Timescales of Polycyclic Aromatic Hydrocarbon and Dust Continuum Emission from Gas Clouds Compared to Molecular Gas Cloud Lifetimes in PHANGS-JWST Galaxies

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A90106%2F25%3A00646482" target="_blank" >RIV/67985815:90106/25:00646482 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3847/1538-4357/ade443" target="_blank" >https://doi.org/10.3847/1538-4357/ade443</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ade443" target="_blank" >10.3847/1538-4357/ade443</a>

Result language

angličtina

Original language name

Timescales of Polycyclic Aromatic Hydrocarbon and Dust Continuum Emission from Gas Clouds Compared to Molecular Gas Cloud Lifetimes in PHANGS-JWST Galaxies

Original language description

Recent JWST mid-infrared (mid-IR) images, tracing polycyclic aromatic hydrocarbons (PAHs) and dust continuum emission, provide detailed views of the interstellar medium (ISM) in nearby galaxies. Leveraging PHANGS-JWST Cycle 1 and PHANGS-MUSE data, we measure the PAH and dust continuum emission lifetimes of gas clouds across 17 nearby star-forming galaxies by analyzing the relative spatial distributions of mid-IR (7.7-11.3 mu m) and H alpha emission at various scales. We find that the mid-IR emitting timescale of gas clouds in galactic disks (excluding centers) ranges from 10-30 Myr. After star formation is detected in H alpha, mid-IR emission persists for 3-7 Myr during the stellar feedback phase, covering 70%-80% of the H alpha emission. This significant overlap is due to intense radiation from star-forming regions, illuminating the surrounding PAHs and dust grains. In most galaxies, the mid-IR time-scale closely matches the molecular cloud lifetime measured with CO. Although mid-IR emission is complex, as influenced by ISM distribution, radiation, and abundances of dust and PAHs, the similarity between the two timescales suggests that once gas clouds form with compact mid-IR emission, they quickly provide sufficient shielding for stable CO formation. This is likely due to our focus on molecular gas-rich regions of galaxies with near-solar metallicity. Finally, we find that the mid-IR emitting timescale is longer in galaxies with well-defined H ii regions and less structured backgrounds, allowing photons to more efficiently heat the ambient ISM surrounding the H ii regions, rather than contributing to diffuse emission. This suggests that the shape of the ISM also influences mid-IR emission.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

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Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

988

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

37

Pages from-to

215

UT code for WoS article

001537215700001

EID of the result in the Scopus database

2-s2.0-105011736130