In October 2022, the Fermi Gamma-ray Space Telescope and the Neil Gehrels Swift Observatory detected an extraordinarily powerful Gamma Ray Burst (GRB). It still stands as the Brightest Of All Time (BOAT), and astronomers have been curious about it ever since.
New research has uncovered more details in the burst. What do they tell us about these forceful explosions?
“When I first saw that signal, it gave me goosebumps.”
Maria Edvige Ravasio, Radboud University, Nijmegen, NetherlandsGRBs are the most powerful energetic events in the Universe, second only to the Big Bang. They’re brief yet powerful explosions that can release as much energy in a few seconds as the Sun will release in its billions of years of fusion. Astronomers don’t completely understand the mechanism behind them. They seem to come from the explosion of an extremely massive star or the merger of two extremely dense objects like neutron stars or black holes.
A GRB’s initial burst is called the prompt emission. While the prompt emissions themselves last anywhere from milliseconds to several hundred seconds, GRBs have afterglows that are much longer-lived and emitted in wavelengths longer than gamma rays: X-ray, ultraviolet, optical, infrared, microwave, and radio emissions. This means that astronomers can still study their source long after the gamma rays have disappeared.
When BOAT, aka GRB 221009A, was discovered, it was so powerful that it saturated Fermi’s detectors. That means astronomers weren’t able to observe some of the GRB’s most energetic moments.
In new research published in Science, astronomers say they’ve found another peak in GRB 221009A’s prompt emissions data. The research is “A mega–electron volt emission line in the spectrum of a gamma-ray burst.” The lead author is Maria Edvige Ravasio, a Post-doctoral Researcher in Astrophysics at Radboud University in Nijmegen, Netherlands. This peak is a new clue about what happens during a GRB.
“The physics of the prompt emission is poorly understood: The dominant form of energy in the relativistic jet is unknown, as is the nature of the radiative process responsible for producing the observed photons,” the authors write in their paper.
In their new research, the team used observations of the GRB and combined them with statistical models to identify new features. They divided the GRB into different time intervals and analyzed them separately and together. They focused on the parts of the prompt emission that weren’t the brightest. “We investigated the less bright portions of the prompt emission,” they write, and they avoided the portion of the signal that was saturated by the GRB’s extraordinary power.
This figure from the research shows some of the analysis. The horizontal axis shows the time since the GBM. GBM is the Gamma-ray Burst Monitor, an instrument on the Fermi Space Telescope that’s triggered by GRBs. The vertical axis shows the count rate, the blue line is the GRB’s light curve, and the numbered segments are the thirteen time intervals the researchers worked with. The grey area labelled BTI stands for Bad Timing Interval, excluded because the detector was saturated by the BOAT’s overwhelming energy. Image Credit: Ravasio et al. 2024.“A few minutes after the BOAT erupted, Fermi’s Gamma-ray Burst Monitor recorded an unusual energy peak that caught our attention,” said Ravasio. “When I first saw that signal, it gave me goosebumps. Our analysis since then shows it to be the first high-confidence emission line ever seen in 50 years of studying GRBs.” A high-confidence emission line is a specific wavelength of light that’s unlikely to be noise. Like everything else about GRBs, the line was transient. It only lasted 40 seconds, but it’s still significant. It occurred about five minutes after the initial burst and peaked at 12 MeV (million electron volts). To put that into context, the light our eyes can sense, called visible light, ranges from only two to three eV.
This figure from the research shows some of the results. The left panel is for the 290 to 295-second interval, and the right panel is for the 300 to 320-second interval. These panels are dense with information, but the main takeaway is the peak shown with black dotted lines in both panels. “We find that the spectra at times 280 to 320 s after the GBM trigger contain a narrow emission feature at ~10 MeV,” the authors write. They used different models and methods to understand the data. SBPL stands for “smoothly-broken power law,” and Gaussian is another data handling method. Image Credit: Ravasio et al. 2024.The newfound emission line is significant because of what happens to the energy emitted by GRBs. When powerful electromagnetic radiation collides with matter, it can be absorbed and then re-emitted at lower wavelengths. Depending on conditions, some wavelengths of light will be more prominent than others. Astronomers examine the light spectroscopically, and depending on the light that’s prominent or obscured, they can learn a lot about the chemistry of the matter that’s emitting the light. Some of the features in the spectrum can also reveal particle processes that are occurring. One of those processes is the annihilation of matter and anti-matter.
When astronomers studied the absorption and emission spectra from GRBs in the past, they couldn’t be certain that what they were seeing wasn’t noise. But this time, it’s different.
“We’ve determined that the odds this feature is just a noise fluctuation are less than one chance in half a billion.”
Om Sharan Salafiam co-author, INAF-Brera Observatory in Milan, Italy“While some previous studies have reported possible evidence for absorption and emission features in other GRBs, subsequent scrutiny revealed that all of these could just be statistical fluctuations. What we see in the BOAT is different,” said coauthor Om Sharan Salafia at INAF-Brera Observatory in Milan, Italy. “We’ve determined that the odds this feature is just a noise fluctuation are less than one chance in half a billion.”
The researchers think that the emission line comes from gamma rays travelling at nearly the speed of light. Their most likely source is exotic: the annihilation of matter and anti-matter.
“When an electron and a positron collide, they annihilate, producing a pair of gamma rays with an energy of 0.511 MeV,” said coauthor Gor Oganesyan at Gran Sasso Science Institute and Gran Sasso National Laboratory in L’Aquila, Italy. “Because we’re looking into the jet, where matter is moving at near light speed, this emission becomes greatly blueshifted and pushed toward much higher energies.”
For the observed peak to reach the 12 MeV level, the electrons and positrons had to be moving at 99.9 % of the speed of light: 299,492,665 meters per second.
This artist’s illustration shows a jet of particles moving at nearly light speed emerging from a massive star. When the star ran out of fuel, it collapsed into a black hole. The black hole’s powerful gravity drew nearby matter toward it, and some of the matter was redirected into dual jets firing in opposite directions. We see a gamma-ray burst when one of these jets happens to point directly at Earth. Image Credit: NASA’s Goddard Space Flight Center Conceptual Image LabThis emission line is a new window into the world of powerful GRBs.
“After decades of studying these incredible cosmic explosions, we still don’t understand the details of how these jets work,” said Elizabeth Hays, the Fermi project scientist at NASA’s Goddard Space Flight Center. “Finding clues like this remarkable emission line will help scientists investigate this extreme environment more deeply.”
The post Astronomers Uncover New Details in the Brightest Gamma Ray Burst Ever Detected appeared first on Universe Today.
This link was sent to me by a despondent (and of course anonymous) New Zealander with the comment, “This is now unstoppable in NZ.” It’s from the Times Higher Education site, and the authors are Mahdis Azarmandi and Sara Tolbert, both on the Faculty of Education of New Zealand’s University of Canterbury.
Click screenshot to read:
It’s fairly clear that by full “decolonization,” the authors propose a full disruption and subversion—yes, they use those words—of universities, with the ideal being to give the lands and waters back to the Māori people, as well as completely transforming college education into a program catering to the indigenous people. I’ll give the authors’ intentions, and then show their “praxis” for decolonization. Excerpts are indented and bolding is mine.
As non-Indigenous scholars, we can engage in anticolonial and feminist practices that subvert the settler colonial university, but we cannot promise “decolonisation”, especially in a country such as New Zealand, where the effects of colonisation are ongoing and where, in the words of Indigenous climate activist India Logan-Riley, “land back, oceans back” is yet to be realised. Unless the university is fully engaged in land back, oceans back, decolonisation will be used by the settler colonial university to justify settler occupation of stolen land, water and knowledge (see “additional links”, below).
Rather than offer how-to tips for “decolonising the university”, we suggest a few points as a call for collective action to change things that are unjust – inside and outside the university. We argue that to engage in anticolonial, feminist practice, we must address the systems that produce violence and exploitation, not just in the scholarly aspect of our work but also within our own institutional and material conditions such as housing, jobs and access to health. Some of these points are taken from our forthcoming chapter “A manifesto for transdisciplinary (transgressive) feminist praxis in the Academy”.
It’s clear from these words that the authors, who are both non-indigenous, don’t want merely a cosmetic redo of universities, which they see as not only having stolen the land and water from the indigenous people, but also “produce violence and exploitation.” They mean what they say: they want a complete rethink and redo of how the country’s universities are run and what they teach.
Unless by “violence” the authors mean “offense”, the hyperbole is strong, especially since New Zealand’s government and universities are doing everything that can to create equity for the Māori. (Indigenous people constitute 16.5% of New Zealand, just ahead of the 15.1% Asian and well behind the 70% European people.) One question underlying all this is whether the whole system has to be transformed to cater to the people who got to the islands first. But I’ll leave that aside and move on, because it’s worth seeing the reforms these two scholars suggest. There are six alterations of “praxis”:
1.) We can’t both love and change the university at the same time. We must actively engage in the disruption of oppressive, settler colonial and patriarchal practices. Learning from abolitionist struggles, we need to engage in non-reformist reform – that is, practices that improve the lives and conditions of those most marginalised (outside and inside the university) but that do not consolidate the power of the institution.
By “most marginalized,” I presume they mean the Māori people, though later they pull others into the reformist tent. Note that their purpose is not education, but social reform—outside as well as inside the university. There is not a word about what sort of education people will get, save that it’s going to be centered on indigenous “ways of knowing”:
2.) A crucial aspect of anticolonial praxis in the university is recognising and respecting Indigenous epistemologies and, where possible, engaging these as central to its curriculum while also peripheralising European and settler knowledge, which has been foundational in its formation. However, how and to what extent Indigenous knowledge should be in the university is not for non-Indigenous people to decide, but the way we act within our natural and knowledge environment must not be extractivist. We can and must resist extracting resources and knowledge from land, water and people. We need also remember that some knowledge is not ours to share; “sometimes the knowledge does not need to be moved out of the communities where it resides into the pages, websites and walls of the academic industrial complex” (Tolbert & Azarmandi, forthcoming). What anticolonial feminist praxis centres is being-in-relation (with place and people). We need to approach the incorporation of Indigenous knowledge with humility – there is a fine line between incorporation of Indigenous knowledge and cultural appropriation. What we can do is make space by disrupting disciplinary boundaries and challenging the limitations of academic disciplines that discourage collaboration and maintain competition.
Here we see that the “settler colonialists”—that is, able-bodied heterosexual males of European descent (see below)—should have no say in what passes for knowledge in the university. Indigenous knowledge must be central, and settler knowledge peripheral. In practice, this means the Māorization of the entire curriculum, including science.
3.) We must build collaborative partnerships and alliances with other marginalised communities, acknowledging the intersections of colonialism, racism, sexism, homo-transphobia, ableism and other forms of oppression. Building genuine relationships and collaborative partnerships with Indigenous and marginalised communities is essential. If these relationships benefit scholars and the academy more than the community, chances are they are meant to further empower settler colonial regimes and not disrupt and decolonise them. Adapt feminist and collaborative writing practices; refuse symbolic service requests and instead strategise and work towards systemic change: unionise, organise for a living wage and improve institutional practices such as parental leave and access to healthcare and housing.
In the above they pull into their tent everyone considered marginalized, including the disabled, people of color, women, gay people, and trans people. It’s not just that these people deserve equal rights and equal educational opportunities—something that nobody would oppose—but that they will also participate in overthrowing and subverting the violent and exploitative universities. As for parental leave, healthcare and the like, that is the responsibility not of the universities themselves, but of the New Zealand government, which funds the universities.
4.) Anticolonial praxis requires institutional transformation at all levels. This also means securing the right to education and making sure public universities exist and are supported. In the institution, we need to critically examine and restructure policies, procedures and practices that perpetuate settler colonial regimes of power. It involves addressing systemic barriers that maintain inequality, such as access to education, hiring practices, tenure and promotion criteria, curricular decisions and funding allocations. Resist symbolic change and cultural window dressing. Name it; make it explicit.
#4 is more of the same, expressing a deep animus towards the “settler colonial regimes of power”, something they never give examples of. They also argue that “systemic barriers” (i.e., codified systems of bigotry) must be dismantled, although they give no examples of such barriers and I know of none.
5.) Anticolonial and feminist praxis requires constant self-reflection and a commitment to unlearning. It involves critically examining our own complicity within the settler colonial structures. Be mindful, however, that this reflective and personal work alone does not create change – and sometimes, as feminist scholar Sara Ahmed has illuminated, it can become another way of not doing things with words. Connect, resist and organise.
6.) Finally, we must dare to dream beyond the university. What if the university can’t be unsettled or decolonised? If we do unsettle or decolonise the institution, will it be recognisable once we are done? As la paperson (the avatar of K. Wayne Yang, an associate professor of ethnic studies at the University of California, San Diego) has written (and we cite in our forthcoming chapter), we should understand “the university as a machine that is the composite of many other [disloyal] machines” – ones that ‘break down and travel in unexpected lines of flight – flights that are at once enabled by the university yet irreverent of that mothership of a machine’. May we find each other…beyond the university, and unite in our irreverent lines of flight”.
Here the universities are seen as mere staging areas for society-wide transformation, something they implied when they said, “Building genuine relationships and collaborative partnerships with Indigenous and marginalised communities is essential. If these relationships benefit scholars and the academy more than the community, chances are they are meant to further empower settler colonial regimes and not disrupt and decolonise them.”
One gets the impression here that the writers would be happiest if all the Europeans (save the marginalized ones, like the gays or people of color, were heaved out of the country so it would revert to a system of Māori governance. Now it’s true that the Māori were historically oppressed, but were also given the rights of “colonialist” settlers as well as the right to keep all their lands and properties by the 1840 Treaty of Waitangi. This treaty, which is ambiguous and wasn’t even signed by all the indigenous leaders, is a holy document in New Zealand, interpreted by locals to mean that they get most of everything (the fearful Europeans dare not say otherwise).
When you read something like this, you wonder about not only the philosophy of Times Higher Education, which decided to print what is largely an incoherent (and incorrect) set of assertions and accusations, but you also wonder about what will happen to New Zealand. The authors, after all, are “settler-colonialists”, calling for their own decimation.
What is happening in New Zealand—with all the many official attempts to create equity only serving to provoke tirades like the one above—is the world’s most far-reaching attempt at ideological capture of an entire country by the people who consider themselves entitled to run the whole country: the descendants of the original Polynesian settlers. But the world has moved on, and who can deny that “settler colonialists”, by bringing with them their knowledge, medicines, free national healthcare, and inventions, have improved the lives of most people in New Zealand? It is not as if the arrival of people from elsewhere has been an unmitigated evil.
I think the person who sent me this screed is right: this movement is unstoppable, and it’s going to ruin New Zealand. Apparently the Luxon government is either ignoring this stuff or doesn’t care to stop it. Soon it will be too late, if it isn’t already.
I pity New Zealanders who want to get a good college education in the face of people like Drs. Azarmandi and Tolbert, whose program will sink New Zealand to the bottom of the academic ranking of comparable countries.
A hypothetical question: You are one of the moderators of the next Presidential debate. (We’re not sure if there will be one, though there surely must.) What question(s) would you most like to ask both candidates together, as well as either one separately. Since Harris hasn’t yet chosen a running mate, we’ll leave out VP questions, though if you want to say what you’d ask Vance, fire away. Be hard on them!
But here’s one question I’d ask both candidates. A version of this was asked in 2007 among the Republican Presidential candidates, with three out of the ten candidates said they didn’t “believe in evolution.” Here’s the video of that:
So here’s what I’d ask both Trump and Harris:
Do you accept that evolution is true? Why or why not?
That’s a touchstone about whether they’d accept established scientific “truth.” If you don’t buy that, then you’re oblivious to evidence. I’m sure Harris would say “yes”, but don’t know what Trump would say. But I’d also like to know if they know the evidence.
Here’s what I’d ask Trump (two questions):
You still maintain that the last Presidential election was rigged, with illegal votes counted in a way that made you lose. If you lost this time, would you still say the same thing?
(This is to determine whether he’d still foment insurrection if he lost.)
As lagniappe, I’d ask him this:
You recently said this:
“You got to get out and vote. In four years, you don’t have to vote again. We’ll have it fixed so good, you’re not going to have to vote.”
And you’re sticking by that statement. Could you explain exactly what you meant by it?
And here are two questions I’d ask Harris:
What do you think you accomplished on your own as Vice-President, as opposed to simply assenting to what Biden accomplished? I am referring to what you actually did to make America progress, as opposed to what you were supposed to do).
I thought of one more:
You are hoping that you will win the Presidency by reinstalling Roe v. Wade as the law of the land. How, exactly, would you accomplish this if at least one house of Congress was majority Republican?
Both of those questions for Harris are designed to make her think on her feet as opposed to her custom of simply repeating a question as if it were an answer.
Put your questions below. Remember, you aren’t supposed to show partisan bias here, but to draw out the candidates, for that’s what debate moderators are supposed to do.
When giant solar storms hit Earth, they trigger beautiful auroral displays high in Earth’s atmosphere. There’s a dark side to this solar activity, though. The “space weather” it sets off also threatens our technology. The potential for damage is why we need highly accurate predictions of just when these storms will impact our planet’s magnetosphere.
To figure that out, scientists in England went to the source: specific places on the Sun where these storms erupt. Those outbursts are called “coronal mass ejections” (CMEs). They’re huge explosions of magnetically charged particles and gases from the Sun. They travel through space and hit whatever is in their way, including planets.
When that cloud of charged particles hits our magnetic field, it sets off a chain reaction of events. Of course, it creates beautiful auroral displays—northern and southern lights that dance in the skies. But, they also slam into and can damage orbiting satellites, including all our telecommunications and navigation systems for planes, boats, and trains. The danger is even greater for astronauts aboard orbiting space stations. That’s because radiation is a constant threat to human life. On Earth, those storms can cause huge circulating electrical currents that can damage electric power grids. The damage to technology just ripples across the planet.
This is why satellite operators and others want more accurate predictions of just when a space weather event triggered by a CME will hit us. To figure that out, solar physicists have to look back at the Sun and the sequence of events that cause CMEs.
Active region outbursts that cause solar storms. Studying the Solar Active RegionsCMEs emanate from active regions on the Sun. These are places with very strong magnetic fields. The magnetic field lines form loops that get twisted and eventually, they break. When that happens, there’s a huge outburst of material—the CME. Typically, they travel out from the Sun at anywhere from 100 km/sec to 3,000 km/sec. That large uncertainty makes it tough to predict when the solar cloud will hit Earth.
Steps in the creation of a CME, showing the root cause of solar storms. Courtesy Temmer, et al. CC BY 4.0.Science teams led by Aberystwyth University solar physicist Harshita Ghandhi, focused on the height above the Sun where the magnetic field becomes unstable. They call it the “critical height” and it can help scientists predict the speed and arrival time of a coronal mass ejection.
“By measuring how the strength of the magnetic field decreases with height, we can determine this critical height,” said Gandhi. “This data can then be used along with a geometric model which is used to track the true speed of CMEs in three dimensions, rather than just two, which is essential for precise predictions.”
The team found a very strong relationship between the critical height of the CME as it gets started and its true speed as it moves out. “This insight allows us to predict the CME’s speed and, consequently, its arrival time on Earth, even before the CME has fully erupted,” Ghandhi said.
Knowing the actual speed of the CME to a higher degree of accuracy will let solar physicists predict when it will hit Earth. That, in turn, will allow satellite operators, grid owners, space agencies, and others to prepare for the action and protect their assets. “Understanding and using the critical height in our forecasts improves our ability to warn about incoming CMEs, helping to protect the technology that our modern lives depend on,” Gandhi pointed out.
Solar Storms and the Damage They CauseOur Sun goes through periods where it is more “outbursty” than others. Some of the strongest solar storms occur during the solar maximum part of the Sun’s 11-year sunspot cycle. That’s not to say they don’t occur at other times. Whenever they happen, however, they can cause a lot of damage. One famous storm occurred on March 13, 1989. It was a combo of two CMEs that lifted off the Sun on March 10th and March 12th. They stirred up currents low in Earth’s atmosphere at the same time they triggered auroral displays. At the time, power grids were not necessarily “hardened” against such events. As a result, the Hydro-Quebec power grid shut down and suffered tremendous damage. The power was out for days across eastern Canada and parts of the United States.
Sensitive to solar activity? Power grids on the ground are vulnerable to interruptions from space weather caused by solar storms. (AP Photo/Smithsonian)Another huge storm hit around Halloween in 2003. It affected satellite systems, cut off communications, some power systems shut down, and people around the world saw a dazzling display of aurorae. In space, the SOHO solar satellite shut down briefly. Astronauts onboard the ISS had to take shelter in a safe place aboard the station.
Today, we’re in another cycle of heightened solar activity. We’ve already seen strong storms in May of 2024, and more will surely occur. So far they haven’t caused much damage, and they’ve given us some lovely auroral displays. Luckily, advanced research on these solar storms has helped technology operators and space agencies “harden” their systems. However, there’s only so much they can do to protect their assets. Having highly accurate advance predictions of just when a CME will impact our planet is a big step forward. At the very least, these operators will be able to reposition satellites, strengthen their power grids and other communications technology, and give astronauts in space advance warning. In future years, when we have people on the Moon or on their way to Mars, such predictions will help keep them safe, too.
For More InformationNew Dawn For Space Storm Alerts Could Help Shield Earth’s Tech
A 21st-Century View of the March 1989 Magnetic Storm
The post Predicting Solar Storms Before They Leave the Sun appeared first on Universe Today.
Today’s Jesus and Mo strip, called “choice,” came with a question, “What’s your favorite verse in the Qur’an?”
Mo’s upset because the Qur’an states that Jesus wasn’t killed on the cross, but ascended alive to heaven, hauled up to be with God. This shows that both religions can’t be true, but of course they can both be false.
Meanwhile the barmaid has a bit of fun.
We’re right at the end of the queue, but I’m leaving on Saturday so hold onto your good wildlife photos until I return at the beginning of September. Today we have some photos from Damon Williford in Texas. His notes and IDs are indented, and you can enlarge the photos by clicking on them:
Here are a few more bird photos from the central Gulf Coast of Texas taken during the spring of this year.
The Laughing Gull (Leucophaeus atricilla) is the only species of gull that breeds along the U.S. Gulf Coast. The individual pictured is an adult in full breeding plumage, which begins to develop in February and March and starts to disappear in mid- summer:
Herring Gull (Larus argentatus) is one of the three species of gulls that regularly spend the winter in Texas. This individual was an immature bird possibly transitioning between second- and third-year plumages:
The Ring-billed Gull (Larus delawarensis) is another gull that winters regularly in Texas:
The Royal Tern (Thalasseus maximus) is one of seven species of terns that breed in the Gulf of Mexico region. It is also one of the most common terns on the Texas coast, and the second largest species of tern in the area: only the Caspian Tern (Hydroprogne caspia) exceeds it in size. The Royal tern pictured has already transitioned to non-breeding plumage, which involves the loss of most of the black plumage on the crown so that it looks like aging punk rocker suffering from a receding hairline:
Black skimmers (Rynchops niger) are regular breeding birds on the Texas coast:
Brown Pelicans (Pelecanus occidentalis):
Snowy Egrets (Egretta thula) are one of the most common species of herons in Texas. It is also one those species (others include the Laughing Gull and Brown Pelican) that I photograph frequently because Snowy Egrets are abundant and are not overly skittish, allowing me to get close. The one in the photo was so intent on catching breakfast that it came very close to where I was standing on a jetty overlooking a salt marsh:
Another Snowy Egret chasing down its own breakfast:
A pair of White Ibises (Eudocimus albus) at a freshwater marsh on the San Bernard National Wildlife Refuge: