the universe - Department of Astronomy - University of Florida

The resulting observations with these instrumentshave led to groundbreaking discoveriesby UF astronomers - in areas ranging fromthe birth of the Universe to the developmentand detection of new planets.These successes positioned the UF Departmentof Astronomy to become apartner with the Spanish and Mexicangovernments in building the world’slargest telescope, the Gran TelescopioCanarias, located in the Canary Islands.The projects discussed here are just a sampleof the cutting edge astronomy research beingconducted at the University of Florida. Newprojects and programs are constantly emergingas the Department of Astronomy continues itswork at the forefront of the field.The Gran Telescopio Canarias (GTC) at Observatorio del Roquede los Muchachos on the island of La Palma, Canary IslandsUF Astronomy:Forming Partnerships For DiscoveryThe goal of the UF Department of Astronomyis to become one of the top 10 pub-astronomical instrumentation.in astronomical research and, in particular,lic astronomy departments in the United In the coming years, the DepartmentStates. Thanks to strong support from the of Astronomy is continuing to grow andUniversity, outstanding faculty and strong broaden the research opportunities at theinternational collaborations, we are well University of Florida. Several key initiativesare already underway. For instance,on our way to achieving this goal. We havepartnered with astronomers in Spain and UF is playing a key role in the developmentMexico to build the world’s largest optical of instrumentation for the proposed $1-billionThirty Meter Telescope (TMT) project.telescope, the GTC. This 10.4-meter telescopeis being constructed in the Canary A team of nine UF faculty, led by ProfessorIslands and will begin operation in 2008. Stephen Eikenberry, have been competitivelyselected to develop detailed scien-The superb image quality will allow the GTCto “see” both the faintest and the most distantobjects in the universe—from nearby, for the top-priority science instrument ontific observation simulations and designsnewborn planets and stars, to the most distantgalaxies.graph (IRMOS). IRMOS will be the work-TMT, the InfraRed Multi-Object Spectro-The formation and evolution of planets,stars and galaxies is the major unify-world’s most powerful tool for investigatinghorse spectrograph for TMT, and will be theing research theme of our department, and many astrophysical phenomena, includingwe are pursuing that theme through related “Cosmic Dawn”—the birth of the first starsobservational, theoretical and instrumentationresearch programs. Our partnership research spectrum, Professor Jian Ge andafter the Big Bang. At the other end of thewith Spain and Mexico has led to the developmentof new instruments that will be the next steps in planet searching with theincoming UF Professor Eric Ford are leadingused to achieve the research goals of the All-Sky Extra-Solar Planet Survey (ASEPS).department, such as CanariCam, FRIDA (InfraredAdaptive Optics Integral Field Unit) Tracker instruments developed at UF toASEPS will use a number of Exoplanetand CIRCE (Canarias Infrared Camera Experiment).UF astronomers are also partners in around nearby stars, revolutionizing thisfind hundreds to thousands of new planetsGOYA, a major near-infrared spectroscopic area of study.survey to be carried out on the GTC to study Through our programs, partnershipsgalaxy formation and evolution. In addition, and future endeavors, the University ofUF has implemented a very successful programto bring Spanish graduate students upward trajectory of distinction that we be-Florida’s Astronomy Department is on anand young postdocs to acquire expertise lieve is limited only by our imagination.Department ChairProfessor Stanley DermottDepartment of Astronomy211 Bryant Space Science CenterPO Box 112055Gainesville FL 32611-2055Phone: (352) 392-2052Fax: (352) 392-5089www.astro.ufl.edudiscovering the universeDepartment of AstronomyThe University of Florida has taken aunique approach to building oneof the nation’s top astronomyprograms.The Department of Astronomy hasbeen able to gain extensive observingtime on the world’s most powerfultelescopes by becoming one of thepremiere centers for astronomicalinstrumentation.The instruments built at UF addressa variety of important areasin science. Infrared cameras constructedat the university are beingused to investigate a wide rangeof astrophysical objects, includingstar-forming regions, circumstellardisks, starbursts and active galaxies.Meanwhile, other devices createdat UF focus on detecting exosolarplanets.Front Cover:Orion Nebula from the Hubble SpaceTelescope Orion Treasury Project Team(top) and a galaxy cluster image fromthe ESO Distant Cluster Survey (bottom)

Professor Jian GeDistant Worlds & Their OriginsWith the first detection in 1995 of a planetorbiting another Sun-like star, a new and excitingera of astronomy began. To date, morethan 180 such exosolar planets have beenfound, mainly using the “radial velocity (RV)technique” that measures the small backand-forthmotion of a star in response to thetug of unseen planets. Professor Jian Ge andhis team are on the verge of revolutionizingthis field by implementing a new approachto RV measurements. The Exoplanet Tracker,or ET for short, permits observations of manystars at once using wide field telescopes suchas the Sloan Digital Sky Survey’s 2.5-metertelescope at Apache Point Observatory. Bygreatly increasing the discovery rate of exosolarplanets, this technique promises to laythe groundwork for a much broader appreciationof the variety of distant worlds beyondour solar system.Professor Ge’s team recently achieved amajor milestone in this quest with the discoveryof a planet, ET-1, found with their ET prototypeinstrument at Kitt Peak National Observatory.The planet has half the mass of Jupiterand orbits its partner star every 4.1 days. InGe’s words, “This approach promises to discoverthousands of planetary systems aroundSun-like stars, as well as hundreds of systemsaround low-mass stars in the solar neighborhoodthat could host life.”ET Comes HomeFunded by the W.M. Keck Foundation, theKeck Exoplanet Tracker (ET) is the first ina new generation of Doppler instruments used fordetecting exosolar planets. This innovative approach,which is completely different from traditionalDoppler techniques, opens up a new capabilityfor simultaneous precision radial velocity measurementsof many stars.How planets like Earth and those detected byProfessor Ge form and evolve is a problem beingaddressed by Professors Stanley Dermott,Bo Gustafson and Charles Telesco. The disksof gas and dust that surround many of thestars in our universe are nurseries for newlyborn planets and provide natural laboratoriesfor observing the evolution of planetary systems.Light from the star is scattered by thedust particles in these disks and the propertiesof these particles are investigated byProfessor Gustafson using replica particles inhis unique Microwave Analog to Light ScatteringFacility. The dust particles are also heatedby the starlight incident upon them and glowwith infrared radiation that is captured byelectronic cameras like the T-ReCS and CanariCamthat were designed and built at UF byProfessor Telesco’s team.In addition, the disks will interact with anyplanetary systems embedded within them toproduce telltale signatures that indicate theirexistence. Professor Dermott and his colleagueDr. Thomas Kehoe have developedmodels using theoretical techniques and numericalsimulations that link the structure observedin some disks to the presence of suchunseen planets. For some stars, the imagesreveal intriguing structures that may insteadbe due to single cataclysmic events. The luminousdisk surrounding the 20-million-year-old“Beta Pictoris” star contains a bright clump ofparticles that could have resulted from thecatastrophic collisional disruption of a smallplanet hundreds-to-thousands of kilometersin size. “We may have captured, for the firsttime, the image of a major, highly energeticevent that must have occurred manytimes in the early history of our ownsolar system, and could even havebeen responsible for the creationof our own moon,” Telesco says.Planetary disk aroundthe nearby star BetaPictoris imaged withT-ReCST-Recs:Thermal-RegionCamera andSpectrographT-ReCS, built by Professor CharlesTelesco and his team, and the firstmajor facility-class instrumentto be built in the Infrared InstrumentationLaboratory, has beenfully operational since 2003 at theGemini South 8-meter telescopein Chile. It is optimized for observationsof thermal-infrared (heat)radiation that dominates the radiationoutput from relatively coolcelestial objects and is nearly imperviousto interstellar extinction.This highly productive imager andspectrograph is now being usedby the international community ofastronomers to search for planetsand brown dwarfs, explore planetformingcircumstellar disks andprobe visually obscured star-formingregions and the hidden cores ofgalaxies.Professor Jonathan TanStars: From Cradle to GraveJust like people, stars experience birth, middle-age,senior citizenship and, eventually,death. The lifespan of stars can be as shortas a few million years, and yet some are almostas old as the universe itself. Researchersin the UF Department of Astronomy areactively studying stars in a variety of lifestages—from the cradle to the grave.Professors Elizabeth Lada and JonathanTan use observational and theoreticalmethods, respectively, to aid in their studyof the birth of stars and planetary systems.They are particularly curious about how thisprocess changes across different areas ofthe universe—from the crowded centers ofstar clusters like the nearby Orion Nebula tothe swirling disks of gas around mysteriousblack holes in the centers of galaxies. “Ourstudies of star formation have determinedthat the first stars in the universe were verymassive, about 200 times that of our Sun,”notes Professor Tan. “Furthermore, it appearsthat massive stars form via the samemechanism as lower-mass stars, namelythe collapse of a gas core to an accretiondisk, which then channels gas to the star.”Stars in their middle to senior years ofage are the focus of Professor Ata Sarajedini’sresearch efforts. He is not only interestedin the properties of the stars themselves,but he is also using stars within the contextof their parent galaxies to understand theprocess of galaxy formation and evolution.“Using stars as tools, we are increasinglyconfident that large galaxies like our ownMilky Way are formed through the disruptionand eventual destruction of smallergalaxies,” says Sarajedini. “Furthermore,the age of the oldest stars—such as those inglobular clusters—sets a lower limit on theFlamingos Survey Serpens Imageage of the universe, which has broad implicationsfor cosmology.”When stars reach the end of their lives,the more massive ones form such exoticobjects as neutron stars and black holes.These remnants of stellar evolution are thefocus of Professor Stephen Eikenberry andDr. Reba Bandyopadhyay’s work. When oneof these stellar remnants interacts in an orbitwith a normal star, spectacular and violentfireworks can result. Studying the detailsof this phenomenon can shed light onboth the most extreme physical conditionsin the universe and on the nature of themost massive stars in the galaxy. ProfessorEikenberry summarizes his work by noting,“Our group focuses on the biggest, the hottestand the fastest things there are.”Flamingos: Florida Multi-object ImagingNear-IR Grism Observational SpectrometerMost stars in our galaxy form in Giant Molecular Clouds (GMCs), yet we still don’t fully understand the process of star formation inthis environment. Professor Elizabeth Lada, Dr. Nick Raines and their group are using FLAMINGOS, the world’s first fully cryogenic,near-infrared multi-object spectrometer, to learn in detail about the birth of stars in these clouds. FLAMINGOS offers unparalleledcapabilities for this research, enabling Lada’s team to observe dozens of stars at a time. This group is currently conducting a largesurvey that will address such fundamental issues as how star formation and the initial mass function vary between different cloudsand how star formation changes with time within a cloud.Flamingos-IIOn large modern telescopes,observational timecan cost more than $1 per second. With target objects numberingin the billions, FLAMINGOS-2, built by Professor StephenEikenberry’s team at UF which includes Dr. Reba Bandyopadhyayand Dr. Nick Raines, offers astronomers a hundred-fold increasein the number of objects they can study at a time—greatlyimproving the “bang for the buck” scientific performance ofmodern observatories.Traditional methods provide for observations of one star orgalaxy at a time, but, using techniques pioneered at the Universityof Florida with the FLAMINGOS instrument by the late ProfessorRichard Elston, FLAMINGOS-2 can gather infrared spectroscopicdata on up to 120 such objects simultaneously on theworld-class Gemini Observatory 8-meter telescopes. Surveysof the cosmos, which used to be prohibitively expensive for astronomersto undertake, can now be accomplished in just a fewnights of observation.The FLAMINGOS-2 Early Science Surveys (f2ESS), led byProfessor Eikenberry and eight other UF faculty, will probe suchdiverse topics as the black hole population and historyof the Galactic Center region, the evolutionof galaxies early in the life of the Universe, theformation of stars in the Milky Way and thebirth of the first galaxies after the BigBang. FLAMINGOS-2 is u n -dergoing final laboratorytesting at UFand is scheduled for“first light” observationsat the GeminiSouth Observatoryon Cerro Pachon,Chile, in late2006.Unlocking the Mysteries of the CosmosHow do galaxies like our own Milky Way formand evolve? Answering this question is at thecore of extragalactic research at the Universityof Florida.It has become quite clear to the scientificcommunity in recent years that supermassiveblack holes, which lie at the center ofall galaxies, play an important role in galaxyevolution. Galaxies where material is flowinginto the central black hole and producingenormous amounts of light and energy areProfessor Anthony Gonzalez and a galaxy clusterimage showing X-ray emission contoursknown as active galaxies. Professors VickiSarajedini and Fred Hamann, along with Dr.Chris Packham, study these active galaxiesin hopes of better understanding how theychange over time and alter the propertiesof their host galaxies. Hamann’s researchfocuses on the most luminous type of activegalaxies known as quasars. These objects,a trillion times brighter than the Sun, arevisible from billions of light years away. Hamann’swork focuses on the early evolutionof both the quasars and their host galaxies.Packham, in collaborationwith Spanishastronomers,is studyingtheinnerProfessor Stephen Eikenberry holdingthe Flamingos-2 infrared detectorregions of such objects in unprecedenteddetail using T-ReCs and Canaricam. Sarajediniis currently using the Hubble Space Telescopeto conduct deep field surveys to identifyvery faint emissions from active galaxiesin the distant universe. She is studying severalthousand galaxies to determine whethertheir central luminosity has changed overtime. “While the fainter active galaxies canbe difficult to detect, understanding theirproperties sheds light on the critical link betweenactive and normal galaxies” she says.Professors Rafael Guzman and AnthonyGonzalez are examining the growth and starformation histories of galaxies and how theenvironment in which a galaxy resides affectsthese properties. Professor Guzman’sresearch focuses on understanding a typeof galaxy that was once common in the universebut today is very rare—luminous bluecompact galaxies. By studying how thesegalaxies evolve his research addresses howmodern galaxies, like our own Milky Way,are formed. Professor Gonzalez also has hisgaze fixed on the distant universe. He hasdiscovered some of the most distant galaxyclusters known and is currently studying howtheir high-density environments influencegalaxy evolution.Astronomy for the PeopleThe department is involved in a wide range of public outreach activities designedto bring the wonders of astronomy to the general public. The campus obervatoryhosts open nights throughout the year, allowing visitors to view night-sky objectsthrough several telescopes. Many of the department’s professors, postdoctoral researchersand students visit local schools to present astronomy-related activities to children. The departmentruns teacher training workshops in the summer and recently worked closely with local officialsto help the school board obtain a $1.1-million grant to provide science training for teachers. TheStarLab Portable Planetarium is being used in kindergarten through 12th grade classrooms acrossNorth Central Florida to get the astronomers of tomorrow excited about science. They learn aboutthe nature of stars and galaxies, the making of comets, our solar system and the Milky Way galaxy.The department also sponsors an annual “museum night” at the local natural history museum,where the public is invited to hear lectures and enjoy many of the activities presented at schools.The GOYA Survey: Exploring The Early Universe“Astronomers are the ultimate explorers,”says Professor Rafael Guzman. “Each newastronomical instrument launches an expeditionto explore the unknown with theexpectation of newd i s c o v e r i e sahead.” Incosmology,these expe d i -t i o n sa r etrips through the vastness of space to thebeginning of time. The new generation oflarge telescopes like the GTC allows observationsof galaxies that are very faint becausethey are very far away. Since the largerthe distance the longer it takes for light totravel from the object to the observer, GTCobservations of very distant galaxies willreveal how the universe looked like when itwas only one tenth of its current age.The exploration of the early universeis the focus of the UF Key Project: GalaxyOrigins and Young Assembly (GOYA). TheGOYA survey is being carried out by a teamof astronomers at UF in collaboration withastronomers from Spain, Mexico and twoProfessor Vicki Sarajedini and theStarlab portable planetariumother European countries. “GOYA will providethe most complete characterizationof the optical properties of galaxies at theearliest epoch of the universe explored thusfar,” says Professor Guzman, co-PrincipalInvestigator for the GOYA team. This surveyis unique in the unparalleled access tothe best instruments ever built for exploringthe early universe: EMIR (built in Spain)and FLAMINGOS-2 (built at UF) at the GTC.Using these instruments, astronomers fromthe GTC partner institutions will be able tomap the distribution of matter in the earlyuniverse, classify its galaxy population andtest our current ideas about the geometryand the fate of the universe itself.CanariCamCanariCam, led by PI Professor charles Telesco and Deputy PI Dr. ChrisPackham, is currently being completed in the UF Infrared InstrumentationLaboratory and will be available for use on the GranTelescope Canarias on its first day of operations. Like T-ReCS,CanariCam is optimized for imaging and spectroscopy in thethermal-infrared spectral region, but it will also have twocompletely new modes of operation: coronagraphy andpolarimetry. For the coronagraphic mode, special occultingand pupil masks suppress a star’s light by anProfessor Rafael Guzmanorder of magnitude to enable astronomers to detectfaint objects such as giant planets or brown dwarfsthat may orbit a bright star. The polarimetric capability will provide a unique probe of accretion disks associatedwith heavily obscured massive black holes found at the center of most galaxies and it will illuminatepreviously inaccessible properties of particles orbiting in circumstellar disks where planets are formed.