Sentences with phrase «active galaxies»

Another type of active galaxy is the radio galaxy, which emits huge amounts of radio energy.

In active galaxies, a region near the center produces enormous amounts of emission across the entire electromagnetic spectrum.

This changed in the 1960s when they became the favored explanation for active galaxies.

Many active galaxies display these brilliant jets, but their origins are mysterious.

As this light can show wide variation across different active galaxies, astronomers use the properties of the light emitted to classify galaxies into different categories.

Active galaxies turned out to be among the brightest sources of X-ray emission in the sky.

Nonetheless, for many years it remained to be proven that active galaxies do indeed contain black holes.

In the 1940s and 1950s research into active galaxies took off seriously.

Researchers hope to extend their measurements to other active galaxies; the technique could eventually help astronomers better understand the rate at which the universe is expanding, study team members said.

The background consists mainly of X rays from numerous active galaxies.

Active galaxies represent an important area of astronomical research.

A map of the southern sky shows the correlation between sources of incoming cosmic rays (circles) and the locations of active galaxies (red dots).

Known as Seyfert galaxies, these are another type of active galaxy with relatively low mass black holes residing at their centers.

On May 22, HALCA observed a distant active galaxy called PKS 1519 - 273, while the VLBA and VLA also observed it.

Astronomers believe that supermassive, central black holes generate the radio, X-ray, and gamma - ray energy radiated by active galaxies such as Centaurus A, as well as quasars like SDSS J1030 +0524.

The ideal background «lights» for such a study are quasars, which are very distant bright cores of active galaxies powered by black holes.

A third type of active galaxy called BL Lacertae objects (BL Lac objects for short) are probably radio galaxies with their jets pointed right at us.

It shows the central starburst galaxy AzTEC - 3 along with its labeled cohorts of smaller, less active galaxies.

Astronomers are aware of many active galaxies which emanate such jets from their centre.

Bright spots in the map include the Crab Nebula, which hosts a radiation - spewing stellar corpse called a pulsar, and several blazars, violent active galaxies where colossal black holes accelerate particles to more than 99 % the speed of light.

his NASA / ESA Hubble Space Telescope image reveals the iridescent interior of one of the most active galaxies in our local neighbourhood — NGC 1569, a small galaxy located about eleven million light - years away in the constellation of Camelopardalis (The Giraffe)(Credit: ESA / Hubble & NASA, Aloisi, Ford)

This rate shows how active a galaxy is: young galaxies with large amounts of gas form many stars, while red and old galaxies that have depleted their gas reservoirs do not actively form stars.

Nuclear fusion, the energy source known to power stars (and hydrogen bombs), is not efficient enough to explain the total energy output from active galaxies, and astronomers have been able to provide only one plausible alternative: accretion of matter onto a super-massive black hole.

But when the astronomers trained the Gemini North Telescope in Hawaii onto M87, scanning it for infrared emissions, they found evidence of at best a meager torusone that, if there at all, is at least 1,000 times fainter than that of Centaurus A, another, less powerful active galaxy.

She has demonstrated that accretion disks in the center of active galaxies lie at random angles relative to their host galaxies.

The particular type of active galaxy seen then simply depends on the angle the accretion disk and dust ring are to the line of sight.

In a recent paper published in The Astrophysical Journal, Boorman (and colleagues from the NuSTAR active galaxies science team) described how data from NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has been used to study the intrinsic behaviour of a «hidden» supermassive black hole in a galaxy nearby to our own — IC 3639 — some 175 million light years from Earth, relatively close by in cosmic terms.

Many galaxies in this catalogue are dwarf galaxies with indistinct structures, or active galaxies generating powerful jets — but a large number of the galaxies are interacting, such as Messier 51, the Antennae Galaxies, and Arp 256.

Still, he says, it's plausible that the team is seeing a real signal, all the more so because Auger has long seen similar clustering in the direction of active galaxy Centaurus A. «We have what you might you might call a warm spot,» he says.

According to the authors, «mergers and interactions involving [active galaxies] occur no more frequently than for inactive galaxies.»

To conduct the study, Mushotzky and his colleagues re-examined data from 836 active galaxies detected by NASA's Swift Burst Alert Telescope that strongly emit high - energy, or «hard,» X-rays — the same X-rays that medical technicians use to visualize the human skeleton.

The two different classes of jet - spewing active galaxies called blazars may, in fact, be a single hybrid type that evolves over time, according to new research.

Active galaxies come in a variety of types, including Seyfert galaxies, radio galaxies, and quasars.

The Hubble Space Telescope has imaged the nuclei of several active galaxies.

Explanation: Peering deep inside Centaurus A, the closest active galaxy to Earth, the Spitzer Space Telescope's penetrating infrared cameras recorded this startling vista.

This is why the less energetic active galaxies are more common than quasars.

Also, galaxy mergers and collisions will keep the gas and stars in the central part of active galaxies sufficiently stirred up so some of that material will become part of the accretion disk.

Such jets, consisting of subatomic particles moving near the speed of light, are seen in many quasars and active galaxies throughout the universe.

To explain active galaxies, scientists must be able to explain how they emit such large amounts of energy from such small areas of the galactic nuclei.

Others still would like to use it to survey active galaxies.

To explain the observed energy output, the black holes in active galaxies must have masses of a million to a billion times that of the Sun.

An international collaboration of astronomers, led by a group at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, has used the unrivalled observing power of MUSE on the Very Large Telescope (VLT) at ESO's Paranal Observatory to study gas around distant active galaxies, less than two billion years after the Big Bang.

The current model of active galaxies such as M87 posits that each one harbors at its center a black hole many millions or even billions of times more massive than our own sun, all packed into a space about the size of our solar system.

Because the gas in the halo is dark, the team measured it by using the light from quasars, the very distant bright cores of active galaxies powered by black holes.

At 50 million light - years away, M87 is the nearest active galaxy and therefore an astronomer's first stop.

Many of the red spots above and below are distant, active galaxies where massive black holes stir up gas and sling it around at close to the speed of light.