Name: Margaret Moerchen

Institution: University of Florida

e-mail: margaret(no-spam)astro.ufl.edu

Partner Contry: USA

Science Meeting: Yes

User Meeting: Yes

NGO Staff Meeting: No

Presentation: Yes

Format: Poster

Title: Challenges of observing structures near the diffraction limit in the mid-IR

Co-author: C. Telesco

Co-authors' Institutions: University of Florida

Abstract:

I will discuss recent results from an ongoing search for resolved debris disk structures and the observational challenges that we have encountered during the course of the project. While some clearly resolved sources subtend several arcseconds in mid-IR images from Gemini, other sources with smaller angular sizes may still be resolved but much less obviously so. At least one such source has been revealed so far: the debris disk of Zeta Lep. The brightness profile of this source is only a fraction of an arcsecond broader than that of its point-spread-function (PSF) reference star, implying a disk diameter of only 6 AU around the star 21 pc away. Seeking resolved structures at this scale requires highly stable PSF observations that test the limits of achievable image quality at large ground-based telescopes. I will review what parameters are examined in assessing the quality of our mid-IR PSF observations; I will also contrast the PSF quality attained in the past versus what can reasonably be attained if certain issues are addressed and more quantifiable constraints can be set by the principal investigators.