|Automatic translation||Updated June 01, 2013|
Milky Way or Galaxy with a capital G, is the name given to our galaxy.
Unfortunately we see our galaxy from within and we see a small part of the whole. However, observing nearby galaxies, astronomers were able to simulate a view of our galaxy. Although all the galaxies are different, our galaxy is very similar to the galaxy M83 or M74.
Image: Our Galaxy is a spiral galaxy like M83 (NGC 5236), on the image against. The bright central bulge surrounded by beautiful spiral arms that wind.
The place of the Sun in the Galaxy
Like almost all galaxies, our galaxy contains at its center a black hole. The center of the galaxy called the Central Molecular Zone. This black hole of several million solar masses, is called Sgr A. The galactic center is also home to the region of star formation, the most active of the galaxy.
In the center of the Milky Way, there is such a density of stars, the heavens are dazzling. Fortunately the sun has chosen the right distance to travel on this ride with stars. The privileged position of our Sun in the Galaxy, has allowed the planet Earth to support life.
Image: Our Galaxy is a very large spiral galaxy and our star, the Sun is located between two of its spiral arms. In this picture, instead of the Sun is indicated by a small round brilliant. credit image: La nuit des étoiles 2011. Au cœur de la Voie Lactée.
Infrared image of our Galaxy
This vast panorama is the sharpest image taken in the infrared galactic nucleus. It is a laboratory for understanding how massive stars shape and influence the environment of the nuclear regions, often violent, other galaxies. This image combines the NICMOS imaging (Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer) imaging with IRAC (Spitzer Space Telescope Infrared Camera). The galactic nucleus is obscured in the spectrum of visible light, but infrared light penetrates dust. NICMOS shows a large number of massive stars spread over the entire region. This view allows astronomers to see that massive stars are not confined to the three known groups of massive stars in the Galactic center (the core, the Arches cluster and the cluster of Quintuplet). In the NICMOS image, these three groups are seen as tight concentrations of massive stars.
The stars were scattered or formed individually or come from grapes that have been disturbed by strong gravitational tidal forces.
Image: Infrared view of the center of our Galaxy. The NICMOS mosaic was made from 2304 images which required 144 rotations of the Hubble telescope around its orbit, between February 22 and June 5, 2008. Image Credits: Hubble: NASA, ESA, and Q.D. Wang (University of Massachusetts, Amherst); Spitzer: NASA, Jet Propulsion Laboratory, and S. Stolovy (Spitzer Science Center/Caltech).NB: The Hubble Space Telescope (Hubble Space Telescope, or HST) is in orbit 560 km above sea level, it performs a full rotation of the Earth every 100 minutes.
Dark matter in the Milky Way
In astrophysics, dark matter is apparently undetectable matter.
Observations (or rather the lack of direct observations) imply a rather non-baryonic, and therefore still unknown. Dark matter is yet more abundant than baryonic A baryon is in particle physics, a Category particles, whose best-known representatives are the proton and the neutron. The term "baryon" is derived from the Greek barys meaning "heavy "It refers to the fact that baryons are generally heavier than other types of particles. matter.
Image: Image Sloan Digital Sky Survey Team, NASA, NSF.