The data reduction pipeline for the Hi-GAL survey

TL;DR

This paper details the development of a specialized data reduction pipeline for the Hi-GAL survey, enabling efficient processing of Herschel satellite data across multiple infrared bands of the Galactic plane.

Contribution

The paper introduces a novel data reduction pipeline with new routines and the ROMAGAL algorithm for improved map-making in the Hi-GAL survey.

Findings

Effective data culling and noise estimation methods

Implementation of the ROMAGAL map-making algorithm

Successful processing of the Hi-GAL Science Demonstration Phase data

Abstract

We present the data reduction pipeline for the Hi-GAL survey. Hi-GAL is a key project of the Herschel satellite which is mapping the inner part of the Galactic plane (|l| <= 70\cdot and |b| <= 1\cdot), using 2 PACS and 3 SPIRE frequency bands, from 70{\mu}m to 500{\mu}m. Our pipeline relies only partially on the Herschel Interactive Standard Environment (HIPE) and features several newly developed routines to perform data reduction, including accurate data culling, noise estimation and minimum variance map-making, the latter performed with the ROMAGAL algorithm, a deep modification of the ROMA code already tested on cosmological surveys. We discuss in depth the properties of the Hi-GAL Science Demonstration Phase (SDP) data.