Sci-tech

Milky Way core may harbor thousands of black holes

Milky Way core may harbor thousands of black holes

Astronomers now believe that most galaxies have massive black holes at their center to help keep everything together. "The galactic centre is a odd place". Typically, one member of the pair is a garden-variety star while the other is either a black hole or a neutron star. But you can see evidence of a black hole's meal.

Using data collected by the Chandra X-ray Observatory telescope, they found 12 black hole binaries within around 3.3 light-years from Sagittarius A*. It can be particularly tricky to distinguish between binary systems involving quiescent (minimally accreting) black holes and millisecond pulsars. By combining all these data, and concentrating on the area close to the centre, the team discovered diffuse X-ray emission and about 100 distinct X-ray sources within 13 light years of Sagittarius A*, 26 of which are contained within just three light years of it. However, there are millions of white dwarfs in the galaxy.

In the new study, Charles Hailey, an astrophysicist at Columbia University, and his colleagues scrutinized the past dozen years of data gathered by the Chandra X-ray Observatory, an orbiting craft whose instruments are created to detect high-energy radiation emitted by the immensely hot material surrounding exploded stars and near black holes.

A new study supports the prevailing theory of where some of the universe's most mysterious inhabitants - black holes - reside.

Researchers have long theorized black holes would be found at the center of galaxies in large numbers, along with gas and stars, however scientists had not been able to find any outside the supermassive one at the center of the Milky Way.

Man United announce cheap youth tickets for 2018-19 season
Reports the France global could depart in summer just two years after his world-record arrival have intensified in recent weeks. And he added fuel to the fire by saying he wants to play alongside Brazilian forward Neymar at some stage in his career.

The astronomers were also careful not to be fooled by the many other intriguing X-ray-emitting objects at the galactic centre.

So to determine the number around the Galactic Center, the researchers had to delve into their knowledge of black hole physics.

High-energy x-ray sources (blue) are seen near the core of the Milky Way (bright region at lower right) in this composite image.

This artist's rendering shows Sagittarius A* surrounded by a cloud of dust and gas, within which are 12 small black holes.

Astronomers poring over old x-ray observations have found signs of a dozen black holes in the inner circle of the Milky Way. The collapsed giant stars have a gravitational pull so strong that even light can't get out.

Missing Daughter Reunites With Family 24 Years Later In China
Qifeng eventually reached out to her parents after coming across an online post describing the incident and her father's quest. The last time Wang Mingquing and his wife Liu Dengying saw their daughter Qifeng was when she was just three-years-old.

Then they analysed the properties and spatial distribution of these binaries, and extrapolated on these findings to conclude that there must be somewhere between 300 and 500 low-mass binaries in the Milky Way's central parsec, and around 10,000 lone black holes. "All the information astrophysicists need is at the center of the galaxy". Our home galaxy consists of several hundred billion stars, with huge amounts of gas and dust, all intermingled and interacting through the force of gravity.

Instead, the researchers looked for slow-burn signals that would also indicate the presence of smaller black holes, in order to spot all of the signals that otherwise can't be observed.

"Isolated black holes just don't do much of anything", says lead author Hailey. "Some of them were formed comparatively recently". But despite their predicted prevalence, these black holes are so dark and quiescent that they have been all but undetectable against the galactic center's stellar splendor-at least, until now. And, Hailey said, perhaps they will find one at the centre of a distant galaxy.

"I think this is a really intriguing result", says Fiona Harrison, an astrophysicist at Caltech.

Google Doodle celebrates the 115th birthday of the Kamladevi Chattopadhyay
Even after India 's independence in 1947, she continued to work for the refugees and also contributed to the cultural landscape. In the year 1974, she was awarded the Sangeet Natak Akademi Fellowship, the highest conferred by the Sangeet Natak Akademi.