Oral Presentation
A New Algorithm of Source Plane Reconstruction and Resolved
 Star-Formation Properties of a Highly Lensed Submillimeter Galaxy
Presenter: Tsuyoshi Ishida (The University of Tokyo)
We have developed a new algorithm, named GLEAN, for the high-resolution reconstruction of gravitationally lensed images. GLEAN is motivated by the fact that existing reconstruction techniques do not fully specify multiply-imaged regions and the precision of determining positions on the source plane becomes low. As a first step, we have implemented iterative processes. GLEAN reconstructs lensed images as follows. (1) It identifies the brightest point and (2) calculates the corresponding position on the source plane. After that, (3) it outputs modeled multiple images and (4) subtracts them from the observed image. These procedures were repeated until reaching the threshold. We note that GLEAN requires known mass models. We applied this algorithm to a lensed submillimeter galaxy at z ~ 3, SDP.81, which was observed by ALMA in 2014 as a part of Science Verification. We used the continuum map and integrated intensity map of CO and H2O. As a result, for the continuum map we could reproduce clumpy structures consistent with previous researches and show each clumps nearly reach the Eddington-limit. On the other hand, for the CO and H2O maps there are some differences between the modeled images and observed images due to the low S/N and resolution. Therefore, to achieve the further precision, it is essential to implement an auto multiple-image fitting.
asiaa.sinica.edu.tw