cheap universe

9
Supermassive black hole Planetary center in Chile Comet halley…

Upload: nicole-cortes

Post on 20-Mar-2016

223 views

Category:

Documents


0 download

DESCRIPTION

magazine of universe

TRANSCRIPT

Page 1: cheap universe

Supermassive black hole

Planetary center in Chile

Comet halley…

Page 2: cheap universe

INDEX

ALMA; Atacama Large Millimeter/submillimeter Array

Centrurus A; the star with a Supermassive black hole at its core

Halley's Comet

Page 3: cheap universe

The Atacama Large Millimeter/submillimeter Array (ALMA) will be unique in its ability to detect the signature of

protostellar collapse on solar-system size scales. We know that star formation involves gravitational collapse, but infall

motions forming a new star have yet to be found. To observe unambiguous evidence for collapse, we require high

spatial and velocity resolution (to map the velocity field across small structures) and high sensitivity (to take advantage

of the spatial and velocity resolution). Furthermore, this must be available at a wavelength at which the collapsing

object emits, and at which the surrounding material is transparent. Of current and planned instruments, only ALMA

has these characteristics.

Further, ALMA will be ideal for studying the

diversity of objects and physical processes

involved in star formation. Its excellent

mapping precision will allow astronomers to

study the characteristics of parent molecular

clouds from which stars form. Its sensitivity,

angular and velocity resolution, and high

frequency performance will allow the study of

smaller structures, including protostellar

fragments, outflows, and disks.

Wolf Simulation. A simulation of ALMA observations

at 950 GHz of a disc shows an embedded protoplanet of

Jupiter Mass around a 0.5 Solar Mass star.

Page 4: cheap universe

D E T E C T I N G E X T R A S O L A R P L A N E T S W I T H A L M A

Detecting planets circling other

stars is a particularly difficult

task. In order to answer

fundamental questions about

planetary systems, such as their

origin, their evolution, and their

frequency in the Universe,

scientists need to find and study

many more extrasolar planets.

According to scientists, ALMA

will provide valuable information

about extrasolar planetary

systems at all stages of their

evolution.

Millimeter and submillimeter

waves occupy the portion of the

electromagnetic spectrum

between radio microwaves and

infrared waves. Telescopes for

observing at millimeter and

submillimeter wavelengths

utilize advanced electronic

equipment similar to that used

in radio telescopes observing at

longer wavelengths.

Millimeter/submillimeter-wave observations offer a

number of advantages in the search for extrasolar

planets. Multi-antenna millimeter/submillimeter-wave

telescope such as ALMA can provide much higher

resolving power, or ability to see fine detail, than

current optical or infrared telescopes. Observations in

millimeter and submillimeter wavelenghts would not be

degraded by interference from the "zodiacal light"

reflected by interplanetary dust, either in the extrasolar

system or our own solar system. Another important

advantage is that, at millimeter and submillimeter

wavelengths, the star's brightness poses less of a

problem for observers because, while it is still brighter

than a planet, the difference in brightness between the

two is far less. Because of the physical nature of the

objects themselves, protoplanets in different stages of

formation could readily be detected by ALMA.

Page 5: cheap universe
Page 6: cheap universe

Centaurus A is a prominent galaxy in the constellation of Centaurus. There is

considerable debate in the literature regarding the galaxy's fundamental properties such

as its Hubble type (lenticular galaxy or a giant elliptical galaxy) and distance (10-16

million light-years). 5128 is one of the closest radio galaxies to Earth, so its active galactic

nucleus has been extensively studied by professional astronomers. The galaxy is also the

fifth brightest in the sky, making it an ideal amateur astronomy target, although the

galaxy is only visible from low northern latitudes and the southern hemisphere.

The center of the galaxy contains a supermassive black hole weighing in at 55 million solar

masses, which ejects a relativistic jet that is responsible for emissions in the X-ray and

radio wavelengths. By taking radio observations of the jet separated by a decade,

astronomers have determined that the inner parts of the jet are moving at about one half

of the speed of light. X-rays are produced farther out as the jet collides with surrounding

gases resulting in the creation of highly energetic particles. The radio jets of Centaurus A

are over a million light years long.

Like other starburst galaxies, a collision is suspected to be responsible for the

intense burst of star formation. Spitzer Space Telescope studies have confirmed

that Centaurus A is colliding with and devouring a smaller spiral galaxy.

Page 7: cheap universe
Page 8: cheap universe

Halley's Comet or Comet Halley ,officially designated 1P/Halley, is the best-known of the

short-period comets and is visible from Earth every 75–76 years.

Halley was the first comet to be recognized as periodic. Until the Renaissance, the

philosophical consensus on the nature of comets, promoted by Aristotle, was that they

were disturbances in the Earth's atmosphere. This idea was disproved in 1577 by Tycho

Brahe, who used parallax measurements to show that comets must lie beyond the Moon.

Many were still unconvinced that comets actually orbited the Sun, and assumed they must

instead follow straight paths through the Solar System.

Page 9: cheap universe