"Characterizing Circumstellar Disks at 5 Myr - a Multiwavelength Gas and Dust Survey in Upper Scorpius"
Circumstellar disks, a byproduct of the star formation process, are the birthplace of planets. Examination of these disks inform our theories of planet formation by constraining the available gas and dust.
I am using millimeter photometry to measure the circumstellar dust mass in a group of 5 Myr old stars in Upper Scorpius, as well as far-infrared and millimeter gas-line spectroscopy to determine the gas content. My observations indicate that by the age of Upper Scorpius, less than 2% of stars could form giant planets. When compared to the field giant planet fraction - ~20% - this suggests that giant planet formation is essentially complete by 5 million years.
Below are links to related papers and posters as well as some images to give a flavor for what I've been been working on for my dissertation.
Refereed PapersMathews, G.S., Williams, J.P., and Menard, F., submitted (draft available upon request). 880 micron Imaging of a Transitional Disk in Upper Scorpius: Holdover from the Era of Giant Planet Formation?
J. Lebreton, J.C. Augereau, W.F. Thi, et al., 10th author, accepted, A&A. An icy Kuiper-Belt around the young solar-type star HD 181327 ArXiV
Mathews, G.S., Williams, J.P., Menard, F., et al., 2012, ApJ, 745, 23. The Late Stages of Protoplanetary Disk Evolution: A Millimeter Survey of Upper Scorpius ADS
Mathews, G.S., Dent., W.R.F., Williams, J.P., et al., 2010, A&A, 518, 127. Gas in Protoplanetary Systems (GASPS). I. First Results ADS
Meeus, G., Pinte, C., Woitke, P., et al. 8th author, 2010, A&A, 518, 124. Gas in the protoplanetary disk of HD 169142: Herschel's view ADS
Thi, W.F., Mathews, G.S., Menard, F., et al., 2010, A&A, 518, 125. Herschel- PACS observation of the 10 Myr old T Tauri disk TW Hya. Constraining the disk gas mass ADS
Pinte, C., Woitke, P., Menard, F., et al. 7th author, 2010, A&A, 518, 126. The Herschel view of gas in Protoplanetary Systems (GASPS). First comparisons with a large grid of models ADS
Collins, K.A., Grady, C.A., Hamaguchi, K., et al. 9th author, 2009, ApJ, 697, 557. HD 100453: A Link Between Gas-Rich Protoplanetary Disks and Gas-Poor Debris Disks ADS
Allers, K.N., Liu, M.C., Shkolnik, E., et al. 6th author, 2009, ApJ, 697, 824. 2MASS 22344161+4041387AB: A Wide, Young, Accreting, Low-mass Binary in the LkHa233 Group ADS
Cieza, L.A., Swift, J.J., Mathews, G.S., & Williams, J.P., 2008, ApJL, 686, 115. The Masses of Transition Circumstellar Disks: Observational Support for Photoevaporation Models ADS
AAS Dissertation Talk, "Out of Gas: Upper Scorpius and the End of Giant Planet Formation". (pdf)