The James Webb Space Telescope has found a lonely black hole in the early universe that’s as heavy as 50 million suns. A major discovery, the object confounds theories of the young cosmos.
Category: cosmology – Page 3
Plasmon effects in neutron star magnetospheres could pose new limits on the detection of axions
Dark matter is an elusive type of matter that does not emit, reflect or absorb light, yet is predicted to account for most of the universe’s mass. As it cannot be detected and studied using conventional experimental techniques, the nature and composition of dark matter have not yet been uncovered.
One of the most promising dark matter candidates (i.e., hypothetical particles that dark matter could be made of) are axions. Theory suggests that axions could convert into light particles (i.e., photons) under specific conditions, which could in turn generate signals that can be picked up by sophisticated equipment.
In strong magnetic fields, such as those surrounding neutron stars with large magnetic fields (i.e., magnetars), the conversion of axions into photons has been predicted to generate weak radio signals that could be detected using powerful Earth-based or space-based radio telescopes.
Primordial black hole’s final burst may solve neutrino mystery
The last gasp of a primordial black hole may be the source of the highest-energy “ghost particle” detected to date, a new MIT study proposes.
In a paper appearing today in Physical Review Letters, MIT physicists put forth a strong theoretical case that a recently observed, highly energetic neutrino may have been the product of a primordial black hole exploding outside our solar system.
Neutrinos are sometimes referred to as ghost particles, for their invisible yet pervasive nature: They are the most abundant particle type in the universe, yet they leave barely a trace. Scientists recently identified signs of a neutrino with the highest energy ever recorded, but the source of such an unusually powerful particle has yet to be confirmed.
Shape-shifting collisions offer new tool for studying early matter produced in Big Bang’s aftermath
This summer, the Large Hadron Collider (LHC) took a breath of fresh air. Normally filled with beams of protons, the 27-km ring was reconfigured to enable its first oxygen–oxygen and neon–neon collisions. First results from the new data, recorded over a period of six days by the ALICE, ATLAS, CMS and LHCb experiments, were presented during the Initial Stages conference held in Taipei, Taiwan, on 7–12 September.
Smashing atomic nuclei into one another allows physicists to study the quark–gluon plasma (QGP), an extreme state of matter that mimics the conditions of the universe during its first microseconds, before atoms formed. Until now, exploration of this hot and dense state of free particles at the LHC relied on collisions between heavy ions (like lead or xenon), which maximize the size of the plasma droplet created.
Collisions between lighter ions, such as oxygen, open a new window on the QGP to better understand its characteristics and evolution. Not only are they smaller than lead or xenon, allowing a better investigation of the minimum size of nuclei needed to create the QGP, but they are less regular in shape. A neon nucleus, for example, is predicted to be elongated like a bowling pin—a picture that has now been brought into sharper focus thanks to the new LHC results.
JWST observations discover a small star-forming complex
Using the James Webb Space Telescope (JWST), astronomers have detected what appears to be a faint and small star-forming complex. The discovery of the new complex, which received the designation LAP2, is detailed in a research paper published Sept. 8 on the arXiv preprint server.
The hypothetical Population III stars, composed almost entirely of primordial gas, are theorized to be the first stars to form after the Big Bang. Finding very low-metallicity, low-mass sources at high-redshifts could be crucial to investigating these stars, as they provide a rare glimpse of galaxies under conditions similar to those of the early universe. This could help us understand, for instance, how the first generations of stars enriched the cosmos with heavier elements.
Recently, a team of astronomers led by Eros Vanzella of the Astrophysics and Space Science Observatory of Bologna, Italy, inspected one such high-redshift, metal-poor and low-mass source. The source was identified behind the galaxy cluster Abell 2,744, which acts as a strong lens.
Gravitational wave analysis confirms theory of merging black holes
Ten years after scientists first detected gravitational waves emerging from two colliding black holes, the LIGO-Virgo-KAGRA collaboration, a research team that includes Columbia astronomy professor Maximiliano Isi, has recorded a signal from a nearly identical black hole collision.
Improvements in the detection technology allowed the researchers to see the black holes almost four times as clearly as they could a decade ago, and to confirm two important predictions: That merging black holes only ever grow or remain stable in size—as the late physicist Stephen Hawking predicted—and that, when disturbed, they ring like a bell, as predicted by Albert Einstein’s theory of general relativity.
“This unprecedentedly clear signal of the black hole merger known as GW250114 puts to the test some of our most important conjectures about black holes and gravitational waves,” Isi said.