Spatially resolved spectrophotometric SED modeling of NGC 253's central molecular zone: I. Star formation in extragalactic giant molecular clouds
Artikel i vetenskaplig tidskrift, 2025
Context. Studying the interstellar medium in nearby starbursts is essential for gaining insights into the physical mechanisms driving these extreme objects, which are thought to be analogs of young, primeval, star-forming galaxies. This task is now feasible due to deep spectro-photometric data enabled by rapid advancements in ground- and space-based facilities. To fully leverage this wealth of information, extracting insights from the spectral line properties and the spectral energy distribution (SED) is imperative.
Aims. This study aims to produce and analyze the physical properties of the first spatially resolved multiwavelength SED of an extragalactic source that covers six decades in frequency (from near-ultraviolet, NUV, to centimeter, cm, wavelengths) at an angular resolution of 3 '', which corresponds to a linear scale of similar to 51 pc at the distance of NGC 253. We focus on the central molecular zone (CMZ) of this starburst galaxy, which contains giant molecular clouds (GMCs) responsible for half of the galaxy's star formation.
Methods. We retrieved archival data from near-UV to centimeter wavelengths, covering six decades of spectral range. We computed the SEDs to fit the observations, using the GalaPy code and confronting the results with the CIGALE code for validation. We also employed the STARLIGHT code to analyze the stellar optical spectra of the GMCs.
Results. Our results reveal significant differences between internal and external GMCs in terms of stellar and dust masses, star formation rates (SFRs), and bolometric luminosities, among others, with internal GMCs doubling maximum values of the external ones in most of the cases. We obtained tight relations between monochromatic stellar tracers and star-forming conditions obtained from panchromatic emission. We find that the best SFR tracers are radio continuum bands at 33 GHz, radio recombination lines (RRLs), and the total infrared (IR) luminosity range (L-IR; 8-1000 mu m) as well as the IR emission at 60 mu m. The emission line diagnostics based on the BPT and WHAN diagrams suggest that the nuclear region of NGC 253 exhibits shock signatures, placing it in the composite zone typically associated with hybrids of active galactic nucleus (AGN) hosting and star-forming regions, while the AGN fraction from panchromatic emission is negligible (<= 7.5%).
Conclusions. Our findings demonstrate the significant heterogeneity within the CMZ of NGC 253, with central GMCs exhibiting high densities, elevated SFRs, and greater dust masses compared to their external counterparts. We confirm the effectiveness of certain centimeter photometric bands as a reliable method to estimate the global SFR, in accordance with previous studies - this time on GMC scales.
Aims. This study aims to produce and analyze the physical properties of the first spatially resolved multiwavelength SED of an extragalactic source that covers six decades in frequency (from near-ultraviolet, NUV, to centimeter, cm, wavelengths) at an angular resolution of 3 '', which corresponds to a linear scale of similar to 51 pc at the distance of NGC 253. We focus on the central molecular zone (CMZ) of this starburst galaxy, which contains giant molecular clouds (GMCs) responsible for half of the galaxy's star formation.
Methods. We retrieved archival data from near-UV to centimeter wavelengths, covering six decades of spectral range. We computed the SEDs to fit the observations, using the GalaPy code and confronting the results with the CIGALE code for validation. We also employed the STARLIGHT code to analyze the stellar optical spectra of the GMCs.
Results. Our results reveal significant differences between internal and external GMCs in terms of stellar and dust masses, star formation rates (SFRs), and bolometric luminosities, among others, with internal GMCs doubling maximum values of the external ones in most of the cases. We obtained tight relations between monochromatic stellar tracers and star-forming conditions obtained from panchromatic emission. We find that the best SFR tracers are radio continuum bands at 33 GHz, radio recombination lines (RRLs), and the total infrared (IR) luminosity range (L-IR; 8-1000 mu m) as well as the IR emission at 60 mu m. The emission line diagnostics based on the BPT and WHAN diagrams suggest that the nuclear region of NGC 253 exhibits shock signatures, placing it in the composite zone typically associated with hybrids of active galactic nucleus (AGN) hosting and star-forming regions, while the AGN fraction from panchromatic emission is negligible (<= 7.5%).
Conclusions. Our findings demonstrate the significant heterogeneity within the CMZ of NGC 253, with central GMCs exhibiting high densities, elevated SFRs, and greater dust masses compared to their external counterparts. We confirm the effectiveness of certain centimeter photometric bands as a reliable method to estimate the global SFR, in accordance with previous studies - this time on GMC scales.
galaxies: individual: NGC 253
galaxies: star formation
evolution
galaxies: starburst
stars: formation
Författare
Pedro K. Humire
Universidade de Sao Paulo (USP)
Subhrata Dey
Uniwersytet Jagiellonski w Krakowie
Narodowe Centrum Badań Jądrowych
Tommaso Ronconi
SISSA Scuola Internazionale Superiore di Studi Avanzati
Istituto nazionale di astrofisica (INAF)
Fondazione ICSC Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing
IFPU—Institute for Fundamental Physics of the Universe
Victor H. Sasse
Universidade Federal de Santa Catarina
Roberto Cid Fernandes
Universidade Federal de Santa Catarina
Sergio Martin
European Southern Observatory Santiago
Atacama Large Millimeter-submillimeter Array (ALMA)
Darko Donevski
SISSA Scuola Internazionale Superiore di Studi Avanzati
Narodowe Centrum Badań Jądrowych
Katarzyna Malek
Narodowe Centrum Badań Jądrowych
Juan A. Fernandez-Ontiveros
Centro de Estudios de Física del Cosmos de Aragón (CEFCA)
Yiqing Song
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
Mahmoud Hamed
Narodowe Centrum Badań Jądrowych
Consejo Superior de Investigaciones Científicas (CSIC)
Jeffrey G. Mangum
National Radio Astronomy Observatory
Christian Henkel
Chinese Academy of Sciences
Max-Planck-Gesellschaft
Victor M. Rivilla
Consejo Superior de Investigaciones Científicas (CSIC)
Laura Colzi
Consejo Superior de Investigaciones Científicas (CSIC)
Nanase Harada
The Graduate University for Advanced Studies (SOKENDAI)
Academia Sinica
National Astronomical Observatory of Japan
Ricardo Demarco
Universidad Andrés Bello
Arti Goyal
Uniwersytet Jagiellonski w Krakowie
David S. Meier
New Mexico Institute of Mining and Technology
Swayamtrupta Panda
NSF's National Optical-Infrared Astronomy Research Laboratory (NOIRLab)
angela C. Krabbe
Universidade de Sao Paulo (USP)
Yaoting Yan
Max-Planck-Gesellschaft
Amanda R. Lopes
Universidad Nacional de La Plata
Kazushi Sakamoto
Academia Sinica
Sebastien Muller
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Kunihiko Tanaka
Keio University
Yuki Yoshimura
University of Tokyo
Kouichiro Nakanishi
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Antonio Kanaan
Universidade Federal de Santa Catarina
Tiago Ribeiro
National Optical Astronomy Observatory
William Schoenell
GMTO Corporation
Claudia Mendes de Oliveira
Universidade de Sao Paulo (USP)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 699 A183Ämneskategorier (SSIF 2025)
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202553897