The Milky Way has accreted many ultra-faint dwarf galaxies (UFDs), and stars from these galaxies can be found throughout our Galaxy today. Studying these stars provides insight into galaxy formation and early chemical enrichment, but identifying them is difficult. Clustering stellar dynamics in 4D phase space (E, L z , J r , J z ) is one method of identifying accreted structure that is currently being utilized in the search for accreted UFDs. We produce 32 simulated stellar halos using particle tagging with the Caterpillar simulation suite and thoroughly test the abilities of different clustering algorithms to recover tidally disrupted UFD remnants. We perform over 10,000 clustering runs, testing seven clustering algorithms, roughly twenty hyperparameter choices per algorithm, and six different types of data sets each with up to 32 simulated samples. Of the seven algorithms, HDBSCAN most consistently balances UFD recovery rates and cluster realness rates. We find that, even in highly idealized cases, the vast majority of clusters found by clustering algorithms do not correspond to real accreted UFD remnants and we can generally only recover 6% of UFDs remnants at best. These results focus exclusively on groups of stars from UFDs, which have weak dynamic signatures compared to the background of other stars. The recoverable UFD remnants are those that accreted recently, z accretion ≲ 0.5. Based on these results, we make recommendations to help guide the search for dynamically linked clusters of UFD stars in observational data. We find that real clusters generally have higher median energy and J r , providing a way to help identify real versus fake clusters. We also recommend incorporating chemical tagging as a way to improve clustering results.

Physics is a human enterprise, yet that humanity is hidden from students. This chapter, authored by two current physics undergraduates and a teacher-researcher, highlights contextualized teaching methods that reintegrate physics into human context. Our metaphorical Landscape of Physics Education represents decontextualization by elevation, with greatest decontextualization at mountain peaks. It uses water to represent educators' contextualizing efforts, with greatest contextualization at sea level. At lowest elevations, physics is fully contextualized: teachers prioritize content and context; students' voices and identities are celebrated. Educators and students throughout this landscape are informed and inspired by: constructivism; nature of science (NOS); student voice; and gradings' adverse impacts. This chapter takes three tours through contextualizing efforts of the physics education research literature: Historical Experiments and Instruments; Contextualization through Narratives, and Feminist and Indigenous Experience. The Historical Experiments and Instruments Tour features teaching projects where students experiment with historical electromagnetic instruments in a museum, flatten gender hierarchies while learning electrostatics, and develop their own understandings of physical phenomena through partnering with historical investigations. It demonstrates how at low elevations, experiences embrace ambiguity and students: initiate questions; exercise agency; and form personal science identities. The Contextualization by Narratives Tour explores short, stand-alone narratives such as anecdotes, vignettes, short stories, case studies, and role-plays. In its low elevation examples, students co-created curriculum together with teacher researchers; their questions and personal experiences redirected lessons. The Feminist and Indigenous Experience Tour documents physics students' adverse experiences relating to identity; presents theoretical approaches to feminist and indigenous student experience, including feminist standpoint theories and indigenous understanding of “place;” and reports on feminist and indigenous perspectives introduced into classrooms, such as investigating home experiences and using African conflict mediation. This landscape is subjective, with its routes viewed differently by each student. We encourage you to review your own landscape, explore new paths within it, and introduce water features and context wherever you may be.