A new hypothesis proposes that a large fraction of dark matter may be bound up inside tight balls the size of Neptune — so-called dark matter planets.
Category: cosmology – Page 244
What remains are mostly neutron stars or black holes. And now, Hubble seems to have documented the instant when a supernova blinked out — implying that it captured the moment a black hole took control.
While some supernova explosions, such as SN 1,054, are violent and leave clouds of debris for thousands of years (a.k.a. nebula), the star in question seems to have exploded and then had all its gas pulled back into the black hole at the core. This may occur if the star’s core collapse is very big. Rather than exploding, the gas falls into the star’s core.
Over the past few years, astronomers have become aware of some shocking new properties of black holes.
As it turned out, they not only mercilessly consume and destroy everything that falls into them.
Black holes can also spew out fountains of hot matter and surround themselves with firewalls.
NASA’s James Webb Space Telescope has peered into the chaos of the Cartwheel Galaxy, revealing new details about star formation and the galaxy’s central black hole. Webb’s powerful infrared gaze produced this detailed image of the Cartwheel and two smaller companion galaxies against a backdrop of many other galaxies.
Scientists used a fossil relic left over from the Big Bang to perform the earliest detection of dark matter ever.
Astronomers used the cosmic microwave background, radiation left over from just after the Big Bang, to conduct the earliest ever detection of dark matter.
Gravitational lensing of the cosmic microwave background has been used to probe the distribution of dark matter around some of the earliest galaxies in the Universe.
Investigating the properties of galaxies is fundamental to uncovering the still-unknown nature of the dominant forms of mass and energy in the Universe: dark matter and dark energy. Dark matter resides in “halos” surrounding galaxies, and information on the evolution of this invisible substance can be obtained by examining galaxies over a wide range of cosmic time. But observing distant galaxies—those at high redshifts—poses a challenge for astronomers because these objects look very dim. Fortunately, there is another way to probe the dark matter around such galaxies: via the imprint it leaves on the pattern of cosmic microwave background (CMB) temperature fluctuations through gravitational lensing (Fig. 1).
Lensing of the cosmic microwave background indicates 12-billion-year-old galaxies had dark matter.
Australian scientists are making strides towards solving one of the greatest mysteries of the universe: the nature of invisible “dark matter”.
Peer long enough into the heavens, and the Universe starts to resemble a city at night. Galaxies take on characteristics of streetlamps cluttering up neighborhoods of dark matter, linked by highways of gas that run along the shores of intergalactic nothingness.
This map of the Universe was preordained, laid out in the tiniest of shivers of quantum physics moments after the Big Bang launched into an expansion of space and time some 13.8 billion years ago.
Yet exactly what those fluctuations were, and how they set in motion the physics that would see atoms pool into the massive cosmic structures we see today is still far from clear.