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New Class of Radio-Astronomical Objects Discovered: Odd Radio Circles | Astronomy – Sci-News.com

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An international team of astronomers has discovered an unexpected new class of radio-astronomical objects, consisting of a circular disk, which in some cases is limb-brightened, and sometimes contains a galaxy at its center. Named ‘Odd Radio Circles,’ these objects do not seem to correspond to any known type of astronomical object.

ASKAP radio continuum image of ORC 1 (contours) overlaid onto a DES 3-color composite image. Two galaxies of interest: ‘C’ lies near the center of ORC 1 and ‘S’ coincides with the southern radio peak. Image credit: Norris et al, arXiv: 2006.14805.

Circular features are well-known in radio-astronomical images, and usually represent a spherical object such as a supernova remnant, a planetary nebula, a shell around a star, or a face-on disk such as a protoplanetary disk or a star-forming galaxy.

They may also arise from imaging artifacts around bright astronomical objects.

Western Sydney University and CSIRO astronomer Ray Norris and his colleagues report the discovery of a class of circular feature in radio images that do not seem to correspond to any of these known types of object or artifact, but rather appear to be a new class of astronomical object.

“For brevity, and lacking an explanation for their origins, we dub these objects Odd Radio Circles (ORCs),” they said.

The researchers spotted three ORCs — named ORCs 1, 2 and 3 — in images from the Pilot Survey of the Evolutionary Map of the Universe, which is an all-sky continuum survey using the Australian Square Kilometre Array Pathfinder telescope (ASKAP).

A further radio source, called ORC 4, was discovered in archival observations of the galaxy cluster Abell 2142 taken with the Giant MetreWave Radio Telescope (GMRT).

All four ORCs are similar in displaying a strong circular symmetry and none of them have obvious counterparts in optical, infrared and X-ray wavelengths.

They differ in that two of them have a central galaxy while two do not, and three of them (ORCs 1, 2 and 4) consist of a partly filled ring while one (ORC 3) seems to be a uniform disk. There is also the puzzling fact that two of them are very close together, implying that these two ORCs have a common cause.

If the central galaxy in ORC 4 is associated with the ring, then the ring is 4.2 billion light-years away and has a size of 1.1 by 0.9 million light-years.

ASKAP radio continuum images of ORCs 2 and 3 from the Pilot Survey of the Evolutionary Map of the Universe and of ORC 4 from GMRT archival data. On the left are gray-scale images, with the synthesized beam shown in the bottom left corner, and radio contours overlaid onto DES optical images on the right. Image credit: Norris et al, arXiv: 2006.14805.

ASKAP radio continuum images of ORCs 2 and 3 from the Pilot Survey of the Evolutionary Map of the Universe and of ORC 4 from GMRT archival data. On the left are gray-scale images, with the synthesized beam shown in the bottom left corner, and radio contours overlaid onto DES optical images on the right. Image credit: Norris et al, arXiv: 2006.14805.

“We consider it likely that the ORCs represent a new type of object found in radio-astronomical images,” the scientists said.

“The edge-brightening in some ORCs suggests that this circular image may represent a spherical object, which in turn suggests a spherical wave from some transient event.”

“Several such classes of transient events, capable of producing a spherical shock wave, have recently been discovered, such as fast radio bursts, gamma-ray bursts, and neutron star mergers. However, because of the large angular size of the ORCs, any such transients would have taken place in the distant past.”

“It is also possible that the ORCs represent a new category of a known phenomenon, such as the jets of a radio galaxy or blazar when seen end-on, down the ‘barrel’ of the jet.”

“Alternatively, they may represent some remnant of a previous outflow from a radio galaxy.”

“However, no existing observations of this phenomenon closely resemble the ORCs in features such as the edge-brightening or the absence of a visual blazar or radio galaxy at the center.”

“We also acknowledge the possibility that the ORCs may represent more than one phenomenon,” they added.

“Further work is continuing to investigate the nature of these objects.”

The astronomers submitted their paper for publication in the journal Nature Astronomy.

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Ray P. Norris et al. 2020. Unexpected Circular Radio Objects at High Galactic Latitude. Nature Astronomy, submitted for publication; arXiv: 2006.14805

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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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.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

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.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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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.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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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.

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