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Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, an international team of astronomers has performed observations of HSC J120505.09−000027.9—the most distant red quasar so far detected and found that it showcases an extended emission of ionized carbon. The finding is reported in a paper published January 4 on arXiv.org.

Quasars, or quasi– (QSOs), are extremely luminous active galactic nuclei (AGN) containing supermassive central black holes with accretion disks. Their redshifts are measured from the strong spectral lines that dominate their visible and . Some QSOs are dust-reddened, hence dubbed red quasars. These objects have a non-negligible amount of dust extinction, but are not completely obscured.

Astronomers are especially interested in studying high-redshift quasars (at redshift higher than 5.0) as they are the most luminous and most distant compact objects in the observable universe. Spectra of such QSOs can be used to estimate the mass of supermassive black holes that constrain the evolution and formation models of quasars. Therefore, could serve as a powerful tool to probe the early universe.

A new study, led by a theoretical physicist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), suggests that never-before-observed particles called axions may be the source of unexplained, high-energy X-ray emissions surrounding a group of neutron stars.

First theorized in the 1970s as part of a solution to a fundamental particle physics problem, axions are expected to be produced at the core of stars, and to convert into particles of light, called photons, in the presence of a magnetic field.

Axions may also make up —the mysterious stuff that accounts for an estimated 85 percent of the total mass of the universe, yet we have so far only seen its gravitational effects on ordinary matter. Even if the X-ray excess turns out not to be axions or dark matter, it could still reveal new physics.

Circa 2019


Conventionally speaking, there is a single physicist named Sean Carroll at Caltech, busily puzzling over the nature of the quantum world. In the theoretical sense, though, he may be one of a multitude, each existing in its own world. And there’s nothing unique about him: Every person, rock, and particle in the universe participates in an endlessly branching reality, Carroll argues, splitting into alternate versions whenever an event occurs that has multiple possible outcomes.

He is well aware that this idea sounds like something from a science fiction movie (and it doesn’t help that he was an advisor on Avengers: Endgame). But these days, a growing number of his colleagues take the idea of multiple worlds seriously. In his new book, Something Deeply Hidden, Carroll proposes that the “Many Worlds Interpretation” is not only a reasonable way to make sense of quantum mechanics, it is the most reasonable way to do so.

Prominent supporters of the Many Worlds Interpretation include physicists David Deutsch at Oxford University and Max Tegmark at MIT. If they are right, our intuitive sense of how reality works is profoundly wrong. Then again, some other researchers think that the Many Worlds way of looking at quantum mechanics is misguided, unproductive, or even downright absurd.

On 14 November 2014, a bright flash flagged the All Sky Automated Survey for Supernovae, or ASAS-SN — a global network of 20 telescopes managed at Ohio State University in the U.S. The flash originated in galaxy ESO 253–3, located 570 million light-years away.

The sudden burst of energy was examined by astronomers and categorized as a likely supernova and assigned the event designation ASASSN-14ko. Six years later, Anna Payne, a NASA Graduate Fellow at the University of Hawai’i at Mānoa, discovered it was something much different.

While sifting through ASAS-SN data on active galactic nuclei, she discovered a previously unnoticed periodic series of bright flares emanating from galaxy ESO 253–3 — repeating in such a way that led directly back to ASASSN-14ko as the point of first detection.

Science Mission Directorate


What is dark energy? More is unknown than is known — we know how much there is, and we know some of its properties; other than that, dark energy is a mystery — but an important one. Roughly 70% of the Universe is made of dark energy. Dark matter makes up about 25%. The rest — everything on Earth, everything ever observed with all of our instruments, all normal matter adds up to less than 5% of the Universe. Then again, maybe it shouldn’t be called “normal” matter since it is a small fraction of the Universe!

A new study shows that not even cosmology can verify Einstein’s assumption about the speed of light.


Special relativity is one of the most strongly validated theories humanity has ever devised. It is central to everything from space travel and GPS to our electrical power grid. Central to relativity is the fact that the speed of light in a vacuum is an absolute constant. The problem is, that fact has never been proven.

When Einstein proposed the theory of relativity, it was to explain why light always had the same speed. In the late 1800s it was thought that since light travels as a wave it must be carried by some kind of invisible material known as the luminiferous aether. The reasoning was that waves require a medium, such as sound in air or water waves in water. But if the aether exists, then the observed speed of light must change as the Earth moves through the aether. But measurements to observe aether drift came up null. The speed of light appeared to be constant.

Einstein found that the problem was in assuming that space and time were absolute and the speed of light could vary. If instead, you assumed the speed of light was absolute, space and time must be affected by relative motion. It’s a radical idea, but it’s supported by every measurement of light’s constant speed.