Astronomers who want more accurate measurements of distant black holes have new assistants - robots who can cope with the tedious task of monitoring the glow of clouds located next to black holes.
The method, known as echo mapping, has been in the service of astronomers for decades, but it takes a lot of cost, both labor and telescope operation time.
The idea is that the radiation from the rotating matter at the entrance to the existing black hole illuminates the distant clouds. Chemical analysis of the gas in the so-called accretion disk around the black hole and comparing it with the glow of gas located at a distance will help astronomers calculate the mass of the black hole and the force of the gravitational field.
“This method takes advantage of the fact that accretion disks do not always shine with the same brightness,” writes the University of Texas Observatory (University of Texas McDonald Observatory) on the Stardate.org website.
“The disk can flare up very brightly when a new substance comes in ... or when magnetic fields cause the disk gas to stick together. Measuring how long the neighboring clouds take to shine from the illumination of these flashes will determine their distance from the black hole. And measuring the width of the lines in the spectra of these clouds will show how fast they move, ”says the observatory. To test whether the robot observatory will be able to map, astronomers launched a pilot program on the Global Telescopes Observatory of Las Cumbres (Las Cumbres Observatory Global Telescope Network, LCOGT), which currently consists of 11 automated telescopes located in Texas, Hawaii, in Australia, South Africa and Chile.
The newest acquisition of this network is FLOYDS, a pair of light-splitting spectrographs mounted on the Folks-North telescope (Faulkes Telescope North) at the Haleakala Observatory in Hawaii and the Folks-South (Faulkes Telescope South) in the Siding Surridor Sprree Sprree in the Sapri Sprree Sprree. Siding Spring Observatory) in New South Wales, Australia.
“A spectrograph is a special kind of camera that splits the light of an object into its constituent colors, like a rainbow, and allows you to, say, measure the chemical composition of an object and how fast it moves relative to you,” said astrophysicist David Sand of Texas Tech University, wrote on e Mail to Discovery News.
Taking pictures of the sky with the help of robots is common, “but spectrographs have been and remain quite a new word.”
(FLOYDS is the name given in honor of the Pink Floyd group and its cult light-splitting prisms adorning the cover of the album “The Dark Side of the Moon”).
For about 200 days, robotic photodetectors and spectrographs of FLOYDS in Hawaii monitored ARP 151, a well-studied galaxy located 300 million light-years in the constellation Ursa Major. The galaxy contains a massive black hole, which the previous eco-mapping estimated at 6.5 - 7 million times the mass of the Sun. The central black hole of the Milky Way, for comparison, has a mass of about 4 million times the mass of the Sun.
Astronomer robots have proven their worth by delivering an ARP 151 black hole mass measurement 6.2 million times the mass of the Sun.
“Apparently the areas around the black hole have changed over the past few years, and this is very interesting,” says Sand.
“These results represent the first step, proving the powerful abilities of the LCOGT robots to carry out long-term programs (at the core of an active galaxy) that are difficult to implement with human effort,” concluded research physicist Stefano Valenti from the University of California at Santa Barbara and his colleagues, published last month in the journal Astrophysical Journal Letters.
With successful proofs behind it, the network of robots is now turning its attention to a more extensive study of nearby and distant black hole galaxies.
“Having such opportunities with our robots, we really try to give the method a new impetus,” says Sand.
