The first map of the Milky Way from infrared images obtained by the European project Hi-GAL
An unprecedented view of our galaxy and its adjacent regions was obtained from the Hi-GAL project coordinated by the National Institute for Astrophysics, which has obtained the first map of the Milky Way in infrared using the observations of the Herschel Space Telescope of the European Space Agency (ESA). The study has also allowed understanding the mechanisms of star formation.
Stars in different stages of their evolution and pre-stellar clumps, on the verge of becoming new stars. These are some of the details released by the first map of our galaxy in the infrared spectrum obtained from the observations of the Herschel space telescope of the European Space Agency (ESA). This important result was achieved by the international Herschel infrared Galactic Plane Survey (Hi-GAL) research project coordinated by the Italian National Institute for Astrophysics (INAF), which has released the new map in an article published in the journal Astronomy & Astrophysics.
Hi-GAL is one of the largest observing programmes carried out with the Herschel space telescope and involved researchers from four continents, who used a special technique to extract individual sources from the maps. This allowed the collection of position, flux, size and other parameters related to hundreds of thousands of objects in the five wavelengths at which the sky was scanned with the Herschel instruments.
“The most fascinating scientific study that can be carried out with the myriad of data provided by Hi-GAL is definitely linked to the understanding of the mechanisms of star formation in our Galaxy ”, said Sergio Molinari from the Institute for Space Astrophysics and Planetology in Rome (INAF-IAPS), Principal Investigator for the Hi-GAL project. “In fact, while ground-based telescopes, which observe in the visible light, can detect new stars only when they emerge for the first time from the dense clouds of gas and dust that generated them, the instruments on board the Herschel mission, observing the light of the far-infrared from space, could look inside these dust clouds and follow the entire phase of star formation, from the early stages of the thickening of the diffused material to fully-fledged stars”.
The Hi-GAL project used data collected by the Herschel telescope during more than 900 hours of observations, equivalent to almost 40 days, covering an area of about 800 square degrees, about 2% of the entire sky. The first 70 maps released, each provided in each of the five surveyed wavelengths, cover the inner part of the Milky Way towards the Galactic Centre, with galactic longitudes between +68° and -70°.
“This new mapping, based on the interpretation of the data produced by the Herschel satellite, is a step forward in the understanding of the mechanisms of star formation”, said Barbara Negri, responsible for Universe Exploration and Observation of the Italian Space Agency (ASI). “This result is further confirmation of the excellent scientific performance of the Herschel satellite, which has provided us with a considerable amount of data to process”.