Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity
Available inventories of baryonic mass in the universe are based largely on galactic data and empirical calculations made >20 years ago. Values falling below cosmological estimates underlie proposals that certain rarified gassy regions could have extremely high <i>T</i>, which motivat...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Galaxies |
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| Online Access: | https://www.mdpi.com/2075-4434/11/5/100 |
| _version_ | 1797626755656187904 |
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| author | Anne M. Hofmeister Robert E. Criss Hugh Chou |
| author_facet | Anne M. Hofmeister Robert E. Criss Hugh Chou |
| author_sort | Anne M. Hofmeister |
| collection | DOAJ |
| description | Available inventories of baryonic mass in the universe are based largely on galactic data and empirical calculations made >20 years ago. Values falling below cosmological estimates underlie proposals that certain rarified gassy regions could have extremely high <i>T</i>, which motivated absorption measurements and hydrodynamic models. Yet, the shortfall remains. We inventory the total baryonic mass, focusing on gravitational interactions and updated measurements. A recent analytical inverse method for analyzing galactic rotation curves quantified how baryon mass and associated volumetric density (<i>ρ</i>) depend on distance (<i>r</i>) from galactic centers. The model is based on the dynamical consequences of the observed oblate shape of galaxies and the Virial Theorem. The parameter-free solution provides ρ(<i>r</i>) ∝ 1/<i>r</i><sup>2</sup> which describes star-rich galactic interiors, gas-rich outer discoids, circumgalactic media, and gradation into intergalactic media. Independent observational determinations of baryonic <i>ρ</i> validate that our 1/<i>r</i><sup>2</sup> result describes baryons alone. This solution shows that total baryonic mass associated with any galaxy is 2.4 to 40 times detectable luminosity, depending on galaxy size and spacing. Luminosity data within 50 Mpc show that Andromeda equivalents separated by ~1 Mpc represent the local universe. Combining the above yields (6 ± 2) × 10<sup>−25</sup> kg m<sup>−3</sup> for the present-day universe. Three other approaches support this high density: (1) evaluating trends and luminosity data near 1000 Mpc; (2) using a recent estimate for the number of galaxies in the universe; (3) calculating an energy balance. We discuss uncertainties in the critical density. Implications of large baryonic ρ are briefly discussed. |
| first_indexed | 2024-03-11T10:14:43Z |
| format | Article |
| id | doaj.art-5fd22d4f41504f9ca624d674054ed53d |
| institution | Directory Open Access Journal |
| issn | 2075-4434 |
| language | English |
| last_indexed | 2024-03-11T10:14:43Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Galaxies |
| spelling | doaj.art-5fd22d4f41504f9ca624d674054ed53d2023-11-16T10:28:54ZengMDPI AGGalaxies2075-44342023-09-0111510010.3390/galaxies11050100Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and LuminosityAnne M. Hofmeister0Robert E. Criss1Hugh Chou2Department of Earth, Environmental, and Planetary Sciences, Washington University, St. Louis, MO 63130, USADepartment of Earth, Environmental, and Planetary Sciences, Washington University, St. Louis, MO 63130, USADepartment of Earth, Environmental, and Planetary Sciences, Washington University, St. Louis, MO 63130, USAAvailable inventories of baryonic mass in the universe are based largely on galactic data and empirical calculations made >20 years ago. Values falling below cosmological estimates underlie proposals that certain rarified gassy regions could have extremely high <i>T</i>, which motivated absorption measurements and hydrodynamic models. Yet, the shortfall remains. We inventory the total baryonic mass, focusing on gravitational interactions and updated measurements. A recent analytical inverse method for analyzing galactic rotation curves quantified how baryon mass and associated volumetric density (<i>ρ</i>) depend on distance (<i>r</i>) from galactic centers. The model is based on the dynamical consequences of the observed oblate shape of galaxies and the Virial Theorem. The parameter-free solution provides ρ(<i>r</i>) ∝ 1/<i>r</i><sup>2</sup> which describes star-rich galactic interiors, gas-rich outer discoids, circumgalactic media, and gradation into intergalactic media. Independent observational determinations of baryonic <i>ρ</i> validate that our 1/<i>r</i><sup>2</sup> result describes baryons alone. This solution shows that total baryonic mass associated with any galaxy is 2.4 to 40 times detectable luminosity, depending on galaxy size and spacing. Luminosity data within 50 Mpc show that Andromeda equivalents separated by ~1 Mpc represent the local universe. Combining the above yields (6 ± 2) × 10<sup>−25</sup> kg m<sup>−3</sup> for the present-day universe. Three other approaches support this high density: (1) evaluating trends and luminosity data near 1000 Mpc; (2) using a recent estimate for the number of galaxies in the universe; (3) calculating an energy balance. We discuss uncertainties in the critical density. Implications of large baryonic ρ are briefly discussed.https://www.mdpi.com/2075-4434/11/5/100baryon densitygalactic rotationgalactic luminositygalactic masslog-normal distribution functionsintergalactic media |
| spellingShingle | Anne M. Hofmeister Robert E. Criss Hugh Chou Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity Galaxies baryon density galactic rotation galactic luminosity galactic mass log-normal distribution functions intergalactic media |
| title | Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity |
| title_full | Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity |
| title_fullStr | Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity |
| title_full_unstemmed | Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity |
| title_short | Baryonic Mass Inventory for Galaxies and Rarefied Media from Theory and Observations of Rotation and Luminosity |
| title_sort | baryonic mass inventory for galaxies and rarefied media from theory and observations of rotation and luminosity |
| topic | baryon density galactic rotation galactic luminosity galactic mass log-normal distribution functions intergalactic media |
| url | https://www.mdpi.com/2075-4434/11/5/100 |
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