By the mid-20th century, astronomers began to detect black holes for the first time using indirect methods, which involved observing surrounding objects and their effects on space.
Since the 1980s, scientists have studied supermassive black holes (SMBHs), which reside at the center of the most massive galaxies in the universe. and as of April 2019, event horizon telescope (EHT) Cooperation free First ever image of an SMBH.
These observations are an opportunity to test the laws of physics under the most extreme conditions and provide insight into the forces that shape the universe.
according to a recent The study, an international research team relied on data from ESA Gaia Observatory Observing a Sun-like star with strange orbital characteristics. Due to the nature of its orbit, the team concluded that it was called a . should be part of black hole binary system.
This makes it the closest black hole to our solar system and indicates the existence of a large population of dormant black holes in our galaxy.
He was joined by researchers from CfA, MPIA, Caltech, UC Berkeley, Flatiron Institute Center for Computational Astrophysics (CCA), weisman institute of scienceThe Paris Observatorywhat Kavli Institute for Astrophysics and Space Researchand many universities.
paper which describes their findings, will be published in Monthly Notice of the Royal Astronomical Society,
As El-Badri explained to Universe Today via email, these observations were part of a broader campaign to identify dormant black hole companions to normal stars in the Milky Way galaxy.
“I have been searching for dormant black holes for the past four years using a wide range of datasets and methods,” he said.
“My previous efforts turned up a diverse menagerie of binaries such as black holes, but this was the first time the discovery bore fruit.”
For this study, El-Badri and his colleagues relied on data obtained by the European Space Agency’s (ESA) Gaia Observatory. The mission has spent nearly a decade measuring the positions, distances and proper motions of nearly 1 billion celestial bodies, such as stars, planets, comets, asteroids and galaxies.
By tracking the motion of objects orbiting the center of the galaxy (a technique known as astrometry), the Gaia mission aims to produce the most accurate 3D space catalog ever created.
For their purposes, El-Badri and his colleagues examined all 168,065 stars in Gaia Data Release 3 (GDR3) that appeared to be in two-body orbits.
One particularly promising candidate in their analysis, a G-type (yellow star) designated Gaia DR3 4373465352415301632 – for their purposes, the team designated it Gaia BH1. Based on its observed orbital resolution, El-Badri and his colleagues determined that the star must have a black hole binary companion.
El-Badri said: “The Gaia data constrain how the star moves across the sky, tracing an ellipsoid as it orbits the black hole. The size of the orbit and its period give us a constraint on the mass of its unseen companion. Gives – about 10 solar masses.
“To confirm that the Gaia solution is correct and to rule out non-black hole options, we observed the star spectroscopically with several other telescopes. This tightened our constraints on the companion’s mass and proved Given that it is really ‘dark’.”
To confirm their observations, the team analyzed Gaia BH1’s radial velocity measurements from several telescopes.
This includes the WM Keck Observatory’s High-Resolution Eschel Spectrometer (appointments), fiber-fed extended range optical spectrograph of the MPG/ESO telescope (Wild) Spectrograph, Very Large Telescope (VLT) X-Shooter SpectrographThe Gemini Multi-Object Spectrograph (GMOS), Magellan Echelet (MagE) spectrograph, and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (Lamost,
Similar to the method used to hunt for exoplanets (Doppler spectroscopy), the spectra provided by these instruments allowed the team to observe and measure the gravitational forces affecting their orbit. These follow-up observations confirmed the orbital resolution of Gaia BH1 and that a companion of about 10 solar masses was co-orbiting with it.
As indicated by El-Badri, these findings may constitute the first black hole in the Milky Way that was not observed based on X-ray emission or other energetic release:
“Models predict that there are about 100 million black holes in the Milky Way. But we’ve only seen 20 of them. All the previous ones we’ve seen are in an ‘X-ray binary’: the black hole eating a companion star.” , and it glows brightly in X-rays because the gravitational potential energy of that material is converted into light.
“But these represent only the tip of the iceberg: a much larger population may lurk, hidden in more widely separated binaries. The discovery of Gaia BH1 sheds early light on this population.”
If confirmed, these findings could mean that the galaxy has a strong population of dormant black holes. It refers to black holes that are not apparent from bright disks, bursts of radiation, or hypervelocity jets emanating from their poles (as is often the case with quasars).
If these objects are ubiquitous in our galaxy, the implications for stellar and galactic evolution could be profound. However, it is possible that this particular dormant black hole is an outlier and is not indicative of a large population.
To verify their findings, el-Badri and his colleagues are looking forward to Gaia Data Release 4 (GDR4), the date of which is still to be determined, consisting of data collected during the five-year nominal mission (GDR4). All data made will be included. ,
This release will include the most up-to-date astrometric, photometric and radial-velocity catalogs for all stars, binaries, galaxies and exoplanets observed.
The fifth and final release (GDR 5) will include data from nominal and extended missions (full 10 years).
“Based on the BH companion event rate implicated by Gaia BH1, we hypothesized that the next Gaia data release will enable the discovery of dozens of similar systems,” El-Badri said.
“With just one object, it’s hard to know what this means about a population (it could just be a weird ball, a fluke. We’re excited about the population demographic study we’re able to do with a larger sample). will be able.”