fermi-LAT can be well fitted either by a log-parabola or by a power-law with a
sub-exponential cutoff for both campaigns. A single-zone
synchrotron-self-Compton model, with an electron spectrum following a power-law
with an exponential cutoff, can explain the broadband SED and the multi-band
behavior of the source. However, this model suggests an untypical low
bulk-Lorentz factor or a velocity alignment closer to the line of sight than
the pc-scale radio jet.
