This black hole is an extreme recycler

Like a cosmic water fountain, a supermassive black hole is cycling gas through a galaxy-sized pump. The black hole powers jets that blast gas over 30,000 light-years away from the galaxy only to rain back down on a reservoir from which the black hole feeds. Yale University astronomer Grant Tremblay described this phenomenon January 6 at a meeting of the American Astronomical Society.

The fountain sits at the heart of a galaxy within the Abell 2597 cluster, a galactic gathering over 1 billion light-years away in the constellation Aquarius. Observations from theAtacama Large Millimeter/submillimeter Array in Chile reveal that the fountain billows into plumes with the mass of about 1 billion suns. The force of the jets appear to trigger the formation of new stars within these plumes. Most of the ejected gas falls back down onto the central region of the galaxy and then slowly trickles back toward the black hole to start the loop again.

This galactic pump might help regulate star formation throughout the galaxy. The fountain can continually stir up gas and prevent much of it from creating stellar nurseries. 

RADICAL RECYCLING  A galaxy bathed in a pool of hot gas (blue) has fountains of hydrogen (red) erupting from its core, as seen in this composite image. A new study shows how these fountains get recycled into new stars and black hole food through a galaxy-sized pump.

Single gene influences a petunia’s primary pollinator

Some petunia flowers use ultraviolet light to attract certain pollinators. And dimming down or cranking up the flowers’ UV light intensity only takes the flip of a genetic switch.
Mutations on one gene in three species of Petunia from South America determine how much UV light petunia flowers absorb, an international research team reports December 14 in Nature Genetics. Variations of the gene, called MYB-FL, cause fluctuations in flavonol, a compound that controls how much UV light the flower absorbs, and, anthocyanin, a pigment compound that controls flower color, the researchers say.
UV and pigment differences among the three petunia species correspond to differences in the flowers’ pollinators. Nocturnal hawkmoths go for flowers that absorb lots of UV light, like the white flowers of P. axillaris. Bees like the small, purple flowers of P. inflata that absorb some UV light. The bright red flowers of P. exserta absorb less UV light and are visited by daytime pollinators such as hummingbirds.

Debate grows over whether X‑rays are a sign of dark matter

The search for a suspected calling card of the universe’s most elusive matter has come up empty.
Multiple days of telescope time spent looking for a specific X-ray glow coming out of the nearby dwarf galaxy Draco failed to turn up any signal, two University of California, Santa Cruz astrophysicists report online December 7 at arXiv.org. Finding such a glow would have offered a compelling clue for the identity of dark matter, the invisible, inert stuff that makes up more than 80 percent of the universe’s matter. The study’s authors say that the absence of the X-rays in Draco, one of the most dark matter–dominated objects known, means that scientists had previously detected the X-ray emissions of interstellar atoms rather than dark matter.
Not everyone agrees with the study’s conclusion, including a different team of scientists who commissioned the lengthy Draco observations and are reviewing the same data. Those scientists, who haven’t yet published their analysis, say they can’t rule out the possibility that dark matter produces the X-rays that have been spotted emanating from other cosmic objects.
Scientists know dark matter permeates the cosmos because, among other evidence, the outer regions of galaxies spin faster than they should based on the distribution of the galaxies’ stars and gas. In an attempt to identify the particles that make up dark matter, some scientists analyze images of dark matter–rich regions like galaxy clusters and dwarf galaxies in search of gamma rays, X-rays or other unexpected signals. Their hope is that dark matter particles emit observable radiation when they decay or collide with each other .
Scientists flagged one promising signal in February 2014: bursts of X-rays with an energy of about 3,500 electron volts that consistently appeared in a set of 73 galaxy clusters. Other groups soon found X-rays streaming from the Perseus galaxy cluster, Andromeda and the center of the Milky Way, too.
Theorists quickly pointed out that dark matter in the form of a proposed particle called a sterile neutrino could decay and emit radiation at that energy. “It was very exciting,” says Stefano Profumo, an author of the new paper. “We had a signal that matched with a predicted dark matter candidate.”
But dark matter isn’t the only way to explain the X-rays. Profumo and others argued that initial studies underestimated the role of a kind of decidedly undark matter — potassium atoms — that can also emit 3,500-eV X-rays in galactic gas clouds. To settle the issue, a team led by Alexey Boyarsky, a particle physicist at Leiden University in the Netherlands, pointed the XMM-Newton space telescope at Draco. The dwarf galaxy, located about 270,000 light-years away, contains lots of dark matter but barely any potassium-carrying gas.
For the new study, Profumo and colleague Tesla Jeltema, who are not part of Boyarsky’s team, analyzed the publicly available XMM-Newton data along with a previous Draco observation. They found no evidence that the galaxy radiates 3,500-eV X-rays. Profumo says their results prove that the X-rays in the other galaxy clusters could not have come from the decay of dark matter.
Boyarsky agrees that there is no strong X-ray signal coming from Draco. But he says he’s not convinced that the data rule out that dark matter decays into X-rays. He expects to share a more careful analysis encompassing more telescope data within the next few weeks.
Esra Bulbul, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who is working with Boyarsky, says the new data hurt the case for sterile neutrinos composing dark matter. But she says that other kinds of dark matter particles could produce a feebler emission of X-rays that might explain the Draco observations. “Draco is a good clue, but I’m afraid it’s not going to be conclusive enough to evaluate the dark matter origin,” she says. “We have seen the signal in so many clusters.”

Pygmy slow loris in Asia takes unusual downtime in winter

PRIMATE CHILL  The pygmy slow loris in Vietnam is upsetting an old idea that lemurs are the only primates that hibernate.

The pygmy slow loris truly hibernates, making it the first primate outside Madagascar found to do so, a new study says.

“Up until now there were only three species of primate known to hibernate: All lemurs in Madagascar,” says Thomas Rufof the University of Veterinary Medicine in Vienna.  But in Vietnam, new measurements of wintertime body temperature for pygmy slow lorises (Nycticebus pygmaeus) show bouts of chilly torpor lasting as long as 63 hours. A plunge in metabolic rate for more than 24 hours counts as hibernation, Ruf says.
There was talk about whether some unique conditions in Madagascar allowed the evolution of primate hibernation only there, Ruf says. But he and his colleagues dismiss that scenario December 3 in Scientific Reports.

Human gene editing gets green light

MAKING THE CUT  CRISPR and other gene editing tools may help cure genetic diseases. Conducting research on embryos and correcting diseases in adults is fine, but researchers should not make gene-edited babies, leaders of an international summit say.

WASHINGTON, D.C. — Human gene-editing research, even on embryos, is needed and should go ahead, with one major caveat: No pregnancies can result, leaders of an international summit on the topic said December 3.
In recent years, scientists have devised increasingly precise molecular scissors for cutting and pasting DNA. These tools, especially the guided scissors known as CRISPR/Cas9, have become so cheap and easy to use that it may be possible to use them to correct genetic diseases.
Many see the technology as a medical boon; others, though, say that the prospect of designer babies and tinkering with the DNA of future generations should be out of bounds . The U.S. National Academies of Sciences and Medicine, the Chinese Academy of Sciences and the United Kingdom’s Royal Society convened the summit to discuss the state of the science as well as ethical, legal and regulatory considerations surrounding gene-editing technology.
Gene editing of human body, or somatic, cells, which do not pass genetic information to future generations, is already in clinical trials. Most of those studies have involved older technologies and cells that were edited outside the body and then given to a patient later, such as a baby with leukemia treated with edited immune cells .
A company called Sangamo BioSciences announced December 1 that clinical trials using gene editing to replace a broken gene in adult hemophiliacs could begin next year. Such research could continue and would fall under current regulations for gene therapy, the 12-member organizing committee of the International Summit on Human Gene Editing said in statement.
But moral, ethical and safety concerns would make it “irresponsible” to proceed with clinical studies in germline cells — eggs, sperm, embryos and other cells that transmit DNA to future generations, the statement added. That doesn’t mean all germ cell editing would be off-limits. Researchers who edit embryos or other germ cells in labs would not be doing germline editing if the resulting embryos are not implanted in the uterus for reproductive purposes, said committee chairman David Baltimore of Caltech.
The scientists purposely did not call their statement a ban or even a moratorium. Instead, the recommendations should be revisited on a regular basis as research advances and societal opinions evolve. The panel also called for an ongoing forum to discuss human germline editing.
Recommendations from the scientists are not legally binding, but peer pressure could be an effective deterrent. For instance, researchers who violate agreements might not be able to get their work published or could lose funding. Scientists also must still follow their individual countries’ laws and regulations on working with embryos. In the United States, such work is not banned, but researchers cannot get government funds to do it.
A study conducted by a separate committee of scientists commissioned by the science academies will produce a report on the advisability of germline editing, expected by the end of 2016.

Humankind’s water use greater than thought

WATER LOSS  Humans water crops, like the rice fields shown here, using methods such as irrigation. Water management practices like these are taking a toll on water sources, a new study finds.

Humans’ global water footprint is up to 18 percent greater than previous estimates, researchers from Sweden report in a new study.
An analysis of water and climate data from 1901 to 2008 from 100 large water basins around the world revealed more water loss to the atmosphere and less water runoff compared with conclusions from earlier studies. The researchers link both water impacts to human activities. Water management techniques such as irrigation and damming rivers to create reservoirs, rather than climate conditions or geographic location, better explain the findings, they say.
On a global scale, the new results suggest that humans use about 10,700 cubic kilometers of water­­ per year, more than all the water in Lakes Michigan, Huron, Ontario and Erie combined. That’s about 18 percent more than a 2012 estimate for current water use. The level is increasingly unsustainable, the scientists report December 4 in Science.

Mysterious cosmic signals carry a clue to their origins

On its way to Earth, burst of radio waves ran into dense plasma, strong magnetic fields

 

 

Enigmatic blasts of cosmic radio waves are dropping hints about their origins. A recently discovered burst appears to originate in or near a relatively young stellar neighborhood in another galaxy, researchers report online December 2 in Nature.

This fast radio burst, FRB 110523, has much in common with previously detected bursts . It lasted for just a few milliseconds, did not repeat and originated well outside the Milky Way — in this case, up to 6 billion light-years away in the constellation Aquarius. But the burst provided an extra piece of information. The radio waves showed signs of having run into strong magnetic fields and dense blobs of plasma, often found near young stars, astrophysicist Kiyoshi Masui of the University of British Columbia in Canada and colleagues report.
The team found the burst in 2011 data recorded by the Green Bank Telescope in West Virginia. The strength of the magnetic fields and the density of the plasma encountered by the signal are greater than what lies within the Milky Way or in intergalactic space, suggesting that FRB 110523 originated close to a magnetized nebula or within the core of its host galaxy. Possible sources include starquakes on highly magnetic neutron stars (the cores of dead massive stars), the delayed formation of a black hole after a supernova or ferocious blasts from pulsars, all of which were recently hinted at by a hiccup seen in another radio burst