Julie E M McGeoch

Julie McGeoch is a Research Associate at the Center for Astrophysics | Harvard & Smithsonian and before that in FAS Molecular and Cellular Biology. The research links protein chemistry to astronomy centering on a polymer termed Hemoglycin of iron, glycine and silicon that forms in molecular clouds. Cosmic dust and asteroid derived sources (carbonaceous meteorites, fossil and present-day stromatolites and sea foam) are chemically treated in a phase system to produce pure polymer that is then characterized by mass spectrometry, isotope analysis, X-ray diffraction, (APS and Diamond Light Source synchrotrons), infrared absorption via FTIR, and TEM electron diffraction (Diamond and Harvard). Telescopes like Hubble in the past and the JWST now, produce spectral data that can be assigned to the polymer from 0.1-15µm. Currently hemoglycin is under consideration as the molecular basis of the “UV bump” because its extinction curve duplicates the nominal 218nm ultraviolet absorption feature, together with two visible absorption features present in a generic compilation of astronomical extinction data. Future hemoglycin research via the JWST in very early galaxies at high red-shift around 200nm (resting) 2-4µm (observed), could be used to produce data that distinguishes metal poor (H/He/Li) stars from those with the first 8 elements and Fe and Si. Hemoglycin could form at about 500Myr when its constituent elements first existed. Image – checking for clean sea foam.

 

Bsc Hons & PhD Southampton University UK