7 Billion Light-Years, and 10 Years Later – Meeting in Beijing
By Zhiying Huo (NAOC):
Almost 10 years ago, I was a Ph.D. student at the National Astronomical Observatories, Chinese Academy of Sciences in Beijing, supervised by Prof. Suijian Xue. We were doing research using Chandra data on one of the highest redshift galaxy clusters known at the time, Cl J0152.7-1357 at z = 0.83.
We were interested in understanding the nature and dynamical structure of the cluster. However, without a complimentary optical image, we could not draw any solid conclusions.
I searched in the literature and found that Dr. Gordon Squires and Dr. Piero Rosati were working on a weak gravitational lensing analysis of the same cluster. I boldly contacted Gordon by email and asked if he would be willing to provide the image of that cluster taken with Keck. I was so thrilled that he kindly offered me the original observations, and the results from their weak lensing analysis.
Although we never met in person, our together work led to a scientific publication (ApJ, 2004, 127:1263).
Before the IAU meeting, I was told by Suijian that he and Gordon are both working on the TMT project, and they had remembered our research together. Earlier this week, we finally met in person at the TMT exhibit at the IAU General Assembly in Beijing. I was so pleased to present Dr. Squires with a bookmark from Peking University, as a gift to recognize and celebrate our collaboration together.
The light we analyzed from CL J0152 traveled for seven billion years to reach our telescopes. It took us two years to do our analysis and write our paper, working in China and California respectively. Now 10 years later, we finally meet Beijing! Thanks to the IAU GA for bringing us a happy reunion!