Modeling the Mass Distribution and Gravitational Potential of Nearby Disk Galaxies: Implications for the Interstellar Medium Dynamical Equilibrium

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A90106%2F25%3A00646728" target="_blank" >RIV/67985815:90106/25:00646728 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3847/1538-4357/ade800" target="_blank" >https://doi.org/10.3847/1538-4357/ade800</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ade800" target="_blank" >10.3847/1538-4357/ade800</a>

Result language

angličtina

Original language name

Modeling the Mass Distribution and Gravitational Potential of Nearby Disk Galaxies: Implications for the Interstellar Medium Dynamical Equilibrium

Original language description

We characterize stellar, gas, and dark matter mass distributions for 17 nearby massive disk galaxies from the PHANGS sample. This allows us to compute the gravitational potential that vertically confines the interstellar gas and determines its equilibrium scale height and weight. We first combine dynamical mass constraints from existing CO and H i rotation curves, together with stellar and gas mass estimates from near-infrared, CO, and H i data. These estimates incorporate current best practices in modeling stellar mass-to-light ratios and CO-to-H2 conversion factor variations. Then, we fit joint stellar-gas-dark matter mass models to the rotation curves, adopting the classic maximal disk assumption to account for remaining zero-point uncertainties on the stellar mass-to-light ratio. After obtaining three-component radial mass profiles, we calculate the vertical equilibrium gas scale height and interstellar medium (ISM) weight in the combined gravitational potential. We find the gas scale height Hgas increases from less than or similar to 100 pc in the inner disks to >500 pc at large radii, consistent with observations of our Galaxy and other edge-on galaxies. The gas weight is dominated by stellar gravity at small radii, but the gas and dark matter gravity often become important beyond 3-6 times the stellar disk radial scale length. Both our gas scale height and weight estimates are dependent on the treatment of stellar disk scale height H star, with Hgas varying by 30%-40% when H star varies by a factor of 3. The relationship between our refined ISM weight estimates and local star formation surface density generally agrees with previous observations and predictions from theory and simulations.

Czech name

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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

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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

989

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

18

Pages from-to

66

UT code for WoS article

001565098500001

EID of the result in the Scopus database

2-s2.0-105012760286