Dark Matter & Large Scale Structures

Dark Matter
Roughly 80 percent of the mass of the universe is made up of material that scientists cannot directly observe. It turns out that roughly 68% of the Universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter - adds up to less than 5% of the Universe. We are much more certain what dark matter is not than we are what it is. First, it is dark, meaning that it is not in the form of stars and planets that we see. Observations show that there is far too little visible matter in the Universe to make up the 27% required by the observations. Second, it is not in the form of dark clouds of normal matter, matter made up of particles called baryons. Third, dark matter is not antimatter, because we do not see the unique gamma rays that are produced when antimatter annihilates with matter. Finally, we can rule out large galaxy-sized black holes on the basis of how many gravitational lenses we see. High concentrations of matter bend light passing near them from objects further away, but we do not see enough lensing events to suggest that such objects to make up the required 25% dark matter contribution. Unlike normal matter, dark matter does not interact with the electromagnetic force. This means it does not absorb, reflect or emit light, making it extremely hard to spot. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter. Many theories say the dark matter particles would be light enough to be produced at the LHC. If they were created at the LHC, they would escape through the detectors unnoticed. However, they would carry away energy and momentum, so physicists could infer their existence from the amount of energy and momentum “missing” after a collision. Dark matter candidates arise frequently in theories that suggest physics beyond the Standard Model, such as supersymmetry and extra dimensions. One theory suggests the existence of a “Hidden Valley”, a parallel world made of dark matter having very little in common with matter we know. If one of these theories proved to be true, it could help scientists gain a better understanding of the composition of our universe and, in particular, how galaxies hold together.

Large Scale Structures
The Universe exhibits structure over a wide range of physical scales – from satellites in orbit around a planet through to the galaxy super clusters, galactic sheets, filaments and voids that span significant fractions of the observable Universe. These latter are commonly referred to as the ‘large-scale structure’ of the Universe. In the local Universe, there are two large-scale structures of particular importance: the Great Wall and the Great Attractor. These structures influence the motions of galaxies in the Local Group, and are ultimately responsible for the fate of the Milky Way. In physical cosmology, the term large-scale structure refers to the characterization of observable distributions of matter and light on the largest scales (typically on the order of billions of light-years).
Prior to 1989, it was commonly assumed that galaxy clusters were the largest structures in existence, and that they were distributed more or less uniformly throughout the universe in every direction. However, based on redshift survey data, in 1989 Margaret Geller and John Huchra discovered the "Great Wall," a sheet of galaxies more than 500 million light-years long and 200 million wide, but only 15 million light-years thick.


References:
http://www.sciencedaily.com/articles/l/large-scale_structure_of_the_cosmos.htm
http://astronomy.swin.edu.au/cosmos/L/large-scale+structure
http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/
http://astro.berkeley.edu/~mwhite/darkmatter/dm.html

OWN picture of the Week #8

The photo above is of the Hercules Cluster. While I got it very faded and dull, I was able to edit it to look bright and amazing.

APOD 4.8

Todays APOD is VERY cool. While I cannot attach a photo, I can provide a link.
http://apod.nasa.gov/apod/ap140514.html
This link was supplied by APOD on May 14th and is a live feed from the international space station of the planet earth. It is really interesting to see how fast the earth is spinning from their point of view as they are going thousands of miles per hour, spinning around the earth in a constant free fall. Just beautiful.

Margaret Burbidge Biography

Born in England, Margaret Burbidge educated at the University of London, where she remained until 1951. She has worked at Yerkes Observatory and the California Institute of Technology and has been at the University of California, San Diego since 1962. She has held many administrative positions, including that of director of the Royal Greenwich Observatory and first director of the Center for Astrophysics and Space Sciences at UCSD. In 1957 she, Geoffrey R. Burbidge, William A. Fowler and Fred Hoyle showed how all of the elements except the very lightest are produced by nuclear reactions in stellar interiors. She has also studied spectra of galaxies, determining their rotations, masses, and chemical composition, and she has achieved particular renown for spectroscopic studies of quasars. She has played a major role in developing instrumentation for the Hubble Space Telescope. She was won dozens of awards in her time including the Helen Warner Prize in 1959, the Henry Norris Russel Lectureship in 1984, the National Medal of Science in 1983, the Karl G. Jansky Lecturship in 1977, The Royal Astronomical Study Gold medal in 2005 and even the Albert Einstein World Award of Science in 1988. With nuclear physicist William A. Fowler, astrophysicist Fred Hoyle, and her husband, astronomer Geoffrey Burbidge, she developed a better explanation of how elements are formed by nuclear reactions inside stars. She was born into a very scientific family with her mother and father Marjorie and Stanley Peachey both being chemists and she appoints much of her success to her family. She married her husband Geoffrey in 1948 and had a daughter, Sarah, in 1956. She was the first woman to be appointed director of the Royal Greenwich Observatory. Burbidge served as assistant director (1948–50) and acting director (1950–51) of the Observatory of the University of London. In 1955 her husband, theoretical astrophysicist Geoffrey Burbidge, obtained a Carnegie fellowship for astronomical research at the Mount Wilson Observatory, near Pasadena, California, U.S. Because women were then ineligible for such an appointment, she chose to accept a minor research post at the California Institute of Technology, Pasadena. In 1957 she became Shirley Farr fellow and, later, associate professor at Yerkes Observatory, Williams Bay, Wisconsin. For several years she worked as a chemist instead of an astronomer, as rules forbidding nepotism left her unable to work in her specialty at the universities that employed her husband. She served as research astronomer (1962–64) and thereafter as professor of astronomy at the University of California, San Diego (UCSD), taking a leave of absence to serve as director of the Royal Greenwich Observatory (1972–73). Her Greenwich duties did not come with the traditional honorary title of Astronomer Royal, which instead was given to a male astronomer; Burbidge saw this as another instance of discrimination against women in the astronomical community. In 1972 she refused the Annie J. Cannon Prize from the American Astronomical Society (AAS) because, as it was an award for women only, it represented for her another facet of the same discrimination. Her action led to the formation of a standing AAS committee for the status of women in astronomy. Burbidge later became a naturalized American citizen. As part of her work in quasars, Burbidge, along with Sir Fred Hoyle and Will Fowler, created the B²FH theory. This theory, published in 1957, provided a revolutionary explanation of the origin in stars of all the elements in the periodic table from helium to iron, starting with the lightest element, hydrogen. Her publications include Quasi-Stellar Objects (1967), with Geoffrey Burbidge. Still alive today, Burbidge continues to teach and was inducted into the Women's Museum of California Hall of Fame honoring her career and achievements. She is currently 94 and still has a passionate love for astrophysics that will be remembered for centuries to come.

APOD 4.7

Today's post is from May 10th and is a photo of the inside of the Flame Nebula.

This is only 1400 light years away and is located in the dense part of the Orion nebula. This is actually an xray photo of the nebula and it was taken by the Spitzer Telescope. This nebula will only get denser for several millions more years and this is visually stunning.

Observational Post

This past week has been the same as ever. I won't bore you with the repetition of the same old story. I go out every night and don't see anything different. It is all the same.

Own picture of the Week #7

Above is the Crab Nebula. It isn't super visible but is more so now because I used the program to enhance it

Observational Post

The past couple of weeks have had literally NOTHING new. I have continued to go out after work and on my days off almost every night to try and see something new, but I just make the exact same observations. I guess that astronomy is about patience.... but it's difficult.

APOD 4.6

Todays APOD is from April 27th and is pretty cool

This is an image of the space suit that was sent into the orbit of the earth with a weak transmitter to signal it's location. This was sent out by the Russians as it was an unneeded Orlan suit that was being used as a closet with old clothes and trash. It orbited the planet twice but lost connection. After about an hour and a half, it fell out of orbit toward the earth and burned up in the atmosphere. Just a cool space story. BTW, these suits cost about 1.2 MILLION dollars each.

OWN Picture of the Week #6

OOOO the orion nebula edited by meeeeeee

APOD 4.5

YET ANOTHER APOD! Todays APOD is from April 21st and is simply beautiful

This is an image of a super massive galaxy that is actually pretty close to us called Spiral Galaxy NGC 2841. Located 46 million light years away in the Ursa Major constellation, this is one of the largest objects known to mankind. This monster has a diameter of over 150,000 light years and is also known as the island universe. Taken by the Hubble, we can clearly see beautiful colors and lights throughout this amazing photo.

OWN Picture of the Week #5

Here is the eagle galaxy that I have edited through the program provided. It is colored and enhanced

Margaret Burbidge Bio Links

Here are the sources that I will use to write my biography on Margaret Burbidge

http://www.phys-astro.sonoma.edu/brucemedalists/burbidgem/

http://www.nndb.com/people/692/000168188/

http://www.britannica.com/EBchecked/topic/84933/Margaret-Burbidge

APOD 4.4

Today's APOD is taken from April 16th and is very very cool.

This is a photo of the lunar eclipse, Mars and Spica all in the same photo. I chose this photo because I actually got up in the morning to watch it and was astounded by how amazing it looked. The red color of the moon is due to the sun actually passing in front of it. The blue star just underneath is Spica which is also relevant as it is within the constellation Virgin which we are learning about this week. And, you guessed it, the red star isn't actually a star but mars itself being very close to Earth due to the rotations lining up just right. Just amazing.

Observational Study 4/5 - 4/17 & Lunar Eclipse

Let me just start off and say that the Lunar Eclipse was very cool. I woke up at about 3:30 in the morning on the 15th and stayed out watching it get more and more orange for about a half hour. Other than the eclipse, I did go out several times during the past couple of weeks and made observations of the night sky but that had little to no new things worth pointing out. The moon however was the coolest thing I've seen in a while and I can't wait till 2017 to view the SOLAR ECLIPSE!

OWN Picture of the Week #3

Whirlpool galaxy edited by Alex Farlow using the application.

APOD 4.3

Todays APOD is, as per Mr. Percival's instruction, from April 11th.

This is a photo of Mars taken on the third of April. Notice how clear the photo is despite the fact it was taken with a high speed camera and a 16" telescope in Brazil? That is because it is nearing it's closest approach as it's orbit aligns with ours in just the right way to make us much closer than normal. In the photo, we can see it's north pole as well as the clouds that fly over its countless volcanoes. It will be closest to us on the 14th, the same day as the lunar eclipse, and will be about 1/100th of the size of the moon (which is actually pretty big).

Milky Way Contributers

Edwin Hubble

• Edwin Hubble showed the scientific community that other galaxies existed beyond our own by proving that what we thought were spiral nebulae are actually other galaxies far outside of the Milky Way
• He used Cepheid variables to measure the distance from us to another nearby galaxy and showed that it was too far away to reside inside of our own
• In 1929, he attempted to provide proof of the expansion of our universe
• the EMR from galaxies is redshifted, indicating that they are moving away from us
• these galaxies are possibly moving away from us at a speed of thousands of miles per second
• the farther away a galaxy is, the greater its redshift (the faster it was moving)

Harlow Shapley

• He used RR Lyrae stars to correctly estimate the size of the Milky Way Galaxy and the sun's position within it. In 1953 he proposed his "liquid water belt" theory, now known as the concept of a habitable zone
• He was the first to realize that the Milky Way Galaxy was much larger than previously believed, and that the Sun's place in the galaxy was in a nondescript location.
• Partook in the debate with Curtis in the “Great Debate” but was incorrect in that

William Herschel

• Herschel ultimately discovered over 2400 objects defined by him as nebulae. (At that time, nebula was the generic term for any visually extended or diffuse astronomical object, including galaxies beyond the Milky Way, until galaxies were confirmed as extragalactic systems by Edwin Hubble in 1924.)
• He also studied the structure of the Milky Way and concluded that it was in the shape of a disk. (the first person to ever come to this conclusion)

Galileo

• Galileo used his telescope to look and view the Milky Way and resolve it into a myriad of individual stars.
• Though the technology of the time was limited, his discovery that the Milky Way was composed of distinct stars has greatly aided our understanding as to the nature of our own galaxy

RR Lyrids & Cepheids - both are different types of variable stars that periodically change their brightness and density as they undergo a period of instability in their stellar evolutionary track

• RR Lyrids
• RR Lyrids are variable stars found in globular clusters and used to measure stellar distances that are too large for spectroscopic parallax to resolve
• More common than Cepheid variables
• Old and of relatively low mass
• Period is typically less than a day
• First identified in RR Lyrae in Lyra
• Cepheids
• Brighter and more massive than RR Lyrids variables
• Used for determining stellar distances
• First identified from Delta Cephei in Cepheus

Immanuel Kant

• The first person to propose that the band of stars in the night sky (we call the Milky Way)
• Proposed that the stars of our galaxy form a broad, flat disk. The Sun and Earth also inhabit this disk. As a result, Kant said, when we look into the disk, we see the combined glow of countless stars, which make up the band of light called the Milky Way. But when we look above or below the disk, we see only a few stars. 
  
  

Henrietta Leavitt

• discovered the relation between the luminosity and the period of Cepheid variable stars.

• it was her discovery that first allowed astronomers to measure the distance between the Earth and faraway galaxies

Heber Curtis

• famous for his role in astronomy's "Great Debate" with Harlow Shapley in which Curtis argued that what astronomers called spiral nebulae were actually spiral galaxies outside our own Milky Way.

“The Great Debate”

• influential debate between the astronomers Harlow Shapley and Heber Curtis which concerned the nature of spiral nebulae and the size of the universe
• Shapley was arguing in favor of the Milky Way as the entirety of the universe. He believed galaxies such as Andromeda and the Spiral Nebulae were simply part of the Milky Way.
• Curtis on the other side contended that Andromeda and other such nebulae were separate galaxies, or "island universes" (a term invented by the 18th-century philosopher Immanuel Kant, who also believed that the spiral nebulae were extragalactic). He showed that there were more novae in Andromeda than in the Milky Way. From this he could ask why there were more novae in one small section of the galaxy than the other sections of the galaxy

OWN Picture of the week #2

The Trifid nebula... ooooooooo....aaaaaaaa

APOD 4.2

Todays APOD is from March 30th and is an especially cool one.

This is an image of the moon Io that flies around the planet Jupiter. This is the first image of the moon in its true color and I love that it looks like cheese. This photo was taken by the Galileo spacecraft that also orbits the planet.The colors on this moon come from sulfur and silicate. This moon gets so hot that it actually glows in the dark. The main reason I chose this though, is because it looks just like a ball of cheese and I love that it follows the stereotype better than out own moon.

Observational Study 3/22 - 4/4

This past several days have been just as uneventful as the last. I have continued to go out regularly and practice pointing out stars and it has even gotten to the point that I have started to teach my sister constellations. Not much else other than that.

OWN Picture of the week

Here is this weeks picture. It is of the Dumbbell Nebula and has been processed to be more visible.

APOD 4.1

Today's picture is a very cool one from March 23rd.

This is an artist's rendition of a black hole. This is described as a swirling whirlpool of hot gas that has an endless void at its heart. While we have never actually seen or even gotten close to a black hole, scientists still know they are there by the effects it has on the surrounding areas. These are created by a solar collapse that leads to an object that is tiny but has a density up to 7 times that of our sun. These rotate very rapidly and suck in all light and objects that come into contact with it. I chose this photo because we have spend the past couple of weeks studying supernovae and back holes and this just seemed like the right photo to choose.

Observational Study 3/15 - 3/21

This past week has been as calm as ever with no real changes in the sky. The moon has been waning from the full state it was in last week and that has made star viewing quite difficult along with the fact that it has been cloudy almost EVERY night. Basically, I have been going out around 11pm or so and try to point out as many stars and constellations I can without any help. But that is all.

APOD 3.8

Today's APOD is from march 18th and is very cool as it is on the topic of a paradigm altering fact about the origin of the universe.

The photo above is a picture of the BICEP2, a satellite in the South Pole, and the readings it took of some gravitational winds. The big bang theory is not only a popular tv show, but also the theory about the origin of the universe that it all began as a hot dense object the size of a marble and it one day exploded. The theory states that the universe is still expanding but there has never been legitimate proof until now. These gravitational winds are proof of the expansion part of the BBT! And it all began 13.8 BILLION years ago, and now, on march 17th 2014, we have conclusive evidence of the process. I chose this because it is an important hallmark in the history of science and I find it amazing.

Observatioanl Study 2/22 - 3/6

The past two weeks have been just a constant state of viewing. Nothing amazing has happened in any way. The moon has been changing and the stars have been moving slightly but that is the extent of change. I have continued to go out most nights and try to identify stars and use the stargazer app on my phone to identify various deep sky objects but it is becoming redundant as nothing changes. I guess astronomy needs quite a bit of patience. Patience that I am struggling to gather.