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Spatially-resolved interstellar dust properties in the face-on spiral galaxy M 99 as observed by NIKA2

Fuente: arXiv

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Detalles Bibliográficos
Autores principales:	Pantoni, L., Galliano, F., Madden, S. C., Adam, R., Ade, P., Ajeddig, H., André, P., Artis, E., Aussel, H., Baes, M., Beelen, A., Benoît, A., Berta, S., Bing, L., Bourrion, O., Calvo, M., Casasola, V., Catalano, A., Chang, I-D., De Looze, I., De Petris, M., Désert, F. -X., Doyle, S., Driessen, E. F. C., Ejlali, G., Gomez, A., Goupy, J., Jones, A. P., Hanser, C., Hughes, A., Katsioli, S., Kéruzoré, F., Koch, E. W., Kramer, C., Ladjelate, B., Lagache, G., Leclercq, S., Lestrade, J. -F., Macías-Pérez, J. F., Maury, A., Mauskopf, P., Mayet, F., Monfardini, A., Moyer-Anin, A., Muñoz-Echeverría, M., Nersesian, A., Paradis, D., Perotto, L., Pisano, G., Ponthieu, N., Revéret, V., Rigby, A. J., Ritacco, A., Romero, C., Roussel, H., Ruppin, F., Schuster, K., Sievers, A., Smith, M. W. L., Tabatabaei, F. S., Tedros, J., Tucker, C., Ysard, N., Xilouris, E. M., Zylka, R.
Formato:	Preprint
Publicado:	2026
Materias:	Astrophysics of Galaxies
Acceso en línea:	Acceder al recurso
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

_version_	1866910191364079616
author	Pantoni, L. Galliano, F. Madden, S. C. Adam, R. Ade, P. Ajeddig, H. André, P. Artis, E. Aussel, H. Baes, M. Beelen, A. Benoît, A. Berta, S. Bing, L. Bourrion, O. Calvo, M. Casasola, V. Catalano, A. Chang, I-D. De Looze, I. De Petris, M. Désert, F. -X. Doyle, S. Driessen, E. F. C. Ejlali, G. Gomez, A. Goupy, J. Jones, A. P. Hanser, C. Hughes, A. Katsioli, S. Kéruzoré, F. Koch, E. W. Kramer, C. Ladjelate, B. Lagache, G. Leclercq, S. Lestrade, J. -F. Macías-Pérez, J. F. Maury, A. Mauskopf, P. Mayet, F. Monfardini, A. Moyer-Anin, A. Muñoz-Echeverría, M. Nersesian, A. Paradis, D. Perotto, L. Pisano, G. Ponthieu, N. Revéret, V. Rigby, A. J. Ritacco, A. Romero, C. Roussel, H. Ruppin, F. Schuster, K. Sievers, A. Smith, M. W. L. Tabatabaei, F. S. Tedros, J. Tucker, C. Ysard, N. Xilouris, E. M. Zylka, R.
author_facet	Pantoni, L. Galliano, F. Madden, S. C. Adam, R. Ade, P. Ajeddig, H. André, P. Artis, E. Aussel, H. Baes, M. Beelen, A. Benoît, A. Berta, S. Bing, L. Bourrion, O. Calvo, M. Casasola, V. Catalano, A. Chang, I-D. De Looze, I. De Petris, M. Désert, F. -X. Doyle, S. Driessen, E. F. C. Ejlali, G. Gomez, A. Goupy, J. Jones, A. P. Hanser, C. Hughes, A. Katsioli, S. Kéruzoré, F. Koch, E. W. Kramer, C. Ladjelate, B. Lagache, G. Leclercq, S. Lestrade, J. -F. Macías-Pérez, J. F. Maury, A. Mauskopf, P. Mayet, F. Monfardini, A. Moyer-Anin, A. Muñoz-Echeverría, M. Nersesian, A. Paradis, D. Perotto, L. Pisano, G. Ponthieu, N. Revéret, V. Rigby, A. J. Ritacco, A. Romero, C. Roussel, H. Ruppin, F. Schuster, K. Sievers, A. Smith, M. W. L. Tabatabaei, F. S. Tedros, J. Tucker, C. Ysard, N. Xilouris, E. M. Zylka, R.
contents	Large dust grains in thermal equilibrium dominate the far-infrared and contribute to the millimetre continuum of star-forming galaxies, but constraining their properties is difficult due to free-free and synchrotron contamination. We study spatial variations in the dust spectral index, mass, and grain properties in the nearby face-on spiral galaxy M 99. We use new 1.15 and 2 mm continuum observations from NIKA2 on the IRAM 30 m telescope (IMEGIN Guaranteed Time Large Programme) combined with multiwavelength data from UV to radio. The infrared-to-radio SED is decomposed into dust, free-free, and synchrotron components using the hierarchical Bayesian code HerBIE. Dust is modelled via a modified blackbody (MBB) with variable millimetre spectral index beta and the THEMIS dust model with fixed beta. We perform spatially-resolved analysis at scales ~1.75 kpc (~25''), covering the centre, spiral arms, and inter-arm regions. MBB fits reveal beta variations from ~1.6-1.7 in diffuse regions to ~2.3-2.5 in dense star-forming areas, likely due to grain coagulation and changes in silicate-to-carbonaceous ratios. Dust masses from variable beta are up to ~4x higher than fixed-beta models, which systematically bias dust-to-stellar and dust-to-gas ratios. The small grain fraction rises from ~10% in the centre to ~15% in the diffuse disc, anti-correlated with the interstellar radiation field; gas-phase metallicity plays a minor role within 8 kpc. Synchrotron spectral index ranges from ~0.6-0.7 in star-forming regions to ~1.2 in the diffuse medium, consistent with cosmic-ray electron ageing.
format	Preprint
id	arxiv_https___arxiv_org_abs_2602_20393
institution	arXiv
publishDate	2026
record_format	arxiv
spellingShingle	Spatially-resolved interstellar dust properties in the face-on spiral galaxy M 99 as observed by NIKA2 Pantoni, L. Galliano, F. Madden, S. C. Adam, R. Ade, P. Ajeddig, H. André, P. Artis, E. Aussel, H. Baes, M. Beelen, A. Benoît, A. Berta, S. Bing, L. Bourrion, O. Calvo, M. Casasola, V. Catalano, A. Chang, I-D. De Looze, I. De Petris, M. Désert, F. -X. Doyle, S. Driessen, E. F. C. Ejlali, G. Gomez, A. Goupy, J. Jones, A. P. Hanser, C. Hughes, A. Katsioli, S. Kéruzoré, F. Koch, E. W. Kramer, C. Ladjelate, B. Lagache, G. Leclercq, S. Lestrade, J. -F. Macías-Pérez, J. F. Maury, A. Mauskopf, P. Mayet, F. Monfardini, A. Moyer-Anin, A. Muñoz-Echeverría, M. Nersesian, A. Paradis, D. Perotto, L. Pisano, G. Ponthieu, N. Revéret, V. Rigby, A. J. Ritacco, A. Romero, C. Roussel, H. Ruppin, F. Schuster, K. Sievers, A. Smith, M. W. L. Tabatabaei, F. S. Tedros, J. Tucker, C. Ysard, N. Xilouris, E. M. Zylka, R. Astrophysics of Galaxies Large dust grains in thermal equilibrium dominate the far-infrared and contribute to the millimetre continuum of star-forming galaxies, but constraining their properties is difficult due to free-free and synchrotron contamination. We study spatial variations in the dust spectral index, mass, and grain properties in the nearby face-on spiral galaxy M 99. We use new 1.15 and 2 mm continuum observations from NIKA2 on the IRAM 30 m telescope (IMEGIN Guaranteed Time Large Programme) combined with multiwavelength data from UV to radio. The infrared-to-radio SED is decomposed into dust, free-free, and synchrotron components using the hierarchical Bayesian code HerBIE. Dust is modelled via a modified blackbody (MBB) with variable millimetre spectral index beta and the THEMIS dust model with fixed beta. We perform spatially-resolved analysis at scales ~1.75 kpc (~25''), covering the centre, spiral arms, and inter-arm regions. MBB fits reveal beta variations from ~1.6-1.7 in diffuse regions to ~2.3-2.5 in dense star-forming areas, likely due to grain coagulation and changes in silicate-to-carbonaceous ratios. Dust masses from variable beta are up to ~4x higher than fixed-beta models, which systematically bias dust-to-stellar and dust-to-gas ratios. The small grain fraction rises from ~10% in the centre to ~15% in the diffuse disc, anti-correlated with the interstellar radiation field; gas-phase metallicity plays a minor role within 8 kpc. Synchrotron spectral index ranges from ~0.6-0.7 in star-forming regions to ~1.2 in the diffuse medium, consistent with cosmic-ray electron ageing.
title	Spatially-resolved interstellar dust properties in the face-on spiral galaxy M 99 as observed by NIKA2
topic	Astrophysics of Galaxies
url	https://arxiv.org/abs/2602.20393