Fig. 3: Isotopic composition of Ryugu carbonaceous grains.
From: Variations of organic functional chemistry in carbonaceous matter from the asteroid 162173 Ryugu
A High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) mosaic of a focused ion beam (FIB) lamella extracted from Chamber A particle A0108-3. B Nanoscale secondary ion mass spectrometry (NanoSIMS) elemental map of O, C, and S (in magenta, green, and blue, respectively). C Isotope ratio image of 13C/12C normalized to the solar value, also showing the location of a presolar SiC grain. D Isotope ratio image of δ15N/14N. Locations of carbonaceous grains in the section for which both x-ray absorption near edge structure (XANES) spectra and isotopic data were acquired are outlined in A–D. E C and N isotope compositions of carbonaceous grains. Grains with corresponding XANES spectra are color-coded by their shape classification. Dashed lines indicate “bulk” values for Ryugu34. Carbon grains that are not correlated with scanning transmission x-ray microscopy (STXM) data (gray points) have error bars (2σ) similar in size to the colored points, but have been removed for clarity. The arrows in (A-E) indicate the location and isotopic composition of the carbon grain shown in Fig. 2C.
