I am working with Dr. Ian S. McLean, head of the UCLA Infrared Lab, on the instrument MOSFIRE for the Keck I telescope. I specifically work on the detector and the detector system. MOSFIRE uses a HAWAII2-RG detector from Teledyne Imaging Sensors. It is a HgCdTel with a 2.5 micron cut-off. We are using an ASIC controller, which is technology created for the James-Webb Space Telescope. I have focused on characterizing the properties of the MOSFIRE detector by testing the noise, linearity, and dark current, as well as finding the optimal settings to obtain the best possible performance. MOSFIRE was delivered in April 2012 and is now available for the Keck observing community.
Link to SPIE paper on Performance of the HgCdTe Detector for the MOSFIRE Imager and Multi-Object Spectrometer for Keck Observatory (presented at SPIE Astronomical Telescopes and Instrumentation Conference, July 2012)
Link to poster presented on the Evaluation of the ASIC-Controlled H2-RG Science Grade Detector for MOSFIRE (presented at the 215th AAS in Washington, DC, Jan. 2010).
In addition to my instrumentation work, I am working with Dr. Alice Shapley on understanding the formation and evolution of high redshift (z=2-3) star-forming galaxies. I have investigated a sample of star-forming galaxies with double-peaked Lyman α emission. These profiles provide additional constraints on the escape of Lyman α photons due to the rich velocity structure in the emergent line. Our database is drawn form the UV-selected star-forming galaxies from Charles Steidel and collaboraters obtained from the LRIS spectragraph. We have determined that roughly 30% of objects with detecable Lyman α emission in this sample display multiple-peaked behavior. Lyman α is a resonant line, making it difficult to measure an accurate systemic redshift. We have obtained Hα or [OIII] for 18 double-peaked objects using NIRSPEC on Keck to measure accurate systemic redshifts, nebular line widths, and intrinsic ionizing photon fluxes. The ultimate goal of this project is to create accurate models for these systems, thus allowing us to understand in better detail different aspects of outflowing (infalling) gas, such as the mass outflow (infall) rate for star-forming galaxies at these redshifts.
Link to poster presented on The Kinematics of Multiple-Peaked Lyman &alpha Emission in Star-Forming Galaxies at z~2-3 (presented at the 216th AAS in Miami, Fl, May 2010).
Link to paper, published on ApJ.
My current work focuses on high-redshift galaxies within protoclusters to understand more about the physics of galaxy formation within an extreme environment by using MOSFIRE spectroscopic data. I have targeted important diagnostic lines (i.e. Hα, [OIII]λ5007, Hβ, and [NII]) to measure properties such as velocity dispersion and gas-phase metallicity for objects within the protocluster, as well as 'field' galaxies, to understand the importance of environment and the role it plays in the formation and evolution of galaxies. Due to MOSFIREs multi-object nature, I have been able to obtain large samples of these high-redshift galaxies with near-IR spectroscopy more efficiently than previously possible.