The Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) recently began studying the monster black hole at the center of the galaxy NGC 4151. The Resolve instrument captured a detailed spectrum of the area surrounding the black hole, providing insights into the elements present and the fate of matter as it nears the black hole. XRISM is a collaborative mission between JAXA, NASA, and ESA, with NASA and JAXA developing the Resolve microcalorimeter spectrometer. NGC 4151 is a spiral galaxy located around 43 million light-years away in the constellation Canes Venatici, with a supermassive black hole at its center holding over 20 million times the Sun’s mass.
The center of NGC 4151 is unusually bright and variable due to its active nature, with gas and dust swirling towards the black hole forming an accretion disk that heats up through gravitational and frictional forces, causing variability. Some matter near the black hole forms twin jets of particles moving at nearly the speed of light, while a torus cloud of material surrounds the accretion disk. The galaxy is one of the closest-known active galaxies, making it an ideal target for missions like XRISM, Chandra X-ray Observatory, and Hubble Space Telescope to study the interaction between black holes and their surroundings and understand how supermassive black holes grow over time.
The Resolve spectrum of NGC 4151 revealed a sharp peak in iron emissions just under 6.5 keV, indicating the presence of iron in the region. X-rays originating from hot, flaring regions close to the black hole and bouncing off cooler gas in the disk cause iron to fluoresce, creating a specific X-ray peak. The spectrum also showed dips around 7 keV, caused by iron in the torus absorbing X-rays due to its cooler temperature compared to the disk. XRISM can detect various elements such as sulfur, calcium, and argon, providing astrophysicists different insights into cosmic phenomena scattered across the X-ray sky.
The data collected by XRISM will help scientists paint a better picture of the accretion disk and erupting regions near the black hole, shedding light on the processes that power active galaxies. The mission is a joint effort between JAXA, NASA, and ESA, with NASA’s contribution including science participation from the Canadian Space Agency. The collaboration between these agencies allows for a more comprehensive study of the cosmic phenomena and the role of supermassive black holes in galactic centers.
In summary, the ongoing science operations of XRISM have provided valuable insights into the supermassive black hole at the center of NGC 4151 and the surrounding active galaxy. The detailed spectrum captured by the Resolve instrument has revealed the presence of various elements, such as iron, sulfur, calcium, and argon, offering astrophysicists a better understanding of the cosmic phenomena observed in the X-ray sky. The collaborative effort between JAXA, NASA, ESA, and the Canadian Space Agency ensures a comprehensive study of active galaxies and the role of supermassive black holes in shaping the universe over cosmic time.
