Science Seminars

1/21/2016 – Brian Fleming; Lyman Alpha and Lyman Ultraviolet Emission from Stars and Galaxies – Instruments and Techniques for Science in the UV

Speaker: Brian Fleming (LASP)
Date: Tuesday, Jan 21, 2020
Time: 4:00 PM
Location: SPSC W120

Seminar Abstract:

Low material transmission and reflection in the far-ultraviolet has posed a major constraint on astronomy in the observed-frame UV. The most prominent NASA observatory with sensitivity in the Lyman ultraviolet, FUSE, had limited angular resolution and high background equivalent flux introduced by the need to minimize reflections to maintain effective area. The spectroscopic imaging capabilities of STIS on the Hubble Space Telescope at λ > 1150 Å are both heavily oversubscribed, and of relatively small grasp (the product of effective area and solid angle). As a result, to date < 0.03% of the sky has been observed by an instrument capable of resolving individual sources to < 1° in the wavelength range spanning from HI Lyman alpha (λ = 1216 Å) to the Lyman break (λ = 912 Å). New advances, both analytical and technical, are changing this paradigm. Using the UV imaging capabilities of the Advanced Camera for Surveys on HST, I’ll discuss new ways of extracting the Lyman alpha flux from low-redshift star-forming galaxies on angular scales ≤ 1 arcsecond, and how these spectral line maps change our understanding of where and how Lyman alpha, which is resonant line with a high scattering cross section, escapes from galaxies. I will then present on-going results from a LASP/GSFC collaboration to qualify new mirror coatings for flight – the first major advance in broadband UV – VIS – IR coating technology for over 30 years. I’ll end by introducing the latest CU/LASP sounding rocket payload, SISTINE, which will flight test these new coatings in the 2018 timeframe to observe the far-UV spectra of planet-hosting M-stars.