Search for: All records

Current models of galaxy formation require strong feedback from active galactic nuclei (AGN) to explain the observed lack of star formation in massive galaxies sincez≈ 2, but direct evidence of this energy input is limited. We use the SIMBA cosmological galaxy formation simulations to assess the ability of thermal Sunyaev–Zel’dovich (tSZ) measurements to provide such evidence, by mapping the pressure structure of the circumgalactic medium around massivez≈ 0.2–1.5 galaxies. We undertake a stacking approach to calculate the total tSZ signal and its radial profile in simulations with varying assumptions of AGN feedback, and we assess its observability with current and future telescopes. By convolving our predictions with the 2.′1 beam of the Atacama Cosmology Telescope, we show that current observations atz≈ 1 are consistent with SIMBA’s fiducial treatment of AGN feedback and inconsistent with SIMBA models without feedback. Atz≈ 0.5, observational signals lie between SIMBA run with and without AGN feedback, suggesting AGN in SIMBA may inject too much energy at late times. By convolving our data with a 9.″5 beam corresponding to the TolTEC camera on the Large Millimeter Telescope Alfonso Serrano, we predict a unique profile for AGN feedback that can be distinguished with future higher-resolution measurements. Finally, we explore a novel approach to quantify the nonspherically symmetric features surrounding our galaxies by plotting radial profiles representing the component of the stack with m-fold symmetry.

 

Course-Based Undergraduate Research Experiences (CUREs) have been shown to provide students with a variety of learning benefits including better conceptual understanding, improved critical thinking and data literacy skills, and increased interest in pursuing scientific careers. Additionally, CUREs provide students with opportunities to participate in authentic research experiences that have a broader impact outside of the classroom. Despite the numerous benefits, the field of astronomy has lagged behind disciplines like biology and chemistry when it comes to including CUREs in the curriculum. Not limited to astronomy, however, is the lack of research opportunities and courses offered to students enrolled in undergraduate degree programs online. In the Fall of 2020, Arizona State University (ASU) introduced the nation’s first online bachelor’s degree program in astronomy and planetary sciences (APS). To make research accessible to a more diverse population of learners, it is imperative that students in this program have access to the same opportunities to participate in authentic research as those in the parallel in-person program. In this work, we describe the development, implementation, and assessment of a fully online CURE for astronomy majors as part of the APS program. We conducted a mixed methods analysis consisting of a Likert style survey administered pre- and postcourse as well as student interviews at the conclusion of the semester. Survey results from the course’s first two offerings (N ¼ 24) indicated that students’ research self-efficacy and science identity both improved. An exoplanet-specific multiple-choice assessment (N ¼ 26) showed statistically significant improvements in conceptual understanding postcourse. Additionally, student interview (N ¼ 11) responses relayed that students felt a stronger sense of belonging to both ASU and the larger astronomy community after participation in the course. The results from this study are encouraging and suggest that student participation in this online CURE led to similar improvements across a variety of outcomes previously identified in studies of in-person CUREs spanning multiple disciplines.