Cozy Dark emerging technology began work in 2010 as a skunkworks-style engineering firm and is registered with CCR and NSPIRES.
Our early engineering & design efforts have focused on orbital debris solutions and electrodynamic tether technology.
Zach Urbina founded Cozy Dark with the cooperation of technical, research, and academic colleagues in the Southern California AeroAstro community.
We also have a growing library of space science talks featuring Apollo astronaut Buzz Aldrin, astrophysicist Sean Carroll and more.
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24 posts tagged black hole
Three-Telescope Interferometry Allows Astrophysicists to Observe How Black Holes Are Fueled |
By combining the light of three powerful infrared telescopes, an international research team has observed the active accretion phase of a supermassive black hole in the center of a galaxy tens of millions of light years away, a method that has yielded an unprecedented amount of data for such observations. The resolution at which they were able to observe this highly luminescent active galactic nucleus (AGN) has given them direct confirmation of how mass accretes onto black holes in centers of galaxies.
“This three-telescope interferometry is a major milestone toward directly imaging the growth phase of supermassive black holes,” said Sebastian Hoenig, a postdoctoral researcher at the UC Santa Barbara Department of Physics, and one of the astrophysicists who utilized this technique to observe the AGN at the center of galaxy NGC 3783. The observation was led by Gerd Weigelt, a director of the Max Planck Institute for Radio Astronomy in Bonn, Germany. continue reading
Overfed Black Holes Shut Down Galactic Star-Making |
The Herschel Space Observatory has shown galaxies with the most powerful, active black holes at their cores produce fewer stars than galaxies with less active black holes. The results are the first to demonstrate black holes suppressed galactic star formation when the universe was less than half its current age.
“We want to know how star formation and black hole activity are linked,” said Mathew Page of University College London’s Mullard Space Science Laboratory in the United Kingdom and lead author of the Nature paper describing these findings. “The two processes increase together up to a point, but the most energetic black holes appear to turn off star formation.”
Supermassive black holes, weighing as much as millions of suns, are believed to reside in the hearts of all large galaxies. When gas falls upon these monsters, the material is accelerated and heated around the black hole, releasing great torrents of energy. Earlier in the history of the universe, these giant, luminous black holes, called active galactic nuclei, were often much brighter and more energetic. Star formation was also livelier back then.
Studies of nearby galaxies suggest active black holes can squash star formation. The revved-up, central black holes likely heat up and disperse the galactic reservoirs of cold gas needed to create new stars. These studies have only provided “snapshots” in time, however, leaving the overall relationship of active galactic nuclei and star formation unclear, especially over the cosmic history of galaxy formation. continue reading
Black Hole Caught Red-Handed in a Stellar Homicide |
Astronomers have gathered the most direct evidence yet of a supermassive black hole shredding a star that wandered too close. NASA’s Galaxy Evolution Explorer, a space-based observatory, and the Pan-STARRS1 telescope on the summit of Haleakala in Hawaii were among the first to help identify the stellar remains.
Supermassive black holes, weighing millions to billions times more than the Sun, lurk in the centers of most galaxies. These hefty monsters lay quietly until an unsuspecting victim, such as a star, wanders close enough to get ripped apart by their powerful gravitational clutches.
Astronomers have spotted these stellar homicides before, but this is the first time they can identify the victim. Using a slew of ground- and space-based telescopes, a team of astronomers led by Suvi Gezari of The Johns Hopkins University in Baltimore, Md., has identified the victim as a star rich in helium gas. The star resides in a galaxy 2.7 billion light-years away.
Her team’s results will appear in May 2 online edition of the journal Nature.
“When the star is ripped apart by the gravitational forces of the black hole, some part of the star’s remains falls into the black hole, while the rest is ejected at high speeds. We are seeing the glow from the stellar gas falling into the black hole over time. We’re also witnessing the spectral signature of the ejected gas, which we find to be mostly helium. It is like we are gathering evidence from a crime scene. Because there is very little hydrogen and mostly helium in the gas we detect, we know from the carnage that the slaughtered star had to have been the helium-rich core of a stripped star,” Gezari explained. continue reading
Rogue Stars Ejected from the Galaxy Are Found in Intergalactic Space |
It’s very difficult to kick a star out of the galaxy. In fact, the primary mechanism that astronomers have come up with that can give a star the two-million-plus mile-per-hour kick it takes requires a close encounter with the supermassive black hole at the galaxy’s core.
So far astronomers have found 16 of these “hypervelocity” stars. Although they are traveling fast enough to eventually escape the galaxy’s gravitational grasp, they have been discovered while they are still inside the galaxy.
Now, Vanderbilt astronomers report in the May issue of the Astronomical Journal that they have identified a group of more than 675 stars on the outskirts of the Milky Way that they argue are hypervelocity stars that have been ejected from the galactic core. They selected these stars based on their location in intergalactic space between the Milky Way and the nearby Andromeda galaxy and by their peculiar red coloration.
“These stars really stand out. They are red giant stars with high metallicity which gives them an unusual color,” says Assistant Professor Kelly Holley-Bockelmann, who conducted the study with graduate student Lauren Palladino. continue reading
Remarkable Outburst Seen from Old Black Hole |
An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. The discovery, made by astronomers using NASA’s Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in X-rays as a million suns radiate at all wavelengths.
Researchers used Chandra to discover a new ultraluminous X-ray source, or ULX. These objects give off more X-rays than most binary systems, in which a companion star orbits the remains of a collapsed star. These collapsed stars form either a dense core called a neutron star or a black hole. The extra X-ray emission suggests ULXs contain black holes that might be much more massive than the ones found elsewhere in our galaxy.
The companion stars to ULXs, when identified, are usually young, massive stars, implying their black holes are also young. The latest research, however, provides direct evidence that ULXs can contain much older black holes and some sources may have been misidentified as young ones.
The intriguing new ULX is located in M83, a spiral galaxy about 15 million light years from Earth, discovered in 2010 with Chandra. Astronomers compared this data with Chandra images from 2000 and 2001, which showed the source had increased in X-ray brightness by at least 3,000 times and has since become the brightest X-ray source in M83. continue reading
Black Holes Grow Feeding on Binary Star Partners |
A study led by a University of Utah astrophysicist found a new explanation for the growth of supermassive black holes in the center of most galaxies: they repeatedly capture and swallow single stars from pairs of stars that wander too close.
Using new calculations and previous observations of our own Milky Way and other galaxies, “we found black holes grow enormously as a result of sucking in captured binary star partners,” says physics and astronomy Professor Ben Bromley, lead author of the study, which is set for online publication April 2 inAstrophysical Journal Letters.
“I believe this has got to be the dominant method for growing supermassive black holes,” he adds. “There are two ways to grow a supermassive black hole: with gas clouds and with stars. Sometimes there’s gas and sometimes there is not. We know that from observations of other galaxies. But there are always stars.” continue reading
Cosmic ‘Leaf Blower’ Robs Galaxy of Star-Making Fuel |
Supernova explosions and the jets of a monstrous black hole are scattering a galaxy’s star-making gas like a cosmic leaf blower, a new study finds. The findings, which relied on ultraviolet observations from NASA’s Galaxy Evolution Explorer and a host of other instruments, fill an important gap in the current understanding of galactic evolution.
It has long been known that gas-rich spiral galaxies like our Milky Way smash together to create elliptical galaxies such as the one observed in the study. These big, round galaxies have very little star formation. The reddish glow of aging stars comes to dominate the complexion of elliptical galaxies, so astronomers refer to them as “red and dead.”
The process that drives the dramatic transformation from spiral galactic youth to elderly elliptical is the rapid loss of cool gas, the fuel from which new stars form. Supernova explosions can start the decline in star formation, and then shock waves from the supermassive black hole finish the job. Now astronomers think they have identified a recently merged galaxy where this gas loss has just gotten underway.
“We have caught a galaxy in the act of destroying its gaseous fuel for new stars and marching toward being a red-and-dead type of galaxy,” said Ananda Hota, lead author of a new paper in the Monthly Notices of the Royal Astronomical Society. Hota, an astronomer in Pune, India, conducted the study as a post-doctoral research fellow at the Institute of Astronomy & Astrophysics at Academia Sinica in Taipei, Taiwan. continue reading
Astronomers Detect Vast Amounts of Gas and Dust Around Black Hole in Early Universe |
Using the IRAM array of millimetre-wave telescopes in the French Alps, a team of European astronomers from Germany, the UK and France have discovered a large reservoir of gas and dust in a galaxy that surrounds the most distant supermassive black hole known. Light from the galaxy, called J1120+0641, has taken so long to reach us that the galaxy is seen as it was only 740 million years after the Big Bang, when the universe was only 1/18th of its current age. Team leader Dr. Bram Venemans of the Max-Planck Institute for Astronomy in Heidelberg, Germany will present the new discovery on Wednesday 28 March at the National Astronomy Meeting in Manchester.
The Institut de Radioastronomie Millimetrique (IRAM) array is made up of six 15-m size telescopes that detect emission at millimetre wavelengths (about ten thousand times as long as visible light) sited on the 2550-m high Plateau de Bure in the French Alps. The IRAM telescopes work together to simulate a single much larger telescope in a so-called interferometer that can study objects in fine detail. continue reading
