What is a nuclear bulge?
What is a nuclear bulge?
nuclear bulge. a distribution of stars in the shape of a flattened sphere that surrounds the nucleus of a spiral galaxy like the Milky Way.
What is the nuclear bulge of our galaxy?
The nuclear bulge is a region with a radius of about 200 parsecs around the centre of the Milky Way1. It contains stars with ages2,3,4 ranging from a few million years to over a billion years, yet its star-formation history and the triggering process for star formation remain to be resolved.
What is the central bulge?
In Milky Way Galaxy: The central bulge. Surrounding the nucleus is an extended bulge of stars that is nearly spherical in shape and that consists primarily of Population II stars, though they are comparatively rich in heavy elements.
What does the galactic bulge contain?
In a spiral galaxy like the Milky Way, the stars, gas, and dust are organized into a “bulge,” a “disk” containing “spiral arms,” and a “halo.” Elliptical galaxies have a bulge-like central region and a halo, but do not have a disk. The bulge is a round structure made primarily of old stars, gas, and dust.
Is the Galaxy merging or disturbed?
Ultimately, the smaller galaxy will be completely disrupted and will merge with the larger galaxy. The Milky Way is currently undergoing minor mergers with both the Sagittarius and Canis Major dwarf galaxies. These galaxies are currently in the process of being shredded and absorbed by the Milky Way.
Where is the bulge in the Milky Way galaxy?
Bulges were historically thought to be elliptical galaxies that happened to have a disk of stars around them, but high-resolution images using the Hubble Space Telescope have revealed that many bulges lie at the heart of a spiral galaxy.
Why bulges are formed?
Gravitational instabilities, such as bars and spirals, are able to transfer efficiently angular momentum, and produce radial mass flows towards the center. Due to vertical resonances, stars in the center are elevated above the plane, and contribute to bulge formation (Combes et al. 1990).
How thick is the bulge of the Milky Way?
In the center of the galaxy is the bar-shaped galactic bulge which harbors a supermassive black hole with a mass equal to that of about 3 million suns. Surrounding the central bulge is a relatively thin disk of stars about two thousand light years thick and roughly 100,000 light years across.
What type of stars are found in the bulge of our galaxy?
The disk contains all the gas and young stars, although old stars are also found there. The bulge is dominated by old stars and a violent core. The halo contains very old stars and globular clusters. The reason for this separation of stellar types is a clue to how the Galaxy formed.
What are the 4 components of a galaxy?
From Earth, the Milky Way seems to be a heavenly mist because the stars blur together. Little do most people know, the stars are broken into four main parts. The four main parts are the disk, the nuclear bulge, the halo, and the galactic corona.
Do elliptical galaxies have halos?
The results are generally consistent with the known dichotomy of elliptical galaxy types, but some galaxies show more complex rotation profiles in their halos and there is a higher incidence of misalignments, indicating triaxiality. …
How many stars are in the galactic bulge?
10 million stars
What will happen to our galaxy in 4 billion years?
The Milky Way is on track to collide and merge with its nearest neighbor, the Andromeda galaxy, in about 4 billion years. The galaxies will pass through each other, get snapped back together by gravity, and eventually merge cores. NASA illustrations show what the arrival of an entire galaxy of stars will look like.
What is in the middle of a galaxy?
The supermassive black hole that lurks at the center of our galaxy, called Sgr A*, has a mass of about 4 million times that of our Sun. A black hole is a place in space where gravity is so strong that neither particles or light can escape from it. Surrounding Sgr A* is a dense cluster of stars.
Where are we in our galaxy?
We’re about 26,000 light-years from the center of the galaxy, on the inner edge of the Orion-Cygnus Arm. It’s sandwiched by two primary spiral arms, the Sagittarius and Perseus Arms.
Can you see the Milky Way from space?
To begin with, the Milky Way is easier to see. It shines a little brighter because of the lack of atmosphere, but astronauts still have to fight light pollution. Ultimately, a majority of the compartments on the ISS have a lot of ambient light.
How can we see the Milky Way if we’re in it?
The stars of the Milky Way merge together into a single band of light. But through a telescope, we see the Milky Way for what it truly is: a spiral arm of our galaxy.
How fast is our galaxy spinning?
130 miles per second
How do we know we are in a spiral galaxy?
1) When you look toward the Galactic Center with your eye, you see a long, thin strip. This suggests a disk seen edge-on, rather than a ellipsoid or another shape. We can also detect the bulge at the center. Since we see spiral galaxies which are disks with central bulges, this is a bit of a tipoff.
What color is the central bulge Why?
blue
Why does the Milky Way have spiral arms?
Astronomers believe that galaxies have spiral arms because galaxies rotate – or spin around a central axis – and because of something called “density waves.” A spiral galaxy’s rotation, or spin, bends the waves into spirals. Stars pass through the wave as they orbit the galaxy center.
How did we infer that the Milky Way is a spiral galaxy?
The concentration of stars in a band adds to the evidence that the Milky Way is a spiral galaxy. If we lived in an elliptical galaxy, we would see the stars of our galaxy spread out all around the sky, not in a single band.
Is the Milky Way constantly moving?
The Milky Way does not sit still, but is constantly rotating. As such, the arms are moving through space. The sun and the solar system travel with them. The solar system travels at an average speed of 515,000 mph (828,000 km/h).
Why does an elliptical galaxy look like one giant star?
An elliptical galaxy looks as if it is a giant star because it lacks the distinctive structure of a spiral galaxy, where the bulge is surrounded by a…
Is the Milky Way an irregular galaxy?
Most galaxies can be categorized by their shape. Our own Milky Way is a spiral galaxy, for example, and the largest galaxies in the Universe are elliptical galaxies. But some galaxies defy categorization. These are the irregular galaxies, and each one is unique in shape, age and structure.
What is the age of an irregular galaxy?
The main body of SagDig is rich in gas, and contains many regions of active star formation. Indeed, the average age of the stars in the galaxy is a relatively young 4 to 8 billion years.
What are the 3 types of galaxies?
Astronomers classify galaxies into three major categories: elliptical, spiral and irregular. These galaxies span a wide range of sizes, from dwarf galaxies containing as few as 100 million stars to giant galaxies with more than a trillion stars.