Jacob (Jake) B. Simon

I am an Associate Professor of Physics and Astronomy at Iowa State University in Ames, Iowa. My primary research focus is on planet formation. My group and I are using sophisticated computer simulations run on some of the largest supercomputers in the US, and we are also closely collaborating with observers to test our theoretical models.

I have also recently become more involved in the next generation of astrophysics codes, working in particular with GPU codes as well numerical algorithm development.

Finally, I maintain a strong interest in how hot gas orbiting nature's most mysterious objects (black holes) spiral into these objects, releasing tremendous radiation as it does so. 

Tabassum (Tab) Tanvir

Tab joined the group in June 2024. Tab is studying how star formation environments influence the properties of planetary systems. He is also interested in questions related to how astrophysical objects get their mass. This connects his previous and ongoing studies of star formation with questions of how planetary embryos and planetesimals form with the the masses that they do. 

Tab is also mentoring undergraduate Quinn Gault on numerical simulations of how stars are born.

Marius Lehmann

Marius joined the group in September of 2025.  He works on global MHD simulations of planet-forming disks, with the aim of making direct connections between observables of processes like magnetically-driven turbulence and magnetically-launched outflows/winds.  

Marius is also working on various hydrodynamic (i.e., no magnetic fields) instabilities in planet-forming disks and their effect on dust concentration and planet migration, and he is mentoring undergraduate Aydean Bejtovic on studies of planetesimal formation.

Marius's ORCID Page: https://orcid.org/0000-0002-0496-3539

Weston Hall

Weston joined the group in Fall 2023. He is testing the streaming instability as a mechanism for planetesimal formation by developing predictions for multiple observable outcomes, including the planetesimal size distribution, final shapes, and binary configurations.

Camden Olds

Camden joined our group in Fall 2024. He is heavily involved in code and algorithm development efforts.  Currently, he is part of the AthenaK Particle collaboration (called "Dust Bunnies") and is testing the particle-gas interaction modules in AthenaK.  He will shortly be working with myself and math professor James Rossmanith on numerical algorithm development.

Kyen Lundgren

Kyen Lundgren is working with myself and graduate student Weston Hall to build a suite of high resolution simulations of various gas dynamical processes in astrophysics.  These simulations will be incorporated into a new educational tool I am developing as part of my recent NSF grant, the Computational Astrophysics Lab (stay tuned for this!)

Quinn Gault

Quinn is working with postdoc Tab Tanvir to run a suite of star formation simulations to better understand how stars get the masses that they do. They were recently part of the prestigious First Year Honors program at Iowa State University. 

Aydean Bejtovic

Aydean is the newest member of our group, and is working with postdoc Marius Lehmann to better understand the conditions under which planetesimals form.

He was also recently part of the prestigious First Year Honors program. 

Jeonghoon (Jay) Lim

Jay was a graduate stduent in my group from 2020 to 2026. He worked on simulations of planetsimal formation iva the streaming instability. Through these calculations, he quantified precise conditions under which planetesimal formation occurs in planet-forming disks. While here, he was a recipient of a prestigious NASA FINESST award.  

Now a Nevada Center for Astrophysics Postdoctoral Fellow at the University of Nevada, Las Vegas.

Jay's website: https://jhlim0918.github.io

David Rea

David was a graduate student in my group from 2020 to 2026. He worked on simulations of magnetically driven turbulence in planet-forming disks.  While he was here, he also won a prestigious NASA FINESST grant. He defended his thesis in the summer of 2026.  He is now looking into industry and national lab positions.  

Daniel Carrera

Daniel was a postdoc in my group from 2019-2023 and a research scientist from 2023-2024. While here, he investigated the formation of planetesimals in high gas pressure regions ("pressure bumps") thought to be present in planet-forming disks.

He also worked with former graduate student Abigail Davenport on a study of particle growth in very young, massive planet-forming disks.

Now a research professor at New Mexico State University

Abigail Davenport

Abigail joined the group in Fall 2022. While here, she worked with research scientist Daniel Carrera to understand the structure and evolution of very young (Class 0/I) protostellar disks and how this structure/evolution influences particle growth. She has now graduated with a Masters Degree, and her work will be continued by Daniel.

Now a Research Analyst at ManTech

Olivia Brouillette

Olivia was an undergraduate student and then a post-bachelor researcher in the group.  While in the group, she worked with David Rea and Jay Lim to carry out extremely high resolution, long time-scale simulations of the streaming instability to quantify the precise critical dust-to-gas ratio needed to activate the streaming instability.

Now in the graduate program at New Mexico State University

Matthew Small

Matt was a member of the Simon Research Group from Fall 2019 to Spring 2022, after which he graduated with a masters degree.  He carried out statistical analyses on the initial mass function of planetesimals produced from simulations of the streaming instability.

Sayantan Auddy

Sayantan was a postdoc in the group from Fall 2020 to Summer 2022. When he was here, he worked on a number of projects, including the nature of magnetically driven winds in planet-forming disks. He also collaborated with us to develop a machine learning tool to quantify the properties of embedded planets from observations of dust rings in protoplanetary disks.

Now an Applied Machine Learning Scienctist at TD Bank

Andrew (Drew) Thomas

Drew was an undergraduate in the group from Fall 2019 to Summer 2021. While here, he worked closely with postdoc Daniel Carrera to study the formation of planetesimals in gaseous pressure bumps. This work led to a paper with Drew as second author (Carrera, Thomas, et al. 2022).

Now employed by Wellmark