An international team led by a university at the northwestern university approaches the understanding of a mysteriously bright object that flew summer in the north sky.
On June 17, two-way telescopes of the ATLAS survey in Hawaii discovered a spectacular light anomaly distant 200 million light-years away in the Hercule constellation. The AT2018cowa or "The Cow" clip was subject to rapid debris, and then disappeared almost immediately.
After merging multiple rendering resources, including hard X-rays and radios, the multinational team now assumes that telescopes have captured the exact moment when the star collapsed and formed a compact object such as a black hole or a neutron star. Stellar waste that is approaching and revolving around the horizon of the event has caused an extremely bright glow.
This rare event will help astronomers better understand physics on the pitch at the first moments of the creation of a black hole or neutron star. "We think" cow "is a black hole or neutron star," said Raffaella Margutti, who led the study. "From the theory, we know that black holes and neutron stars are formed when the star dies, but we have never seen them immediately after birth."
Margutti will present her findings at the 233rd meeting of the American Astronomical Society at 2:15 pm. 10th of January in Seattle. (Journalists can join the meeting to watch, listen and ask questions via online transfer.) The survey will then be published in the Astrophysical Journal.
Margutti is an assistant professor of physics and astronomy at Northwestern Northwestern College of Arts and Sciences and a member of CIERA (Center for Interdisciplinary Research and Research in Astrophysics), Northwestern Research Center, which focuses on the advancement of astrophysics studies with an emphasis on interdisciplinary connections. .
When it was first discovered, The Cow caught the immediate international interest and left the astronomers to browse their heads. "We thought it must be a supernova," said Margutti. "But what we have noticed has provoked our current perception of star death."
First, the anomaly was unnaturally bright – 10 to 100 times brighter than the typical supernova. It also exploded and disappeared much faster than other known explosions of stars, with particles flying at 30,000 kilometers per second (or 10 percent of the light velocity). In just 16 days, the facility has already given away most of its power. In the universe, where some phenomena last for millions and billions of years, two weeks are equal to the eye.
"We knew at once that this source went from inactive to maximum luminosity in just a few days," said Margutti. "It was enough that everyone was excited, because it was so unusual and according to astronomical standards it was very close."
Use of access to observation facilities in the north-west of W.M. The Keck Observatory in Hawaii and the MMT Observatory in Arizona, and remote access to the SoAR telescope in Chile, Margutti looked at the subject in more detail. Margutti and her team examined the chemical composition of the cow to find clear evidence of hydrogen and helium, which excluded models of pooling compact objects – just like those that produce gravity waves.
A comprehensive strategy
Astronomers have traditionally studied stellar death in optical wavelengths using telescopes to capture visible light. The Margutti team uses a more holistic approach. Her team watched an object with X-rays, hard X-rays (which are 10 times stronger than conventional X-rays), radio waves and gamma rays. This allowed them to continue exploring the anomaly, long after its original visible light faded.
When ATLAS spotted the object, Marguttti's team quickly gained further cow observations with NASA's Nuclear Mass Spectroscopy Laboratory (NuSTAR) and X-ray Newton's XTE-XRM XTM XTM Xanty X-ray Laboratories and radio antennas in a very large field. against the cow.
Margutti attaches a relatively naked cow to the potential discovery of this intergalactic secret. Although stars may collapse into black holes all the time, a large amount of material around newly born black holes blocks the vision of astronomers. Fortunately, about 10 times less ebb around the cow spun around the typical starburst explosion. The lack of material enabled the astronomers to glide straight to the "central engine" of the building, which proved to be a probable black hole or neutron star.
"The light bulb" was sitting deep inside the explosion, "said Margutti." It would be hard to see in a normal star explosion. But The Cow had very little weight, which allowed us to directly see the radiation of the central engine. "
Margutt's team also benefited from the relative proximity of the star to the Earth. Though it was nested in a remote ground galaxy called the CGCG 137-068, astronomers consider it to be "just around the corner".
"By the way, for us it's nearly two hundred million light-years away," said Margutti. "This is the closest transient object of this kind that we have ever found."
Marguttti's team at Northwestern University includes Graduate Student Apriya Hail, Post Graduate Scholarship Program Giacomo Terreran, Deanne Coppejans and Kate Alexander (who is a Hubble co-worker) and the first year of undergraduate student Daniel Brethauer.
"Let's give an opportunity to contribute to something that is state of the art and international, because understanding AT2018cow as an undergrad is a surreal experience," said Brethauer. "Helping global experts to find out what AT2018cow is, even in the smallest way, surpassed my quickest expectations at the beginning of the summer and something I will remember for the rest of my life."