Black holes, their disks and how they behave in dwarf galaxies

Black holes generate energy and radiation (light) from the matter that falls onto them.  They accrete matter from orbiting celestial objects such as stars, planets, asteroids, comets, and other forms of debris. This accreted matter falls onto the black holes through their accretion disks and these disks produce the energy and radiation (light). This is the reason why we can "see" black holes, because we don't actually see the black hole we see the accretion disk. If there was not matter accretion  producing radiation (light) there would not be any light emitted from a black hole, hints the "black" hole. Here is a black hole; as you can see the very center is dark and the outer parts a luminous.

A black hole in a dwarf galaxy effects its surroundings differently than a black hole in a regular galaxy.  A black hole in a dwarf galaxy changes the speed of the objects a lot. It effects many more objects in a dwarf galaxy than a regular galaxy because a regular galaxy is much bigger and more spaced out than a dwarf galaxy.  Here is a picture of our Milky Way; the picture shows a band of stars left over by a dwarf galaxy collision with our Milky Way (seen in the blue). This leads astronomers to believe the Milky Way formed from a number of dwarf galaxies, that in previous years collided with one another.

My experience

Thanks to this student blog, over the semester, I have deepened my knowledge of some very useful astronomy concepts.  I have learned more about binary systems, black holes, star formation, exoplanets, and many other extremely interesting astronomy concepts. 

Astronomy is my major and it is a very important part of my life so doing something i love and getting to express some of my thoughts about it to this big internet community has been a blessing.  I loved the fact that I got so many views and I even got comments and or questions on some of my blog posts.  I have to say that I liked the questions the most because they were really good questions. 

I want to thank everyone for ready this blog and I hope you all will continue to read the blog in the future!

ASTRONOMY IS THE FUTURE!!!!!!!!

Colloquium November 29

On November 29, 2012 the University of Michigan welcomed Andy Fabian to speak on Black holes and their environments.

 

Andy Fabian is a professor at the University of Cambridge. He has received many awards through out his career and he has taught around the world.

During his lecture Fabian focused primarily on the way we view black holes. He talked about how the amount of radiation (energy from matter around the black hole) depends on what surrounds the black hole.  He gave details about how we view the spectra of the released energy. He said that the radiation that is sent out by black holes is often in the X-ray band because it has such high energy. 

Fabian talked about how the energy of a black hole varies if it has a spinning accretion disk or a non spinning accretion disk.  He said that spinning accretion disks release 5 times more energy (radiation) than non spinning disks release.  He also said that some black hole shoot jets and these jets can go out as far as 5 Mpcs.

Black hole's affected by surrounding matter

Many black holes are affected by matter that is found around them. These objects that affect black       holes include orbiting stars, gas, planetary objects, comets, asteroids,  and many other celestial object.

When Black holes are affected astronomers can view the effects through X-ray emissions from the luminous black holes.  Astronomers, through X-ray emissions, can see the black hole's strong gravitational affects, its gravity redshifts, its gravitational light bending, its delays, and its dragging of inertial frames in the Kerr metric. 

The accretion disks that surround black holes include lots of dust that affect the energy outputs of the black holes.  These disks can create soft X-ray emission or hard X-ray emission.  These accretion disks can surround both spinning and non spinning black holes.  However, spinning black holes produce 5 times as much power as non spinning black holes.

End of Term Evaluation

If you've been reading this blog this term, we'd really appreciate it if you could take a minute or two to let us know what you thought.
It really is quick!

Colluqium November 15

On November 15, 2012 the University of Michigan welcomed Dennis Bodewits to speak on comets and asteroids.

Dennis Bodewits is an assistant research scientist in the Astronomy Department at the University of Maryland.  "His research emphasizes comets and asteroids, and he is a member of the EPOXI/Deep Impact and Stardust-Next science teams. His observational studies encompass X-ray, UV and visible regions, and makes use of mostly space-born telescopes, such as Swift, Chandra, and XMM-Newton".(http://www.astro.umd.edu/people/dennis.html)

In his speech Bodewits focused on the roles comets and asteroids played in the creation of water on Earth.  He had videos and many photos of artistic interpretations of water formation of Earth. Bodewits also gave detailed explanations of the compositions of asteroids and comets.

For more information on comets here is a link: http://www.michastrostudent.blogspot.com/2012/11/comets.html. For more information on asteroids here is a link: http://www.michastrostudent.blogspot.com/2012/11/asteroids.html. For more information on water formation on Earth here is a link: http://www.michastrostudent.blogspot.com/2012/11/the-water-of-earth-contribution-of.html.

The Water of Earth. The Contribution of Asteroids, Comets, and Meteors

Earth is a fascinating and amazing planet to study because it has surface water. Surface water is an extremely valuable resource. It is arguably the most valuable resource on Earth because it is essential to all living organisms and it formed over a large amount of time. Water formed on Earth through a process that lasted millions of years. 

The process that allowed water to form on Earth included; asteroids, comets, and meteors. Astronomers have many theories about this process. Some astronomers have different beliefs about the ratio of comets, meteors, and asteroids that were involved in the formation of water on Earth. All of the different theories that involve the different ratios and time scales can all be justified because no one really knows how water formed on the surface of the Earth. It is impossible to know because humans had not even been created when water formed on Earth. However, astronomers know that asteroids, meteors, and comets played a role in water formation on the surface of earth because the water had to have come from some outside source. 

Asteroids, comets, and meteors are very important celestial bodies that have been found in our solar system. Most importantly asteroids, comets, and meteors, contributed to water formation on the surface of the Earth. These celestial bodies, any natural body outside of the solar system, have been studied for many years and they are all very different from one another. Their differences make them very interesting. 

Asteroids are airless objects, most commonly found in the asteroid belt. The asteroid belt is located Mars and Jupiter. For more information on asteroids here is a link http://www.michastrostudent.blogspot.com/2012/11/asteroids.html

Comets are icy objects, most commonly found in the Oort cloud. The Oort cloud is a spherical cloud located 50,000 AU from the Sun. For more information on comets here is a link http://www.michastrostudent.blogspot.com/2012/11/comets.html

Meteors are dust to bolder sized particles of debris that are found in the solar system. 

Meteorites that astronomers have studied on Earth have hydrogen isotope ratios that help explain how elements like hydrogen and nitrogen got on the Earth. 

The biggest question astronomers are trying to answer is how volatiles like hydrogen, nitrogen, and carbon first arrived on Earth. Astronomers mostly believe that these elements arrived on Earth through collisions with comets and asteroids. One of the most accepted theories on how water formed on Earth suggests that during the creation of the solar system Jupiter and Saturn's orbits were disturbed and that caused comets in the outer solar system to move inward and later make their way towards Earth. These comets collided with Earth and left ice and other elements behind. Later when an asteroid collided with the Earth, the ice was melted and liquid water was then formed on the surface of the Earth. This process, according to astronomers, happened many times and it took millions of years.