A global team of scientists have provided an unprecedented tally of elemental sulfur spread between the celebrities using data from the Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) spacecraft.
Astronomers used X-rays from two binary star systems to detect sulfur within the interstellar medium, the gas and dirt present in the space between stars. It’s the primary direct measurement of each sulfur’s gas and solid phases, a singular capability of X-ray spectroscopy, XRISM’s (pronounced “crism”) primary approach to studying the cosmos.
“Sulfur is very important for a way cells function in our bodies here on Earth, but we still have a number of questions on where it’s discovered within the universe,” said Lía Corrales, an assistant professor of astronomy on the University of Michigan in Ann Arbor. “Sulfur can easily change from a gas to a solid and back again. The XRISM spacecraft provides the resolution and sensitivity we want to search out it in each forms and learn more about where it may be hiding.”
A paper about these results, led by Corrales, published June 27 within the Publications of the Astronomical Society of Japan.
Using ultraviolet light, researchers have found gaseous sulfur within the space between stars. In denser parts of the interstellar medium, comparable to the molecular clouds where stars and planets are born, this kind of sulfur quickly disappears.
Scientists assume the sulfur condenses right into a solid, either by combining with ice or mixing with other elements.
When a physician performs an X-ray here on Earth, they place the patient between an X-ray source and a detector. Bone and tissue absorb different amounts of the sunshine because it travels through the patient’s body, creating contrast within the detector.
To check sulfur, Corrales and her team did something similar.
They picked a portion of the interstellar medium with the precise density — not so thin that every one the X-rays would go through unchanged, but in addition not so dense that they’d all be absorbed.
Then the team chosen a shiny X-ray source behind that section of the medium, a binary star system called GX 340+0 positioned over 35,000 light-years away within the southern constellation Scorpius.
Using the Resolve instrument on XRISM, the scientists were in a position to measure the energy of GX 340+0’s X-rays and determined that sulfur was present not only as a gas, but in addition as a solid, possibly mixed with iron.
“Chemistry in environments just like the interstellar medium may be very different from anything we are able to do on Earth, but we modeled sulfur combined with iron, and it seems to match what we’re seeing with XRISM,” said co-author Elisa Costantini, a senior astronomer on the Space Research Organization Netherlands and the University of Amsterdam. “Our lab has created models for various elements to check with astronomical data for years. The campaign is ongoing, and shortly we’ll have recent sulfur measurements to check with the XRISM data to learn much more.”
Iron-sulfur compounds are sometimes present in meteorites, so scientists have long thought they may be a technique sulfur solidifies out of molecular clouds to travel through the universe.
Of their paper, Corrales and her team propose just a few compounds that may match XRISM’s observations — pyrrhotite, troilite, and pyrite, which is typically called idiot’s gold.
The researchers were also in a position to use measurements from a second X-ray binary called 4U 1630-472 that helped confirm their findings.
“NASA’s Chandra X-ray Observatory has previously studied sulfur, but XRISM’s measurements are probably the most detailed yet,” said Brian Williams, the XRISM project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Since GX 340+0 is on the opposite side of the galaxy from us, XRISM’s X-ray observations are a singular probe of sulfur in a big section of the Milky Way. There’s still a lot to learn in regards to the galaxy we call home.”
XRISM is led by JAXA (Japan Aerospace Exploration Agency) in collaboration with NASA, together with contributions from ESA (European Space Agency). NASA and JAXA developed Resolve, the mission’s microcalorimeter spectrometer.