JWST Observations of Starbursts: Relations Between PAH Features and CO Clouds in the Starburst Galaxy M 82

We present a study of new 7.7-11.3 μm data obtained with the James Webb Space Telescope Mid-InfraRed Instrument in the starburst galaxy M 82.
In particular, we focus on the dependency of the integrated CO(1-0) line intensity on the MIRI-F770W and MIRI-F1130W filter intensities to investigate the correlation between CO content and the 7.7 and 11.3 μm features from polycyclic aromatic hydrocarbons (PAH) in M 82’s outflows.
To perform our analysis, we identify CO clouds using archival 12CO(J=1-0) NOEMA moment 0 map within 2 kpc from the center of M 82, with sizes ranging between ∼21 and 270 pc; then, we compute the CO-to-PAH relations for the 306 validated CO clouds. On average, the power-law slopes for the two relations in M 82 are lower than what is seen in local main-sequence spirals.
In addition, there is a moderate correlation between ICO(1−0)-I7.7μm/I11.3μm for most of the CO cloud groups analyzed in this this http URL results suggest that the extreme conditions in M 82 translate into CO not tracing the full budget of molecular gas in smaller clouds, perhaps as a consequence of photoionization and/or emission suppression of CO molecules due to hard radiation fields from the central starburst.
V. Villanueva, A. D. Bolatto, R. Herrera-Camus, A. Leroy, D. B. Fisher, R. C. Levy, T. Böker, L. Boogaard, S. A. Cronin, D. A. Dale, K. Emig, I. De Looze, G. P. Donnelly, T. S.-Y. Lai, L. Lenkic, S. Lopez, D. S. Meier, J. Ott, M. Relano, J. D. Smith, E. Tarantino, S. Veilleux, P. van der Werf
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2501.14893 [astro-ph.GA] (or arXiv:2501.14893v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2501.14893
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Submission history
From: Vicente Villanueva
[v1] Fri, 24 Jan 2025 19:33:31 UTC (5,437 KB)
https://arxiv.org/abs/2501.14893
Astrobiology,