A dance of death is taking place at the heart of a galaxy in the distant Universe.
Some 10 billion light-years away, two supermassive black holes are locked in an orbit so tight that they will collide with each other and form one much larger black hole in the relatively short time of just 10,000 years.
That equates to an orbital distance of just 0.03 light-years, around 50 times the average distance between the Sun and Pluto. Yet, so fast are they moving that it takes just two Earth years for the two objects to complete a binary orbit, compared to Pluto’s 248 years.
There are multiple reasons why supermassive black hole binaries are of interest to astronomers.
Supermassive black holes are found at the centers of most galaxies, the nuclei around which everything else whirls. When two are found together, it indicates that two galaxies have come together.
We know this process occurs, so finding a supermassive black hole binary can tell us what it looks like in the final stages.
Supermassive black hole binaries can also tell us something about how these colossal objects – millions to billions of times the mass of the Sun – can get so incredibly massive.
Binary black hole mergers are one way this growth can occur. Finding binary supermassive black holes will help us understand if it’s a common pathway for this growth, and that could lead to more accurate modeling.
The object in question is a quasar, named PKS 2131-021. These are galaxies in which the galactic nucleus is active; that is, the supermassive black hole is accreting matter at a furious rate, blazing with the heat generated by friction and gravity in the material roiling around the nucleus.
Some quasars blast jets of plasma almost at light-speed from the polar regions of the black hole, funneled along and accelerated by magnetic field lines around the object’s exterior. PKS 2131 is a quasar blasting out a jet right in the direction of Earth, making it what we call a blazar.
A team of astronomers studying brightness variations in quasars noticed something odd about the PKS 2131 blazar beam in radio frequencies, finding the same signature in data collected back in 2008. It seemed to oscillate on regular timescales, its brightness fluctuating with an almost perfect sine wave pattern never before seen in a quasar.
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“PKS 2131 was varying not just periodically, but sinusoidally,” astronomer Tony Readhead of Caltech said. “That means that there is a pattern we can trace continuously over time.”
The trail seemed to end when only two more peaks were found in archival data, one in 2005, and another in 1981. But then, in 2021, the project piqued the interest of astronomer Sandra O’Neill of Caltech. She and a team of researchers revisited data archives to see how far back in time they could trace this strange pattern.
They hit paydirt. In data from the Haystack Observatory made between 1975 and 1983, more of the pattern emerged, consistent with the timing of the rest of the observations.
“When we realized that the peaks and troughs of the light curve detected from recent times matched the peaks and troughs observed between 1975 and 1983, we knew something very special was going on,” O’Neill said.
According to the team’s analysis, the regular ‘ticking’ of the signal is generated by the orbital motion of the two black holes. As they go around each other on two-year timescales, the radio light dims and brightens, due to the orbital motion of the jet, which causes a Doppler shift that boosts the light when the black hole is moving towards us.
The archival data shows that this sine wave can be observed consistently for eight years from 1976, after which it disappeared for 20 years. This was probably due to a change or disruption in the supply of material feeding into the supermassive black hole. After 20 years, the pattern re-emerged, and has continued ever since, about 17 years now, the researchers said.
Another similar system, OJ 287, suggests that the interpretation is valid. This blazar has two close supermassive black holes orbiting each other every 12 years, at a separation of a third of a light-year. It shows fluctuations in radio brightness, too, albeit more irregularly and without the sinusoidal waveform.
Although we won’t be around to see the eventual merger of the supermassive black holes in PKS 2131, they could show us how to look for similar systems. In turn, these could bring us closer to understanding how these colossal collisions take place.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
