Speaker
Description
Accurate distance measurements are fundamental to understanding the formation and distribution of galaxies in the nearby universe. For faint and diffuse systems, such as dwarf and low-surface-brightness (LSB) galaxies, distances are needed to distinguish satellites from background systems, to derive physical properties such as mass and size, and to map the structure of the local volume (LV). However, measuring these distances remains challenging. Redshift-based estimates are unreliable due to the local velocity field, while stellar-based methods such as the tip of the red giant branch (TRGB) require resolved imaging that is often unavailable for LSB dwarfs.
The surface brightness fluctuation (SBF) method provides a robust method for measuring distances to dwarf galaxies in the nearby universe. With the advent of deep, wide-field surveys such as the DESI Legacy Imaging Surveys (LS), Euclid, and the upcoming LSST, the SBF method has seen renewed interest as a tool for mapping the nearby dwarf galaxy population.
In this work, we apply and adapt the SBF method to LS imaging. We introduce two key modifications to account for 1) correlated noise and 2) varying point-spread function (PSF) in the coadd images. We demonstrate that reliable SBF distances can be recovered for dwarf galaxies within $\sim10$ Mpc by measuring the SBF of galaxies with known TRGB distances and mock dwarfs injected into LS coadds.
Finally, we perform a systematic search for dwarf galaxies across the LS footprint and aim to build a catalogue of SBF distances. This catalogue will provide new insights into the three-dimensional distribution of satellite and field dwarf galaxies, helping to constrain the large-scale structure and star formation history of the local volume.
| Participate the oral/poster presentation award competition | Yes |
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