Searching for Smallest Star Clusters and Galaxies with Zooniverse
Session Number
3
Advisor(s)
Alex Drlica-Wagner, University of Chicago, Chin-Yi Tan, University of Chicago, Kate Overdeck, University of Chicago
Location
A133
Discipline
Physical Science
Start Date
15-4-2026 2:15 PM
End Date
15-4-2026 3:00 PM
Abstract
Although dark matter makes up much of the universe, its particle identity is still unknown. Ultra-faint dwarf galaxies near the Milky Way form in large, gravitationally-bound clumps of dark matter known as dark matter halos. Different dark matter models predict different distributions of dark matter halos which in turn predicts vastly different amounts of satellite galaxies. Thus by counting dwarf galaxies around the Milky Way much can be learned about dark matter. However, there are many limitations in this counting, one being not all of the satellite galaxies have been discovered. A new dwarf galaxy search attempt has been performed using DELVE, a survey of the southern sky, and citizen scientists from Zooniverse, which has resulted in new promising candidates. Another limitation is that ultra-faint dwarf galaxies look similar to star clusters and it is difficult to distinguish between them without further observations. To categorize these ambiguous cases, better models of the star cluster population are needed. One limitation of current models is the apparent lack of star clusters with the absolute magnitude (Mv) of -3. A study has been conducted to show that current search methods are sensitive to these star clusters. Therefore better modeling is needed to explain their absence.
Searching for Smallest Star Clusters and Galaxies with Zooniverse
A133
Although dark matter makes up much of the universe, its particle identity is still unknown. Ultra-faint dwarf galaxies near the Milky Way form in large, gravitationally-bound clumps of dark matter known as dark matter halos. Different dark matter models predict different distributions of dark matter halos which in turn predicts vastly different amounts of satellite galaxies. Thus by counting dwarf galaxies around the Milky Way much can be learned about dark matter. However, there are many limitations in this counting, one being not all of the satellite galaxies have been discovered. A new dwarf galaxy search attempt has been performed using DELVE, a survey of the southern sky, and citizen scientists from Zooniverse, which has resulted in new promising candidates. Another limitation is that ultra-faint dwarf galaxies look similar to star clusters and it is difficult to distinguish between them without further observations. To categorize these ambiguous cases, better models of the star cluster population are needed. One limitation of current models is the apparent lack of star clusters with the absolute magnitude (Mv) of -3. A study has been conducted to show that current search methods are sensitive to these star clusters. Therefore better modeling is needed to explain their absence.