When Galaxies Eat Galaxies: Gravity Lenses Suggest Big Collisions Make Galaxies Denser

ScienceDaily (Oct. 12, 2012) — Using gravitational "lenses" in space, University of Utah astronomers discovered that the centers of the biggest galaxies are growing denser -- evidence of repeated collisions and mergers by massive galaxies with 100 billion stars.

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"We found that during the last 6 billion years, the matter that makes up massive elliptical galaxies is getting more concentrated toward the centers of those galaxies. This is evidence that big galaxies are crashing into other big galaxies to make even bigger galaxies," says astronomer Adam Bolton, principal author of the new study.

"Most recent studies have indicated that these massive galaxies primarily grow by eating lots of smaller galaxies," he adds. "We're suggesting that major collisions between massive galaxies are just as important as those many small snacks."

The new study -- published recently in The Astrophysical Journal -- was conducted by Bolton's team from the Sloan Digital Sky Survey-III using the survey's 2.5-meter optical telescope at Apache Point, N.M., and the Earth-orbiting Hubble Space Telescope.

The telescopes were used to observe and analyze 79 "gravitational lenses," which are galaxies between Earth and more distant galaxies. A lens galaxy's gravity bends light from a more distant galaxy, creating a ring or partial ring of light around the lens galaxy.

The size of the ring was used to determine the mass of each lens galaxy, and the speed of stars was used to calculate the concentration of mass in each lens galaxy.

Bolton conducted the study with three other University of Utah astronomers -- postdoctoral researcher Joel Brownstein, graduate student Yiping Shu and undergraduate Ryan Arneson -- and with these members of the Sloan Digital Sky Survey: Christopher Kochanek, Ohio State University; David Schlegel, Lawrence Berkeley National Laboratory; Daniel Eisenstein, Harvard-Smithsonian Center for Astrophysics; David Wake, Yale University; Natalia Connolly, Hamilton College, Clinton, N.Y.; Claudia Maraston, University of Portsmouth, U.K.; and Benjamin Weaver, New York University.

Big Meals and Snacks for Massive Elliptical Galaxies

The new study deals with the biggest, most massive kind of galaxies, known as massive elliptical galaxies, which each contain about 100 billion stars. Counting unseen "dark matter," they contain the mass of 1 trillion stars like our sun.

"They are the end products of all the collisions and mergers of previous generations of galaxies," perhaps hundreds of collisions," Bolton says.

Despite recent evidence from other studies that massive elliptical galaxies grow by eating much smaller galaxies, Bolton's previous computer simulations showed that collisions between large galaxies are the only galaxy mergers that lead, over time, to increased mass density on the center of massive elliptical galaxies.

When a small galaxy merges with a larger one, the pattern is different. The smaller galaxy is ripped apart by gravity from the larger galaxy. Stars from the smaller galaxy remain near the outskirts -- not the center -- of the larger galaxy.

"But if you have two roughly comparable galaxies and they are on a collision course, each one penetrates more toward the center of the other, so more mass ends up in the center," Bolton says.

Other recent studies indicate stars are spread more widely within galaxies over time, supporting the idea that massive galaxies snack on much smaller ones.

"We're finding galaxies are getting more concentrated in their mass over time even though they are getting less concentrated in the light they emit," Bolton says.

He believes large galaxy collisions explain the growing mass concentration, while galaxies gobbling smaller galaxies explain more starlight away from galactic centers.

"Both processes are important to explain the overall picture," Bolton says. "The way the starlight evolves cannot be explained by the big collisions, so we really need both kinds of collisions, major and minor -- a few big ones and a lot of small ones."

The new study also suggests the collisions between large galaxies are "dry collisions" -- meaning the colliding galaxies lack large amounts of gas because most of the gas already has congealed to form stars -- and that the colliding galaxies hit each other "off axis" or with what Bolton calls "glancing blows" rather than head-on.

Sloan Meets Hubble: How the Study Was Conducted

The University of Utah joined the third phase of the Sloan Digital Sky Survey, known as SDSS-III, in 2008. It involves about 20 research institutions around the world. The project, which continues until 2014, is a major international effort to map the heavens as a way to search for giant planets in other solar systems, study the origin of galaxies and expansion of the universe, and probe the mysterious dark matter and dark energy that make up most of the universe.

Bolton says his new study was "almost gravy" that accompanied an SDSS-III project named BOSS, for Baryon Oscillation Spectrographic Survey. BOSS is measuring the history of the universe's expansion with unprecedented precision. That allows scientists to study the dark energy that accelerates expansion of the universe. The universe is believed to be made of only 4 percent regular matter, 24 percent unseen "dark matter" and 72 percent yet-unexplained dark energy.

During BOSS' study of galaxies, computer analysis of light spectra emitted by galaxies revealed dozens of gravitational lenses, which were discovered because the signatures of two different galaxies are lined up.

Bolton's new study involved 79 gravitational lenses observed by two surveys:

- The Sloan Survey and the Hubble Space Telescope collected images and emitted-light color spectra from relatively nearby, older galaxies -- including 57 gravitational lenses -- 1 billion to 3 billion years back into the cosmic past.

- Another survey identified 22 lenses among more distant, younger galaxies from 4 billion to 6 billion years in the past.

The rings of light around gravitational-lens galaxies are named "Einstein rings" because Albert Einstein predicted the effect, although he wasn't the first to do so.

"The more distant galaxy sends out diverging light rays, but those that pass near the closer galaxy get bent into converging light rays that appear to us as of a ring of light around the closer galaxy," says Bolton.

The greater the amount of matter in a lens galaxy, the bigger the ring. That seems counterintuitive, but the larger mass pulls with enough gravity to make the distant star's light bend so much that lines of light cross as seen by the observer, creating a bigger ring.

If there is more matter concentrated near the center of a galaxy, the faster stars will be seen moving toward or being slung away from the galactic center, Bolton says.

Alternative Theories

Bolton and colleagues acknowledge their observations might be explained by theories other than the idea that galaxies are getting denser in their centers over time:

- Gas that is collapsing to form stars can increase the concentration of mass in a galaxy. Bolton argues the stars in these galaxies are too old for that explanation to work.

- Gravity from the largest massive galaxies strips neighboring "satellite" galaxies of their outskirts, leaving more mass concentrated in the centers of the satellite galaxies. Bolton contends that process is not likely to produce the concentration of mass observed in the new study and explain how the extent of that central mass increases over time.

- The researchers merely detected the boundary in each galaxy between the star-dominated inner regions and the outer regions, which are dominated by unseen dark matter. Under this hypothesis, the appearance of growing galaxy mass concentration over time is due to a coincidence in researchers' measurement method, namely that they are measuring younger galaxies farther from their centers and measuring older galaxies closer to their centers, giving an illusion of growing mass concentration in galactic centers over time. Bolton says this measurement difference is too minor to explain the observed pattern of matter density within the lens galaxies.

Leila Sunier October 19, 2012

Earth Science C Even – Ms. Davies

University of Utah (2012, October 12). When galaxies eat galaxies: Gravity lenses suggest big collisions make galaxies denser.ScienceDaily. Retrieved October 19, 2012, from http://www.sciencedaily.com­/releases/2012/10/121012082115.htm

Recent studies on the formation of galaxies suggest that when larger and smaller galaxies collide, the larger of the two in a manner of speaking “eat” the smaller ones, resulting in growth in the larger of the two. This process they believe is what results in the more concentrated centers of the galaxies. Adam Bolton, astronomer and principle author of this new study, with his team conducted the research by using telescopes that bent the light from more distant galaxies around those that are closer, creating a sort of ring of light around the galaxy being observed. Using the size of the rings to determine the mass of each lens galaxy and the speed of the stars to calculate the concentration of mass, they were able to determine that galaxy’s indeed do get denser towards their center. Bolton believes this to mean that large collisions of galaxies are responsible for the increase in density while smaller, more common collisions between a large and small galaxy result in the less concentrated emitting light that we witness. The main point is that he and his team are fairly confident that over time, galaxies do indeed get denser towards their core. This study, called Sloan Digital Sky Survey, is the third of an international effort to map the heavens in order to discover large planets and other solar systems, the origin of galaxies and the universe, and research more extensively dark matter and dark energy, which make up most of the universe.

This article reveals more detail into the formation of galaxies, and if we consider the similarities we find between the formations of Earth, the Solar System, our galaxy, and the Universe, it probably hints to more information on the structure of Earth. It’s also important in terms of our increasing understanding of space and the “world” around us. I think however the greatest importance in this is the technological feat in actually recognizing increase in density as one gets closer to the center of a galaxy and the significance in how this is an international effort to discover and understand our origins. I chose this article because I knew I’d be interested in the topic. It concerned deep space and galaxies and their formation, something that to me is beyond intriguing.

Honestly, I hold no criticisms for this article. It even provided opposing theories and Bolton’s opinion on each of them and a brief explanation of why he thought they were wrong. It was organized clearly, with the information titled and placed into separate groups, with the accomplishment stated at the beginning, how the research was accomplished, as well as alternative theories. It was a really well done article, and I think I’d be picking at bones if I were to try and point out some flaw that doesn’t exist.

Jesse Whang- October 18th 2012
Earth Science- C Even
Overbye, Dennis  "New Planet in Neighborhood, Astronomically Speaking" New York Times, October 16 2012
 http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?ref=science

         The Article " New Planet in Neighborhood, Astronomially speaking" was about a team of European Astronomers on  Wednesday October 17th 2012 announcing that they have found a planet like ours. For example with about the same mass as Earth's but orbits a different star, Alpha Centauri B.  This star is our sun's closest neighbor about 4.4 light years away. Alpha Centauri Bis half as luminous as our sun, but the new planet revolves so close which makes the surface temperature about 1200 degrees Fahrenheit. The habitable zone of the star to have moderate temperature, water, and life would have to be at about 65 million miles away, having about 200 days in a year and the same orbit as Venus in our system.
        This article is important to our society because it expands our knowledge of what we know of Alpha Centauri B and other stars and their orbits and many possibilities and theories are created. For example the possibility raised by astronomers that there must be other habitable planets next door, which answers would branch out to many other questions. It is also important because the discovery of this one planet can lead to many other orbiting planets. I chose this article because it was it was very interesting even though there wasn't too much information, it still taught me a lot about the other stars neighboring our star.
        
           Overall this article was enjoyable and  had many interesting facts and possibilities. Things i liked about this article was that there were many quotes which showed me the thoughts of many scientists about the planet and even though it is very far away it was still interesting to find out whether the planet was able to sustain life or not .

New Planet Discovery

             

John George Brakatselos                                                                            10/19/12

Earth Science                                                                                    Ms. Davies

Citation: Overbye, Dennis. "New Planet Found in Alpha Centauri." The New York Times. The New York Times, 17 Oct. 2012. Web. 17 Oct. 2012. <http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?ref=science>.

          This article come back to the main topic of discussion going on right now in our solar system; the possibility of life supporting planets. This has been a huge debatable topic over the years. This article says that this planet is “about as close as it will ever get.” This is in response to the search for another Earth. It was announced on the Wednesday of this week that this new planet was found in Alpha Centauri. Alpha Centauri is a triple star system that is 4.4 light years away from us. The man responsible for the discovery, Xavier Dumusque, who is a graduate student at the Geneva Observatory claims that we will never find anything like it. However this is the downside if the fact that it is close to its very hot star, Alpha Centauri B, which is only four million miles away. This is a problem because it is very difficult to support life at a surface temperature of 1,200 degrees. The good thing we can gain from this is the fact that if there is this similar planet in the area, then there may be others. The data shows that the possibility of life in the other system of Alpha Centauri B is more likely due to its distance of 64 million miles from its sun. This distance is key because it allows for essential things like water and survival. Scientists have also begun to use a method of wobbling to find the location of planets. They can easily track the movement of stars and trace back to where the gravity from one of the planets could be pulling them. This is very smart because it may be difficult to find new planets, but there are a lot of stars to track.

          I thought that this article is important to our society because this question has been asked for many years. “Is there life on other planets?” These small breakthroughs could eventually lead to a big discovery of a plant with intelligent life. If we do find another plant like our own, it could arguably be the biggest scientific discovery in years. These are the kinds of questions people devote their whole lives trying to answer. Eventually all this work will pay off and we will be one step closer to figuring out why we are here, and how we got here in the first place.

          I thought this was an interesting article. However in my opinion it is just one more planet to add to the list of planets that turned out to be too hot. I have noticed this to be a recurring theme in the discovery of planets. Unless there has been a discovery of something drastically different that it should be shared, then they should really wait to share these discoveries in the newspaper. I can understand why they would put this planet in the paper due to its mass similarity, so it would make sense why they decided to share information about this specific planet.

Efrosyni's post

Efrosyni Daskalakis - October 18^th 2012

Core Earth Science - Ms. Davies

Fazekas, Andrew. "Diamond Planet Found-Part of "Whole New Class?"" National Geographic. National Geographic Society, 11 Oct. 2012. Web. 18 Oct. 2012. file://localhost/<http/::news.nationalgeographic.com:news:2012:10:121011-diamond-planet-space-solar-system-astronomy-science:>.

           

            The National Geographic article “Diamond Planet Found – Part of “Whole New Class?”” written by Andrew Fazekas is an educational article about the recent discovery of a new planet orbiting a star, that is thought to be composed to carbon and could contain diamonds. This new planet was named 55 Cancri e and can orbit its star in about 18 earth hours. Considering this planet is only about 40 light years away it is similar to earth. 55 Cancri e is about twice the size of earth but has a mass that is six times that of earth. The surface temperatures reach an uninhabitable 3,900 degrees Fahrenheit (2,150 degrees Celsius)—which, along with carbon, make perfect conditions for creating diamonds. "It's the first time we know of such an exotic planet that we think was born mostly of carbon—which really makes this a fundamental game-changer in our understanding of what's possible in planetary chemistry." This quote by Nikku Madhusudhan a postdoctoral researcher at Yale University proposes the question that maybe we as a society do not really understand fully what actually is in our universe.

            Overall, I think that the idea of this article is excellent, and it really intrigues me that there could possibly be more valuable materials in distant planets. This article effect human society because it raises many questions about what could possibly be in our solar system. With this new discovery many other scientific explorations could take place to maybe get a better look and understanding of the materials and other existing planets in our universe. I really enjoy finding out new facts about the planets in our universe because it adds to my understanding of what is actually there. Even though scientists do not fully have a good understanding of the formation on our universe and what is in it, every little discovery is one step closer to fully understanding the galaxy.

            Even though I enjoyed reading this article, I think it was a little brief in the complete facts that were discovered of Cancri e. There might not be that much information on this new “diamond planet” yet, but it would have been more interesting if the article had suggested more areas of research within this topic. Fasekas could have included facts about other diamond like planets in our universe and how they compare to Cancri e. However these basic facts about the new “diamond planet:” are excellent bases for future study on this subject.  

Charlotte's Post

Charlotte Reynolds - October 9^th 2012

Core Earth Science - Ms. Davies

Romero, Simon. “At the End of the Earth, Seeking Clues to the Universe.” New York Times. 7 April 2012. <http://www.nytimes.com/2012/04/08/world/americas/high-in-chilean-desert-a-huge-astronomy-project.html?_r=0>

The article that I read for current events relates to astronomy and the study of stars. 16,597 ft above the plateau in the Atacama Desert, scientists have built one of the largest ground-based astronomical projects. This project filled with satellites and antennas, was designed to study parts of the universe that are dark, like the clouds of cold gas from which stars are formed. This does not detect optical light so it can focus on the dark light and hope to see where galaxies were formed. This project also detects the solar systems with the conditions to support life, like water baring planets. However, with all these studies using expensive equipment, the ALMA, or the ground-based project, cost over $1 billion dollars to create. Other countries are trying to mimic this experiment in Chile. Many scientists from all over the world come to take part in the study of Astronomy. The ALMA has brought new studies to our history. For example, in 2010, the ALMA discovered the world’s largest star observed to date. Although finding out new facts about space was intriguing, the journey to get here was not. Using a facility of living quarters near the project, about 500 people were able to board for a small period of time. Life in this desert was not easy. People related the feeling of being on it to the feeling you get when you complete a marathon. Legs are wobbly and shaky and the human body feels week after doing nothing. Along with nosebleeds and headaches due to the high altitude, this project in the Atacama Desert was all worth wild and gave valuable information to our scientific studies today.

I chose this article because I was scrolling down the New York Times website, the cover picture of all the satellites stuck out at me. There seemed to be so many and I wondered the reason behind it. As I read on, it caught my attention about how disconnected these space projects need to be from society in order to be accurate. The nearest town from the ALMA is about a 30 minute drive away. In the article, it states that here is very little light pollution so the sky is vivid and clear every night, not including dust storms. The climate and weather was a reason why this huge experiment wasn’t as fun. However, I valued the fact that people would go the extra step to make history in science. New discoveries were made including the largest star found in 2010. This project also focused on what many people ignores, which was the dark parts of space and trying to find what is in it. All these technologies and inventions really add knowledge to our society that benefits the better understanding of how this Earth was even created and to me, that’s interesting!

Overall I thought this article was well written. However, there were some parts of it that didn’t seem quite relevant to the main topic. I wish the author could have included a little more information. The new discoveries were interesting, but I wish there was more. I liked the way he set up the article though. It was well spaced out and always kept my attention, due to the fact that some articles are hard to read. This is where the evidence to the topic of the article was lacking. But overall it was a fun article to read!

NASA Mars Curiosity Rover Prepars to Study Martian Soil

Lucy Kohlhoff-October 8^th, 2012

Core Earth Science/ Ms. Davies

 "NASA Mars Curiosity Rover Prepares to Study Martian Soil." ScienceDaily. ScienceDaily, 04 Oct. 2012. Web. 08 Oct. 2012. <http://www.sciencedaily.com/releases/2012/10/121004155335.htm>.

            On October 2^nd, Curiosity, the rover of the Mars Science Laboratory, rolled onto a part of the Gale Crater of Mars called “Rocknest” and is preparing to get samples of the soil so scientists will be able to test if there is any microbial life. The scientists will analyze the minerals for the past environmental conditions and perform chemical analysis for the ingredients that are crucial for life, to see if life could have been possible. The process of the soil collection for Curiosity is to scoop it up and then dump it out, then scoop up more dirt and soil and store it as a sample. To ground up and make rocks into powder, Curiosity will use its hammer drill and then store the powder. Inside Curiosity are many different gears and chambers for sorting and separating the different samples, which will be helpful in sorting the samples for the labs they will be given to for testing.
            Curiosity and searching for life on Mars is very important to our nation’s science department moving forward. I think life on planets is a very important part of our solar system to explore, because if there is microbial life on mars, it may lead to newer and deeper discoveries of life on other planets. This may eventually also help us find the first signs of bacteria life, on any planet in our solar system. The topic of possible life on Mars is a discussion topic in science that intrigues me, and learning more about the current and future research being done is something I would like to follow up on.
            Though this article was quite fascinating to read, I felt there could be some improvements to make what the reader got out of the article increase. The article explains well how the rover collects the soil and rocks, but I think they should briefly mention how these samples are going to get back to earth for the labs to test them. Also, the description of Curiosity could have been a little more in depth, so that the reader can have a clear image of what she looks like because a picture was not included. Besides for these faults, the article was well written, insightful, and thought provoking for what the future holds for research in our solar system.

Electronic Medical Records

Original Article: http://www.nytimes.com/2012/10/09/health/the-ups-and-downs-of-electronic-medical-records-the-digital-doctor.html?pagewanted=2&_r=0&ref=science

Electronic Medical Records

by Natalie Knight

            The New York Times article “The Ups and Downs of Electronic Medical Records” written by Milt Freudenheim is an informative account of newly installed electronic methods of recording information of patients. Freudenheim includes details of various doctors throughout the country of differing specializations. One general issue with electronics, as he highlights, is the necessary tolerance for things such as crashes and bugs that threaten all technology. Many of the doctors featured by Freudenheim agreed on the fact that electronics could not possibly fit all the necessary aspects of a doctor or patient. Dr. David J. Brailer, a national coordinator for health information technology, originally supported the idea of incorporating technology into doctors’ offices, but later stated, “The current information tools are still difficult to set up. They are hard to use. They fit only parts of what doctors do, and not the rest.” However, other doctors and clinics have found new technology helpful, not limiting. For example, the Mayo Clinic in Rochester, Minnesota has overcome many issues with the technology. They are now making the best use out of it, and have detailed plans of what to do if something fails.

            Overall, it appears that technology will eventually benefit both doctors and patients. Despite the fact that there are still many issues that need to be worked out, the advantages over handwritten medical records are tremendous. As one doctor states, typed records eliminate the contemplation over bad handwriting. Apps have been created that patients can access on their phones, which allow them to retrieve previous records from certain doctors and healthcare centers. However, since the whole idea of technology in the medical field is relatively new to many medical centers, the kinks that go along with it are numerous. It is important for doctors to get these worked out before transferring all information.

It seems that, based on his research, Freudenheim is predominantly against the use of electronic medical records. Though he does underline a few benefits of the technology, including accessibility to medical records, he mostly focuses on the downsides and flaws. He highlights the fact that there are many issues with the systems currently, but he does not go into detail about how the technology will eventually help society. These benefits are innumerable, and Freudenheim should have focused more on them. He also kept citing more and more doctors, without giving readers a chance to process his thoughts.

Water on Mars

Preston Klimley

Earth Science Current Events Report

            In this article they discussed a rover that had landed on Mars and what it found. The rover named Curiosity found different pebbles in several exploring sites. The patterns on certain rocks and the pebbles in the exploring sites showed some evidence that there was once a water source in that location. Further exploration showed that there was a canyon 18 kilometers long, about 600 meters across and 30 meters deep, the canyon was called Peace Vallis. Peace Vallis stretched into the creator rim and sediments were swept onto the creator floor forming a floodplain. If the Curiosity had landed 2.5 billion years earlier, scientists said that it would have ben in a stream about the depth of your ankle to your hip. The rover did not stop there however, it is still moving around trying to find signs of life friendly environment, more water and organic carbon that we could build life from.

            Overall I enjoyed this article. I think that the possibility of life on other planets is fascinating. However I would have liked to read more about the possibility of life forms living on Mars. They told us that there was water there but does this mean that we can grow food or live there. Also one thing that I would have liked to read about would be what further research is being done on Mars if anything. One thing that I did like about the article was that they talked about what mars would have looked like 2.5 billion years ago if we were to have landed on it. This just shows the radical changes that planets undergo over time.

            This article has a lot of importance in our world today. With all of the theories about the world exploding and everyone dying, imagine if we could simply live somewhere else. Imagine if there was a planet that we could live on besides Earth. Maybe in he years to come we will figure out away to move people to another planet and make a civilization there.