Continuum, CO, and water vapour maps of the Orion Nebula

Year: 2025

Type: article

Abstract: Context. The millimetre spectrum of Galactic regions and galaxies is rich in continuum and molecular lines. This diversity is mostly explored using either broad-band photometry or high-resolution heterodyne spectroscopy. Aims. We aim to map the millimetre continuum emission of Galactic regions with an intermediate spectral resolution between broadband photometry and heterodyne spectroscopy, enabling us to rapidly cover large sky areas with spectroscopy. Methods. We report observations of the Orion Nebula with the CONCERTO instrument, which was installed at the APEX telescope focal plane from 2021 to 2023. Results. We find that the spectrum of Orion is dominated by dust emission with an emissivity index ranging between 1.3 and 2.0, along with strong CO(2-1) and H2O lines, which are naturally separated from the continuum due to the CONCERTO spectral capabilities. Many regions also show strong free-free emission at lower frequencies. Conclusions. We demonstrate the spectral capabilities of CONCERTO at intermediate spectral resolution, with a frequency coverage from 130 to 310 GHz. A sensitivity of 200 mK is achieved in one second, for one beam and a 6 GHz frequency width, over an 18 arcmin diameter field of view, which is within a factor of three of the expectations. We show that we can spectrally disentangle the continuum from the CO line emission, but the line is not resolved at a resolution of ~8000 km s–1. The slope of the millimetre continuum is line-free mapped for the first time in Orion.

Source: Astronomy and Astrophysics

DOI: 10.1051/0004-6361/202555320

Institutions: Institut de Planétologie et d'Astrophysique de Grenoble, Laboratoire de Physique Subatomique et de Cosmologie, Laboratoire d’Astrophysique de Marseille, Institut Néel, Observatoire astronomique de Strasbourg, European Southern Observatory, Instituto de Radioastronomía Milimétrica, University of Valparaíso, Cardiff University, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA Paris-Saclay - Etablissement de Saclay, Astrophysique, Instrumentation et Modélisation, CEA Paris-Saclay, Institut de Radioastronomie Millimétrique, Institute for Research in Fundamental Sciences, Centro de Astrobiología, National Observatory of Athens, Argonne National Laboratory, Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, Université de Cergy-Pontoise, Institute of Space Sciences, Institut de Recherche en Astrophysique et Planétologie, University of Leeds, Institut d'Astrophysique de Paris, Institut de Physique des 2 Infinis de Lyon

Language: English

Topic: Astrophysics and Star Formation Studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,865

Funders: Arizona State University, Aix-Marseille Université, Agenția Națională pentru Cercetare și Dezvoltare, European Commission, Agence Nationale de la Recherche, Agencia Nacional de Investigación y Desarrollo, CHIST-ERA

Awards: THE INTERSTELLAR PHYSICS OF NORMAL GALAXIES AS REVEALED BY ALMA, UNVEILING THE NATURE OF THE FIRST GALAXIES AT THE END OF COSMIC REIONIZATION, G2121614283, EXPLOITING CONCERTO FOR COSMOLOGICAL EXPERIMENTS, G292453335, Des détecteurs pour Observer l'Univers, G434337789, MILLENIUM NUCLEUS FOR GALAXIES, G5631513353, G5850839165, G6122222817, Observing the millimeter sky with the NIKA2 camera, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA), G8964069747, G994248709

OpenAlex ID: W4413305290