Brooke Kimsey-Miller

Research

Summary

You may have heard the phrase “We are all stardust.” This is absolutely true! Most elements, including oxygen, are created in stars and redistributed when the more massive stars die. Galaxies can have 100s of billions of stars, and those galaxies that are currently creating lots of stars are called star-forming galaxies (SFGs). The more stars in a galaxy that are created and die, the more oxygen that is created and redistributed within that galaxy. The environment that a galaxy lives in can impact how many stars the galaxy makes. When a galaxy interacts with another galaxy it can trigger creating more stars. By studying the environment of SFGs, we study how the elements that make-up ‘us’ and all living things came to be.

The Star Formation Across Cosmic Time (SFACT) Survey

I've been a collaborator on the SFACT survey since Fall 2021. SFACT is a narrowband imaging survey that searches for sources of optical line emission, such as star formation. Using the One Degree Imager on the WIYN 3.5m telescope, it detects emission-line galaxies (ELGs) by identifying objects with excess flux in three specially designed narrowband (NB) filters. The filters were designed to span a broad wavelength range and not overlap in wavelength. This enables the SFACT survey to detect SFGs in discrete redshift intervals out to z ∼ 1. The survey has a median sample depth of r ∼ 22.5, with the faintest objects reaching r ∼ 25.8 (Salzer et al. 2023; Sieben et al. 2023). Follow-up spectroscopy is conducted using the multi-fiber positioner Hydra, also on the WIYN 3.5m (Salzer et al. 2023; Carr et al. 2023).

The Environments of Green Pea Galaxies

Originally discovered by citizen scientists, Green Pea galaxies (GPs) are compact, extreme SFGs with low metallicities, low to intermediate masses, and high star formation rates (SFRs) that are found at intermediate redshifts (Cardamone et al. 2009).

We applied the clustering analysis developed by Brunker et al. (2022) to determine the local galactic environments of 18 GPs ( Kimsey-Miller et al. 2024). We found that the Hα Dot GPs typically reside in low-density environments, in agreement with other authors (Cardamone et al. 2009; Brunker et al. 2022). We interpreted the low-density environments of the Hα Dot GPs to indicate that major mergers and interactions with other galaxies do not appear to drive the star formation activities within these extreme starbursts.

The Environments of SFACT Galaxies

The majority of SFACT galaxies are star forming. Determining whether the environment drives the star formation activity within these galaxies is important to the overall field of galaxy evolution.

We utilize a visual representation and three density estimators as a measurement of environment. We find a clear picture for each density estimator over four preliminary fields. SFACT galaxies are found in a range of environments. However, they tend to be found in lower density environments than the redshift survey comparison sample. We perform statistical tests on our environmental estimators. In nearly all cases, we are able to reject the hypothesis that the SFACT star-forming galaxies and redshift survey comparison sample of galaxies are drawn from the same population. To complete the work, we are currently in the process of acquiring the necessary spectroscopic data to perform the environmental analysis on all six fields.

Outreach

I love getting to take the time to share the amazing wonders of the universe with diverse audiences. I've presented to amateur astronomers, kids, and even in a local factory. Through my association with the Department of Astronomy at Indiana University, I have been fortunate enough to organize and/or participate in over 70 outreach events!

I was the graduate student Outreach Coordinator in the Department of Astronomy at Indiana University for two years (2021-2023). One of the activities I am most proud of during my tenure includes helping to organize the university-wide Science Fests of 2021 and 2022, where the university had a record number of visitors. The University also had to protect out attendees, who at the time, could not be vaccinated against COVID-19. Another activity I am proud of is the Department's first attendance at a STEM festival at the world's largest children's museum, the Children's Museum of Indianapolis (pictured above).

Teaching

I enjoy getting the opportunity to teach about the wonders of the Universe. I have taught a variety of courses, from the solar system to stars and galaxies. I have also been associate instructur, learning from the excellent faculty in the Department of Astronomy.

Instructor of Record

A105: Stars and Galaxies, Summer 2023

A100: The Solar System, Summer 2022

A107: The Art of Astronomy, Summer 2021

Associate Instructor

A103: Search for Life in the Universe, Fall 2020

A105: Stars and Galaxies, Spring 2019, 2020, 2021

A107: The Art of Astronomy, Fall 2019

Guest Lecturer

A115: Birth and Death of the Universe, Spring 2023

About Me

Hi, I’m Brooke Kimsey-Miller (she/her) and I’m a doctoral candidate at Indiana University in the Department of Astronomy. I work on the Star Formation Across Cosmic Time (SFACT) survey and utilize this survey to explore the environments of star-forming galaxies. I received my bachelor's degrees in Math, Physics, and Astronomy & Astrophysics at IU. I’m a 21st Century Scholars alumna, an Indiana Space Grant Consortium Doctoral Fellow, and a College of Arts and Sciences Dissertation Research Fellow.

Contact

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