The X-Ray Imaging and Spectroscopy Mission (XRISM) has delivered groundbreaking insights into the structure, motion, and temperature of material surrounding both a supermassive black hole and a supernova remnant.

By providing unprecedented detail, XRISM has advanced our understanding of the complex dynamics at play in these extreme cosmic environments.

Unveiling Cosmic Dynamics: XRISM's First Discoveries

The XRISM space telescope, led by the Japan Aerospace Exploration Agency (JAXA) with contributions from the European Space Agency (ESA), has already made significant strides in revealing the temperature, velocity, and three-dimensional structure of material around some of the universe’s most extreme objects.

Its early observations have provided detailed views of the supernova remnant N132D in the Large Magellanic Cloud and a supermassive black hole in the spiral galaxy NGC 4151.

"These new observations provide crucial information for understanding how black holes grow by capturing surrounding matter and offer new insights into the life and death of massive stars," said ESA XRISM Project Scientist Matteo Guainazzi. "They showcase the mission's exceptional capability to explore the high-energy universe."

Insights into the Supernova Remnant N132D

One of XRISM's "first light" observations focused on N132D, a supernova remnant located about 160,000 light-years away in the Large Magellanic Cloud.

This remnant, a bubble of hot gas formed by the explosion of a massive star roughly 3,000 years ago, had long been assumed to be a simple spherical structure. However, XRISM revealed that N132D has a far more complex doughnut-like shape.

Using its advanced Resolve instrument, XRISM captured the velocity of the hot plasma within the remnant, revealing that the material is expanding at around 1,200 kilometers per second. Resolve also detected iron in the remnant at an extraordinary temperature of 10 billion degrees Kelvin, a phenomenon predicted by theoretical models but never observed before.

These findings offer a deeper understanding of how supernovae distribute heavy elements like iron throughout interstellar space, a process critical to the formation of planets and life.

Previous X-ray observatories struggled to uncover the detailed distribution of velocity and temperature within supernova remnants, making XRISM’s observations a significant leap forward.

JAXA’s XRISM X-ray telescope captured the distribution of matter falling into the supermassive black hole in galaxy NGC 4151 over a wide radius, spanning from 0.001 to 0.1 light-years. By determining the speed of the iron atoms from their X-ray signature, scientists have mapped out a sequence of structures surrounding the central ‘monster’: the disk closest to the black hole (in blue) where gas moves at a speed a few percent of the speed of light, followed by a transition region where gas is moving at speed of thousands of km/s and which astronomers call “the broad line region (BLR)” (in orange), and finally the doughnut-shaped torus (in red). Credit: JAXA

Shedding Light on a Supermassive Black Hole in NGC 4151

XRISM's observations also provided a new perspective on the structure surrounding a supermassive black hole in NGC 4151, a spiral galaxy located 62 million light-years away. This black hole, 30 million times more massive than the Sun, is surrounded by a vast region of swirling matter.

XRISM was able to map the material over a range extending from 0.001 to 0.1 light-years—a distance comparable to the Sun-Uranus separation—revealing intricate details of the matter’s motion as it spirals inward.

By tracking the motions of iron atoms through their X-ray emissions, XRISM mapped the layers of material surrounding the black hole, from the inner accretion disk feeding the black hole to the outer doughnut-shaped torus.

This is the first time such detailed structures have been observed around a black hole using spectroscopic techniques, offering critical insights into how black holes grow by consuming surrounding matter.

While radio and infrared observations have previously indicated the existence of torus-like structures around black holes, XRISM's X-ray data provides the most precise view yet of how gas near a black hole is structured and how it moves.

Future Observations and Discoveries

Over the coming year, XRISM will continue to observe key cosmic targets, drawing from over 300 proposals submitted by scientists worldwide. The mission team has already selected 104 new sets of observations, promising many more discoveries ahead.

As XRISM’s instruments exceed initial expectations, researchers are excited for what lies ahead. With its ability to capture high-energy X-ray emissions, XRISM is poised to illuminate new frontiers in our understanding of the universe, from the evolution of massive stars to the growth of supermassive black holes.

These early results from XRISM are just the beginning, with many more celestial phenomena waiting to be explored in unprecedented detail.

Sources:

“XRISM Spectroscopy of the Fe Kα Emission Line in the Seyfert AGN NGC 4151 Reveals the Disk, Broad Line Region, and Torus” by XRISM Collaboration, Accepted, Astronomical Society of Japan. arXiv:2408.14300

“The XRISM First Light Observation: Velocity Structure and Thermal Properties of the Supernova Remnant N132D” by XRISM Collaboration, Accepted, The Astrophysical Journal. arXiv:2408.14301

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