The compact object draws material from the star and gradually adds it to its own mass, using a spiral disk formed around it. This process was called accretion. There are currently 20 known X-ray black hole binary systems, and the IAC researchers estimate that there are 5,000 X-ray black hole binary systems in our galaxy.
Researchers from the Instituto de Astrofisica de Canarias (IAC) have discovered a black hole with a mass 5.4 times that of our Sun in an X-ray binary system called XTE J1859+226. The observations conducted with the Gran Telescopio Canarias (GTC) telescope and managed to obtain initial spectroscopic information from the binary system for publication, were decisive observations for this discovery. Star systems that are X-ray binary systems consist of a compact object (which can be a neutron star or a black hole) and a "normal" star.
The compact object draws material from the star and gradually adds it to its own mass, using a spiral disk formed around it. This process was called accretion. There are currently 20 known X-ray black hole binary systems. The IAC researchers estimate that there are about 5,000 X-ray black hole binaries in our galaxy.
The XTE system J1859+226 is a variable X-ray system located in the Vulpecula group. It was discovered by the RXTE satellite during an outburst captured in 1999.
"Variable X-ray systems are characterized by the fact that they spend most of their lives in a quiescent state, but occasionally they enter a state of eruption. In this situation, the rate of absorption of matter into the black hole gained momentum," explains Chazos Corral Santana, an astrophysicist from the IAC, who headed the research published in the Monthly Notices of the Royal Astronomical Society (MNRAS).
Neutron stars, similar to black holes, are the remnants left after the death of a giant star. Most known neutron stars have a mass of about 1.4 times that of our Sun, but there are cases where masses of more than 2 times that of the Sun have been measured. Astronomers believe that when the mass is more than three times the mass of the Sun, neutron stars are unstable and eventually collapse to form a black hole.
Corale-Santana explains, "Measuring the mass of compact objects is essential for determining the type of object. If its mass is more than 3 times the mass of the Sun, then it must be a black hole. We found that the mass of XTE J1859+226 is 5.4 times the mass of the Sun. This is a sure confirmation that there is a black hole in this system."
"With the help of this result, we have added another piece of information to the study of the mass distribution of black holes. The shape of the distribution has extremely important implications for our knowledge of the death of massive stars, the formation of black holes, and the evolution of X-ray binaries." added the astrophysicist from the IAC.
Twelve years of observation: measuring the visible and the invisible
The team of astrophysicists at the IAC began making systematic observations of the object when the eruption began in 1999, and they continue to monitor its evolution. The researchers combined the photometric measurements from the Isaac Newton Telescope (INT) and the William Herschel Telescope (WHT) from 2000, with the measurements from the Nordic Optical Telescope (NOT) from 2008, and with the spectroscopic measurements from the GTC from 2010, which were the first published on this celestial object .
"Because of the low brightness of the observed system, we needed telescopes with a diameter of 10 meters to get information about the spectrum. From this point of view, the fact that we were able to make observations at the GTC was of crucial importance," emphasized Coral-Santa.
The measurements at GTC were made using the OSIRIS instrument, which can be used as a camera or spectrograph in the visible range. The spectrograph separates the light created by the star into the different frequencies and makes it possible to distinguish the lines that correspond to the different chemical elements that exist in its atmosphere. These lines confirm the information about the physical properties of the star and its movement.
The photometric measurements make it possible to determine the orbital cycle of the binary star, while the spectroscopic information provides additional information on the speed of the star in its movement around the black hole. The combination of parameters was essential to calculate the mass of the black hole.
The Gran Telescopo Canarias - GTC telescope located at the Roque de los Muchachos Observatory, in La Palma, Canary Islands, is the largest infrared optical telescope in the world, and its mirror diameter is 10.4 meters.
JM Corral-Santana, J. Casares, T. Shahbaz, C. Zurita, IG Martínez-Pais, P. Rodríguez-Gil. Evidence for a black hole in the X-ray transient XTE J1859 226. Monthly Notices of the Royal Astronomical Society: Letters, 2011; DOI: 10.1111/j.1745-3933.2011.01022.x
12 תגובות
What is this nonsense there are far more than 5000
To Ronan - this is a double star system, meaning that it has two suns.
What is a binary system?
Thanks.
After checking with Mr. Coral-Santana, 5000 refers to the estimated number of X-ray black hole binaries in the Milky Way Galaxy, not all binaries, which are obviously more numerous.
1/3 according to one of the sources cited here. 40%-50% according to Mr. Coral Santana.
fixed
Yehuda, A. Ben Ner:
Not a majority and not 5000.
Wikipedia Write:
"It is estimated that approximately 1/3 of the star systems in the Milky Way are binary or multiple, with the remaining 2/3 consisting of single stars.[57]"
5000 binary systems only? Not a little bit?
Perhaps the reference is to documented and marked binary systems in the "close environment"?
Aviv - like the warning about Sinai - it does not pose a real threat since we are not going there soon...
Rami K:
There is no contradiction between what you learned and what is written here.
What you learned talks about the size of the star before the supernova explosion.
So it is still much more massive.
During the explosion most of the mass is blown away and only a part of it eventually becomes a neutron star or a black hole.
3 times creates a black hole at the end? I learned that much more???
Most of the stars in our galaxy are binary star systems and not just five thousand as written in the article.
It is possible that the reference is to five thousand stars that have a spiral disk and adsorption systems.
In addition, it must be remembered that it is impossible to see black holes and all reference to them is from the behavior of their environment.
Shabbat Shalom
Sabdarmish Yehuda
It. threatening us or something like that?
Is there a connection between a black hole and antimatter? Thanks.
By the way, a new interesting article about antimatter and lightning
http://www.nasa.gov/mission_pages/GLAST/news/fermi-thunderstorms.html