JWST Observations of Starbursts: Relations between PAH features and CO clouds in the starburst galaxy M 82

Abstract

We present a study of new 7.7-11.3 $\mu$m 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 $\mu$m features from polycyclic aromatic hydrocarbons (PAH) in M 82's outflows. To perform our analysis, we identify CO clouds using archival ${}^{12}$CO($J$=1-0) NOEMA moment 0 map within 2 kpc from the center of M 82, with sizes ranging between $\sim$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 $I_{\mathrm{CO}(1-0)}$-$I_{7.7\mu \mathrm{m}}/I_{11.3\mu \mathrm{m}}$ for most of the CO cloud groups analyzed in this work. Our 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.

References in corpus (29)

• Array Programming with NumPy
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
• Structural Analysis of Molecular Clouds: Dendrograms
• PHANGS-ALMA Data Processing and Pipeline
• Excitation of Polycyclic Aromatic Hydrocarbon (PAH) Emission: Dependence on Size Distribution, Ionization, and Starlight Spectrum and Intensity
• New Constraints on the ${}^{12}$CO(2-1)/(1-0) Line Ratio Across Nearby Disc Galaxies
• HST/STIS Spectroscopy of Five Super Star Clusters in the Starburst Galaxy M82
• Low-J CO Line Ratios From Single Dish CO Mapping Surveys and PHANGS-ALMA
• Decomposing Dusty Galaxies. I. Multi-Component Spectral Energy Distribution Fitting
• Massive quenched galaxies at z~0.7 retain large molecular gas reservoirs
• Spatial variations in aromatic hydrocarbon emission in a dust-rich galaxy
• PHANGS-JWST First Results: Destruction of the PAH molecules in HII regions probed by JWST and MUSE
• CO Multi-line Imaging of Nearby Galaxies (COMING). IX. ${}^{12}$CO($J$=2-1)/${}^{12}$CO($J$=1-0) line ratio on kiloparsec scales
• Molecular Gas Properties and CO-to-H2 Conversion Factors in the Central Kiloparsec of NGC 3351
• Spatially Resolved Spitzer-IRS Spectroscopy of the Central Region of M82
• PHANGS-JWST First Results: Variations in PAH Fraction as a Function of ISM Phase and Metallicity
• Outflows from Super Star Clusters in the Central Starburst of NGC253
• HST/ACS imaging of M82: A comparison of mass and size distribution functions of the younger nuclear and older disk clusters
• GATOS: missing molecular gas in the outflow of NGC5728 revealed by JWST
• A new census of dust and polycyclic aromatic hydrocarbons at z=0.7-2 with JWST MIRI
• Cold molecular gas and PAH emission in Seyfert galaxies
• PHANGS-JWST First Results: A Global and Moderately Resolved View of Mid-Infrared and CO Line Emission from Galaxies at the Start of the JWST Era
• NOEMA High Fidelity Imaging of the Molecular Gas in and around M82
• Estimating the molecular gas mass of low-redshift galaxies from a combination of mid-infrared luminosity and optical properties
• Structural and Dynamical Analysis of 0.1pc Cores and Filaments in the 30~Doradus-10 Giant Molecular Cloud
• CO Excitation and its Connection to Star Formation at 200 pc in NGC 1365
• JWST MIRI and NIRCam observations of NGC 891 and its circumgalactic medium
• The tight correlation of PAH and CO emission from z~0-4

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• Stars Born in the Wind: M82's Outflow and Halo Star Formation
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