Coronagraphic Quasar Imaging

Featured by this NASA news release, I led the first extragalactic science demo for the only-operating coronagraph onboard the Hubble Space Telescope (HST) –  the Space Telescope Imaging Spectrograph (STIS). This program – GO 16715 – uses 8 orbits of coronagraphic observations to image the host galaxy that is previously overwhelmed by the point spread function of the original quasar, 3C 273. (Project duration: 2022 January – 2024 February). You can access the paper at this ADS link.

Instrument facts: 

1. STIS offers a 1024*1024 pixel (≈50 arcsec * 50 arcsec) field view to image astrophysical objects mainly in visible light (~0.2 µm to ~1.2 µm, see here for the filter response). 

2. There are four occulters that you can use, and the typical locations are listed here.

Background: upon my arrival as a postdoc in Caltech in 2019 fall, I was assigned to the office of Marteen Schmidt –  who identified 3C 273 as the first quasar in history – as my office right after his moving out. While I started developing the idea with John Debes the HST/STIS team leader then in 2019 summer, the proposal did not get approved until in 2021. Although I wanted to show the results to Prof. Schmidt earlier, I was at a period of crisis for both my career and life, and he passed away in 2022 september so that didn't pan out. His pioneering discovery, and our sharing of office in space (but not time), stimulates me to keep moving forward towards new directions.