X-Ray Astronomy Archives

June 28, 2024June 28, 2024 by Matt Williams

These Three Neutron Stars Shouldn't Be So Cold

Artist's impression of a neutron star, with white/blue filaments are streaming out from its polar regions, representing magnetic field lines. Credit: ESA

Neutron stars are among the densest objects in the Universe, second only to black holes. Like black holes, neutron stars are what remains after a star reaches the end of its life cycle and undergoes gravitational collapse. This produces a massive explosion (a supernova), in which a star sheds its outer layers and leaves behind a super-compressed stellar remnant. In fact, scientists speculate that matter at the center of the star is compressed to the point that even atoms collapse and electrons merge with protons to create neutrons.

Traditionally, scientists have relied on the “Equation of State” – a theoretical model that describes the state of matter under a given set of physical conditions – to understand what physical processes can occur inside a neutron star. But when a team led by scientists from the Spanish National Research Council (CSIC) examined three exceptionally young neutron stars, they noticed they were 10-100 times colder than other neutron stars of the same age. For this, the researchers concluded that these three stars are inconsistent with most of the proposed equations of state.

May 21, 2024May 21, 2024 by Andy Tomaswick

After Swirling Around a Black Hole, Matter Just Falls Straight In

On the left, an optical image from the Digitized Sky Survey shows Cygnus X-1, outlined in a red box. Cygnus X-1 is located near large active regions of star formation in the Milky Way, as seen in this image that spans some 700 light years across. An artist's illustration on the right depicts what astronomers think is happening within the Cygnus X-1 system. Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. New studies with data from Chandra and several other telescopes have determined the black hole's spin, mass, and distance with unprecedented accuracy.

The physics surrounding black holes is just plain weird. A gravitational well so strong that not even light can escape can do some pretty strange things to normal matter. Over the decades, plenty of theories have been put forward about what those strange things might be. And now, a new paper from physicists at the University of Oxford has proved that, once again, Einstein’s theory of gravity was right.

April 29, 2024April 29, 2024 by Mark Thompson

First Light from Einstein Probe: A Supernova Remnant

On 9 January 2024, the Einstein probe was launched, its mission to study the night sky in X-rays. The first image from the probe that explores the Universe in these energetic wavelengths has just been released. It shows Puppis A, the supernova remnant from a massive star that exploded 4,000 years ago. The image showed the expanding cloud of ejecta from the explosion but now, Einstein will continue to scan the skies for other X-ray events.

April 13, 2024April 13, 2024 by Matt Williams

Stellar Winds Coming From Other Stars Measured for the First Time

Infrared image of the shockwave created by the massive giant star Zeta Ophiuchi in an interstellar dust cloud. Credit: NASA/JPL-Caltech; NASA and The Hubble Heritage Team (STScI/AURA); C. R. O'Dell, Vanderbilt University

An international research team led by the University of Vienna has made a major breakthrough. In a study recently published in Nature Astronomy, they describe how they conducted the first direct measurements of stellar wind in three Sun-like star systems. Using X-ray emission data obtained by the ESA’s X-ray Multi-Mirror-Newton (XMM-Newton) of these stars’ “astrospheres,” they measured the mass loss rate of these stars via stellar winds. The study of how stars and planets co-evolve could assist in the search for life while also helping astronomers predict the future evolution of our Solar System.

March 28, 2024March 28, 2024 by Andy Tomaswick

This Black Hole is a Total Underachiever

Anyone can be an underachiever, even if you’re an astronomical singularity weighing over four billion times the mass of the Sun. At least the quasar H1821+643 doesn’t have parents to be disappointed in it. But its underachievement could shed light on how quasars, a potent type of black hole, can come to influence entire clusters of galaxies, as described in a new paper from researchers at the University of Nottingham and Harvard.

February 2, 2024February 2, 2024 by Carolyn Collins Petersen

Half the Entire Sky, Seen in X-Rays

This image show half of the X-ray sky, projected onto a circle with the center of the Milky Way on the left and the galactic plane running horizontally. Photons have been colour-coded according to their energy (red for energies 0.3-0.6 keV, green for 0.6-1 keV, blue for 1-2.3 keV). Credit: MPE, J. Sanders for the eROSITA consortium

There’s an old trope in science fiction about someone suddenly getting X-ray vision and looking through solid objects. It turns out to be a physical impossibility with our Mark I eyeballs. However, astronomers have found a way around that challenge that lets us study the Universe with X-ray vision.

January 10, 2024January 10, 2024 by Mark Thompson

Chinese Rocket Lofts the Einstein Probe and its “Lobster Eyes”

Any astronomical instrument dubbed “Lobster Eyes” is bound to grab attention. It’s actually unlike scientists to give anything creative names, take the big red coloured storm on Jupiter which resembles a spot…aka the Great Red Spot! Lobster Eyes is the name adtoped by the X-ray telescope that just been launched from China and will scan the sky looking for X-rays coming from high-energy transients.

January 6, 2024January 6, 2024 by Evan Gough

Japan’s New X-Ray Observatory Sees First Light

Supernova remnant N132D lies in the central portion of the Large Magellanic Cloud, a dwarf galaxy about 160,000 light-years away. XRISM’s Xtend captured the remnant in X-rays, displayed in the inset. Although bright in X-rays, the stellar wreckage is almost invisible in the ground-based background view taken in optical light. Credit: Inset, JAXA/NASA/XRISM Xtend; background, C. Smith, S. Points, the MCELS Team and NOIRLab/NSF/AURA

XRISM, the X-ray Imaging and Spectroscopy Mission, is a joint NASA/JAXA mission led by JAXA. The X-ray space telescope began its mission in low-Earth orbit on September 6th, 2023. Science operations won’t begin until later this year, but the satellite’s science team has released some of the telescope’s first images.

November 30, 2023November 30, 2023 by Evan Gough

Spider Pulsars are Tearing Apart Stars in the Omega Cluster

Omega Centauri is the brightest globular cluster in the night sky. It holds about 10 million stars and is the most massive globular cluster in the Milky Way. It's possible that globulars and nuclear star clusters are related in some way as a galaxy evolves. Image Credit: ESO.

Pulsars are extreme objects. They’re what’s left over when a massive star collapses on itself and explodes as a supernova. This creates a neutron star. Neutron stars spin, and some of them emit radiation. When they emit radiation from their poles that we can see, we call them pulsars.

May 15, 2023May 15, 2023 by Andy Tomaswick

Confirmed. Ultra-Luminous X-Ray Sources are Really That Bright

At the extreme end of astrophysics, there are all sorts of phenomena that seem to be counter-intuitive. For example, how can an object not possibly get any brighter? For a long time, this limit, known as the Eddington limit, was thought to be an upper bound on how bright an object could be, and it was directly correlated with the mass of that object. But observations showed that some objects were even brighter than this theoretical limit, and now data collected by NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) confirms that these objects are, in fact, breaking the Eddington limit. But why?