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Timber Rattlesnakes vs. Lyme Disease

August 6, 2013

Karen Lips 240-393-5397
Lee Tune 301-405-4679

COLLEGE PARK, Md. - The scientific name of the timber rattlesnake, Crotalus horridus, is a sign of the fear and loathing this native North American viper has inspired for centuries. But new research by a team of University of Maryland biologists shows the timber rattlesnake indirectly benefits humans by keeping Lyme disease in check. The team's findings, presented today at the annual conference of the Ecological Society of America in Minneapolis, highlight the potential benefits of conserving all species – even those some people dislike.

An adult male timber rattlesnake can remove 2,500 to 4,500 of the ticks that carry Lyme disease each year. Photo credit: Ed KabayHuman cases of Lyme disease, a bacterial illness that can cause serious neurological problems if left untreated, are on the rise. The disease is spread by black-legged ticks, which feed on infected mice and other small mammals. Foxes and other mammal predators help control the disease by keeping small mammal populations in check. The decline of these mammal predators may be a factor in Lyme disease's prevalence among humans.

Timber rattlers are also top predators in Eastern forests, and their numbers are also falling, so former University of Maryland graduate student Edward Kabay wanted to know whether the rattlers also play a role in controlling Lyme disease.

Kabay used published studies of timber rattlers' diets at four Eastern forest sites to estimate the number of small mammals the snakes consume, and matched that with information on the average number of ticks each small mammal carried. The results showed that each timber rattler removed 2,500-4,500 ticks from each site annually.

Because not every human bitten by an infected tick develops Lyme disease, the team did not estimate how many people are spared from the disease because of the ecosystem service that timber rattlesnakes provide. But Kabay, who is now a science teacher at East Chapel Hill High School, and his research colleagues will talk about the implications of their findings at 4:20 p.m. today, Aug. 6, 2013, in Room 1011 of the Minneapolis Convention Center.

Timber rattlesnakes are endangered in six Eastern states and threatened in five more.

"Habitat loss, road kills, and people killing them out of fear are the big issues," said Kabay's advisor, associate biology professor Karen Lips. "They are non-aggressive and rarely bite unless provoked or stepped upon."

Lips directs the UMD graduate program in Sustainable Development and Conservation Biology. Her research focuses on the ecology, evolution, and conservation of amphibians, with interests at multiple scales (including populations, communities, and ecosystems), and with special interest in how amphibians are affected by emerging infectious disease and global change.

Lips is most widely known for her work studying, and trying to prevent, the world-wide loss of amphibian species that has been called the great amphibian extinction mystery. Read her personal, compelling account of 15 years of leading involvement in this effort in a May 15, 2013, Scientific American blog: "What If There Is No Happy Ending? Science Communication as a Path to Change." Follow her on Twitter @kwren88.

Povich Center Announces Sam Lacy-Wendell Smith Award

August 5, 2013

Dave Ottalini 301-405-1321

The Shirley Povich Center for Sports Journalism at the University of Maryland's Philip Merrill College of Journalism announces the creation of The Sam Lacy-Wendell Smith AwardCOLLEGE PARK, Md. – The Shirley Povich Center for Sports Journalism at the University of Maryland's Philip Merrill College of Journalism announces the creation of The Sam Lacy-Wendell Smith Award to be presented annually in conjunction with the Shirley Povich Symposium. The award will go to a sports journalist or broadcaster who has made significant contributions to racial and gender equality in sports.

"All someone has to do to see how important Pittsburgh Courier sportswriter Wendell Smith was to Jackie Robinson integrating Major League Baseball is to see the movie, '42,'" said Povich Center Director George Solomon. "And Baltimore Afro American columnist Sam Lacy was just as important. Both men worked tirelessly over the years–writing, lobbying and cajoling MLB's owners, many of them resistant, into trying to see the importance of integration to the future of not only the sport of baseball but to the country."

"Wendell Smith and Sam Lacy pushed sports owners, media, corporations, players, Halls of Fame, fans–really, everyone involved in sports–to end segregation and racism and admit all athletes to top competition," said Margaret Engel, executive director at the Alicia Patterson Journalism Foundation. "They possessed a courage and determination that changed sports forever."

The winner will be chosen by a committee comprised of Kevin Blackistone (visiting professor, Merrill College and commentator, ESPN's "Around the Horn"), Mary Byrne (sports managing editor, USA Today), Engel, Garry Howard (editor, The Sporting News), Diana Huffman (Baltimore Sun distinguished lecturer, Merrill College), Greg Lee (sports editor of the Fort Lauderdale Sentinel and president of the National Association of Black Journalists), George Solomon (director, Shirley Povich Center for Sports Journalism) and Rick "Doc" Walker (commentator, ESPN-980, Comcast SportsNet).

"For the Shirley Povich Center for Sports Journalism to annually cite a current journalist whose values and determination in seeking justice and equality in sports honors these two great journalists," said the Povich Center's Solomon."Hopefully, more journalists and broadcasters will follow in their footsteps, and students will come to understand more fully what these men accomplished."

About Sam Lacy and Wendell Smith
Sam Lacy was an African-American and Native American sportswriter who was a reporter, columnist, editor and TV/Radio host. He worked for the Washington Tribune, the Chicago Defender and the Baltimore Afro-American where he wrote about baseball's need for integration and Jackie Robinson's ascent to the Major Leagues. He was the first African American member of the Baseball Writers of America Association. He won the Red Smith Award for contributions to sports journalism in 1998. Lacy died in 2003 at the age of 99.

Wendell Smith was an African-American sportswriter who covered the Negro leagues for many African-American newspapers and boxing for the Chicago Tribune. He was also a TV sports anchor in Chicago and sports columnist for the Chicago Sun-Times. Smith was a chronicler of Jackie Robinson for the Pittsburgh Courier and is credited with encouraging Branch Rickey to give Robinson an opportunity to play in the major leagues. Smith died in 1972 at the age of 58.

UMD Honored for Excellence in Sustainable Dining

July 31, 2013

Alana Carchedi 301-405-0235

NACUFS Sustainability AwardsCOLLEGE PARK, Md. – The University of Maryland's Dining Services was honored for excellence in sustainable dining as the grand prize winner of the Sustainability Awards, announced during the National Association of College & University Food Service (NACUFS) National Conference.

The NACUFS Sustainability Awards annually recognize member institutions that have demonstrated outstanding leadership in the promotion and implementation of environmental sustainability, specifically as it relates to campus dining operations. The grand prize winner is honored for modeling exemplary excellence in the pursuit of a sustainable dining practice, resulting in a significantly reduced environmental impact and providing a best practice model for the NACUFS membership.

"We are extremely proud of the department’s sustainability efforts that led to this honor," says Allison Lilly, sustainability and wellness coordinator for UMD's Dining Services. "The NACUFS award is the result of collaboration and dedication demonstrated by the entire Dining Services team alongside the campus community. Our waste management program is a success because the entire campus works together to make it possible. We are thankful to the students for their energy and ideas to push the Green Dining Program forward." 

Post consumer waste sorting station @ the South Campus Dining RoomUMD's Dining Services was first awarded the Gold Medal for Waste Management for its community engagement program, which put them in the running for the grand prize. The community engagement program features expanded post-consumer compost collection, streamlined waste sorting, the reusable carryout program and collaboration with the Food Recovery Network. Additionally, student activism and volunteerism through the creation of a Green Dining Internship Program, a Sustainable Food Working Group, and a Peer Education Volunteer Program serve as cornerstones of the educational program supporting this effort.

For additional information on the university's green dining initiatives, visit http://dining.umd.edu/greendining.

Climate Changes Will Produce Wine Winners and Losers

July 30, 2013

Lee Tune 301-405-4679

COLLEGE PARK, Md. – In the not too distant future, your favorite French wine may not come from its namesake region or even from France!

Climate change is altering growing conditions in wine producing regions and in coming decades will change the wines produced there, in some cases shifting to new areas the growth of grape varieties long associated with regions further south, says leading climate scientist and wine expert Antonio Busalacchi of the University of Maryland.Climate change is altering growing conditions in wine producing regions and in coming decades will change the wines produced there, in some cases shifting to new areas the growth of grape varieties long associated with regions further south, says leading climate scientist and wine expert Antonio Busalacchi (pictured right) of the University of Maryland.

"Climate change will produce winners and losers among wine growing regions, and for every region it will result in changes to the alcohol, acid, sugar, tannins, and color in wine," says Busalacchi, who directs the UMD Earth System Science Interdisciplinary Center and chairs the World Climate Research Programme's Joint Scientific Committee and the National Academy of Sciences/National Research Council Board on Atmospheric Sciences and Climate.

Busalacchi and research assistant Eric Hackert have analyzed climate change impacts on 24 of the world's major wine producing regions; providing snapshots of what conditions will be like at the middle and end of this century. Busalacchi notes that several Champagne houses already are looking at land in Sussex and Kent in southern England as potential sites for new vineyards because as climate warms the region is becoming more hospitable to quality grape growing. The soil type in the region, as seen in the white cliffs of Dover, is similar to the chalky substrate of Champagne, and the cost of land is 30 times less than in France.

"Vineyards in higher latitudes, at higher altitudes or surrounded by ocean will benefit from climate change with more consistent growing seasons and a greater number of favorable growing days," he says.

"These include the Rhine in Germany, U.S. states Oregon and Washington, the Mendoza Province of Argentina and New Zealand." says Busalacchi who comes from a family of restaurateurs, is an advanced sommelier and operates a wine and vineyard consulting firm

Bordeaux and some other regions will suffer compressed growing seasons that yield unbalanced, low acid wines that lack complexity.On the other hand, Bordeaux (pictured left) and some other regions will suffer compressed growing seasons that yield unbalanced, low acid wines that lack complexity.  South Africa and South Australia, likely will see declines in wine production due to severe droughts, according to Busalacchi. More generally, extreme events such as heat waves that shut down photosynthesis and hail storms that can ruin a chateau's annual production in a matter of minutes will become more commonplace.

In both warm and cooler regions, one result will be the same; wines will lose their traditional character.

"Taken to an extreme, a wine from the Left Bank of Bordeaux may move away from the classic aromas of cedar cigar box, blackcurrants and green pepper and more toward the full, rich, spicy peppery profile of a Chateauneuf-du-Pape from the Southern Rhone," says Busalacchi. "Given that most grapevines produce fruit for 25 to 50 years, grape growers and wine makers must consider the long term when determining what to plant, where to plant, and how to manage their vineyards."

Building Climate Understanding
The University of Maryland is a national leader in collaborative research to understand our earth and its changing climate. As part of that work, UMD has major research partnerships with federal agencies in earth science, climate and energy research. These include a NOAA-supported Cooperative Institute for Climate and Satellites; the long-standing cooperative agreement between UMD's Earth System Science Interdisciplinary Center and the NASA/Goddard Space Flight Center; and the Joint Global Change Research Institute, a partnership between the university and the Department of Energy's Pacific Northwest National Laboratory. 

To aid individuals, institutions, industries and governments in effectively planning for and responding to climate change impacts, UMD's CIRUN initiative (Climate Information: Responding to User Needs) is building diverse partnerships among climate scientists, behavioral and social scientists, engineers, agricultural scientists, public health and risk management experts and private and public sector decision makers.

Exercise May be the Best Medicine for Alzheimer's

July 30, 2013

Kelly Blake 301-405-9418

COLLEGE PARK, Md. – New research out of the University of Maryland School of Public Health shows that exercise may improve cognitive function in those at risk for Alzheimer’s by improving the efficiency of brain activity associated with memory. Memory loss leading to Alzheimer’s disease is one of the greatest fears among older Americans. While some memory loss is normal and to be expected as we age, a diagnosis of mild cognitive impairment, or MCI, signals more substantial memory loss and a greater risk for Alzheimer’s, for which there currently is no cure. 

The study, led by Dr. J. Carson Smith, assistant professor in the Department of Kinesiology, provides new hope for those diagnosed with MCI. It is the first to show that an exercise intervention with older adults with mild cognitive impairment (average age 78) improved not only memory recall, but also brain function, as measured by functional neuroimaging (via fMRI).The study, led by Dr. J. Carson Smith, assistant professor in the Department of Kinesiology, provides new hope for those diagnosed with MCI. It is the first to show that an exercise intervention with older adults with mild cognitive impairment (average age 78) improved not only memory recall, but also brain function, as measured by functional neuroimaging (via fMRI). The findings are published in the Journal of Alzheimer’s Disease.

“We found that after 12 weeks of being on a moderate exercise program, study participants improved their neural efficiency – basically they were using fewer neural resources to perform the same memory task,” says Dr. Smith. “No study has shown that a drug can do what we showed is possible with exercise.”

Recommended Daily Activity: Good for the Body, Good for the Brain
Two groups of physically inactive older adults (ranging from 60-88 years old) were put on a 12-week exercise program that focused on regular treadmill walking and was guided by a personal trainer.  Both groups – one which included adults with MCI and the other with healthy brain function – improved their cardiovascular fitness by about ten percent at the end of the intervention. More notably, both groups also improved their memory performance and showed enhanced neural efficiency while engaged in memory retrieval tasks.

The good news is that these results were achieved with a dose of exercise consistent with the physical activity recommendations for older adults. These guidelines urge moderate intensity exercise (activity that increases your heart rate and makes you sweat, but isn’t so strenuous that you can’t hold a conversation while doing it) on most days for a weekly total of 150 minutes.

Measuring Exercise’s Impact on Brain Health and Memory
One of the first observable symptoms of Alzheimer’s disease is the inability to remember familiar names. Smith and colleagues had study participants identify famous names and measured their brain activation while engaged in correctly recognizing a name – e.g., Frank Sinatra, or other celebrities well known to adults born in the 1930s and 40s. “The task gives us the ability to see what is going on in the brain when there is a correct memory performance,” Smith explains.

Tests and imaging were performed both before and after the 12-week exercise intervention. Brain scans taken after the exercise intervention showed a significant decrease in the intensity of brain activation in eleven brain regions while participants correctly identified famous names. The brain regions with improved efficiency corresponded to those involved in the pathology of Alzheimer’s disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus.

The exercise intervention was also effective in improving word recall via a “list learning task,” i.e., when people were read a list of 15 words and asked to remember and repeat as many words as possible on five consecutive attempts, and again after a distraction of being given another list of words.

“People with MCI are on a very sharp decline in their memory function, so being able to improve their recall is a very big step in the right direction,” Smith states.

The results of Smith’s study suggest that exercise may reduce the need for over-activation of the brain to correctly remember something.  That is encouraging news for those who are looking for something they can do to help preserve brain function.

Dr. Smith has plans for a larger study that would include more participants, including those who are healthy but have a genetic risk for Alzheimer’s, and follow them for a longer time period with exercise in comparison to other types of treatments. He and his team hope to learn more about the impact of exercise on brain function and whether it could delay the onset or progression of Alzheimer’s disease.

UMD Soars to #14 on Forbes' Top Public Colleges List

July 29, 2013

Alana Carchedi 301-405-0235

The University of Maryland ranks #14 among public colleges, according to Forbes' 2013 list of America's Top Colleges.COLLEGE PARK, Md. – The University of Maryland ranks #14 among public colleges, according to Forbes' 2013 list of America's Top Colleges. In the 6th annual rankings, the university also ranks #40 among research universities and #73 among all U.S. colleges, up from #168 in 2012.

According to Forbes, the list focuses on student satisfaction, post-graduate success, student debt, graduation rate and nationally competitive awards.

"Providing broad access to the highest quality education is a task that has never been more important to our children, our state and our nation," says UMD President Wallace Loh. "Forbes' new ranking is particularly gratifying because it stresses academic excellence, the impact of a quality education, and affordability.  With strong support from our state leaders, the University of Maryland is succeeding in meeting these goals."

UMD is also ranked #19 among public universities by U.S. News & World Report. In addition, The Institute of Higher Education, which ranks the world’s top universities based on research, puts UMD at #38 in the world and #29 among U.S. universities.

The full list of America's Top Colleges is available here.

UMD Students, Alumni Win 15 Fulbright Grants

July 26, 2013

Beth Cavanaugh 301-405-4625
Francis DuVinage 301-314-9458 (National Scholarships Office)

COLLEGE PARK, Md. - Twelve University of Maryland students and three recent graduates were awarded Fulbright grants to study, conduct research, or teach English abroad during the 2013-14 academic year. The students and alumni will travel to 12 different countries on five continents to carry out projects in fields such as theatre studies, government and politics, environmental conservation, history, geography and education policy. Others will teach English at schools and universities. The Fulbright U.S. Student Program provides more than 1,900 awards annually for students and young professionals to pursue international study, research, and teaching experience.

Katherine RennenkampfHarrison Guthorn, a doctoral student in the College of Arts and Humanities (ARHU), and Ashley Enrici, a doctoral student in the College of Behavioral and Social Sciences (BSOS), were also awardedthe Fulbright Critical Language Enhancement Award, which provides advanced language training during their grant period.

"Maryland's undergraduate and graduate recipients of the Fulbright grant are an extraordinarily talented and adventuresome group of students and a credit to the departments where they study.  From teaching English in Turkey, to exploring the experiences of women secondary school teachers in Ethiopia, to learning about the art and practice of clowning in Indonesia, these students set a high standard of accomplishment for the whole University," said Professor James Gilbert, UMD’s Fulbright program adviser.

In the last five years, UMD students and recent graduates have earned a total of 70 Fulbright grants. This year’s recipients include three seniors, three recent graduates, and nine graduate students. One additional student is an alternate.

Dave BalwanzThe Fulbright Program is the flagship international educational exchange program sponsored by the U.S. Department of State. Since its establishment in 1946 under legislation introduced by the late U.S. Senator J. William Fulbright of Ark., the Fulbright Program has given approximately 318,000 individuals the opportunity to study, teach, conduct research, exchange ideas and contribute to finding solutions to shared international concerns. Recipients of Fulbright grants are selected on the basis of academic or professional achievement, as well as demonstrated leadership potential in their fields. The Fulbright U.S. Student Program operates in over 140 countries worldwide.

2013 University of Maryland Fulbright Recipients

Negar Ashtari Abay - Ethiopia

Negar Ashtari Abay is a doctoral student in the College of Education’s department of counseling, higher education, and special education. Abay’s research will focus on the experiences of women secondary school teachers in Ethiopia during their university training, transition to work, and first year of teaching. By giving voice to female perspectives and revealing strategies employed by women to overcome obstacles, her study hopes to inform policies aimed at the greater inclusion of women in teaching in Sub-Saharan Africa and to fill a gap in the gender and education literature.

Amy Austin - Germany 

Amy Austin graduated with a B.A. in government and politics from BSOS in 2010. She will be an English teaching assistant in Berlin, Germany. Austin recently completed service as a Teach for America corps member teaching fourth grade at the Wounded Knee District School on an Oglala Lakota Native American Reservation in South Dakota. After completing her Fulbright year, Austin plans to pursue a master’s degree in public policy or education and then work at an organization that aims to eliminate educational inequalities.

Dave Balwanz - South Africa

Dave Balwanz is a doctoral student in the College of Education's department of counseling, higher education, and special education. He will examine secondary education and training programs for marginalized youth in two school districts in the Johannesburg. He will elicit perspectives from these youth on the skills and learning experiences they see as important in their transition to adulthood and the world of work.

Ashley Enrici - Indonesia

Ashley Enrici, a doctoral candidate in BSOS’ department of geographical sciences, will research the recent extension of the UN’s Reducing Emissions from Deforestation and Forest Degradation (REDD) program. REDD+ moves beyond REDD’s focus on emissions reduction to include environmental and socioeconomic benefits. Enrici will examine implementation challenges of the REDD+ program that two forest communities face. Enrici received Fulbright’s Critical Language Enhancement Award to study Bahasa Indonesia.

Alex Gittelson - Russia

Alex Gittelson, a 2009 graduate of the College of Agriculture and Natural Resources (AGNR), will research alternatives to agricultural burning in Russia. He is currently an international affairs specialist with the Foreign Agricultural Service of the U.S. Department of Agriculture, focusing on policy issues related to energy, climate, safety, and security. Gittelson plans to pursue graduate studies in public policy after his Fulbright project.

Amina Goheer - Turkey

Amina Goheer, a 2012 BSOS and ARHU graduate, has been awarded an English teaching assistantship to Turkey. As an undergraduate student, Goheer studied abroad in Alexandria, Egypt and held internships at Search for Common Ground, an NGO that encourages collaborative solutions to conflict, and the Embassy of Pakistan. Following her Fulbright year, she plans to pursue a master’s degree in international development or global public health.

Harrison Guthorn - Jordan

Harrison Guthorn, a doctoral student in ARHU’s department of history, will examine how the city of Amman developed. He will focus on its development as the capital of Transjordan during the Mandate period. He will demonstrate how the history of Amman is also the history of Transjordan by focusing upon the development of Amman’s infrastructure, elites, and its civil society. Guthorn also received Fulbright’s Critical Enhancement Award to study Arabic.

James Hesla - Indonesia

James Hesla, a doctoral student in ARHU’s department of theatre, dance and performance studies, will research Balinese clowns and clowning in traditional masked dance-drama. Hesla asserts that clowns have the freedom to comment on pressing social and cultural concerns through comic actions and dialogue. He will consider how clowns and clowning both reflect and impact Balinese cultural values in performance and performer training.

Elana Mayer - Mexico

A 2013 ARHU graduate, Elana Mayer has been awarded an English teaching assistantship to Mexico where she will serve as an English language and cultural assistant at a public university. Upon her return from Mexico, Mayer plans to complete the Masters Certification (MCERT) Program at UMD to become a high school Spanish and/or ESL teacher.

Sonia Prescott - Panama

Sonia Prescott, a doctoral student in ARHU’s department of history, will research Afro Antillean contributions to the labor movement in Panama, particularly the Silver Roll strike of 1919 and the rent strikes of 1925 and 1932. She will focus on the role of racial propaganda in defining how these protests gained or lost the support of the larger Panamanian society.

Katherine Rennenkampf - Indonesia

A 2013 graduate of the College of Computer, Mathematical, and Natural Sciences (CMNS), Katherine Rennenkampf has been awarded a Fulbright English teaching assistantship to Indonesia. Rennenkampf, who aspires to become a math educator at the secondary level, will also be pursuing a project to learn about Indonesia’s recent steps in reforming its mathematics curricula. Upon her return from Indonesia, she plans to take an assignment as a Teach for America corps member.

Mary Kate Schneider - Bosnia and Herzegovina

Mary Kate Schneider is adoctoral student BSOS’ department of government and politics. Through her Fulbright grant, she will research the effects of divided education in Bosnia and Herzegovina by exploring how education policies affect interethnic perceptions and attitudes. She plans to survey and conduct focus groups with students from 10 cities and villages in Bosnia and Herzegovina, assessing interethnic attitudes that emerge among students.

Yu-Chi Wang - Taiwan

Yu-Chi Wang is a May 2013 graduate from BSOS and CMNS and has been awarded a Fulbright grant to teach English in Taiwan.  After her Fulbright year in Taiwan, Wang plans to pursue a master’s degree in industrial/organizational psychology and to use her Chinese-language skills to work internationally.

Kimberly Wilson - Taiwan

Kimberly Wilson, a doctoral student in BSOS, will examine Taiwan's maritime and territorial claims in the South China Sea. She will be based in Taipei, utilizing Taipei's academic and policy making sources and collecting data through interviews and documentary analysis. Wilson’s project will build on her current dissertation research in China, which is funded by a 2012-13 Boren Fellowship. 

Jesse Zarley - Chile 

Jesse Zarley is a doctoral student in ARHU and will research how the indigenous Mapuche population of southern Chile successfully resisted conquest and colonization by the Spanish Empire and the Chilean nation during the eighteenth and nineteenth centuries. He will work with primary documents and twentieth-century ethnographies to reconstruct a more coherent view of Mapuche cultural practices, rituals, and leadership structures. 

Dig at Eastern Shore site, built by freed slaves, shows it may be U.S.’s oldest black community (Washington Post)

Some were the freed slaves of conscience-stricken Quakers. Others were freed by a sea captain in his will. Still others were freed by a slave midwife who bought freedom for herself and her family. Together, here in Talbot County on the Eastern Shore, they may have given birth to what scholars at the University of Maryland and Morgan State suspect could be the oldest enclave of free African Americans, and possibly the oldest existing black neighborhood, in the country.

In Easton, archaeologists hope to uncover earliest free African American settlement (Baltimore Sun)

In Easton, an untold story of free African Americans is being discovered through bits of glass, shards of pottery and oyster shells. Piece by piece, University of Maryland archaeologists, historians from Morgan State, and the local community are uncovering the history of The Hill, a community they believe to be the earliest settlement of free African Americans in the United States, dating to 1790.


Starburst Wind Keeps Galaxies 'Thin'

July 24, 2013

Lee Tune 301-405-4679

Unlike humans, galaxies don’t have an obesity problem. In fact there are far fewer galaxies at the most massive end of the galactic scale than expected and scientists have long sought to explain why. A new, UMD-led study published in the journal Nature suggests that one answer lies in a kind of feast and fast sequence through which large galaxies can keep their mass down.COLLEGE PARK, Md. -- Unlike humans, galaxies don’t have an obesity problem. In fact there are far fewer galaxies at the most massive end of the galactic scale than expected and scientists have long sought to explain why. A new, UMD-led study published in the journal Nature suggests that one answer lies in a kind of feast and fast sequence through which large galaxies can keep their mass down.

Galaxies become more massive by ‘consuming’ vast clouds of gas and turning them into new stars. The new study shows in unprecedented detail how a burst of star formation in a galaxy can blow most of the remaining star-building gas out to the edge of the galaxy, resulting in a long period of starvation during which few new stars are produced.

“For the first time, we can clearly see massive concentrations of cold molecular gas being jettisoned by expanding shells of intense pressure created by young stars,” says lead author Alberto Bolatto of the University of Maryland. “The amount of gas we measure gives us very convincing evidence that some growing galaxies blow out more gas than they take in, slowing star formation down to a crawl.”

The team of astronomers used the new Atacama Large Millimeter/submillimeter Array (ALMA), a giant radio telescope in the high desert of northern Chile, to discover billowing columns of cold, dense gas being pushed out of starburst galaxy NGC 253, also known as the Silver Dollar or Sculptor Galaxy. In starburst galaxies, stars form about 100 times faster than in more normal galaxies like our Milky Way.

NGC 253 – with its slightly askew orientation – offers astronomers an excellent view of the star formation clusters near the galaxy’s center, clusters that turn out to be the point of departure for material being pushed from the galaxy.

“ALMA is opening a new window for observations of galactic winds,” says Sylvain Veilleux, also at the University of Maryland and a coauthor on the paper. “Winds have the potential to be incredibly disruptive and carry away a significant fraction of the star-forming material of a galaxy.”

The team says their results may help explain the universe’s surprising paucity of high-mass galaxies. Computer models indicate that old red galaxies, which are far more massive than the Milky Way, should be considerably more common than they are. In their youth, these galaxies likely ejected a large fraction of their gas that would have otherwise formed stars.

Gas can be removed from a galaxy in two ways. One is through the action of a central, supermassive black hole, called an active galactic nucleus.  Material is pulled into the black hole, becomes superheated and produces powerful jets or wide-angle winds that can propel material far from the galactic disk. However, evidence suggests that the black hole at the center of NGC 253 is not currently active.

The other way to potentially blow gas out of a galaxy is through galactic winds generated by star formation, but previously this had not been observed with enough resolution or sensitivity to measure the outflow of gas or its reductive impact on subsequent star formation.

As new stars form they exert powerful destructive influences on their environment. Initially, their light and winds of particles push on the surrounding gas. Later, if they are massive enough, stars explode as supernovas, a process that further drives the surrounding material away from the stellar birthplace. The current study indicates that in NGC 253, the concentration of hundreds or thousands of such destructive stars in one region is responsible for launching powerful flows of gas out of the galaxy.NASA image of NGC 253

Previous X-ray spectrum observations of NGC 253 have shown gas made of hot ionized hydrogen atoms streaming away from its star-forming regions. However, alone this insubstantial gas would have little if any impact on the fate of the galaxy and its ability to form future generations of stars. The new ALMA data show the far-more-dense molecular gas getting its initial “kick” from the formation of new stars and then being swept along with the thin, hot gas on its way to the galactic halo.
Using only a portion of its eventual full complement of 66 antennas, ALMA measured the mass and motion of carbon monoxide (CO) in the gas ejected from the central regions of this galaxy. The researchers determined that vast quantities of molecular gas – likely 9 times the mass of our Sun and possibly much more – were being ejected from the galaxy each year. At this rate, the galaxy could run out of gas and star formation slow to a crawl as in as few as 60 million years.
The researchers also determined that the gas is traveling somewhere between 25 to 155 miles (40 to 250 kilometers) per second, streaming approximately 1,500 light-years above and below the disk.  This may not be fast enough for the gas to reach escape velocity from the galaxy. If not, the gas will likely get suspended in the galactic halo for many millions of years.
 “More studies with the full ALMA array will help us figure out the ultimate fate of the gas carried away by the wind,” said Adam Leroy with the National Radio Astronomy Observatory, a facility of the National Science Foundation (NSF). “This will help us understand whether these starburst-driven winds recycle or truly remove star forming material.”

Bolatto agrees, but says: “Probably in a galaxy like this, the gas is pulled back into the heart of the galaxy, perhaps after several hundred million years. Star formation then takes off again and the whole process repeats itself.”

The National Science Foundation (NSF) provided core funding for this research through multiple grants to the university-based U.S. scientists as well as through NSF support of NRAO and ALMA construction and operations.

“Understanding how galaxies can evolve so radically and so dramatically is one of the hottest topics in astronomy today,” said Dan Evans, NSF program officer. “This work will have far-reaching implications for our understanding of the evolution of the cosmos. The result also is a true testament to the partnerships forged over many years between the University of Maryland research team, NSF and its international partners in the ALMA Project.


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