The XRISM satellite has provided unprecedented X-ray observations of sulfur in our Milky Way galaxy, revealing its presence in both gaseous and solid forms. Scientists utilized the Resolve instrument on XRISM to analyze X-rays emitted from the vicinity of the X-ray binary GX 340+0.
These detailed measurements allowed researchers to determine that sulfur is not only present as a gas but also as a solid, possibly in compounds with iron. Elisa Costantini, a senior astronomer at the Space Research Institution Netherlands and the University of Amsterdam, noted that laboratory models of sulfur combined with iron appear to match the XRISM data. Her team has been developing models of various elements for comparison with astronomical data for years, and ongoing campaigns will provide further sulfur measurements to enhance understanding.
The presence of iron-sulfur compounds,such as those found in meteorites,has long been theorized as a mechanism for sulfur to solidify from molecular clouds and travel through space. The research paper proposes specific compounds like pyrrhotite, troilite, and pyrite as potential matches for XRISM’s observations. Data from a second X-ray binary, 4U 1630-472, was also used to corroborate these findings.
Brian Williams, the XRISM project scientist at NASA’s Goddard Space Flight Center, highlighted that while NASA’s Chandra X-ray Observatory has previously studied sulfur, XRISM’s measurements offer greater detail. he emphasized that XRISM’s observations of GX 340+0, located on the opposite side of the galaxy, offer a unique perspective on sulfur distribution across a meaningful portion of the Milky Way.
The XRISM mission is a collaborative effort led by the Japan Aerospace Exploration Agency (JAXA), with participation from NASA and contributions from the European Space Agency (ESA).NASA and JAXA jointly developed Resolve, the mission’s microcalorimeter spectrometer.
