Galaxies and the Milky Way

Spiral galaxy NGC1232

The galaxy NGC 1232 is in the constellation Eridanus (the river).
Distant about 100 million light years. At this distance, the size of the image corresponds to approximately 200 000 light years, is twice the size of our Milky Way.
We can notice below to the left, the small galaxy was deformed by the enormous galaxy NGC on 1232.

Image: We notice the difference of color enter the reddish nucleus (old stars) and the arms populated with young stars, thus blue stars. To note the small galaxy companion below to the left.

credit photo: European Southern Observatory ESO/VLT
 

Spiral galaxy M104 or NGC 4594

Galaxy of the Sombrero M104 NGC 4594 in the heap Virgo. This brilliant galaxy owes this name of Sombrero to its appearance.
According De Vaucouleurs, we see it since just 6 degrees in the South of the equatorial plan, realized by a thick dark band of opaque dust.
This characteristic was probably the William Herschel's first discovery with its big telescope.

Image: Opposite, the dissimilar image of 3 photos taken by the camera FORS1 of the VLT Antu (European telescope of 8,2 m of the ESO based in Chile).
It was obtained after an exposure of 6:20 am on January 30th, 2000.

Spiral galaxy M101 or NGC 5457

Galaxy " Pinwheel " M101 or NGC 5457, called also the Galaxy of the Mill, is a spiral galaxy among the most brilliant of the sky. M101 belongs to a group of at least 9 galaxies, the most striking members of which are NGC 5474 and NGC 5585. Other likely members of the group NGC 5204, NGC 5238, NGC 5477, UGC 8508, UGC 8837, and UGC 9405.
The distance of M101: 24 (+/-2) million light years. With a diameter of 170 000 light years it is situated among the biggest galaxies.
M 101, is a striking example of spiral galaxy, the relative nearness of which about 22 million light years allows to study it in detail.
It seems that gravitational interactions with a nearby galaxy create waves of high mass and condense the gas which continues to turn around the center of the galaxy. These waves compress the incited gas and provoke the formation of stars.

The result is that M 101, has numerous regions of formation of extremely brilliant stars (called regions HII) spread over the spiral arms.
M 101 is so big as its immense gravity deforms the smallest close galaxies.

Spiral galaxy M81 or NGC 3031 et M82

The buxom and beautiful spiral galaxy M81 lies in the constellation Ursa Major.
It was discovered by Johann Elert Bode in 1774. M81 NGC 3031, is a spectacular galaxy, easily detectable with binoculars.
This galaxy forms a pair with remarkable M82, a member of the group called M81 group. The two galaxies are close enough because the distance between their centers is only about 150 000 light years. This is one of the brightest galaxies in the heavens land, M 81 is also home to the second brightest supernova.
The view below cons, reveals a bright yellow nucleus, blue spiral arms and large streaks of dust, all characteristics quite similar to the Milky Way.
A trail of dust especially remarkable, pierces the galactic disk, below, left and right kernel.

This vein of dust may be wandering the trace of a persistent rustling between M81 and its smaller satellite galaxy, M82.
An examination of variable stars in M81 has yielded a distance determinations of the most reliable external galaxy, with 11.8 million light years.

Image: Ci-cons, the galaxies M81 and M82 right to left. These two giant galaxies deliver an intense gravitational battle that has lasted for billions of years. The severity of each galaxy in a major way affects the other.
Credit & Copyright: Leonardo Orazi

Spiral galaxy M74

With a striking nucleus and spiral arms developed possessions, M74 is a spiral galaxy, distant from 30 million light years, seen by the top situated in the Whale.
It was discovered by Pierre Méchain in 1780 then observed by Charles Messier who integrated it into the catalog, some weeks later.
Its mass is only 1/5 of that of our Galaxy but its diameter is 80 000 light years.
The spiral arms contain many young stars or still in formation.

M74 is the most brilliant constituent of a heap of galaxies which includes besides: NGC 660, UGC on 1171, UGC on 1175, UGC on 1176, UGC on 1195 and UGC on 1200.

Galaxy NGC1672

Numerous spiral galaxies present a bar in their center, but it certainly has nothing to do with prominent bar of the spiral galaxy NGC on visible 1672 opposite.
We distinguish, veins of dusts represented by dark strands, of young people heap of blue stars, nebulas to the characteristic red brightness of the hydrogen, the long and brilliant one bar of stars there overlapping in the center, and to finish a brilliant active nucleus which accommodates probably a super massive black hole. The light puts not less than 60 million years to reach us from NGC on 1672, which measures about 75 000 light years of diameter.
NGC 1672 is visible in the constellation of the Sea bream and makes the object of studies to discover how the bar can contribute to the formation of stars in the central regions of the galaxy.
NGC 1672 shows here its region of formation of stars which is in a central galactic bar.

Arms in spiral do not twist themselves completely since the center as we are in the habit of seeing it on the spiral galaxies but are attached to both ends of a straight bar of stars including the nucleus. The question which settles is: they develop systematically in the center of the spiral galaxies to disappear then.
The visible galaxies behind NGC 1672 give the illusion to be incorporated into the leading galaxy, while they are much more taken away.

Image: This remarkable image supplies a sight high definition of the big bar of the galaxy NGC on visible 1672 in the southern hemisphere, in the constellation of the Sea bream. Credit NASA: image of the spatial telescope Hubble

Galaxy Cartwheel or ESO 350-40

The Galaxy of the wheel of the cart (so known under the name of ESO 350-40) is a lenticular or annular galaxy situated in approximately 500 million years light of distance in the constellation of the sculptor in the southern hemisphere.
It is surrounded with a ring of 150 000 light years of diameter, consisted of young and brilliant stars.
This galaxy was a galaxy identical to the Milky Way before it undergoes a head-on collision with a nearby galaxy. When the nearby galaxy crossed the Galaxy Cartwheel, the strength of the collision caused a powerful shock wave on the galaxy, as a stone thrown in one has a good laugh.
By moving at high speed, this shock wave swept the gas and the dust, so creating a halo around the central part of the galaxy remained unhurt.
It explains the bluish cloud around the center, the more brilliant part.

Image: Galaxy CartWheel seen by the telescope Hubble.