Joseph Wong

UC Santa Barbara

Identifying and Massing Galaxies at Medium Distance

At the present time, only the immediate universe has been observed in detail. However, recent observations allow us to look farther out. Our research is currently looking at a survey of objects approximately six billion light years away which used a technique called narrow-band slit spectroscopy. This technique can identify the spectrum of light emitted by an object very well, but has considerable error in determining where it is physically. Our current project aims to identify these objects in preexisting optical data coming from a number of ground-based and spacebased telescopes. In particular, some of the spectroscopically identified objects do not have clear counterparts in existing object catalogs. We have already identified their closest counterparts, and aim to fit the telescope data to templates (predictions of what galaxies should look like based on observations of our immediate universe) to determine if these objects are of interest, that is, if they are galaxies undergoing star formation approxmately six billion light years away. Though other objects might be of interest in different research projects, our research at the present time is focused only on studying certain types of galaxies. Once we have identified which objects are of interest, we can measure certain properties of these objects, primarily their mass. Mass can be determined more exactly by measuring spectral indicators to determine the mass-to-light ratio at a given wavelength for which we know the amount of emitted light, and multiply the two to determine the mass.

UC Santa Barbara Center for Science and Engineering Partnerships UCSB California NanoSystems Institute