1. Brown Dwarf Desert Project: Second Presentation
Peter Jumper

2. Results Ultimately inconclusive this semester
Have been deadlocked for some time

3. The Problem When we ran the code, we got NaN values
Occurs even during the test of a simplified case, a rigid, rotating body
Affects period, semimajor axis, and specific angular momentum outputs
Module testing will be critical

4. Using a Debugger Dr. Fisher suggested this
In principle, this should be greatly helpful
I have experience using debuggers in ECE 160
I have never run a debugger on the command line, however
My efforts to run the debugger have been unsuccessful

5. Plans to Solve the Problem
Participation in CSUMS program during the summer

6. Conferences Prepared presentation and poster on my work
Presented at four conferences during April (SPS, APS-AAPT, Sigma Xi, Massachusetts Statewide Undergraduate Research Conference)
These conferences provided valuable experience

7. My Presentation

8. Dr. Robert T. Fisher, Peter Jumper, and Deivid Ribeiro
Shaping the Brown Dwarf Desert: Constraints from Turbulent Fragmentation
Dr. Robert T. Fisher,
Peter Jumper,
and Deivid Ribeiro

9. What is the Brown Dwarf Desert?
The notable absence of brown dwarfs within five times the Earth-Sun distance from their central star
(Grether and Lineweaver 2004)

10. Why Do We Care?
Improve understanding of angular momentum transfer in the star formation process
Scaled-up planets?
Scaled-down stars?

11. Past Research Brown dwarfs migrating into the central stars proposed
Credit: Phil Armitage

12. Gravitational Fragmentation Model
Core: star-forming gaseous cloud
Models deal with the formation of two stars from the core
Mass and angular momentum of stars dependent on the core
ε* = (M1 + M2)/Mcore
εJ = J/Jcore

13. Turbulent Fragmentation
Core angular momentum comes from turbulence
Net angular momentum is nonzero
Credit: (Seinfeld 1986)

14. Methodology Draw masses from the initial mass function
Gaussian random field gives turbulence and angular momentum
Calculate orbital parameters

15. Research Progress
Conducting verification by reproducing results of an earlier paper
Troubleshooting
New initial mass function code prepared

16. Future Plans Conduct simulations for 200 brown dwarf – binary systems
Analysis of results

17. Questions?