Hyper: Hybrid Photometry and Extraction Routine
  We present a new Hybrid Photometry and Extraction Routine: Hyper. It is
designed to do compact source photometry allowing for varying spatial
resolution and sensitivity in multi-wavelength surveys. Hyper combines
multi-Gaussian fitting with aperture photometry to provide reliable photometry
in regions with variable backgrounds and in crowded fields. The background is
evaluated and removed locally for each source using polynomial fits of various
orders. Source de-blending is done through simultaneous multi-Gaussian fitting
of the main source and its companion(s), followed by the subtraction of the
companion(s). Hyper allows also simultaneous multi-wavelength photometry by
setting a fixed aperture size independent of the map resolution and evaluating
the source flux within the same region of the sky at multiple wavelengths at
the same time. This new code has been initially designed for precise aperture
photometry in complex fields such as the Galactic plane observed in the far
infrared (FIR) by the Herschel infrared survey of the Galactic plane (Hi-GAL).
Hyper has been tested on both simulated and real Herschel fields to quantify
the quality of the source identification and photometry. The code is highly
modular and fully parameterisable, therefore it can be easily adapted to
different experiments. Comparison of the Hyper photometry with the catalogued
sources in the Bolocam Galactic Plane survey (BGPS), the 1.1 mm survey of the
Galactic Plane carried out with the Caltech Sub-millimeter observatory,
demonstrates the versatility of Hyper on different datasets. It is fast and
light in its memory usage, and it is freely available to the scientific
community.
