As the name suggests, X-ray binaries are star systems made up of two parts: a compact stellar remnant -- either a neutron star or a black hole; and a companion star -- a normal star like our sun.
Circinus X-1: Supernova Blast Provides Clues to Age of Binary Star System
Credit: X-ray: NASA/CXC/Univ. of Wisconsin-Madison/S.Heinz et al; Optical: DSS; Radio: CSIRO/ATNF/ATCA
As they orbit one another, the neutron star or black hole pulls in gas from the companion star. This heats the gas to millions of degrees, producing intense X-ray radiation and making these star systems some of the brightest X-ray sources in the sky.
Sebastian Heinz and his team at the University of Wisconsin-Madison (UW) discovered Circinus X-1 is less than 4,600 years old, making it the youngest X-ray binary system ever seen. This discovery, made in parallel with a radio telescope in Australia, provides scientists unique insight into the formation of neutron stars and supernovas, and the effect of the supernova's explosion on a nearby companion star.
"X-ray binaries provide us with opportunities to study matter under extreme conditions that would be impossible to recreate in a laboratory," Heinz said. "For the first time, we can study a newly minted neutron star in an X-ray binary system."
Astronomers have detected hundreds of X-ray binaries throughout the Milky Way and other nearby galaxies. However, these older X-ray binaries, with ages typically measured in millions of years, only reveal information about what happens much later in the evolution of these systems.
"It's critical that we see what these X-ray binaries are doing at all stages of their lives," said co-author Paul Sell, also of UW. "Circinus X-1 is showing us what happens in a cosmic blink of an eye after one of these objects is born."
To determine the age of Circinus X-1, the team of astronomers needed to examine the material around the orbiting pair of stars. However, the overwhelming brightness of the neutron star made it too difficult for researchers to observe that interstellar gas. The team recently caught a break, when they observed the neutron star in a very faint state -- dim enough for scientists to detect the X-rays from the supernova shock wave that plowed through the surrounding interstellar gas.
"Since the supernova was triggered by the formation of the neutron star, our limit on the age of the supernova remnant also limits the age of the neutron star in Circinus X-1," said co-author Robert Fender of the University of Oxford in the U.K.
The youth of Circinus X-1 helps explain its wild swings in brightness and the highly unusual orbit of its two stars, which had puzzled astronomers for years. The orbit is very eccentric -- non-circular -- and the period during which the two stars orbit each other is decreasing by several minutes every year. This is exactly what is expected for a young X-ray binary disrupted by a supernova explosion before the gravitational pull of the stars on each other has had time to circularize and stabilize the orbit.
Previous observations with other telescopes indicated the magnetic field of the neutron star in Circinus X-1 is weak. That, in addition to the star system's young age, has led to two possible theories: either a neutron star can be born with a weak magnetic field, or it can quickly become de-magnetized as it pulls material from its companion star onto itself. Neither conclusion was expected from existing theories of neutron star evolution.
In our galaxy, the only other established X-ray binary within a supernova remnant is SS 433, which is between 10,000 and 100,000 years old, and behaves in many ways like an older version of Circinus X-1. Two other candidate X-ray binaries in nearby galaxies have ages similar to SS 433.
In addition to the Chandra data, radio observations from the Australia Telescope Compact Array were critical in these findings. A paper describing these results is available online and appears in the Dec. 4 issue of The Astrophysical Journal.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Mass., controls Chandra's science and flight operations.For Chandra images, multimedia and related materials, visit:
Megan Watzke | EurekAlert!
Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory
SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences