Lomaeva, Maria;
(2024)
Galaxy evolution in the local Universe: tracing recent star formation histories in disk galaxies.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Lomaeva_10192285_Thesis.pdf Download (21MB) | Preview |
Abstract
Understanding galactic star formation histories (SFHs) is essential in galaxy evolution studies. In this Thesis, we calibrate a new method that traces recent SFHs in star-forming disk galaxies on resolved scales. The metric gauges changes in the star formation rate (SFR), dSFR/dt, while only requiring simple observables rather than full spectral energy distribution (SED) fitting. Through generating a set of models in the SED modelling tool CIGALE, we defined dSFR/dt = hSF R5i hSF R200i, that is, the ratio of the SFR averaged over the past 5 and 200 Myr, as a function of the H FUV colour. Applying the hSF R5i hSF R200i metric onto a grand-design, face-on galaxy NGC 628, we saw a declining recent star formation (SF) activity, with the SF being somewhat higher in the spiral arms. Our findings highlight the sensitivity of hSF R5i hSF R200i to the molecular gas content, spiral arm structure, and disk pressure. Extending this study to a sample of similar eleven disk galaxies with diverse external (field vs. group/cluster) and internal (AGN vs. inactive; barred, unbarred, and disks without spirals) properties, we found that the hSF R5i hSF R200i distribution stretches out to lower values in the interarms of some galaxies, and in those cases, the difference between the hSF R5i hSF R200i in the arms and interarms tends to be larger. This suggests that recent SFHs in the arm versus interarm regions of these galaxies, that also display higher global stellar masses and earlier morphological types, differ more as well. We connect this distinct behaviour in the arms-interarms to the differences in the molecular gas availability. However, to fully understand these observations, simulations of the resolved SFR evolution in galaxies with corresponding properties are necessary. In conclusion, this Thesis contributes to the emerging picture essential for a general theory of SF, where the local environment is tightly linked to the rate and efficiency of the SF processes.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Galaxy evolution in the local Universe: tracing recent star formation histories in disk galaxies |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2023. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10192285 |
Archive Staff Only
 |
View Item |
