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Mars Base

The feeding habits of teenage galaxies - 0 views

www.physorg.com/...3-habits-teenage-galaxies.html

scibyte38 galaxies

shared by Mars Base on 14 Mar 12 - No Cached
  • New observations made with ESO’s Very Large Telescope are making a major contribution to understanding the growth of adolescent galaxies
  • biggest survey of its kind astronomers have found that galaxies changed their eating habits during their teenage years - the period from about 3 to 5 billion years after the Big Bang
  • start of this phase smooth gas flow was the preferred snack, but later, galaxies mostly grew by cannibalising other smaller galaxies.
  • ...8 more annotations...
  • Astronomers have known for some time that the earliest galaxies were much smaller than the impressive spiral and elliptical galaxies that now fill the Universe
  • employing the state-of-the-art instruments on ESO's Very Large Telescope an international team is unravelling what really happened
  • more than one hundred hours of observations the team has collected the biggest ever set of detailed observations of gas-rich galaxies at this early stage of their development.
  • Two different ways of growing galaxies are competing
  • violent merging events when larger galaxies eat smaller ones
  • smoother and continuous flow of gas onto galaxies
  • zoom sequence starts
  • Smooth gas flow (eso1040) seems to have been a big factor in the building of galaxies in the very young Universe, whereas mergers became more important later.
Mars Base

Astrophysicists spy ultra-distant galaxy amidst cosmic 'dark ages' - 0 views

phys.org/...tra-distant-galaxy-cosmic.html

scibyte64 galaxy

shared by Mars Base on 20 Sep 12 - No Cached
  • combined power of NASA's Spitzer and Hubble space telescopes as well as a cosmic magnification effect, a team
  • has spotted what could be the most distant galaxy ever detected.
  • Light from the young galaxy captured by the orbiting observatories shone forth when the 13.7-billion-year-old universe was just 500 million years old
  • ...19 more annotations...
  • This galaxy is the most distant object we have ever observed with high confidence
  • Future work involving this galaxy—as well as others like it that we hope to find—will allow us to study the universe's earliest objects and how the Dark Ages ended
  • traveled approximately 13.2 billion light-years
  • the universe was just 3.6 percent
  • Objects at these extreme distances are mostly beyond the detection sensitivity of today's largest telescopes
  • astronomers rely on "gravitational lensing
  • predicted by Albert Einstein a century ago
  • gravity of foreground objects warps and magnifies the light from background objects
  • brightening the remote object some 15 times and bringing it into view.
  • small and compact, containing only about 1 percent of the Milky Way's mass
  • leading cosmological theories, the first galaxies should indeed have started out tiny
  • then progressively merged
  • omers plan to study the rise of the first stars and galaxies and the epoch of reionization with the successor to both Spitzer and Hubble—NASA's James Webb Telescope, slated for launch in 2018
  • newly described distant galaxy will likely be a prime target.
  • first galaxies likely played the dominant role in the epoch of reionization
  • event that signaled the demise of the universe's Dark Ages
  • About 400,000 years after the Big Bang, neutral hydrogen gas formed from cooling particles
  • these earliest galaxies is thought to have caused the neutral hydrogen strewn throughout the universe to ionize, or lose an electron
  • during the epoch of reionization, the lights came on in the universe
Mars Base

Ancient Quasar Shines Brightly, But All the Galaxy's Stars Are Missing - 0 views

www.universetoday.com/...-the-galaxys-stars-are-missing

scibyte69 quasar

shared by Mars Base on 24 Oct 12 - No Cached
  • Quasars have been the best and most easily observed beacons for astronomers to probe the distant Universe
  • one of the most distant and brightest quasars is providing a bit of a surprise
  • Astronomers studying a distant galaxy, dubbed J1148+5251 and which contains a bright quasar, are seeing only the quasar and not the host galaxy itself
  • ...15 more annotations...
  • has been thought that the quasar has been feeding on a handful of stars every year in order to bulk up to its size of three billion solar masses over just a few hundred million years. But where are all the stars
  • Near infrared views with the Hubble Space Telescope’s Wide Field Camera 3 are only providing hints of what might be taking place
  • galaxy is so enshrouded with dust that none of the starlight can be seen
  • only the bright, blaring quasar shines through
  • most early galaxies contain hardly any dust
  • the early universe was dust-free until the first generation of stars started making dust through nuclear fusion
  • quasar was first identified in the Sloan Digital Sky Survey (SDSS) and the follow-up submillimeter observations showed significant dust but not how and where
  • If you want to hide the stars with dust
  • make lots of short-lived massive stars earlier on that lose their mass at the end of their lifetime
  • used Hubble to very carefully subtract light from the quasar image and look for the glow of surrounding stars.
  • remarkable
  • Hubble didn’t find any of the underlying galaxy
  • Because we don’t see the stars, we can rule out that the galaxy that hosts this quasar is a normal galaxy
  • It’s among the dustiest galaxies in the universe
  • so widely distributed that not even a single clump of stars is peeking through
Mars Base

Runaway Planets Tossed From Galaxy at Fraction of Speed of Light | Space.com - 1 views

www.space.com/speed-planets-light-speed.html

scibyte40 exoplanet

shared by Mars Base on 24 Mar 12 - No Cached
  • Planets in tight orbits around stars that get ejected from our galaxy may actually themselves be tossed out of the Milky Way at blisteringly fast speeds of up to 30 million miles per hour, or a fraction of the speed of light, a new study finds.
  • would be some of the fastest objects in the galaxy, aside from photons
  • In terms of large, solid objects, they would be the fastest. It would take them 10 seconds or so to cross the diameter of the Earth
  • ...10 more annotations...
  • In 2005, astronomers found evidence of a runaway star that was flying out of the Milky Way galaxy at a speed of 1.5 million mph (2.4 million kph).
  • part of a double-star system that wandered too close to the supermassive black hole
  • In the seven years since, 16 of these hypervelocity stars have been found
  • typical runaway planet would likely dash outward at 7 to 10 million mph (11.3 to 16.1 million kph), but given the right circumstances, a small fraction could have their speeds boosted to up to 30 million mph (48.3 million kph).
  • hypervelocity planets will escape the Milky Way and travel through interstellar space
  • a civilization on such a planet, they would have a very exciting journe
  • Once the planet exits from the local group of galaxies, it will be accelerated away by cosmic expansion. So, within 10 billion years, it would go from the center of the galaxy to all the way to the edge of the observable universe
  • planet that tightly orbits a runaway star will cross in front and cause its brightness to dim slightly in what astronomers call a "transit
  • To hitch a ride on a hypervelocity star, a planet would have to be locked in a tight orbit, which ups the odds of witnessing a transit to around 50 percent
  • first time someone is talking about searching for planets around hypervelocity stars
Mars Base

Astronomers Watch as a Black Hole Eats a Rogue Planet - 0 views

www.universetoday.com/...black-hole-eats-a-rogue-planet

scibyte89 BlackHole

shared by Mars Base on 03 Apr 13 - No Cached
  • Astronomers using the Integral space observatory were able to watch as the planet was eaten by a black hole that had been inactive for decades
  • The observation was
  • from a galaxy that has been quiet for at least 20–30 years
  • ...14 more annotations...
  • the event is a preview of a similar feeding event that is expected to take place with the black hole at the center of our own Milky Way Galaxy
  • galaxy NGC 4845, 47 million light-years away
  • Astronomers were using Integral to study a different galaxy when they noticed a bright X-ray flare coming from another location in the same wide field-of-view
  • the origin was confirmed as NGC 4845, a galaxy never before detected at high energies
  • the emission was traced from its maximum in January 2011, when the galaxy brightened by a factor of a thousand, and then as it subsided over the course of the year
  • By analyzing the characteristics of the flare, the astronomers could determine that the emission came from a halo of material around the galaxy’s central black hole as it tore apart and fed on an object of 14–30 Jupiter masses, and so the astronomers say the object was either a super-Jupiter or a brown dwarf
  • This object appears to have been ‘wandering,’ which would fit the description of recent studies
  • The black hole in the center of NGC 4845 is estimated to have a mass of around 300,000 times that of our own Sun
  • This is the first time where we have seen the disruption of a substellar object by a black hole
  • estimate that only its external layers were eaten by the black hole, amounting to about 10% of the object’s total mass, and that a denser core has been left orbiting the black hole
  • The flaring event in NGC 4845 might be similar to what is expected to happen with the supermassive black hole at the center of our own Milky Way Galaxy
  • these events will tell astronomers more about what happens to the demise of different types of objects as they encounter black holes of varying sizes
  • Estimates are that events like these may be detectable every few years in galaxies around us
  • the emission brightened and decayed shows there was a delay of 2–3 months between the object being disrupted and the heating of the debris in the vicinity of the black hole.
Mars Base

For the first time, astronomers have measured the radius of a black hole - 0 views

phys.org/...onomers-radius-black-hole.html

scibyte65 black holes

shared by Mars Base on 30 Sep 12 - No Cached
  • an international team
  • , has for the first time measured the radius of a black hole at the center of a distant galaxy—the closest distance at which matter can approach before being irretrievably pulled into the black hole.
  • scientists linked together radio dishes in Hawaii, Arizona and California to create a telescope array called the "Event Horizon Telescope" (EHT) that can see details 2,000 times finer than what's visible to the Hubble Space Telescope.
  • ...20 more annotations...
  • , the team observed the glow of matter near the edge of this black hole—a region known as the "event horizon."
  • , not everything can cross the event horizon to squeeze into a black hole
  • "cosmic traffic jam" in which gas and dust build up, creating a flat pancake of matter known as an accretion disk
  • disk of matter orbits the black hole at nearly the speed of light, feeding the black hole a steady diet of superheated material
  • Over time, this disk can cause the black hole to spin in the same direction as the orbiting material
  • Caught up in this spiraling flow are magnetic fields, which accelerate hot material along powerful beams above the accretion disk
  • resulting high-speed jet, launched by the black hole and the disk, shoots out across the galaxy, extending for hundreds of thousands of light-years
  • jets can influence many galactic processes, including how fast stars form.
  • . Because M87's jet is magnetically launched from this smallest orbit,
  • astronomers can estimate the black hole's spin through careful measurement of the jet's size as it leaves the black hole
  • Until now, no telescope has had the magnifying power required for this kind of observation
  • team used a technique called Very Long Baseline Interferometry, or VLBI, which links data from radio dishes located thousands of miles apart.
  • , taken together, create a "virtual telescope" with the resolving power of a single telescope as big as the space between the disparate dishes
  • enables scientists to view extremely precise details in faraway galaxies.
  • Using the technique
  • team measured the innermost orbit of the accretion disk to be only 5.5 times the size of the black hole event horizon
  • According to the laws of physics, this size suggests that the accretion disk is spinning in the same direction as the black hole
  • first direct observation to confirm theories of how black holes power jets from the centers of galaxies
  • The team plans to expand its telescope array, adding radio dishes in Chile, Europe, Mexico, Greenland and Antarctica, in order to obtain even more detailed pictures of black holes in the future.
  • www.eventhorizontelescope.org/
Mars Base

2013 in science - Wikipedia, the free encyclopedia - 0 views

en.wikipedia.org/...2013_in_science

scibyte114 2013YearInReview

shared by Mars Base on 23 Dec 13 - No Cached
  • Morocco in 2011, and report that it is a new type of Mars rock with an unusually high water content.[8][9][10] American researchers state that a gene associated with active personality traits is also linked to
  • Astronomers affiliated with the Kepler space observatory announce the discovery of KOI-172.02, an Earth-like exoplanet candidate which orbits a star similar to the Sun in the habitable zone
  • 13 January – Massachusetts doctors invent a pill-sized medical scanner that can be safely swallowed by patients, allowing the esophagus to be more easily scanned for disease
  • ...101 more annotations...
  • 17 January – NASA announces that the Kepler space observatory has developed a reaction wheel issue
  • 2 January A study by Caltech astronomers reports that the Milky Way Galaxy contains at least one planet per sta
  • 3 January
  • 8 January
  • 20 January – Scientists prove that quadruple-helix DNA is present in human cells
  • 25 January
  • An international team of scientists develops a functional light-based "tractor beam", which allows individual cells to be selected and moved at will. The invention could have broad applications in medicine and microbiology
  • 30 January – South Korea conducts its first successful orbital launch
  • 6 February
  • Astronomers report that 6% of all dwarf stars – the most common stars in the known universe – may host Earthlike planets
  • Scientists discover live bacteria in the subglacial Antarctic Lake Whillans
  • American scientists finish drilling down to the subglacial Lake Whillans, which is buried around 1 kilometre (0.62 mi) under the Antarctic ice
  • 10 February NASA's Curiosity Mars rover uses its onboard drill to obtain the first deep rock sample ever retrieved from the surface of another plane
  • 15 February A 10-ton meteoroid impacts in Chelyabinsk, Russia, producing a powerful shockwave and injuring over 1,000 people
  • 28 February
  • Astronomers make the first direct observation of a protoplanet forming in a disk of gas and dust around a distant sta
  • A third radiation belt is discovered around the Eart
  • 1 March – Boston Dynamics demonstrates an updated version of its BigDog military robot
  • 3 March – American scientists report that they have cured HIV in an infant by giving the child a course of antiretroviral drugs very early in its life. The previously HIV-positive child has reportedly exhibited no HIV symptoms since its treatment, despite having no further medication for a year
  • researchers replace 75 percent of an injured patient's skull with a precision 3D-printed polymer replacement implant. In future, damaged bones may routinely be replaced with custom-manufactured implants
  • 7 March
  • A study concludes that heart disease was common among ancient mummies
  • 11 March
  • 12 March NASA's Curiosity rover finds evidence that conditions on Mars were once suitable for microbial life after analyzing the first drilled sample of Martian rock, "John Klein" rock at Yellowknife Bay in Gale Crater. The rover detected water, carbon dioxide, oxygen, sulfur dioxide, hydrogen sulfide, chloromethane and dichloromethane. Related tests found results consistent with the presence of smectite clay minerals
  • 14 March CERN scientists confirm, with a very high degree of certainty, that a new particle identified by the Large Hadron Collider in July 2012 is the long-sought Higgs boson
  • 18 March
  • NASA reports evidence from the Curiosity rover on Mars of mineral hydration, likely hydrated calcium sulfate, in several rock samples, including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in the veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock.[177] Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of 60 cm
  • 27 March – A potential new weight loss method is discovered, after a 20% weight reduction was achieved in mice simply by having their gut microbes altered.
  • NASA scientists report that hints of dark matter may have been detected by the Alpha Magnetic Spectrometer on the International Space Station
  • 3 April
  • 15 April A functional lab-grown kidney is successfully transplanted into a live rat in Massachusetts General Hospital
  • 18 April – NASA announces the discovery of three new Earthlike exoplanets – Kepler-62e, Kepler-62f, and Kepler-69c – in the habitable zones of their respective host stars, Kepler-62 and Kepler-69. The new exoplanets, which are considered prime candidates for possessing liquid water and thus potentially life, were identified using the Kepler spacecraft
  • 21 April The Antares rocket, a commercial launch vehicle developed by Orbital Sciences Corporation, successfully conducts its maiden flight
  • After years of unpowered glide tests, Scaled Composites' SpaceShipTwo hybrid spaceplane successfully conducts its first rocket-powered fligh
  • 29 April
  • 1 May IBM scientists release A Boy and His Atom, the smallest stop-motion animation ever created, made by manipulating individual carbon monoxide molecules with a scanning tunnelling microscope
  • A new study finds that children whose parents suck on their pacifiers have fewer allergies later in life
  • NASA reports that a reaction wheel on the Kepler space observatory may be malfunctioning and may result in the premature termination of the observatory's search for Earth-like
  • 15 May
  • 16 May Water dating back 2.6 billion years, by far the oldest ever found, is discovered in a Canadian mine
  • 27 May Four-hundred-year-old bryophyte specimens left behind by retreating glaciers in Canada are brought back to life in the laboratory
  • 29 May
  • Russian scientists announce the discovery of mammoth blood and well-preserved muscle tissue from an adult female specimen in Siberia
  • A new treatment to "reset" the immune system of multiple sclerosis patients is reported to reduce their reactivity to myelin by 50 to 75 percent
  • 4 June
  • During the Shenzhou 10 mission, Chinese astronauts deliver the country's first public video broadcast from the orbiting Tiangong-1 space laboratory
  • 20 June
  • China's Shenzhou 10 manned spacecraft returns safely to Earth, having conducted China's longest manned space mission to date
  • 26 June
  • 20 June
  • 20 June
  • 6 July
  • Scientists report that a wide variety of microbial life exists in the subglacial Antarctic Lake Vostok, which has been buried in ice for around 15 million years. Samples of the lake's water obtained by drilling were found to contain traces of DNA from over 3,000 tiny organisms
  • 15 July
  • ASA engineers successfully test a rocket engine with a fully 3D-printed injector
  • 19 July
  • NASA scientists publish the results of a new analysis of the atmosphere of Mars, reporting a lack of methane around the landing site of the Curiosity rover
  • Earth is photographed from the outer solar system. NASA's Cassini spacecraft releases images of the Earth and Moon taken from the orbit of Saturn
  • 29 July – Astronomers discover the first exoplanet orbiting a brown dwarf, 6,000 light years from Earth
  • exoplanet
  • 7 January
  • Astronomers
  • report that "at least 17 billion" Earth-sized exoplanets are estimated to reside in the Milky Way Galaxy
  • 20 February
  • NASA reports the discovery of Kepler-37b, the smallest exoplanet yet known, around the size of Earth's Moon
  • 10 June
  • Scientists report that the earlier claims of an Earth-like exoplanet orbiting Alpha Centauri B, a star close to our Solar System, may not be supported by astronomical evidence
  • 25 June – In an unprecedented discovery, astronomers detect three potentially Earthlike exoplanets orbiting a single star in the Gliese 667
  • 11 July For the first time, astronomers determine the true colour of a distant exoplanet. HD 189733 b, a searing-hot gas giant, is said to be a vivid blue colour, most likely due to clouds of silica in its atmosphere
  • NASA announces that the failing Kepler space observatory may never fully recover. New missions are being considered
  • 15 August
  • Phase I clinical trials of SAV001 – the first and only preventative HIV vaccine – have been successfully completed with no adverse effects in all patients. Antibody production was greatly boosted after vaccination
  • 3 September
  • 12 September NASA announces that Voyager I has officially left the Solar System, having travelled since 1977
  • NASA scientists report the Mars Curiosity rover detected "abundant, easily accessible" water (1.5 to 3 weight percent) in soil samples
  • 26 September
  • In addition, the rover found two principal soil types: a fine-grained mafic type and a locally derived, coarse-grained felsic type
  • mafic
  • as associated with hydration of the amorphous phases of the soi
  • perchlorates, the presence of which may make detection of life-related organic molecules difficult, were found at the Curiosity rover landing site
  • earlier at the more polar site of the Phoenix lander) suggesting a "global distribution of these salts
  • Astronomers have created the first cloud map of an exoplanet, Kepler-7b
  • 30 September
  • 8 October The Nobel Prize in Physics has been awarded to François Englert and Peter Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider"
  • 16 October Russian authorities raise a large fragment, 654 kg (1,440 lb) total weight, of the Chelyabinsk meteor, a Near-Earth asteroid that entered Earth's atmosphere over Russia on 15 February 2013, from the bottom of Chebarkul lake.
  • Researchers have shown that a fundamental reason for sleep is to clean the brain of toxins. This is achieved by brain cells shrinking to create gaps between neurons, allowing fluid to wash through
  • 17 October
  • 22 October – Astronomers have discovered the 1,000th known exoplanet
  • 4 November - Astronomers report, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of sun-like stars and red dwarf stars within the Milky Way Galaxy
  • 11 billion of these estimated planets may be orbiting sun-like stars
  • 5 November – India launches its first Mars probe, Mangalyaan
  • The IceCube Neutrino Observatory has made the first discovery of very high energy neutrinos on Earth which had originated from beyond our Solar System
  • 21 November
  • 1 December – China launches the Chang'e 3 lunar rover mission, with a planned landing on December 16
  • 3 December – The Hubble Space Telescope has found evidence of water in the atmospheres of five distant exoplanets: HD 209458b, XO-1b, WASP-12b, WASP-17b and WASP-19b
  • 9 December NASA scientists report that the planet Mars had a large freshwater lake (which could have been a hospitable environment for microbial life) based on evidence from the Curiosity rover studying Aeolis Palus near Mount Sharp in Gale Crater
  • 12 December NASA announces, based on studies with the Hubble Space Telescope, that water vapor plumes were detected on Europa, moon of Jupiter
  • 14 December – The unmanned Chinese lunar rover Chang'e 3 lands on the Moon, making China the third country to achieve a soft landing there
  • 18 December
  • nomers have spotted what appears to be the first known "exomoon", located 1,800 light years away
  • 20 December – NASA reports that the Curiosity rover has successfully upgraded, for the third time since landing, its software programs and is now operating with version 11. The new software is expected to provide the rover with better robotic arm and autonomous driving abilities. Due to wheel wear, a need to drive more carefully, over the rough terrain the rover is currently traveling on its way to Mount Sharp, was also reported
Mars Base

Mysterious Extragalactic Explosions Baffle Astronomers | Fast Radio Bursts | Space.com - 0 views

www.space.com/-radio-explosions-mystery.html

scibyte100 RadioSignal

shared by Mars Base on 07 Jul 13 - No Cached
  • known as fast radio bursts (FRBs), above the plane of our Milky Way Galaxy.
  • These bursts gave off more energy in a millisecond than the sun does in 300,000 years
  • The bursts ranged from 5.5 to 10 billion light-years away, meaning it took the light from some of them 10 billion years to reach Earth. (The Big Bang 
  • ...17 more annotations...
  • occurred 13.8 billion years ago
  • These newfound objects allowed the researchers to calculate that an FRB should occur once every 10 seconds
  • whether the new signals came from inside or outside the Milky Way.
  • they studied how the radio waves were affected by the material they pass through — a technique that could allow these new objects to shed light on the components of space.
  • As radio waves travel in space, they are stretched and slowed by the ionized material through which they move
  • Using models, the team concluded that the FRBs traveled billions of light-years — much farther than the edge of Earth's galaxy
  • the source is likely located in another galaxy
  • They are so bright and narrow that we can limit the size of the emission region at the source to just a few hundred kilometers
  • Although the explosions are brief, the astronomers can pinpoint the bursts' locations pretty accurately
  • No corresponding object could be observed in optical, gamma or X-ray wavelengths, so the explosions' origins remain unknown to scientists
  • Possible sources
  • intersecting magnetic fields from two neutron stars, extremely dense city-size bodies packing the mass of the sun.
  • A special kind of supernova orbited by a neutron star could potentially produce radio bursts as the star's magnetic field interacts with the explosion of the supernova
  • such combinations would be rare
  • favorite explanation is a giant burst from a magnetar, a highly magnetized type of neutron star
  • performed approximately a year after the FRBs were first spotted, looked at whether the objects continued to produce emission, but the signals appear to be nonrepeating
  • Efforts are ongoing at the moment to detect FRBs in close to real time, such that they can be followed up quickly
Mars Base

Astronomers discover the largest structure in the universe - 0 views

phys.org/...ronomers-largest-universe.html

scibyte77 LQG

shared by Mars Base on 13 Jan 13 - No Cached
  • The large quasar group (LQG) is so large that it would take a vehicle travelling at the speed of light some 4 billion years to cross it.
  • Quasars are the nuclei of galaxies from the early days of the universe that undergo brief periods of extremely high brightness that make them visible across huge distances.
  • 'brief' in astrophysics terms but actually last 10-100 million years.
  • ...11 more annotations...
  • Since 1982 it has been known that quasars tend to group together in clumps or 'structures' of surprisingly large sizes, forming large quasar groups or LQGs.
  • the LQG which is so significant in size it also challenges the Cosmological Principle: the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from.
  • The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle
  • he Principle is assumed but has never been demonstrated observationally 'beyond reasonable doubt'.
  • the Milky Way, is separated from its nearest neighbour, the Andromeda Galaxy, by about 0.75 Megaparsecs (Mpc) or 2.5 million light-years.
  • Whole clusters of galaxies can be 2-3 Mpc
  • LQGs can be 200 Mpc or more across.
  • Based on the Cosmological Principle and the modern theory of cosmology, calculations suggest that astrophysicists should not be able to find a structure larger than 370 Mpc.
  • newly discovered LQG however has a typical dimension of 500 Mpc.
  • it is elongated, its longest dimension is 1200 Mpc (or 4 billion light years)
  • some 1600 times larger than the distance from the Milky Way to Andromed
Mars Base

Quasar may be embedded in unusually dusty galaxy - 0 views

phys.org/...ed-unusually-dusty-galaxy.html

scibyte69 quasar

shared by Mars Base on 24 Oct 12 - No Cached
  • Quasars (short for quasi-stellar object) are the brilliant cores of galaxies where infalling material fuels a super-massive black hole
  • black hole is so engorged that some of the energy escapes as powerful blasts of radiation from the surrounding disk of accreting material
  • can appear as a jet-like feature
  • ...4 more annotations...
  • If the beam shines in Earth's direction
  • can appear as a quasar that can outshine its surrounding galaxy a hundred or a thousand times.
  • first identified in the Sloan Digital Sky Survey (SDSS).
  • Only a handful of these very distant ultra-luminous quasars were found by the SDSS in about one quarter of the whole sky
Mars Base

Hubble Space Telescope Passes Major Science Milestone | Hubble 10,000th Science Paper |... - 0 views

www.space.com/cope-10000-science-papers.html

scibyte25

shared by Mars Base on 09 Dec 11 - No Cached
  • Hubble Space Telescope has crossed a major milestone, accumulating 10,000 science papers based on its observations
  • After 21 years
  • it's actually in the best shape of its life
  • ...14 more annotations...
  • last space shuttle servicing mission was in May 2009.
  • Papers describing discoveries in nearly every field of astronomy and cosmology have been published based on data gathered by the Hubble Space Telescope.
  • conducted by scientists in more than 35 countries
  • most papers written by researchers in the United States, the United Kingdom, Germany, Italy, France, and Spain
  • Hubble's top five most referenced papers are on
  • The search for distant supernovas used to characterize dark energy
  • The precise measurement of the universe's rate of expansion
  • The apparent link between galaxy mass and central black hole mass
  • Early galaxy formation in the Hubble Deep Field
  • The evolutionary models for low-mass stars and brown dwarfs
  • 10,000th Hubble science paper
  • announces the discovery of the faintest supernova ever associated with a cosmic explosion called a long-duration gamma-ray burst, which spews high-energy radiation into space when a star dies
  • The first science paper based on Hubble data came about six months after the telescope's launch
  • a paper on observations of the center of galaxy NGC 7457, where scientists suspected a huge black hole lurked
Mars Base

Early Black Holes were Grazers Rather than Glutonous Eaters - 0 views

www.universetoday.com/...s-rather-than-glutonous-eaters

scibyte52 black holes

shared by Mars Base on 21 Jun 12 - No Cached
  • Black holes powering distant quasars in the early Universe grazed on patches of gas or passing galaxies rather than glutting themselves in dramatic collisions according to new observations from NASA’s Spitzer and Hubble space telescopes
  • A black hole doesn’t need much gas to satisfy its hunger and turn into a quasar
  • Quasars are distant and brilliant galactic powerhouses. These far-off objects are powered by black holes that glut themselves on captured material; this in turn heats the matter to millions of degrees making it super luminous
  • ...10 more annotations...
  • team studied 30 quasars with NASA’s orbiting telescopes Hubble and Spitzer
  • These quasars, glowing extremely bright in the infrared images
  • telltale sign that resident black holes are actively scooping up gas and dust into their gravitational whirlpool
  • formed during a time of peak black-hole growth between eight and twelve billion years
  • supports evidence that the creation of the most massive black holes in the early Universe was fueled not by dramatic bursts of major mergers but by smaller, long-term events
  • found 26 of the host galaxies
  • about the size of our own Milky Way Galaxy, showed no signs of collisions
  • Quasars that are products of galaxy collisions are very bright
  • the process powering the quasars and their black holes lies below the detection of Hubble
  • prime targets for the upcoming James Webb Space Telescope, a large infrared orbiting observatory scheduled for launch in 2018
Mars Base

'Runaway' Star Cluster Breaks Free from Distant Galaxy - 0 views

www.universetoday.com/...reaks-free-from-distant-galaxy

scibyte129 StarCluster

shared by Mars Base on 01 May 14 - No Cached
  • discovered dozens of so-called “hypervelocity stars” — single stars that break the stellar speed limit
  • The Virgo Cluster galaxy, M87, has ejected an entire star cluster, throwing it toward us at more than two million miles per hour.
  • Astronomers have found runaway stars before, but this is the first time we’ve found a runaway star cluster
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  • About one in a billion stars travel at a speed roughly three times greater than our Sun
  • at 220 km/s with respect to the galactic center
  • At a speed that fast, these stars can easily escape the galaxy entirely, traveling rapidly throughout intergalactic space.
  • this is the first time an entire star cluster has broken free
  • hypervelocity stars have puzzled astronomers for years. But by observing their speed and direction, astronomers can trace these stars backward, finding that some began moving quickly in the Galactic Center
  • Here, an interaction with the supermassive black hole can kick a star away at an alarming speed
  • Another option is that a supernova explosion propelled a nearby star to a huge speed
  • think M87 might have two supermassive black holes at its center
  • The star cluster wandered too close to the pair, which picked off many of the cluster’s outer stars while the inner core remained intact
  • The black holes then acted like a slingshot, flinging the cluster away at a tremendous speed
Mars Base

Planck's most detailed map ever reveals an almost perfect Universe - 0 views

phys.org/...3-planck-reveals-universe.html

scibyte87 PlanckConstant

shared by Mars Base on 22 Mar 13 - No Cached
  • the most detailed map ever created of the cosmic microwave background
  • the relic radiation from the Big Bang
  • was released
  • ...31 more annotations...
  • revealing the existence of features that challenge the foundations of our current understanding of the Universe
  • The image is based on the initial 15.5 months of data from Planck and is the mission's first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380 000 years old.
  • At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2700ºC
  • protons and electrons joined to form hydrogen atoms, the light was set free
  • As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero.
  • that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today
  • According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.
  • Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before
  • By analysing the nature and distribution of the seeds in Planck's CMB image, we can determine the composition and evolution of the Universe from its birth to the present day
  • because precision of Planck's map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood
  • Since the release of Planck's first all-sky image in 2010, we have been carefully extracting and analysing all of the foreground emissions that lie between us and the Universe's first light
  • revealing the cosmic microwave background in the greatest detail yet
  • One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model
  • their signals are not as strong as expected from the smaller scale structure
  • Another is an asymmetry in the average temperatures on opposite hemispheres of the sky
  • This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look
  • a cold spot extends over a patch of sky that is much larger than expected.
  • The asymmetry and the cold spot had already been hinted at with Planck's predecessor
  • NASA's WMAP mission, but were largely ignored because of lingering doubts about their cosmic origin
  • One way to explain the anomalies is to propose that the Universe is in fact not the same in all directions on a larger scale than we can observe
  • In this scenario, the light rays from the CMB may have taken a more complicated route through the Universe than previously understood, resulting in some of the unusual patterns observed today.
  • ultimate goal would be to construct a new model that predicts the anomalies and links them together
  • we don't know whether this is possible and what type of new physics might be needed
  • the Planck data conform spectacularly well to the expectations of a rather simple model of the Universe, allowing scientists to extract the most refined values yet for its ingredients
  • dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for less than previously thought.
  • Normal matter that makes up stars and galaxies contributes just 4.9% of the mass/energy density of the Universe
  • Dark matter, which has thus far only been detected indirectly by its gravitational influence, makes up 26.8%, nearly a fifth more than the previous estimate.
  • Planck data also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant
  • At 67.15 kilometres per second per megaparsec, this is significantly less than the current standard value in astronomy
  • The data imply that the age of the Universe is 13.82 billion years.
  • We see an almost perfect fit to the standard model of cosmology, but with intriguing features that force us to rethink some of our basic assumptions
Mars Base

Biggest Thing in Universe Found-Defies Scientific Theory - 0 views

news.nationalgeographic.com/...iverse-science-space-evolution

scibyte77 LQG

shared by Mars Base on 13 Jan 13 - No Cached
  • Using data from the Sloan Digital Sky Survey, an international team of researchers has discovered a record-breaking cluster of quasars—young active galaxies
  • the Milky Way, is just a hundred thousand light-years across
  • the local supercluster of galaxies in which it's located, the Virgo Cluster, is only a hundred million light-years wide
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  • "It could mean that our mathematical description of the universe has been oversimplified-and that would represent a serious difficulty and a serious increase in complexity,"
Mars Base

Zoom Through 84 Million Stars in Gigantic New 9-Gigapixel Image - 0 views

www.universetoday.com/...gigantic-new-9-gigapixel-image

scibyte69 media

shared by Mars Base on 24 Oct 12 - No Cached
  • new gigantic nine-gigapixel image from the VISTA infrared survey telescope at ESO’s Paranal Observatory of the central portion of the Milky Way Galaxy
  • resolution of this image is so great, that if it was printed out in the resolution of a typical book, it would be 9 meters long and 7 meters tall
  • The huge dataset contains more than ten times more stars than previous studies
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  • By observing
  • we can learn a lot more about the formation and evolution of not only our galaxy, but also spiral galaxies in general
  • To help analyze this huge catalogue, the brightness of each star is plotted against its color for about 84 million stars to create a color–magnitude diagram
  • plot contains more than ten times more stars than any previous study
Mars Base

Supernova Candidate Stars May Signal "Impending Doom" - 0 views

www.universetoday.com/...tars-may-signal-impending-doom

scibyte24

shared by Mars Base on 02 Dec 11 - No Cached
  • very visible supernova event. Hosted in the Whirlpool Galaxy (M51),
  • researchers at Ohio State University, a galaxy survey may have captured evidence of a “stellar signal” just before it went supernova
  • OSU team was undertaking a survey of 25 galaxies for stars that changed their magnitude in usual ways
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  • goal was to find a star just before it ended its life
  • a binary star system located in M51 produced just the results they were looking fo
  • ne star dropped amplitude just a short period of time before the other exploded
  • Maybe stars give off a clear signal of impending doom, maybe they don’t
  • But we’ll learn something new about dying stars no matter the outcome
  • it was a binary star system being studied by the OSU team
  • consisted of both a blue and red star
  • At this point, the astronomers surmise the red star was the one that dimmed significantly over the three-year period while the blue one blew its top
  • reviewing the LBT data
  • when compared with Hubble images, the red star dimmed at about 10% over the final three-year period at an estimated 3% per previous years
  • researchers surmise the red star may have actually survived the supernova event
  • After the light from the explosion fades away, we should be able to see the companion that did not explode
Mars Base

Hubble directly observes the disc around a black hole - 0 views

www.physorg.com/...11-hubble-disc-black-hole.html

scibyte20 black holes quasar

shared by Mars Base on 06 Nov 11 - No Cached
  • Scientists have used the NASA/ESA Hubble Space Telescope to observe a quasar accretion disc -- a glowing disc of matter that is slowly being sucked into its galaxy's central black hole
  • Scientists have used the NASA/ESA Hubble Space Telescope to observe a quasar accretion disc -- a glowing disc of matter that is slowly being sucked into its galaxy's central black hole.
  • the team measured the disc's size and studied the colours (and hence the temperatures) of different parts of the disc
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  • Using the NASA/ESA Hubble Space Telescope, combined with the gravitational lensing effect of stars in a distant galaxy, the team measured the disc's size and studied the colours (and hence the temperatures) of different parts of the disc.
  • These observations show a level of precision equivalent to spotting individual grains of sand on the surface of the Moon.
  • show a level of precision equivalent to spotting individual grains of sand on the surface of the Moon
  • Quasars — short for quasi-stellar objects — are glowing discs of matter that orbit supermassive black holes, heating up and emitting extremely bright radiation as they do so.
  • Until now, the minute apparent size of quasars has meant that most of our knowledge of their inner structure has been based on theoretical extrapolations, rather than direct observations.
  • using the stars in an intervening galaxy as a scanning microscope to probe features in the quasar's disc that would otherwise be far too small to see
  • As these stars move across the light from the quasar, gravitational effects amplify the light from different parts of the quasar, giving detailed colour information for a line that crosses through the accretion disc.
  • the team were able to reconstruct the colour profile across the accretion disc
  • allowed the team to measure the diameter of the disc of hot matter, and plot how hot it is at different distances from the centre
  • Quasars' physical properties are not yet well understood
  • This new ability to obtain observational measurements is therefore opening a new window to help understand the nature of these objects."
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