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Sample records for first-year fermi large

  1. The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data

    SciTech Connect

    Abdo, A. A.

    2011-08-19

    We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called 'extra-galactic' diffuse {gamma}-ray emission (EGB). This component of the diffuse {gamma}-ray emission is generally considered to have an isotropic or nearly isotropic distribution on the sky with diverse contributions discussed in the literature. The derivation of the EGB is based on detailed modelling of the bright foreground diffuse Galactic {gamma}-ray emission (DGE), the detected LAT sources and the solar {gamma}-ray emission. We find the spectrum of the EGB is consistent with a power law with differential spectral index {gamma} = 2.41 {+-} 0.05 and intensity, I(> 100 MeV) = (1.03 {+-} 0.17) x 10{sup -5} cm{sup -2} s{sup -1} sr{sup -1}, where the error is systematics dominated. Our EGB spectrum is featureless, less intense, and softer than that derived from EGRET data.

  2. Fermi GBM: Results from the First Year +

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2009-01-01

    Gamma-ray Burst Monitor (GBM) has performed well in the first year+. GBM triggers 353 Gamma-ray Bursts (GRBs), 168 SGR events, 18 TGFs, and 1 solar flare to date. Short GRBs appear contracted in time and shifted to higher energy than long GRBs. Pulsed persistent emission from SGR 1550-5418 detected. TGFs are shorter, have higher average photon energies, and much higher count rates than GRBs. GBM monitoring of accreting pulsars provides long-term spin-histories. GBM Earth occultation monitoring complements Swift.

  3. A First Year View of the Galaxy with the Fermi Gamma-ray Space Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    After one year of survey observations and more than 70 billion triggers, Fermi is revealing an unprecedented view of the high energy gamma-ray sky. The observatory carries two instruments, the Gamma-ray Burst Monitor (GBM, 8 keV - 40 MeV) and the Large Area Telescope (LAT, 20 MeV - X300 GeV), which in combination cover over 7 orders of magnitude in energy. The LAT provides substantially more sensitivity than previous instruments in this waveband and has opened up the energy window from 10-100 GeV. This is particularly relevant for the study of gamma-ray sources in the Galaxy. The first year data have revealed new classes of Galactic emitters as well as providing spectacular detail on some old friends. I'll review the fascinating range of Galactic emission now seen - from pulsars their nebulae to X-ray binaries and supernova remnants - with particular emphasis on the impact of the Fermi pulsars.

  4. First Year Results from the Fermi Gamma-Ray Space Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    After one year of survey observations and more than 70 billion triggers, Fermi is revealing an unprecedented view of the high energy gamma-ray sky. The observatory .carries two instruments, the Gamma-ray Burst Monitor (GB, 8 keV - 40 MeV) and the Large Area Telescope (LAT, 20 MeV greater than or equal to 300 GeV), which in combination cover over 7 orders of magnitude in energy for transient phenomena. The LAT provides substantially more sensitivity than previous instruments in this waveband and has opened up the energy window from 10-100 GeV. The first year has produced many important results, from detections of extremely energetic and distant gamma-ray bursts, to monitoring daily variations in emission caused by massive black holes at the cores of galaxies, to identifying a new population of gamma-ray bright pulsars, to measuring the spectrum of diffuse emission from our own. Galaxy and the spectrum of the local cosmic electrons. I'll review highlights from the first year and discuss how the data are answering questions from the past and raising new ones for the future.

  5. On Flipping the Classroom in Large First Year Calculus Courses

    ERIC Educational Resources Information Center

    Jungic, Veselin; Kaur, Harpreet; Mulholland, Jamie; Xin, Cindy

    2015-01-01

    Over the course of two years, 2012-2014, we have implemented a "flipping" the classroom approach in three of our large enrolment first year calculus courses: differential and integral calculus for scientists and engineers. In this article we describe the details of our particular approach and share with the reader some experiences of…

  6. Fermi's Large Area Telescope (LAT)

    NASA Video Gallery

    Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientificinstrument. This animation shows a gamma ray (purple) entering the LAT,where it is converted into an electron (red) and a...

  7. Enhancing Student Engagement in Large, Non-Disciplinary First Year Survey Courses

    ERIC Educational Resources Information Center

    Baldwin, Annabelle; Koh, Ernest

    2012-01-01

    Large first year survey units pose unique challenges to both teachers and learners. Survey units are designed to deliver non-disciplinary specific knowledge about a given subject to a wide audience of learners. However, first year students in these units often find that they are unable to identify the architecture of such units, and are hence…

  8. Integration of Information Literacy Components into a Large First-Year Lecture-Based Chemistry Course

    ERIC Educational Resources Information Center

    Locknar, Angela; Mitchell, Rudolph; Rankin, Janet; Sadoway, Donald R.

    2012-01-01

    A first-year chemistry course is ideal for introducing students to finding and using scholarly information early in their academic careers. A four-pronged approach (lectures, homework problems, videos, and model solutions) was used to incorporate library research skills into a large lecture-based course. Pre- and post-course surveying demonstrated…

  9. Establishing Peer Mentor-Led Writing Groups in Large First-Year Courses

    ERIC Educational Resources Information Center

    Marcoux, Sarah; Marken, Liv; Yu, Stan

    2012-01-01

    This paper describes the results of a pilot project designed to improve students' academic writing in a large (200-student) first-year Agriculture class at the University of Saskatchewan. In collaboration with the course's professor, the Writing Centre coordinator and a summer student designed curriculum for four two-hour Writing Group sessions…

  10. Assessing Core Manipulative Skills in a Large, First-Year Laboratory

    ERIC Educational Resources Information Center

    Moni, Roger W.; Hryciw, Deanne H.; Poronnik, Philip; Lluka, Lesley J.; Moni, Karen B.

    2007-01-01

    Responding to the concern from our faculty that undergraduate students do not have robust laboratory skills, we designed and implemented a strategy to individually teach and assess the manipulative skills of students in first-year laboratories. Five core laboratory skills were selected for the course entitled Human Biology, a large, first-year…

  11. Biohorizons: An eConference to Assess Human Biology in Large, First-Year Classes

    ERIC Educational Resources Information Center

    Moni, Roger W.; Moni, Karen B.; Poronnik, Philip; Lluka, Lesley J.

    2007-01-01

    The authors detail the design, implementation and evaluation of an eConference entitled "Biohorizons," using a presage-process-product model to describe the development of an eLearning community. Biohorizons was a summative learning and assessment task aiming to introduce large classes of first-year Human Biology students to the practices of…

  12. Supernova Remnants with Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Caragiulo, M.; Di Venere, L.

    2017-03-01

    The Large Area Telescope (LAT), on-board the Fermi satellite, proved to be, after 8 years of data taking, an excellent instrument to detect and observe Supernova Remnants (SNRs) in a range of energies running from few hundred MeV up to few hundred GeV. It provides essential information on physical processes that occur at the source, involving both accelerated leptons and hadrons, in order to understand the mechanisms responsible for the primary Cosmic Ray (CR) acceleration. We show the latest results in the observation of Galactic SNRs by Fermi-LAT.

  13. FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG

    SciTech Connect

    Nolan, P. L.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Abdo, A. A.; Ackermann, M.; Antolini, E.; Bonamente, E.; Atwood, W. B.; Belfiore, A.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Ballet, J.; Bastieri, D.; Bignami, G. F. E-mail: Gino.Tosti@pg.infn.it E-mail: tburnett@u.washington.edu; and others

    2012-04-01

    We present the second catalog of high-energy {gamma}-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely {gamma}-ray-producing source classes.

  14. Fermi Large Area Telescope Second Source Catalog

    NASA Technical Reports Server (NTRS)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M; Allafort, A.; Antolini, E; Bonnell, J.; Cannon, A.; Celik O.; Corbet, R.; Davis, D. S.; DeCesar, M. E.; Ferrara, E. C.; Gehrels, N.; Harding, A. K.; Hays, E.; Johnson, T. E.; McConville, W.; McEnery, J. E; Perkins, J. S.; Racusin, J. L; Scargle, J. D.; Stephens, T. E.; Thompson, D. J.; Troja, E.

    2012-01-01

    We present the second catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24-month period. The Second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in 5 energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 11eV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely gamma-ray-producing source classes.

  15. Fermi Large Area Telescope First Source Catalog

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Belli, F.; Berenji, B.; Bisello, D.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Campana, R.; Canadas, B.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Ceccanti, M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Cillis, A. N.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Corbet, R.; Davis, D. S.; DeKlotz, M.; den Hartog, P. R.; Dermer, C. D.; de Angelis, A.; de Luca, A.; de Palma, F.; Digel, S. W.; Dormody, M.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Fabiani, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giavitto, G.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Healey, S. E.; Hill, A. B.; Horan, D.; Hughes, R. E.; Iafrate, G.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Lande, J.; Landriu, D.; Latronico, L.; Lee, S.-H.; Lemoine-Goumard, M.; Lionetto, A. M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Marangelli, B.; Marelli, M.; Massaro, E.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Michelson, P. F.; Minuti, M.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakajima, H.; Nakamori, T.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paccagnella, A.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Pinchera, M.; Piron, F.; Porter, T. A.; Poupard, L.; Rainò, S.; Rando, R.; Ray, P. S.; Razzano, M.; Razzaque, S.; Rea, N.; Reimer, A.; Reimer, O.; Reposeur, T.; Ripken, J.; Ritz, S.; Rochester, L. S.; Rodriguez, A. Y.; Romani, R. W.; Roth, M.; Sadrozinski, H. F.-W.; Salvetti, D.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schalk, T. L.; Scolieri, G.; Sgrò, C.; Shaw, M. S.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, J.-L.; Stephens, T. E.; Striani, E.; Strickman, M. S.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Tinebra, F.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Van Etten, A.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wallace, E.; Wang, P.; Watters, K.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.; Fermi LAT Collaboration

    2010-06-01

    We present a catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), during the first 11 months of the science phase of the mission, which began on 2008 August 4. The First Fermi-LAT catalog (1FGL) contains 1451 sources detected and characterized in the 100 MeV to 100 GeV range. Source detection was based on the average flux over the 11 month period, and the threshold likelihood Test Statistic is 25, corresponding to a significance of just over 4σ. The 1FGL catalog includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and power-law spectral fits as well as flux measurements in five energy bands for each source. In addition, monthly light curves are provided. Using a protocol defined before launch we have tested for several populations of gamma-ray sources among the sources in the catalog. For individual LAT-detected sources we provide firm identifications or plausible associations with sources in other astronomical catalogs. Identifications are based on correlated variability with counterparts at other wavelengths, or on spin or orbital periodicity. For the catalogs and association criteria that we have selected, 630 of the sources are unassociated. Care was taken to characterize the sensitivity of the results to the model of interstellar diffuse gamma-ray emission used to model the bright foreground, with the result that 161 sources at low Galactic latitudes and toward bright local interstellar clouds are flagged as having properties that are strongly dependent on the model or as potentially being due to incorrectly modeled structure in the Galactic diffuse emission.

  16. A First-Year Chemistry Undergraduate "Course Community" at a Large, Research-Intensive University

    ERIC Educational Resources Information Center

    De La Franier, Brian J.; Diep, Jenny; Menzies, Perry J. C.; Morra, Barbora; Koroluk, Katherine J.; Dicks, Andrew P.

    2016-01-01

    This article describes the integration of a cocurricular "Community" into a first-year undergraduate chemistry course at the University of Toronto. The Community has been in existence since 2006, with over 700 students being involved. Its broad objectives have been three-fold: to inform course members about departmental resources and…

  17. Designed for Learning: A Case Study in Rethinking Teaching and Learning for a Large First Year Class

    ERIC Educational Resources Information Center

    Goldacre, Lisa; Bolt, Susan; Lambiris, Michael

    2013-01-01

    This paper presents a case study in which the principles of scholarship were applied to designing an approach to learning suitable for large classes. While this case study describes an Australian first year Business Law unit, the findings presented in this paper would be relevant to a wide range of teachers faced with large enrollments in first…

  18. Applying a Linked-Course Model to Foster Inquiry and Integration across Large First-Year Courses

    ERIC Educational Resources Information Center

    Husband, Brian C.; Bettger, William J.; Murrant, Coral L.; Kirby, Kim; Wright, Patricia A.; Newmaster, Steven G.; Dawson, John F.; Gregory, T. Ryan; Mullen, Robert T.; Nejedly, April; van der Merwe, George; Yankulov, Krassimir; Wolf, Peter

    2015-01-01

    Many first-year university courses are large and content-driven, which can contribute to low student engagement and difficulty involving students in the dynamic, cross-disciplinary nature of inquiry. Learning communities can address these goals, but their implementation often poses logistical challenges, especially in large courses. Here, we apply…

  19. Student Engagement in a Large Classroom: Using Technology to Generate a Hybridized Problem- Based Learning Experience in a Large First Year Undergraduate Class

    ERIC Educational Resources Information Center

    Fukuzawa, Sherry; Boyd, Cleo

    2016-01-01

    Large first year undergraduate courses have unique challenges in the promotion of student engagement and self-directed learning due to resource constraints that prohibit small group discussions with instructors. The Monthly Virtual Mystery was developed to increase student engagement in a large (N = 725) first year undergraduate class in…

  20. Technology Supported Facilitation and Assessment of Small Group Collaborative Inquiry Learning in Large First-Year Classes

    ERIC Educational Resources Information Center

    Lawrie, Gwendolyn A.; Gahan, Lawrence R.; Matthews, Kelly E.; Weaver, Gabriela C.; Bailey, Chantal; Adams, Peter; Kavanagh, Lydia J.; Long, Phillip D.; Taylor, Matthew

    2014-01-01

    Collaborative learning activities offer the potential to support mutual knowledge construction and shared understanding amongst students. Introducing collaborative tasks into large first-year undergraduate science classes to create learning environments that foster student engagement and enhance communication skills is appealing. However,…

  1. First-Year Students' Perceptions of Instruction in Large Lectures: The Top-10 Mistakes Made by Instructors

    ERIC Educational Resources Information Center

    Richards, K. Andrew R.; Velasquez, Juan D.

    2014-01-01

    Constructivist approaches to education embrace students' prior learning experiences and preference for learning in social environments. However, many postsecondary classes continue to embrace lecture-styles of teaching. This study sought to understand first-year students' perceptions of the mistakes instructors make in large lecture classes.…

  2. Introducing a Learning Management System in a Large First Year Class: Impact on Lecturers and Students

    ERIC Educational Resources Information Center

    Snowball, J.; Mostert, M.

    2010-01-01

    The challenges of teaching large classes are well documented in the literature on teaching in higher education. Information and communication technologies (ICTs) have the potential to address some of these challenges, but, used inappropriately, technology can perpetuate entrenched practices and simply support performance models of teaching that…

  3. A method of providing engaging formative feedback to large cohort first-year physiology and anatomy students.

    PubMed

    Weston-Green, Katrina; Wallace, Margaret

    2016-09-01

    A growing body of evidence demonstrates a critical role for effective, meaningful feedback to enhance student learning. Effective feedback can become part of the learning cycle that is not only a learning opportunity for the student but can also be used to inform the teacher and ongoing curriculum development. Feedback is considered particularly important during the first year of university and can even be viewed as a retention strategy that can help attenuate student performance anxieties and solidify perceptions of academic support. Unfortunately, the provision of individualized, timely feedback can be particularly challenging in first-year courses as they tend to be large and diverse cohort classes that pose challenges of time and logistics. Various forms of generic feedback can provide rapid and cost-effect feedback to large cohorts but may be of limited benefit to students other than signaling weaknesses in knowledge. The present study describes a method that was used to provide formative task-related feedback to a large cohort of first-year physiology and anatomy students. Based on student evaluations presented in this study, this method provided feedback in a manner that engaged students, uncovered underlying misconceptions, facilitated peer discussion, and provided opportunity for new instruction while allowing the lecturer to recognize common gaps in knowledge and inform ongoing curriculum development.

  4. Fermi Large Area Telescope Bright Gamma-ray Source List

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Band, D.L.; Barbiellini, Guido; Bastieri, Denis; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bignami, G.F.; Bloom, Elliott D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Burnett, Thompson H.; /more authors..

    2009-05-15

    Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

  5. Fermi Large Area Telescope Operations: Progress Over 4 Years

    SciTech Connect

    Cameron, Robert A.; /SLAC

    2012-06-28

    The Fermi Gamma-ray Space Telescope was launched into orbit in June 2008, and is conducting a multi-year gamma-ray all-sky survey, using the main instrument on Fermi, the Large Area Telescope (LAT). Fermi began its science mission in August 2008, and has now been operating for almost 4 years. The SLAC National Accelerator Laboratory hosts the LAT Instrument Science Operations Center (ISOC), which supports the operation of the LAT in conjunction with the Mission Operations Center (MOC) and the Fermi Science Support Center (FSSC), both at NASA's Goddard Space Flight Center. The LAT has a continuous output data rate of about 1.5 Mbits per second, and data from the LAT are stored on Fermi and transmitted to the ground through TDRS and the MOC to the ISOC about 10 times per day. Several hundred computers at SLAC are used to process LAT data to perform event reconstruction, and gamma-ray photon data are subsequently delivered to the FSSC for public release with a few hours of being detected by the LAT. We summarize the current status of the LAT, and the evolution of the data processing and monitoring performed by the ISOC during the first 4 years of the Fermi mission, together with future plans for further changes to detected event data processing and instrument operations and monitoring.

  6. Closing the feedback loop: engaging students in large first-year mathematics test revision sessions using pen-enabled screens

    NASA Astrophysics Data System (ADS)

    Donovan, Diane; Loch, Birgit

    2013-01-01

    How can active learning, peer learning and prompt feedback be achieved in large first-year mathematics classes? Further, what technologies may support these aims? In this article, we assert that test revision sessions in first-year mathematics held in a technology-enhanced lecture theatre can be highly interactive with students solving problems, learning from each other and receiving immediate feedback. This is facilitated by pen-enabled screens and synchronization software. We argue that the educational benefits achievable through the technology do outweigh the technological distractions, and that these benefits can be achieved by focused, targeted one-off sessions and not only by a semester-long, regular approach. Repeat mid-semester test revision sessions were offered on a non-compulsory basis using pen-enabled screens for all students. Students worked practice test questions and marked solutions to mathematical problems on the screens. Students' work was then displayed anonymously for their peers to see. Answers were discussed with the whole class. We discuss outcomes from two offerings of these sessions using student feedback and lecturer reflections and show the impact of participation on self-reported student confidence. Pedagogical approaches that the technology allowed for the first time in a large class are highlighted. Students responded uniformly positively.

  7. The role of the iPad in collaborative learning in a large-enrollment first-year physics module

    NASA Astrophysics Data System (ADS)

    van der Ventel, Brandon; Newman, Richard; Botes, Lise; Goldberg, Alan

    2016-07-01

    The role of the iPad was investigated in the possible enhancement of collaborative learning within a tutorial setting in a large-enrollment first-year physics module. Every tutorial session was divided into an ‘iPad group’ and a ‘non-iPad group’. A set of core apps was chosen to facilitate discussion within the group. In order to maintain parity across the two groups, all the tutorial questions had to be refitted into a form suitable for use with the iPad. The results of a survey done after each tutorial indicates that, qualitatively, the iPad significantly enhanced the learning experience and strongly contributed to discussion within the group.

  8. Searches for Axionlike Particles with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Albert, Andrea; Meyer, Manuel; Sanchez-Conde, Miguel; Wood, Matthew; LAT Collaboration

    2017-01-01

    Axionlike particles (ALPs) are dark-matter candidates that occur in a variety of extensions of the Standard Model. These particles could leave signatures in gamma rays, due to the coupling of ALPs to photons in external electromagnetic fields. To date, observations with Fermi Large Area Telescope (LAT) provide the strongest constraints on the photon-ALP coupling for ALP masses between 0.5 and 20 neV. Here, we summarize these constraints and present the sensitivity to detect an ALP induced gamma-ray burst from a Galactic core-collapse supernova. ALPs would be produced in the stellar medium via the Primakoff effect and convert into gamma rays in the Galactic magnetic field. Fermi LAT observations would be able to probe couplings where ALPs could constitute the entirety of dark matter. Below 1 neV, the Fermi-LAT sensitivity would surpass that of future laboratory experiments by one order of magnitude.

  9. The Fermi Large Area Telescope on Orbit: Event Classification, Instrument Response Functions, and Calibration

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Celik, Q.; Cobet, R.; Davis, D. S.; Ferrara, E. C.; Gehrels, N.; Guiriec, S.; McConville, W.; McEnery, J. E.; Nemmen, R.; Perkins, J. S.; Thompson, D. J.

    2012-01-01

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy -ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the Instrument Response Functions (IRFs), the description of the instrument performance provided for data analysis. In this paper we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  10. THE FERMI LARGE AREA TELESCOPE ON ORBIT: EVENT CLASSIFICATION, INSTRUMENT RESPONSE FUNCTIONS, AND CALIBRATION

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Borgland, A. W.; Bottacini, E.; Albert, A.; Atwood, W. B.; Bouvier, A.; Axelsson, M.; Baldini, L.; Ballet, J.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonamente, E. E-mail: luca.baldini@pi.infn.it; and others

    2012-11-15

    The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy {gamma}-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission, the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the instrument response functions (IRFs), the description of the instrument performance provided for data analysis. In this paper, we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

  11. High Energy Astrophysics with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    This slide presentation reviews some of the findings of the Large Area Telescope (LAT) aboard the Fermi Observatory. It includes information about the LAT, and the Gamma-Ray Burst Monitor (GBM), detection of the quiet sun and the moon in gamma rays, Pulsars observed by the observatory, Globular Star Clusters, Active Galactic Nucleus, and Gamma-Ray Bursts, with specific information about GRB 080916C.

  12. Dark Matter Searches with the Fermi Large Area Telescope

    SciTech Connect

    Meurer, Christine

    2008-12-24

    The Fermi Gamma-Ray Space Telescope, successfully launched on June 11th, 2008, is the next generation satellite experiment for high-energy gamma-ray astronomy. The main instrument, the Fermi Large Area Telescope (LAT), with a wide field of view (>2 sr), a large effective area (>8000 cm{sup 2} at 1 GeV), sub-arcminute source localization, a large energy range (20 MeV-300 GeV) and a good energy resolution (close to 8% at 1 GeV), has excellent potential to either discover or to constrain a Dark Matter signal. The Fermi LAT team pursues complementary searches for signatures of particle Dark Matter in different search regions such as the galactic center, galactic satellites and subhalos, the milky way halo, extragalactic regions as well as the search for spectral lines. In these proceedings we examine the potential of the LAT to detect gamma-rays coming from Weakly Interacting Massive Particle annihilations in these regions with special focus on the galactic center region.

  13. Fermi Large Area Telescope as a Galactic Supernovae Axionscope.

    PubMed

    Meyer, M; Giannotti, M; Mirizzi, A; Conrad, J; Sánchez-Conde, M A

    2017-01-06

    In a Galactic core-collapse supernova (SN), axionlike particles (ALPs) could be emitted via the Primakoff process and eventually convert into γ rays in the magnetic field of the Milky Way. From a data-driven sensitivity estimate, we find that, for a SN exploding in our Galaxy, the Fermi Large Area Telescope (LAT) would be able to explore the photon-ALP coupling down to g_{aγ}≃2×10^{-13}  GeV^{-1} for an ALP mass m_{a}≲10^{-9}  eV. These values are out of reach of next generation laboratory experiments. In this event, the Fermi LAT would probe large regions of the ALP parameter space invoked to explain the anomalous transparency of the Universe to γ rays, stellar cooling anomalies, and cold dark matter. If no γ-ray emission were to be detected, Fermi-LAT observations would improve current bounds derived from SN 1987A by more than 1 order of magnitude.

  14. Fermi Large Area Telescope as a Galactic Supernovae Axionscope

    NASA Astrophysics Data System (ADS)

    Meyer, M.; Giannotti, M.; Mirizzi, A.; Conrad, J.; Sánchez-Conde, M. A.

    2017-01-01

    In a Galactic core-collapse supernova (SN), axionlike particles (ALPs) could be emitted via the Primakoff process and eventually convert into γ rays in the magnetic field of the Milky Way. From a data-driven sensitivity estimate, we find that, for a SN exploding in our Galaxy, the Fermi Large Area Telescope (LAT) would be able to explore the photon-ALP coupling down to ga γ≃2 ×10-13 GeV-1 for an ALP mass ma≲10-9 eV . These values are out of reach of next generation laboratory experiments. In this event, the Fermi LAT would probe large regions of the ALP parameter space invoked to explain the anomalous transparency of the Universe to γ rays, stellar cooling anomalies, and cold dark matter. If no γ -ray emission were to be detected, Fermi-LAT observations would improve current bounds derived from SN 1987A by more than 1 order of magnitude.

  15. The Second Fermi Large Area Telescope GRB Catalog

    NASA Astrophysics Data System (ADS)

    Kocevski, Daniel; Fermi Large Area Telescope Collaboration

    2017-01-01

    The high-energy emission from gamma-ray bursts (GRBs) is a formidable probe of extreme physics, requiring rapid variability from highly relativistic sources. Despite the advancements in our understanding of GRBs through observations by NASA's Swift and Fermi spacecraft, many fundemental questions regarding the particle acceleration and radiative processes associated with these events remain unanswered. Here we present the most extensive search for emission from GRBs above 40 MeV performed by the Fermi Large Area Telescope (LAT). The resulting catalog includes more than 130 detections and represents an improvement in the detection efficency of GRBs at high-energies of over 50% compared to the first LAT GRB catalog. We utilize this improved sensativity to characterize the high-energy emission from GRBs and review how these observations further our understanding of the nature of these events.

  16. The Personal Response: A Novel Writing Assignment to Engage First Year Students in Large Human Biology Classes

    ERIC Educational Resources Information Center

    Moni, Roger W.; Moni, Karen B.; Poronnik, Philip

    2007-01-01

    The teaching of highly valued scientific writing skills in the first year of university is challenging. This report describes the design, implementation, and evaluation of a novel written assignment, "The Personal Response" and accompanying Peer Review, in the course, Human Biology (BIOL1015) at The University of Queensland. These assignments were…

  17. The personal response: A novel writing assignment to engage first year students in large human biology classes.

    PubMed

    Moni, Roger W; Moni, Karen B; Lluka, Lesley J; Poronnik, Philip

    2007-03-01

    The teaching of highly valued scientific writing skills in the first year of university is challenging. This report describes the design, implementation, and evaluation of a novel written assignment, The Personal Response and accompanying Peer Review, in the course, Human Biology (BIOL1015) at The University of Queensland. These assignments were the first assessment tasks of the course and were set early in the first semester of university. BIOL1015 had a diverse cohort of 319 first year students from five bachelor degree programs, primarily from Pharmacy and Human Movement Studies. Audio files in the form of interviews with eminent biomedical scientists were obtained from a leading public radio program. Students used these files as triggers to submit a short but highly structured assignment written from a personal perspective and in an expressive style. Evaluations revealed that overall, students found the task interesting and challenging. Students performed well, regardless of their background knowledge, disciplinary interest, or preference for topics within human biology. This study demonstrated that The Personal Response was an appropriate task for these first year students of human biology. It represents an alternative to traditional essay writing.

  18. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE VELA PULSAR

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Bartelt, J.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Atwood, W. B.; Bagagli, R.; Baldini, L.; Bellardi, F.; Bellazzini, R.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bisello, D.; Baughman, B. M. E-mail: massimiliano.razzano@pi.infn.it

    2009-05-10

    The Vela pulsar is the brightest persistent source in the GeV sky and thus is the traditional first target for new {gamma}-ray observatories. We report here on initial Fermi Large Area Telescope observations during verification phase pointed exposure and early sky survey scanning. We have used the Vela signal to verify Fermi timing and angular resolution. The high-quality pulse profile, with some 32,400 pulsed photons at E {>=} 0.03 GeV, shows new features, including pulse structure as fine as 0.3 ms and a distinct third peak, which shifts in phase with energy. We examine the high-energy behavior of the pulsed emission; initial spectra suggest a phase-averaged power-law index of {gamma} = 1.51{sup +0.05} {sub -0.04} with an exponential cutoff at E{sub c} = 2.9 {+-} 0.1 GeV. Spectral fits with generalized cutoffs of the form e{sup -(E/E{sub c}){sup b}} require b {<=} 1, which is inconsistent with magnetic pair attenuation, and thus favor outer-magnetosphere emission models. Finally, we report on upper limits to any unpulsed component, as might be associated with a surrounding pulsar wind nebula.

  19. Large and Small Scale Nitrogen and Phosporous Manipulation Experiment in a Tree-Grass Ecosystem: first year of results

    NASA Astrophysics Data System (ADS)

    Migliavacca, Mirco; Perez Priego, Oscar; El-Madany, Tarek; Guan, JinHong; Carrara, Arnaud; Fava, Francesco; Moreno, Gerardo; Kolle, Olaf; Rossini, Micol; Schrumpf, Marion; Julitta, Tommaso; Reichstein, Markus

    2015-04-01

    Recent studies have shown how human induced N/P imbalances affect essential ecosystem processes (e.g. photosynthesis, plant growth rate, respiration), and might be particularly important in water-limited ecosystems. In this contribution we will present the experimental design and the results of the first year of two nutrient manipulation experiments conducted at different spatial scale. In the first experiment a cluster of 2 eddy covariance (EC) flux towers has been set up beside a long-term EC site (Las Majadas del Tietar, Spain). Sites are selected in a way to have similar nutrient conditions, canopy structure, and stoichiometry of the different vegetation and soil pools. Two of the three footprints will be manipulated with addition of N and NP fertilizer at the beginning of 2015. The comparison of the three EC flux towers installed during the first year of the experiment (without fertilization) will be shown. We characterized the differences of the responses of carbon and water fluxes measured by the EC systems to environmental drivers, and structural and biophysical properties of the canopy. The second experiment was conducted over a Mediterranean grassland, where 16 plots of 10x10 meters that were manipulated by adding nutrient (N, P, and NP). The overall objective was to investigate the response of the gross primary productivity (GPP), assessed by using transparent transient-state canopy chambers, to different nutrient availability. The second objective was to evaluate the capability of hyperspectral data and Solar induced fluorescence to track short- and long-term GPP and light use efficiency variation under different N and P fertilization treatments. Spectral vegetation indices (VIs) were acquired manually using high resolution spectrometers (HR4000, OceanOptics, USA) along a phenological cycle. The VIs used included photochemical reflectance index (PRI), MERIS terrestrial-chlorophyll index (MTCI) and normalized difference vegetation index (NDVI). Solar

  20. Performance of first-year health sciences students in a large, diverse, multidisciplinary, first-semester, physiology service module.

    PubMed

    Higgins-Opitz, Susan B; Tufts, Mark

    2014-06-01

    Health Science students at the University of KwaZulu-Natal perform better in their professional modules compared with their physiology modules. The pass rates of physiology service modules have steadily declined over the years. While a system is in place to identify "at-risk" students, it is only activated after the first semester. As a result, it is only from the second semester of their first year studies onward that at-risk students can be formally assisted. The challenge is thus to devise an appropriate strategy to identify struggling students earlier in the semester. Using questionnaires, students were asked about attendance, financing of their studies, and relevance of physiology. After the first class test, failing students were invited to complete a second questionnaire. In addition, demographic data were also collected and analyzed. Correlation analyses were undertaken of performance indicators based on the demographical data collected. The 2011 class comprised mainly sport science students (57%). The pass rate of sport science students was lower than the pass rates of other students (42% vs. 70%, P < 0.001). Most students were positive about physiology and recognized its relevance. Key issues identified were problems understanding concepts and terminology, poor study environment and skills, and lack of matriculation biology. The results of the first class test and final module marks correlated well. It is clear from this study that student performance in the first class test is a valuable tool to identify struggling students and that appropriate testing should be held as early as possible.

  1. Putting the S(ensational) Back into Sociology--Developing Strategies for Enhancing Teaching and Learning for First Year Student Teachers in Large Classes

    ERIC Educational Resources Information Center

    Daniell, Linda; Hogan, Vivienne

    2012-01-01

    The focus of the research was to develop a model for effective learning and teaching of sociology in a large class to promote active engagement with first year undergraduate student teachers and encourage deep learning. By seeking regular feedback from students and recording their own reflections on each lecture, the teaching team and…

  2. A Large, First-Year, Introductory, Multi-Sectional Biological Concepts of Health Course Designed to Develop Skills and Enhance Deeper Learning

    ERIC Educational Resources Information Center

    Murrant, Coral L.; Dyck, David J.; Kirkland, James B.; Newton, Genevieve S.; Ritchie, Kerry L.; Tishinsky, Justine M.; Bettger, William J.; Richardson, Nicolette S.

    2015-01-01

    Large first-year biology classes, with their heavy emphasis on factual content, contribute to low student engagement and misrepresent the dynamic, interdisciplinary nature of biological science. We sought to redesign a course to deliver fundamental biology curriculum through the study of health, promote skills development, and encourage a deeper…

  3. SENSITIVITY OF BLIND PULSAR SEARCHES WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Dormody, M.; Johnson, R. P.; Atwood, W. B.; Belfiore, A.; Razzano, M.; Saz Parkinson, P. M.; Grenier, I. A.

    2011-12-01

    We quantitatively establish the sensitivity to the detection of young to middle-aged, isolated, gamma-ray pulsars through blind searches of Fermi Large Area Telescope (LAT) data using a Monte Carlo simulation. We detail a sensitivity study of the time-differencing blind search code used to discover gamma-ray pulsars in the first year of observations. We simulate 10,000 pulsars across a broad parameter space and distribute them across the sky. We replicate the analysis in the Fermi LAT First Source Catalog to localize the sources, and the blind search analysis to find the pulsars. We analyze the results and discuss the effect of positional error and spin frequency on gamma-ray pulsar detections. Finally, we construct a formula to determine the sensitivity of the blind search and present a sensitivity map assuming a standard set of pulsar parameters. The results of this study can be applied to population studies and are useful in characterizing unidentified LAT sources.

  4. FERMI LARGE AREA TELESCOPE DETECTION OF SUPERNOVA REMNANT RCW 86

    SciTech Connect

    Yuan, Qiang; Huang, Xiaoyuan; Liu, Siming; Zhang, Bing

    2014-04-20

    Using 5.4 yr Fermi Large Area Telescope data, we report the detection of GeV γ-ray emission from the shell-type supernova remnant RCW 86 (G315.4-2.3) with a significance of ∼5.1σ. The data slightly favors an extended emission of this supernova remnant. The spectral index of RCW 86 is found to be very hard, Γ ∼ 1.4, in the 0.4-300 GeV range. A one-zone leptonic model can well fit the multi-wavelength data from radio to very high energy γ-rays. The very hard GeV γ-ray spectrum and the inferred low gas density seem to disfavor a hadronic origin for the γ-rays. The γ-ray behavior of RCW 86 is very similar to several other TeV shell-type supernova remnants, e.g., RX J1713.7-3946, RX J0852.0-4622, SN 1006, and HESS J1731-347.

  5. Automated Science Processing for the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Chiang, James

    2012-03-01

    The Large Area Telescope (LAT) onboard the Fermi γ-ray Space Telescope provides high sensitivity to emission from astronomical sources over a broad energy range (20MeV to >300 GeV) and has substantially improved spatial, energy, and timing resolution compared with previous observatories at these energies [4]. One of the LAT's most innovative features is that it performs continuous monitoring of the gamma-ray sky with all-sky coverage every 3 h. This survey strategy greatly enables the search for transient behavior from both previously known and unknown sources. In addition, the constant accumulation of data allows for increasingly improved measurements of persistent sources. These include the Milky Way Galaxy itself, which produces gamma-ray emission as a result from interactions of cosmic rays with gas in the Galaxy, and potential signals from candidate dark matter particles in the Milky Way and its neighboring galaxies. The automated science processing (ASP) functionality of the Fermi Instrument Science Operations Center (ISOC) is a part of the automated data pipeline that processes the raw data arriving from the spacecraft and puts it into a form amenable to scientific analysis. ASP operates at the end of the pipeline on the processed data and is intended to detect and characterize transient behavior (e.g., short time scale increases or “flares” in the gamma-ray flux) from astronomical sources. On detection of a flaring event, ASP will alert other observatories on a timely basis so that they may train their telescopes on the flaring source in order to detect possible correlated activity in other wavelength bands. Since the data from the LAT is archived and publicly available as soon as it is processed, ASP serves mainly to provide triggers for those follow-up observations; its estimates of the properties of the flaring sources (flux, spectral index, location) need not be the best possible, as subsequent off-line analysis can provide more refined

  6. Fermi: The Gamma-Ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  7. Fermi: The Gamma-Ray Large Area Telescope

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2015-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  8. Fermi: The Gamma-Ray Large Area Telescope

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10 seconds of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  9. Fermi: The Gamma-Ray Large Area Telescope Mission Status

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  10. A Characterization of Areas of Racial Tension among First Year Students: A Focus Group Follow-Up to a Large Survey.

    ERIC Educational Resources Information Center

    Grayson, J. Paul

    This study examined areas of racial tension and racial attitudes among first-year students at York University in Ontario (Canada). A survey of 1,129 first-year students in 1993-94 indicated that the vast majority believed that visible minority students had been treated equally by professors, staff, and other students. However, the first year was…

  11. The Fermi Large Area Telescope Flare Advocate Program: Rapid Sharing of Results with the Community

    NASA Astrophysics Data System (ADS)

    Thompson, David John; Ciprini, Stefano; Gasparrini, Dario; Fermi Large Area Telescope Collaboration

    2015-01-01

    The Fermi Flare Advocate (also known as Gamma-ray Sky Watcher) program provides a quick look and review of the gamma-ray sky observed daily by the Fermi Large Area Telescope (LAT) through on-duty LAT Flare Advocates and high-level software pipelines like the LAT Automatic Science Processing and the Fermi All-sky Variability Analysis. The FA-GSW service provides rapid alerts and communicates to the external scientific community potentially new gamma-ray sources, interesting transients and flares. News items are regularly posted through the Fermi multiwavelength mailing list, Astronomer's Telegrams and Gamma-ray Coordinates Network notices. A weekly digest containing the highlights about the variable LAT gamma-ray sky at E>100 MeV is published on the web ("Fermi Sky Blog"). From July 2008 to September 2014 more than 290 ATels and 90 GCNs have been published by the Fermi LAT Collaboration. Target of opportunity observing programs with other satellites and telescopes have been triggered by Flare Advocates based on gamma-ray flares from blazars and other kinds of sources.

  12. REFINING THE ASSOCIATIONS OF THE FERMI LARGE AREA TELESCOPE SOURCE CATALOGS

    SciTech Connect

    Massaro, F.; D’Abrusco, R.; Paggi, A.; Smith, Howard A.; Landoni, M.; Masetti, N.; Giroletti, M.; Otí-Floranes, H.; Jiménez-Bailón, E.; Chavushyan, V.; Patiño-Álvarez, V.; Digel, S. W.; Tosti, G.

    2015-03-15

    The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL) was released in 2010 February and the Fermi-LAT 2-Year Source Catalog (2FGL) appeared in 2012 April, based on data from 24 months of operation. Since they were released, many follow up observations of unidentified γ-ray sources have been performed and new procedures for associating γ-ray sources with potential counterparts at other wavelengths have been developed. Here we review and characterize all of the associations as published in the 1FGL and 2FGL catalogs on the basis of multifrequency archival observations. In particular, we located 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition we present new spectroscopic observations of eight γ-ray blazar candidates. Based on our investigations, we introduce a new counterpart category of “candidate associations” and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. We compare the 1FGL-assigned counterparts with those listed in 2FGL to determine which unassociated sources became associated in later releases of the Fermi catalogs. We also search for potential counterparts to all of the remaining unassociated Fermi sources. Finally, we prepare a refined and merged list of all of the associations of 1FGL plus 2FGL that includes 2219 unique Fermi objects. This is the most comprehensive and systematic study of all the associations collected for the γ-ray sources available to date. We conclude that 80% of the Fermi sources have at least one known plausible γ-ray emitter within their positional uncertainty regions.

  13. The VELA-X-Pulsar Wind Nebula Revisited with Four Years of Fermi Large Area Telescope Observations

    NASA Technical Reports Server (NTRS)

    Grondin, M. -H.; Romani, R. W.; Lemoine-Goumard, M.; Guillemot, L.; Harding, Alice K.; Reposeur, T.

    2013-01-01

    The Vela supernova remnant (SNR) is the closest SNR to Earth containing an active pulsar, the Vela pulsar (PSR B0833-45). This pulsar is an archetype of the middle-aged pulsar class and powers a bright pulsar wind nebula (PWN), Vela-X, spanning a region of 2deg × 3deg south of the pulsar and observed in the radio, X-ray, and very high energy ?-ray domains. The detection of the Vela-X PWN by the Fermi Large Area Telescope (LAT) was reported in the first year of the mission. Subsequently, we have reinvestigated this complex region and performed a detailed morphological and spectral analysis of this source using 4 yr of Fermi-LAT observations. This study lowers the threshold for morphological analysis of the nebula from 0.8 GeV to 0.3 GeV, allowing for the inspection of distinct energy bands by the LAT for the first time. We describe the recent results obtained on this PWN and discuss the origin of the newly detected spatial features.

  14. THE VELA-X PULSAR WIND NEBULA REVISITED WITH FOUR YEARS OF FERMI LARGE AREA TELESCOPE OBSERVATIONS

    SciTech Connect

    Grondin, M.-H.; Romani, R. W.; Lemoine-Goumard, M.; Reposeur, T.; Harding, A. K.

    2013-09-10

    The Vela supernova remnant (SNR) is the closest SNR to Earth containing an active pulsar, the Vela pulsar (PSR B0833-45). This pulsar is an archetype of the middle-aged pulsar class and powers a bright pulsar wind nebula (PWN), Vela-X, spanning a region of 2 Degree-Sign Multiplication-Sign 3 Degree-Sign south of the pulsar and observed in the radio, X-ray, and very high energy {gamma}-ray domains. The detection of the Vela-X PWN by the Fermi Large Area Telescope (LAT) was reported in the first year of the mission. Subsequently, we have reinvestigated this complex region and performed a detailed morphological and spectral analysis of this source using 4 yr of Fermi-LAT observations. This study lowers the threshold for morphological analysis of the nebula from 0.8 GeV to 0.3 GeV, allowing for the inspection of distinct energy bands by the LAT for the first time. We describe the recent results obtained on this PWN and discuss the origin of the newly detected spatial features.

  15. Indirect searches for dark matter with the Fermi large area telescope

    DOE PAGES

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce γ rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for γ-ray spectral lines and γ-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  16. Indirect searches for dark matter with the Fermi large area telescope

    SciTech Connect

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce γ rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for γ-ray spectral lines and γ-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  17. Active Learning in a Large First Year Biology Class: A Collaborative Resource-Based Study Project on "AIDS in Science and Society".

    ERIC Educational Resources Information Center

    Sutcliffe, Roger G.; Cogdell, Barbara; Hansell, Mike H.; McAteer, Erica

    1999-01-01

    Describes a student-directed learning program called "AIDS in Science and Society" that was developed as a resource-based, collaborative project at the University of Glasgow (United Kingdom) for a first-year biology class. Discusses materials, written assignments, oral presentations, and feedback from students and faculty, and includes a…

  18. Recent Results on SNRs and PWNe from the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2010-01-01

    Topics include: Fermi LAT Collaboration groups; galactic results from LAT; a GeV, wide-field instrument; the 1FGL catalog, the Fermi LAT 1FGL source catalog, unidentified gamma-ray sources; variability in 1FGL sources; curvature in 1FGL sources; spectral-variability classification; pulsars and their wind nebulae; gamma-ray pulsars and MSPs; GeV PWN search; Crab pulsar and nebula; Vela X nebular of Vela pulsar; MSH 15-52; supernova remnants, resolved GeV sources, galactic transients, LAT unassociated transient detections; gamma rays from a nova; V407 Cyngi - a symbiotic nova; V407 Cygni: a variable star; and March 11 - a nova. Summary slides include pulsars everywhere, blazars, LAT as an electron detector, cosmic ray spectrum, the Large Area Telescope, the Fermi Observatory, LAT sensitivity with time, candidate gamma-ray events, on-orbit energy calibration and rate, a 1 year sky map, LAT automated science processing, reported GeV flares, early activity and spectacular flare, gamma-ray transients near the galactic plane , two early unassociated transients, counter part search - Fermi J0910-5404; counterpart search 3EG J0903-3531, and a new LAT transient - J1057-6027.

  19. Fermi Large Area Telescope observations of high-energy gamma-ray emission from Solar flares

    NASA Astrophysics Data System (ADS)

    Pesce Rollins, Melissa

    2017-01-01

    The Fermi Large Area Telescope (LAT) observations of the active Sun provide the largest sample of detected solar flares with emission greater than 30 MeV to date. These include detections of impulsive and sustained emission, extending up to 20 hours in the case of the 2012 March 7 X-class flares. These high-energy flares are coincident with GOES X-ray flares of X, M and C classes as well as very fast Coronal Mass Ejections (CME). We will present results from the First Fermi-LAT solar flare catalog covering the majority of Solar Cycle 24 including correlation studies with the associated Solar Energetic Particles (SEP) and CMEs.

  20. Recent Results on SNRs and PWNe from the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth A.

    2010-01-01

    Topics include: Fermi LAT Collaboration groups; galactic results from LAT; a GeV, wide-field instrument; the 1FGL catalog, the Fermi LAT 1FGL source catalog, unidentified gamma-ray sources; variability in 1FGL sources; curvature in 1FGL sources; spectral-variability classification; gamma-ray pulsars and MSPs; GeV PWN - where to look; Crab pulsar and nebula; Vela X nebular of Vela pulsar; MSH 15-52; GeV PWNe spectra; GeV nebula limits; Nebula search of LAT pulsars; supernova remnants; SNR: GeV morphology; SNR: molecular connection; SNR: GeV breaks; SNR: young vs. old. The summary includes slides about the Large Area Telescope (LAT) and LAT sensitivity with time.

  1. NASA Goddard Space Flight Center, on Behalf of the Fermi Large Area Telescope Collaboration

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2010-01-01

    Because high-energy gamma rays can be produced by processes that also produce neutrinos, the gamma-ray survey of the sky by the Fermi (Gamma-ray Space Telescope offers a view of potential targets for neutrino observations. Gamma-ray bursts. Active Galactic Nuclei, and supernova remnants are all sites where hadronic, neutrino-producing interactions are plausible. Pulsars, pulsar wind nebulae, and binary sources are all phenomena that reveal leptonic particle acceleration through their gamma-ray emission. While important to gamma-ray astrophysics, such sources are of less interest to neutrino studies. This talk will present a broad overview of the constantly changing sky seen with the Large Area Telescope (LAT)on the Fermi spacecraft.

  2. Fermi Large Area Telescope Observations of the Dark Accelerator HESS J1745-303

    NASA Astrophysics Data System (ADS)

    Yeung, Paul

    2016-12-01

    Reviewing the two MeV-GeV investigations in the field of the HESS J1745-303 performed using Fermi Large Area Telescope data, we confirmed that the emission peak comfortably coincides with ‘Region A’ in the TeV regime, which is the brightest part of this feature. The MeV–TeV spectrum can be precisely described by a single power-law. Also, recent investigation has shown that the MeV-GeV feature is elongated from ‘Region A’ toward the north-west, which is similar to the case of large- scale atomic/molecular gas distribution.

  3. International Student Adaptation to a U.S. College: A Mixed Methods Exploration of the Impact of a Specialized First-Year Foundations Course at a Large Midwestern Institution

    ERIC Educational Resources Information Center

    Kovtun, Olena

    2010-01-01

    The present study assessed the effects of a specialized first-year foundations course as an intervention for international students' academic and cultural adaptation at a large, Midwestern, public research institution (very high research activity). This was a quasi-experimental, mixed methods study, consisting of two quantitative and two…

  4. The First Year and Beyond.

    ERIC Educational Resources Information Center

    Schroeder, Charles

    2003-01-01

    John Gardner reflects on everything from current efforts to improve the first-year experience to the assessment movement, student expectations of college, professional preparation for student affairs, and more. (Author)

  5. The Radio/Gamma-Ray Connection in Active Galactic Nuclei in the Era of the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Angelakis, E.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Gehrels, N.; Hays, E.; MeEnery, J. E.; Scargle, J. D.; Thompson, D. J.

    2011-01-01

    We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose.We use both archival interferometric 8.4 GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz measurements from the OwensValley RadioObservatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities. We find that the statistical significance of a positive correlation between the centimeter radio and the broadband (E > 100 MeV) gamma-ray energy flux is very high for the whole AGN sample, with a probability of <10(exp -7) for the correlation appearing by chance. Using the OVRO data, we find that concurrent data improve the significance of the correlation from 1.6 10(exp -6) to 9.0 10(exp -8). Our large sample size allows us to study the dependence of correlation strength and significance on specific source types and gamma-ray energy band. We find that the correlation is very significant (chance probability < 10(exp -7)) for both flat spectrum radio quasars and BL Lac objects separately; a dependence of the correlation strength on the considered gamma-ray energy band is also present, but additional data will be necessary to constrain its significance.

  6. Coordinate-Space Hartree-Fock-Bogoliubov Solvers for Superfluid Fermi Systems in Large Boxes

    SciTech Connect

    Pei, J. C.; Fann, George I; Harrison, Robert J; Nazarewicz, W.; Hill, Judith C; Galindo, Diego A; Jia, Jun

    2012-01-01

    The self-consistent Hartree-Fock-Bogoliubov problem in large boxes can be solved accurately in the coordinate space with the recently developed solvers HFB-AX (2D) and MADNESS-HFB (3D). This is essential for the description of superfluid Fermi systems with complicated topologies and significant spatial extend, such as fissioning nuclei, weakly-bound nuclei, nuclear matter in the neutron star rust, and ultracold Fermi atoms in elongated traps. The HFB-AX solver based on B-spline techniques uses a hybrid MPI and OpenMP programming model for parallel computation for distributed parallel computation, within a node multi-threaded LAPACK and BLAS libraries are used to further enable parallel calculations of large eigensystems. The MADNESS-HFB solver uses a novel multi-resolution analysis based adaptive pseudo-spectral techniques to enable fully parallel 3D calculations of very large systems. In this work we present benchmark results for HFB-AX and MADNESS-HFB on ultracold trapped fermions.

  7. Large-momentum distribution of a polarized Fermi gas and p -wave contacts

    NASA Astrophysics Data System (ADS)

    Peng, Shi-Guo; Liu, Xia-Ji; Hu, Hui

    2016-12-01

    We present a derivation of the adiabatic energy relations as well as the large momentum distribution of a polarized Fermi gas near p -wave Feshbach resonances. The leading asymptotic behavior k-2 and subleading behavior k-4 of the large momentum distribution have recently been predicted by Z. Yu et al. [Phys. Rev. Lett. 115, 135304 (2015), 10.1103/PhysRevLett.115.135304] and by M. Y. He et al. [Phys. Rev. Lett. 116, 045301 (2016), 10.1103/PhysRevLett.116.045301] using two different approaches. Here, we show that the subleading asymptotic behavior (˜k-4 ) cannot fully be captured by the contact defined from the adiabatic energy relation related to the p -wave effective range, and there should be an extra term resulting from the center-of-mass motion of the pairs. The omission of this extra term is perhaps a reasonable approximation at zero temperature. However, it should be taken into account at finite temperature and should have significant importance to understand the recently measured momentum distribution in a resonant p -wave Fermi gas of ultracold 40K atoms [C. Luciuk et al., Nat. Phys. 12, 599 (2016), 10.1038/nphys3670].

  8. The second fermi large area telescope catalog of gamma-ray pulsars

    SciTech Connect

    Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

    2013-09-19

    This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  9. Observing two dark accelerators around the Galactic Centre with Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Hui, C. Y.; Yeung, P. K. H.; Ng, C. W.; Lin, L. C. C.; Tam, P. H. T.; Cheng, K. S.; Kong, A. K. H.; Chernyshov, D. O.; Dogiel, V. A.

    2016-04-01

    We report the results from a detailed γ-ray investigation in the field of two `dark accelerators', HESS J1745-303 and HESS J1741-302, with 6.9 yr of data obtained by the Fermi Large Area Telescope. For HESS J1745-303, we found that its MeV-GeV emission is mainly originated from the `Region A' of the TeV feature. Its γ-ray spectrum can be modelled with a single power law with a photon index of Γ ˜ 2.5 from few hundreds MeV-TeV. Moreover, an elongated feature, which extends from `Region A' towards north-west for ˜1.3°, is discovered for the first time. The orientation of this feature is similar to that of a large-scale atomic/molecular gas distribution. For HESS J1741-302, our analysis does not yield any MeV-GeV counterpart for this unidentified TeV source. On the other hand, we have detected a new point source, Fermi J1740.1-3013, serendipitously. Its spectrum is apparently curved which resembles that of a γ-ray pulsar. This makes it possibly associated with PSR B1737-20 or PSR J1739-3023.

  10. The Second Fermi Large Area Telescope Catalog of Gamma-Ray Pulsars

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

    2013-10-01

    This catalog summarizes 117 high-confidence >=0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  11. THE SECOND FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS

    SciTech Connect

    Abdo, A. A.; Ajello, M.; Allafort, A.; Bloom, E. D.; Bottacini, E.; Baldini, L.; Ballet, J.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bregeon, J.; Bhattacharyya, B.; Bissaldi, E.; Bonamente, E.; Brandt, T. J.; Brigida, M.; and others

    2013-10-01

    This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  12. The second FERMI large area telescope catalog of gamma-ray pulsars

    SciTech Connect

    Abdo, A. A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T. H.; Busetto, G.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Camilo, F.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R. C. G.; Chekhtman, A.; Chen, A. W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; DeCesar, M. E.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Desvignes, G.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C. M.; Falletti, L.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Freire, P. C. C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E. V.; Grenier, I. A.; Grondin, M. -H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Jackson, M. S.; Janssen, G. H.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knödlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Lyne, A. G.; Manchester, R. N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; McLaughlin, M. A.; Mehault, J.; Michelson, P. F.; Mignani, R. P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H. J.; Porter, T. A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S. M.; Ray, P. S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R. W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P. M.; Scargle, J. D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stappers, B. W.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Theureau, G.; Thompson, D. J.; Thorsett, S. E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B. L.; Wolff, M. T.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.

    2013-09-19

    This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.

  13. On the Fermi Large Area Telescope Surplus of Diffuse Galactic Gamma-Ray Emission

    NASA Astrophysics Data System (ADS)

    Völk, H. J.; Berezhko, E. G.

    2013-11-01

    Recent observations of diffuse Galactic γ-ray emission (DGE) by the Fermi Large Area Telescope (Fermi-LAT) have shown significant deviations, above a few GeV to about 100 GeV, from DGE models that use the GALPROP code for the propagation of cosmic ray (CR) particles outside their sources in the Galaxy and their interaction with the target distributions of the interstellar gas and radiation fields. The surplus of radiation observed is most pronounced in the inner Galaxy, where the concentration of CR sources is strongest. The present study investigates this "Fermi-LAT Galactic Plane Surplus" by estimating the γ-ray emission from the sources themselves, which is disregarded in the above DGE models. It is shown that the expected hard spectrum of CRs, still confined in their sources (source cosmic rays, SCRs), can indeed explain this surplus. The method is based on earlier studies regarding the so-called EGRET GeV excess, which by now is generally interpreted as an instrumental effect. The contribution from SCRs is also predicted to increasingly exceed the DGE models above 100 GeV, up to γ-ray energies of about 10 TeV, where the corresponding surplus exceeds the hadronic part of the DGE by about one order of magnitude. Above such energies, the emission surplus should decrease again with energy due to the finite lifetime of the assumed supernova remnant sources. Observations of the DGE in the inner Galaxy at 15 TeV with the ground-based Milagro γ-ray detector and, at TeV energies, with the ARGO-YBJ detector are interpreted to provide confirmation of a significant SCR contribution to the DGE.

  14. Measurement of the cosmic-ray proton spectrum with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Green, David; Fermi LAT Area Telescope Collaboration Collaboration

    2017-01-01

    We present the measurement of the cosmic-ray proton spectrum between 54 GeV and 9.5 TeV using 7 years of Pass 8 flight data from the Fermi Large Area Telescope (LAT). We developed a dedicated proton event selection with an acceptance of 0.25 m2 sr. Our analysis yields a large dataset with low statistical uncertainty and low residual contamination for a spectral measurement. The systematic errors associated with the acceptance, energy measurement, GEANT4 Monte-Carlo simulations are an order of magnitude larger than the statistical uncertainty. The event selection and spectral measurement of the proton analysis create the opportunity for additional proton analyses with the LAT, such as a dedicated proton anisotropy search.

  15. FERMI LARGE AREA TELESCOPE CONSTRAINTS ON THE GAMMA-RAY OPACITY OF THE UNIVERSE

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Atwood, W. B.; Baldini, L.; Bellazzini, R.; Ballet, J.; Baring, M. G.; Bastieri, D.; Baughman, B. M.; Bhat, P. N.; Bonamente, E. E-mail: bouvier@stanford.ed E-mail: silvia.raino@ba.infn.i E-mail: lreyes@kicp.uchicago.ed

    2010-11-10

    The extragalactic background light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above {approx}10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the {gamma}-ray flux of extragalactic sources such as blazars and gamma-ray bursts (GRBs). The Large Area Telescope on board Fermi detects a sample of {gamma}-ray blazars with redshift up to z {approx} 3, and GRBs with redshift up to z {approx} 4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of {gamma}-ray flux attenuation by the EBL. We place upper limits on the {gamma}-ray opacity of the universe at various energies and redshifts and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the 'baseline' model of Stecker et al. can be ruled out with high confidence.

  16. Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

    SciTech Connect

    Berenji, Bijan

    2012-09-19

    Large extra dimensions (LED) have been proposed to account for the apparent weakness of gravitation. These theories also indicate that the postulated massive Kaluza-Klein (KK) gravitons may be produced by nucleon-nucleon bremsstrahlung in the course of core collapse of supernovae. Hannestad and Raffelt have predicted energy spectra of gamma ray emission from the decay of KK gravitons trapped by the gravity of the remnant neutron stars (NS). These and other authors have used EGRET data on NS to obtain stringent limits on LED. Fermi-LAT is observing radio pulsar positions obtained from radio and x-ray catalogs. NS with certain characteristics are unlikely emitter of gamma rays, and emit in radio and perhaps x-rays. This talk will focus on the blind analysis we plan to perform, which has been developed using the 1st 2 months of all sky data and Monte Carlo simulations, to obtain limits on LED based on about 1 year of Fermi-LAT data. Preliminary limits from this analysis using these first 2 months of data will be also be discussed.

  17. Teen Parenting: The First Year.

    ERIC Educational Resources Information Center

    McCamey, Jody

    This guide for teenage mothers discusses the needs of the mother and her child during the first year of the child's life. Information on the child's and the mother's behavior and emotions just after the child's birth is presented. Also presented is information on the following: procuring items needed for tending the baby; playing; crying; breast…

  18. Limits on large extra dimensions based on observations of neutron stars with the Fermi-LAT

    SciTech Connect

    Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E.D.; Borgland, A.W.; Buehler, R.; Cameron, R.A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Barbiellini, G.; Bastieri, D.; Buson, S.; Bonamente, E.; Cecchi, C.; Brigida, M.; Bruel, P.; Caraveo, P.A.; Casandjian, J.M. E-mail: elliott@slac.stanford.edu [Laboratoire AIM, CEA-IRFU Collaboration: Fermi-LAT collaboration; and others

    2012-02-01

    We present limits for the compactification scale in the theory of Large Extra Dimensions (LED) proposed by Arkani-Hamed, Dimopoulos, and Dvali. We use 11 months of data from the Fermi Large Area Telescope (Fermi-LAT) to set gamma ray flux limits for 6 gamma-ray faint neutron stars (NS). To set limits on LED we use the model of Hannestad and Raffelt (HR) that calculates the Kaluza-Klein (KK) graviton production in supernova cores and the large fraction subsequently gravitationally bound around the resulting NS. The predicted decay of the bound KK gravitons to γγ should contribute to the flux from NSs. Considering 2 to 7 extra dimensions of the same size in the context of the HR model, we use Monte Carlo techniques to calculate the expected differential flux of gamma-rays arising from these KK gravitons, including the effects of the age of the NS, graviton orbit, and absorption of gamma-rays in the magnetosphere of the NS. We compare our Monte Carlo-based differential flux to the experimental differential flux using maximum likelihood techniques to obtain our limits on LED. Our limits are more restrictive than past EGRET-based optimistic limits that do not include these important corrections. Additionally, our limits are more stringent than LHC based limits for 3 or fewer LED, and comparable for 4 LED. We conclude that if the effective Planck scale is around a TeV, then for 2 or 3 LED the compactification topology must be more complicated than a torus.

  19. Limits on Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

    SciTech Connect

    Ajello, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G.A.; Cameron, R.A.; Caraveo, P.A.; Casandjian, J.M.; Cecchi, C.; Charles, E.; /more authors..

    2012-08-17

    We present limits for the compactification scale in the theory of Large Extra Dimensions (LED) proposed by Arkani-Hamed, Dimopoulos, and Dvali. We use 11 months of data from the Fermi Large Area Telescope (Fermi-LAT) to set gamma ray flux limits for 6 gamma-ray faint neutron stars (NS). To set limits on LED we use the model of Hannestad and Raffelt (HR) that calculates the Kaluza-Klein (KK) graviton production in supernova cores and the large fraction subsequently gravitationally bound around the resulting NS. The predicted decay of the bound KK gravitons to {gamma}{gamma} should contribute to the flux from NSs. Considering 2 to 7 extra dimensions of the same size in the context of the HR model, we use Monte Carlo techniques to calculate the expected differential flux of gamma-rays arising from these KK gravitons, including the effects of the age of the NS, graviton orbit, and absorption of gamma-rays in the magnetosphere of the NS. We compare our Monte Carlo-based differential flux to the experimental differential flux using maximum likelihood techniques to obtain our limits on LED. Our limits are more restrictive than past EGRET-based optimistic limits that do not include these important corrections. Additionally, our limits are more stringent than LHC based limits for 3 or fewer LED, and comparable for 4 LED. We conclude that if the effective Planck scale is around a TeV, then for 2 or 3 LED the compactification topology must be more complicated than a torus.

  20. Limits on Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT

    NASA Technical Reports Server (NTRS)

    Ferrara, E. C.; Scargle, J. D.; Troja, E.

    2012-01-01

    We present limits for the compactification scale in the theory of Large Extra Dimensions (LED) proposed by Arkani-Hamed, Dimopoulos, and Dvali. We use 11 months of data from the Fermi Large Area Telescope (Fermi-LAT) to set gamma ray flux limits for 6 gamma-ray faint neutron stars (NS). To set limits on LED we use the model of Hannestad and Raffelt (HR) that calculates the Kaluza-Klein (KK) graviton production in supernova cores and the large fraction subsequently gravitationally bound around the resulting NS. The predicted decay of the bound KK gravitons to should contribute to the flux from NSs. Considering 2 to 7 extra dimensions of the same size in the context of the HR model, we use Monte Carlo techniques to calculate the expected differential flux of gamma-rays arising from these KK gravitons, including the effects of the age of the NS, graviton orbit, and absorption of gamma-rays in the magnetosphere of the NS. We compare our Monte Carlo-based differential flux to the experimental differential flux using maximum likelihood techniques to obtain our limits on LED. Our limits are more restrictive than past EGRET-based optimistic limits that do not include these important corrections. Additionally, our limits are more stringent than LHC based limits for 3 or fewer LED, and comparable for 4 LED. We conclude that if the effective Planck scale is around a TeV, then for 2 or 3 LED the compactification topology must be more complicated than a torus.

  1. The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission

    SciTech Connect

    Atwood, W.B.; Abdo, Aous A.; Ackermann, M.; Anderson, B. Axelsson, M.; Baldini, L.; Ballet, J.; Band, D.L.; Barbiellini, Guido; Bartelt, J.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bederede, D.; Bellardi, F.; Bellazzini, R.; Berenji, B.; Bignami, G.F.; Bisello, D.; Bissaldi, E.; Blandford, R.D.; /more authors..

    2009-05-15

    The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view (FoV), high-energy {gamma}-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. The LAT was built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. This paper describes the LAT, its preflight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4 x 4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 (x, y) tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an eight-layer hodoscopic configuration with a total depth of 8.6 radiation lengths, giving both longitudinal and transverse information about the energy deposition pattern. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large FoV (2.4 sr) and ensuring that most pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. Data obtained with the LAT are intended to (1) permit rapid notification of high-energy {gamma}-ray bursts and transients and facilitate monitoring of variable sources, (2) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (3) measure

  2. Fermi Observations of Resolved Large-Scale Jets: Testing the IC/CMB Model

    NASA Astrophysics Data System (ADS)

    Breiding, Peter; Meyer, Eileen T.; Georganopoulos, Markos

    2017-01-01

    It has been observed with the Chandra X-ray Observatory since the early 2000s that many powerful quasar jets show X-ray emission on the kpc scale (Harris & Krawczynski, 2006). In many cases these X-rays cannot be explained by the extension of the radio-optical spectrum produced by synchrotron emitting electrons in the jet, since the observed X-ray flux is too high and the X-ray spectral index too hard. A widely accepted model for the X-ray emission first proposed by Celotti et al. 2001 and Tavecchio et al. 2000 posits that the X-rays are produced when relativistic electrons in the jet up-scatter ambient cosmic microwave background (CMB) photons via inverse Compton scattering from microwave to X-ray energies (the IC/CMB model). However, explaining the X-ray emission for these jets with the IC/CMB model requires high levels of IC/CMB γ-ray emission (Georganopoulos et al., 2006), which we are looking for using the FERMI/LAT γ-ray space telescope. Another viable model for the large scale jet X-ray emission favored by the results of Meyer et al. 2015 and Meyer & Georganopoulos 2014 is an alternate population of synchrotron emitting electrons. In contrast with the second synchrotron interpretation; the IC/CMB model requires jets with high kinetic powers which can exceed the Eddington luminsoity (Dermer & Atoyan 2004 and Atoyan & Dermer 2004) and be very fast on the kpc scale with a Γ~10 (Celotti et al. 2001 and Tavecchio et al. 2000). New results from data obtained with the Fermi/LAT will be shown for several quasars not in the Fermi/LAT 3FGL catalog whose large scale X-ray jets are attributed to IC/CMB. Additionally, recent work on the γ-ray bright blazar AP Librae will be shown which helps to constrain some models attempting to explain the high energy component of its SED, which extends from X-ray to TeV energies (e.g., Zacharias & Wagner 2016 & Petropoulou et al. 2016).

  3. Measurement of Separate Cosmic-Ray Electron and Positron Spectra with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Brogland, A. W.; Bouvier, A.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Ferrara, E. C.; Harding, A. K.; McEnery, J. E.

    2011-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting the Earth's shadow, which is offset in opposite directions for opposite charges due to the Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 GeV and 200 GeV, We confirm that the fraction rises with energy in the 20-100 GeV range and determine for the first time that it continues to rise between 100 and 200 GeV,

  4. Spontaneous separation of large-spin Fermi gas in the harmonic trap: a density functional study

    PubMed Central

    Sun, Zongli; Gu, Qiang

    2016-01-01

    The component separation of the trapped large-spin Fermi gas is studied within density functional theory. The ground state and ferromagnetic transition in the gas, with and without the spin mixing collision, are calculated. In the absence of spin mixing, two patterns of separation are observed as the interaction between atoms increases, whereas only one of them corresponds to a ferromagnetic transition. The phase diagram suggests that the pattern which the system chooses depends on the interaction strength in the collision channels. With the presence of spin mixing, the distribution of phase region changes because of the interplay between different collision channels. Specifically, the spin exchange benefits the FM transition, while it suppresses the component separation of CS-II pattern. PMID:27549012

  5. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, David J.; Baldini, L.; Uchiyama, Y.

    2012-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TeV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  6. A population of gamma-ray millisecond pulsars seen with the Fermi Large Area Telescope.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Bignami, G F; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Caliandro, G A; Cameron, R A; Camilo, F; Caraveo, P A; Carlson, P; Casandjian, J M; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cognard, I; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Corbet, R; Cutini, S; Dermer, C D; Desvignes, G; de Angelis, A; de Luca, A; de Palma, F; Digel, S W; Dormody, M; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Edmonds, Y; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Frailis, M; Freire, P C C; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M H; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hobbs, G; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Johnston, S; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kramer, M; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Manchester, R N; Marelli, M; Mazziotta, M N; McConville, W; McEnery, J E; McLaughlin, M A; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Ransom, S M; Ray, P S; Razzano, M; Rea, N; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Roth, M; Ryde, F; Sadrozinski, H F W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stappers, B W; Starck, J L; Striani, E; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Tanaka, T; Thayer, J B; Thayer, J G; Theureau, G; Thompson, D J; Thorsett, S E; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Van Etten, A; Vasileiou, V; Venter, C; Vilchez, N; Vitale, V; Waite, A P; Wallace, E; Wang, P; Watters, K; Webb, N; Weltevrede, P; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

    2009-08-14

    Pulsars are born with subsecond spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched Fermi Large Area Telescope data for pulsations from all known millisecond pulsars (MSPs) outside of globular clusters, using rotation parameters from radio telescopes. Strong gamma-ray pulsations were detected for eight MSPs. The gamma-ray pulse profiles and spectral properties resemble those of young gamma-ray pulsars. The basic emission mechanism seems to be the same for MSPs and young pulsars, with the emission originating in regions far from the neutron star surface.

  7. Cosmic Ray Studies with the Fermi Gamma-ray Space Telescope Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Baldini, L.; Uchiyama, Y.

    2011-01-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope provides both direct and indirect measurements of Galactic cosmic rays (CR). The LAT high-statistics observations of the 7 GeV - 1 TcV electron plus positron spectrum and limits on spatial anisotropy constrain models for this cosmic-ray component. On a Galactic scale, the LAT observations indicate that cosmic-ray sources may be more plentiful in the outer Galaxy than expected or that the scale height of the cosmic-ray diffusive halo is larger than conventional models. Production of cosmic rays in supernova remnants (SNR) is supported by the LAT gamma-ray studies of several of these, both young SNR and those interacting with molecular clouds.

  8. Fermi Large Area Telescope Observations of the Cosmic-Ray Induced

    SciTech Connect

    Abdo, A.

    2012-02-29

    We report on measurements of the cosmic-ray induced {gamma}-ray emission of Earth's atmosphere by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The LAT has observed the Earth during its commissioning phase and with a dedicated Earth-limb following observation in September 2008. These measurements yielded {approx} 6.4 x 10{sup 6} photons with energies > 100 MeV and {approx} 250 hours total livetime for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. The spectrum of the emission - often referred to as Earth albedo gamma-ray emission - has a power-law shape up to 500 GeV with spectral index {Lambda} = 2.79 {+-} 0.06.

  9. The On-Orbit Calibrations for the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Ampe, J.; Anderson, B.; Atwood, W.B.; Axelsson, M.; Bagagli, R.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bartelt, J.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bederede, D.; Bellardi, F.; Bellazzini, R.; Belli, F.; Berenji, B.; Bisello, D.; /more authors..

    2011-11-17

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope began its on-orbit operations on June 23, 2008. Calibrations, defined in a generic sense, correspond to synchronization of trigger signals, optimization of delays for latching data, determination of detector thresholds, gains and responses, evaluation of the perimeter of the South Atlantic Anomaly (SAA), measurements of live time, of absolute time, and internal and spacecraft boresight alignments. Here we describe on-orbit calibration results obtained using known astrophysical sources, galactic cosmic rays, and charge injection into the front-end electronics of each detector. Instrument response functions will be described in a separate publication. This paper demonstrates the stability of calibrations and describes minor changes observed since launch. These results have been used to calibrate the LAT datasets to be publicly released in August 2009.

  10. Measurement of Separate Cosmic-Ray Electron and Positron Spectra with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ferrara, E. C.; Harding, A. K.; McEnery, J. E.; Moiseev, A. A.; Ackemann, M.

    2012-01-01

    We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth's shadow, which, is offset in opposite directions for opposite charges due to Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 and 200 Ge V. We confirm that the fraction rises with energy in the 20-100 Ge V range. The three new spectral points between 100 and 200 GeV are consistent with a fraction that is continuing to rise with energy.

  11. Fermi Large Area Telescope Observations of Markarian 421: The Missing Piece of its Spectral Energy Distribution

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cannon, A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Escande, L.; Favuzzi, C.; Fegan, S. J.; Finke, J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Fukuyama, T.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Georganopoulos, M.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kadler, M.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Max-Moerbeck, W.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Nishino, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pavlidou, V.; Pearson, T. J.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Readhead, A.; Reimer, A.; Reimer, O.; Reyes, L. C.; Richards, J. L.; Ritz, S.; Roth, M.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stawarz, Ł.; Stevenson, M.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Wehrle, A. E.; Winer, B. L.; Wood, K. S.; Yang, Z.; Yatsu, Y.; Ylinen, T.; Zensus, J. A.; Ziegler, M.; Fermi LAT Collaboration; Aleksić, J.; Antonelli, L. A.; Antoranz, P.; Backes, M.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Bordas, P.; Borla Tridon, D.; Bosch-Ramon, V.; Bose, D.; Braun, I.; Bretz, T.; Camara, M.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Dazzi, F.; de Angelis, A.; De Cea del Pozo, E.; Delgado Mendez, C.; De Lotto, B.; De Maria, M.; De Sabata, F.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giavitto, G.; Godinovi, N.; Hadasch, D.; Herrero, A.; Hildebrand, D.; Höhne-Mönch, D.; Hose, J.; Hrupec, D.; Jogler, T.; Klepser, S.; Krähenbühl, T.; Kranich, D.; Krause, J.; La Barbera, A.; Leonardo, E.; Lindfors, E.; Lombardi, S.; López, M.; Lorenz, E.; Majumdar, P.; Makariev, E.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Miyamoto, H.; Moldón, J.; Moralejo, A.; Nieto, D.; Nilsson, K.; Orito, R.; Oya, I.; Paoletti, R.; Paredes, J. M.; Partini, S.; Pasanen, M.; Pauss, F.; Pegna, R. G.; Perez-Torres, M. A.; Persic, M.; Peruzzo, J.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puchades, N.; Puljak, I.; Reichardt, T.; Rhode, W.; Ribó, M.; Rico, J.; Rissi, M.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Sánchez-Conde, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shayduk, M.; Shore, S. N.; Sierpowska-Bartosik, A.; Sillanpää, A.; Sitarek, J.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Struebig, J. C.; Suric, T.; Takalo, L. O.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Vankov, H.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.; MAGIC Collaboration; Villata, M.; Raiteri, C.; Aller, H. D.; Aller, M. F.; Chen, W. P.; Jordan, B.; Koptelova, E.; Kurtanidze, O. M.; Lähteenmäki, A.; McBreen, B.; Larionov, V. M.; Lin, C. S.; Nikolashvili, M. G.; Reinthal, R.; Angelakis, E.; Capalbi, M.; Carramiñana, A.; Carrasco, L.; Cassaro, P.; Cesarini, A.; Falcone, A.; Gurwell, M. A.; Hovatta, T.; Kovalev, Yu. A.; Kovalev, Y. Y.; Krichbaum, T. P.; Krimm, H. A.; Lister, M. L.; Moody, J. W.; Maccaferri, G.; Mori, Y.; Nestoras, I.; Orlati, A.; Pace, C.; Pagani, C.; Pearson, R.; Perri, M.; Piner, B. G.; Ros, E.; Sadun, A. C.; Sakamoto, T.; Tammi, J.; Zook, A.

    2011-08-01

    We report on the γ-ray activity of the high-synchrotron-peaked BL Lacertae object Markarian 421 (Mrk 421) during the first 1.5 years of Fermi operation, from 2008 August 5 to 2010 March 12. We find that the Large Area Telescope (LAT) γ-ray spectrum above 0.3 GeV can be well described by a power-law function with photon index Γ = 1.78 ± 0.02 and average photon flux F(> 0.3 GeV) = (7.23 ± 0.16) × 10-8 ph cm-2 s-1. Over this time period, the Fermi-LAT spectrum above 0.3 GeV was evaluated on seven-day-long time intervals, showing significant variations in the photon flux (up to a factor ~3 from the minimum to the maximum flux) but mild spectral variations. The variability amplitude at X-ray frequencies measured by RXTE/ASM and Swift/BAT is substantially larger than that in γ-rays measured by Fermi-LAT, and these two energy ranges are not significantly correlated. We also present the first results from the 4.5 month long multifrequency campaign on Mrk 421, which included the VLBA, Swift, RXTE, MAGIC, the F-GAMMA, GASP-WEBT, and other collaborations and instruments that provided excellent temporal and energy coverage of the source throughout the entire campaign (2009 January 19 to 2009 June 1). During this campaign, Mrk 421 showed a low activity at all wavebands. The extensive multi-instrument (radio to TeV) data set provides an unprecedented, complete look at the quiescent spectral energy distribution (SED) for this source. The broadband SED was reproduced with a leptonic (one-zone synchrotron self-Compton) and a hadronic model (synchrotron proton blazar). Both frameworks are able to describe the average SED reasonably well, implying comparable jet powers but very different characteristics for the blazar emission site.

  12. Jet Emission in Young Radio Sources: A Fermi Large Area Telescope Gamma-Ray View

    NASA Astrophysics Data System (ADS)

    Migliori, G.; Siemiginowska, A.; Kelly, B. C.; Stawarz, Ł.; Celotti, A.; Begelman, M. C.

    2014-01-01

    We investigate the contribution of the beamed jet component to the high-energy emission in young and compact extragalactic radio sources, focusing for the first time on the γ-ray band. We derive predictions on the γ-ray luminosities associated with the relativistic jet assuming a leptonic radiative model. The high-energy emission is produced via Compton scattering by the relativistic electrons in a spherical region at the considered scales (lsim10 kpc). Simulations show a wide range of γ-ray luminosities, with intensities up to ~1046-1048 erg s-1 depending on the assumed jet parameters. We find a highly linear relation between the simulated X-ray and γ-ray luminosities that can be used to select candidates for γ-ray detection. We compare the simulated luminosity distributions in the radio, X-ray, and γ-ray regimes with observations for the largest sample of X-ray-detected young radio quasars. Our analysis of ~4-yr Fermi Large Area Telescope (LAT) data does not yield any statistically significant detections. However, the majority of the model-predicted γ-ray fluxes for the sample are near or below the current Fermi-LAT flux threshold and compatible with the derived upper limits. Our study gives constraints on the minimum jet power (L jet, kin/L disk > 0.01) of a potential jet contribution to the X-ray emission in the most compact sources (lsim 1 kpc) and on the particle-to-magnetic field energy density ratio that are in broad agreement with equipartition assumptions.

  13. Constraints on Lorentz Invariance Violation from Fermi -Large Area Telescope Observations of Gamma-Ray Bursts

    NASA Technical Reports Server (NTRS)

    Vasileiou, V.; Jacholkowska, A.; Piron, F.; Bolmont, J.; Courturier, C.; Granot, J.; Stecker, Floyd William; Cohen-Tanugi, J.; Longo, F.

    2013-01-01

    We analyze the MeV/GeV emission from four bright Gamma-Ray Bursts (GRBs) observed by the Fermi-Large Area Telescope to produce robust, stringent constraints on a dependence of the speed of light in vacuo on the photon energy (vacuum dispersion), a form of Lorentz invariance violation (LIV) allowed by some Quantum Gravity (QG) theories. First, we use three different and complementary techniques to constrain the total degree of dispersion observed in the data. Additionally, using a maximally conservative set of assumptions on possible source-intrinsic spectral-evolution effects, we constrain any vacuum dispersion solely attributed to LIV. We then derive limits on the "QG energy scale" (the energy scale that LIV-inducing QG effects become important, E(sub QG)) and the coefficients of the Standard Model Extension. For the subluminal case (where high energy photons propagate more slowly than lower energy photons) and without taking into account any source-intrinsic dispersion, our most stringent limits (at 95% CL) are obtained from GRB 090510 and are E(sub QG,1) > 7.6 times the Planck energy (E(sub Pl)) and E(sub QG,2) > 1.3×10(exp 11) GeV for linear and quadratic leading order LIV-induced vacuum dispersion, respectively. These limits improve the latest constraints by Fermi and H.E.S.S. by a factor of approx. 2. Our results disfavor any class of models requiring E(sub QG,1) < or approx. E(sub Pl)

  14. Electromagnetic counterparts to Gravitational Wave events with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Vianello, Giacomo; Omodei, Nicola; Racusin, Judith L.; McEnery, Julie E.; Chiang, James; Buson, Sara; Fermi LAT Collaboration

    2017-01-01

    At least a fraction of Gravitational Wave (GW) progenitors is expected to emit an electromagnetic (EM) signal in the form of a short gamma-ray burst (sGRB). The discovery of such a transient EM counterpart is challenging because the LIGO/VIRGO localization region is much larger (several hundreds of square degrees) than the field of view of X-ray, optical and radio telescopes. The Fermi Large Area Telescope (LAT) has a wide field of view (~ 2.4 sr), and detects ~2-3 sGRBs per year above 100 MeV. It can detect them not only during the short prompt phase but also during their long-lasting high-energy afterglow phase. If other wide-field high-energy instruments such as Fermi-GBM, Swift-BAT or INTEGRAL-ISGRI cannot detect or localize with enough precision an EM counterpart during the prompt phase, the LAT can potentially pinpoint it with < 10 arcmin accuracy during the afterglow phase. This routinely happens in the case of gamma-ray bursts. Moreover, the LAT covers the entire localization region within hours of any GW triggers during normal operations, allowing upper bounds to be evaluated. This has been demonstrated in the case of the three known GW events (GW150914, LVT151012, and GW151226). Over the coming years, as LIGO and Virgo approach design sensitivity and will soon be able to detect these mergers, LAT will continue to provide a unique capability to potentially localize and characterize gravitational wave events.

  15. Deep view of the Large Magellanic Cloud with six years of Fermi-LAT observations

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hill, A. B.; Horan, D.; Jóhannesson, G.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Martin, P.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, M.; Zimmer, S.

    2016-02-01

    Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in γ-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims: Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the γ-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods: We revisited the γ-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results: In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1-100 GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations

  16. First year results from LOTIS

    NASA Astrophysics Data System (ADS)

    Williams, G. G.; Parks, H. S.; Ables, E.

    1997-11-01

    LOTIS (Livermore Optical Transient Imaging System) is a gamma-ray burst optical couterpart search experiment located near Lawrence Livermore National Laboratory in California. The system is linked to the GCN (GRB Coordinates Network) real-time coordinate distribution network and can respond to a burst trigger in 6-15 seconds. LOTIS has a total field-of-view of 17.4 degrees x 17.4 degrees with a completeness sensitivity of mv approximately 11 for a 10 second integration time. Since operations began in October 1996, LOTIS has responded to over 30 GCN/BATSE GRB triggers. Seven of these triggers are considered good events subject to the criteria of clear weather conditions, (lt) 60 S RESPONSE TIME, AND (gt)50% coverage of the final BATSE 3(sigma) error circle. We discuss results from the first year of LOTIS operations with an emphasis on the observations and analysis of GRB 971006 (BATSE trigger 6414) .

  17. Correlation of Fermi Large Area Telescope sources with the 20-GHz Australia Telescope Compact Array radio survey

    NASA Astrophysics Data System (ADS)

    Ghirlanda, G.; Ghisellini, G.; Tavecchio, F.; Foschini, L.

    2010-09-01

    We cross-correlate the Fermi 11-month survey (1FGL) catalogue with the 20-GHz Australia Telescope Compact Array (AT20G) radio survey catalogue composed of 5890 sources at declination < 0°. Among the 738 Fermi sources distributed in the southern sky, we find 230 highly probable candidate counterparts in the AT20G survey. Of these, 222 are already classified in the Fermi one-year Large Area Telescope (LAT) active galactic nucleus (AGN) catalogue (1LAC) as blazars [either flat spectrum radio quasars (FSRQs) or BL Lacertae objects (BL Lacs)], AGNs or sources of unknown class but with an associated counterpart, while eight are new associations. By studying the γ-ray and radio properties of these associations, we find a correlation between the γ-ray flux (above 100 MeV) and the 20-GHz flux density. This correlation is more than 3σ statistically significant, both for the population of BL Lacs and for FSRQs considered separately. We also find that the radio counterparts associated with the Fermi sources have, on average, flat radio spectra between 5 and 20 GHz and that Fermi γ-ray sources are not preferentially associated with `ultra-inverted spectrum' radio sources. For two of the eight new associations, we build the broad-band spectral energy distribution combining Fermi, Swift and radio observations. One of these two sources is identified with the high-redshift FSRQ Swift J1656.3-3302 (z = 2.4) and we classify the other source as a candidate new FSRQ. We also study the brightest radio source of the 46 associations without an optical classification and classify it as a new BL Lac candidate `twin' of the prototypical BL Lac OJ 287 if its redshift is larger, z ~ 0.4.

  18. OBSERVATIONS OF ENERGETIC HIGH MAGNETIC FIELD PULSARS WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Parent, D.; Abdo, A. A.; Kerr, M.; Den Hartog, P. R.; Romani, R. W.; Watters, K.; Craig, H. A.; Baring, M. G.; DeCesar, M. E.; Harding, A. K.; Espinoza, C. M.; Stappers, B. W.; Weltevrede, P.; Gotthelf, E. V.; Camilo, F.; Johnston, S.; Kaspi, V. M.; Livingstone, M.; Burgay, M.; Freire, P. C. C. E-mail: kerrm@stanford.edu; and others

    2011-12-20

    We report the detection of {gamma}-ray pulsations from the high-magnetic-field rotation-powered pulsar PSR J1119-6127 using data from the Fermi Large Area Telescope. The {gamma}-ray light curve of PSR J1119-6127 shows a single, wide peak offset from the radio peak by 0.43 {+-} 0.02 in phase. Spectral analysis suggests a power law of index 1.0 {+-} 0.3{sup +0.4}{sub -0.2} with an energy cutoff at 0.8 {+-} 0.2{sup +2.0}{sub -0.5} GeV. The first uncertainty is statistical and the second is systematic. We discuss the emission models of PSR J1119-6127 and demonstrate that despite the object's high surface magnetic field-near that of magnetars-the field strength and structure in the {gamma}-ray emitting zone are apparently similar to those of typical young pulsars. Additionally, we present upper limits on the {gamma}-ray pulsed emission for the magnetically active PSR J1846-0258 in the supernova remnant Kesteven 75 and two other energetic high-B pulsars, PSRs J1718-3718 and J1734-3333. We explore possible explanations for the non-detection of these three objects, including peculiarities in their emission geometry.

  19. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; /more authors..

    2012-09-20

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between {approx}6 and {approx}13 GeV with an estimated uncertainty of {approx}2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  20. Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes

    SciTech Connect

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Anderson, B.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; /more authors..

    2012-04-11

    The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

  1. Constraints on axions and axionlike particles from Fermi Large Area Telescope observations of neutron stars

    NASA Astrophysics Data System (ADS)

    Berenji, B.; Gaskins, J.; Meyer, M.

    2016-02-01

    We present constraints on the nature of axions and axionlike particles (ALPs) by analyzing gamma-ray data from neutron stars using the Fermi Large Area Telescope. In addition to axions solving the strong C P problem of particle physics, axions and ALPs are also possible dark matter candidates. We investigate axions and ALPs produced by nucleon-nucleon bremsstrahlung within neutron stars. We derive a phenomenological model for the gamma-ray spectrum arising from subsequent axion decays. By analyzing five years of gamma-ray data (between 60 and 200 MeV) for a sample of four nearby neutron stars, we do not find evidence for an axion or ALP signal; thus we obtain a combined 95% confidence level upper limit on the axion mass of 7.9 ×10-2 eV , which corresponds to a lower limit for the Peccei-Quinn scale fa of 7.6 ×107 GeV . Our constraints are more stringent than previous results probing the same physical process, and are competitive with results probing axions and ALPs by different mechanisms.

  2. Fermi Large Area Telescope Observations of the Cygnus Loop Supernova Remnant

    SciTech Connect

    Katagiri, H.; Tibaldo, L.; Ballet, J.; Giordano, F.; Grenier, I.A.; Porter, T.A.; Roth, M.; Tibolla, O.; Uchiyama, Y.; Yamazaki, R.; /Sagamihara, Aoyama Gakuin U.

    2011-11-08

    We present an analysis of the gamma-ray measurements by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) Cygnus Loop (G74.0-8.5). We detect significant gamma-ray emission associated with the SNR in the energy band 0.2-100 GeV. The gamma-ray spectrum shows a break in the range 2-3 GeV. The gamma-ray luminosity is {approx} 1 x 10{sup 33} erg s{sup -1} between 1-100 GeV, much lower than those of other GeV-emitting SNRs. The morphology is best represented by a ring shape, with inner/outer radii 0{sup o}.7 {+-} 0{sup o}.1 and 1{sup o}.6 {+-} 0{sup o}.1. Given the association among X-ray rims, H{alpha} filaments and gamma-ray emission, we argue that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields adjacent to the shock regions. The decay of neutral pions produced in nucleon-nucleon interactions between accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray spectrum.

  3. Observations of Energetic High Magnetic Field Pulsars with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Parent, D.; Kerr, M.; DenHartog, P. R.; Baring, M. G.; DeCesar, M. E.; Espinoza, C. M.; Harding, A. K.; Romani, R. W.; Stappers, B. W.; Watters, K.; Weltevrde, P.; Abdo, A. A.; Craig, H. A.; Kramer, M.; Lyne, A. G.

    2011-01-01

    We report the detection of gamma-ray pulsations from the high-magnetic-field rotation-powered pulsar PSR J1119.6127 using data from the Fermi Large Area Telescope. The gamma-ray light curve of PSR J1119.6127 shows a single, wide peak offset from the radio peak by 0.43 +/- 0.02 in phase. Spectral analysis suggests a power law of index 1.0 +/- 0.3(+0.4 -0.2) with an energy cut-off at 0.8 +/- 0.2(+2.0 -0.5) GeV. The first uncertainty is statistical and the second is systematic. We discuss the emission models of PSR J1119.6127 and demonstrate that despite the object's high surface magnetic field--near that of magnetars -- the field strength and structure in the gamma-ray emitting zone are apparently similar to those of typical young pulsars. Additionally, we present upper limits on the gamma-ray pulsed emission for the magnetically active PSR J1846.0258 in the supernova remnant Kesteven 75 and two other energetic high-Beta pulsars, PSRs J1718.3718 and J1734.3333. We explore possible explanations for the non-detection of these three objects, including peculiarities in their emission geometry.

  4. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbielini, G; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B,; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Gehrels, N.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E. J.

    2012-01-01

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron- plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between approx. 6 and approx. 13 GeV with an estimated uncertainty of approx. 2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  5. Probing Millisecond Pulsar Emission Geometry Using Light Curves From the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Venter, Christo; Harding, Alice; Guillemot, L.

    2009-01-01

    An interesting new high-energy pulsar sub-population is emerging following early discoveries of gamma-ray millisecond pulsars (MSPs) by the Fermi Large Area Telescope (LAT). We present results from 3D emission modeling, including the Special Relativistic effects of aberration and time-of-flight delays and also rotational sweepback of 13-field lines, in the geometric context of polar cap (PC), slot gap (SG), outer gap (OG), and two-pole caustic (TPC) pulsar models. In contrast to the general belief that these very old, rapidly-rotating neutron stars (NSs) should have largely pair-starved magnetospheres due to the absence of significant pair production, we find that most of the light curves are best fit by SG and OG models, which indicates the presence of narrow accelerating gaps limited by robust pair production -- even in these pulsars with very low spin-down luminosities. The gamma-ray pulse shapes and relative phase lags with respect to the radio pulses point to high-altitude emission being dominant for all geometries. We also find exclusive differentiation of the current gamma-ray MSP population into two MSP sub-classes: light curve shapes and lags across wavebands impose either pair-starved PC (PSPC) or SG / OG-type geometries. In the first case, the radio pulse has a small lag with respect to the single gamma-ray pulse, while the (first) gamma-ray peak usually trails the radio by a large phase offset in the latter case. Finally, we find that the flux correction factor as a function of magnetic inclination and observer angles is typically of order unity for all models. Our calculation of light curves and flux correction factor f(_, _, P) for the case of MSPs is therefore complementary to the "ATLAS paper" of Watters et al. for younger pulsars.

  6. Investigating First Year Education Students' Stress Level

    ERIC Educational Resources Information Center

    Geng, Gretchen; Midford, Richard

    2015-01-01

    This paper investigated the stress levels of first-year education students who undertake teaching practicum and theory units during their first year of teacher education program. First, 139 first-year and 143 other years' education students completed the PSS-10 scale, which measures perceived level of stress. Then, 147 first-year education…

  7. Sensitivity projections for dark matter dearches with the Fermi large area telescope

    DOE PAGES

    Charles, E.; M. Sanchez-Conde; Anderson, B.; ...

    2016-05-20

    The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of themore » $$\\gamma$$-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the $$b\\bar{b}$$ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the $$b\\bar{b}$$ ($$\\tau^+ \\tau^-$$) annihilation channels.« less

  8. A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope

    SciTech Connect

    Weniger, Christoph

    2012-08-01

    The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large Area Telescope (LAT), concentrating on energies between 20 and 300 GeV. Besides updating to 43 months of data, we use a new data-driven technique to select optimized target regions depending on the profile of the Galactic dark matter halo. In regions close to the Galactic center, we find a 4.6σ indication for a gamma-ray line at E{sub γ} ≈ 130 GeV. When taking into account the look-elsewhere effect the significance of the observed excess is 3.2σ. If interpreted in terms of dark matter particles annihilating into a photon pair, the observations imply a dark matter mass of m{sub χ} = 129.8±2.4 {sup +7}{sub −13} GeV and a partial annihilation cross-section of (σv){sub χχ} {sub →} {sub γγ} = (1.27±0.32 {sup +0.18}{sub −0.28}) × 10{sup −27}cm{sup 3}s{sup −1} when using the Einasto dark matter profile. The evidence for the signal is based on about 50 photons; it will take a few years of additional data to clarify its existence.

  9. Sensitivity projections for dark matter dearches with the Fermi large area telescope

    SciTech Connect

    Charles, E.; M. Sanchez-Conde; Anderson, B.; Caputo, R.; Cuoco, A.; Di Mauro, M.; Drlica-Wagner, A.; Gomez-Vargas, G. A.; Meyer, M.; Tibaldo, L.; Wood, M.; Zaharijas, G.; Zimmer, S.; Ajello, M.; Albert, A.; Baldini, L.; Bechtol, K.; Bloom, E. D.; Ceraudo, F.; Cohen-Tanugi, J.; Gaskins, J.; Gustafsson, M.; Mirabal, N.; Razzano, M.

    2016-05-20

    The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of the $\\gamma$-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the $b\\bar{b}$ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the $b\\bar{b}$ ($\\tau^+ \\tau^-$) annihilation channels.

  10. Gamma-Ray Observations of the Orion Molecular Clouds with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Ferrara, E. C.; Harding, A. K.; Troja, E.

    2012-01-01

    We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between approx 100 MeV and approx 100 GeV is predicted to trace the gas mass distribution in the clouds through nuclear interactions between the Galactic cosmic rays (CRs) and interstellar gas. The gamma-ray production cross-section for the nuclear interaction is known to approx 10% precision which makes the LAT a powerful tool to measure the gas mass column density distribution of molecular clouds for a known CR intensity. We present here such distributions for Orion A and B, and correlate them with those of the velocity-integrated CO intensity (W(sub CO)) at a 1 deg 1 deg pixel level. The correlation is found to be linear over a W(sub CO) range of approx 10-fold when divided in three regions, suggesting penetration of nuclear CRs to most of the cloud volumes. The W(sub CO)-to-mass conversion factor, X(sub CO), is found to be approx 2.3 10(exp 20) / sq cm (K km/s)(exp -1) for the high-longitude part of Orion A (l > 212 deg), approx 1.7 times higher than approx 1.3 10(exp 20) found for the rest of Orion A and B. We interpret the apparent high X(sub CO) in the high-longitude region of Orion A in the light of recent works proposing a nonlinear relation between H2 and CO densities in the diffuse molecular gas.W(sub CO) decreases faster than the H2 column density in the region making the gas "darker" to W(sub CO).

  11. THE SECOND CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Antolini, E.; Bonamente, E.; Atwood, W. B.; Bouvier, A.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Bastieri, D. E-mail: sarac@slac.stanford.edu E-mail: charles.dermer@nrl.navy.mil; and others

    2011-12-20

    The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented. The second LAT AGN catalog (2LAC) includes 1017 {gamma}-ray sources located at high Galactic latitudes (|b| > 10 Degree-Sign ) that are detected with a test statistic (TS) greater than 25 and associated statistically with AGNs. However, some of these are affected by analysis issues and some are associated with multiple AGNs. Consequently, we define a Clean Sample which includes 886 AGNs, comprising 395 BL Lacertae objects (BL Lac objects), 310 flat-spectrum radio quasars (FSRQs), 157 candidate blazars of unknown type (i.e., with broadband blazar characteristics but with no optical spectral measurement yet), 8 misaligned AGNs, 4 narrow-line Seyfert 1 (NLS1s), 10 AGNs of other types, and 2 starburst galaxies. Where possible, the blazars have been further classified based on their spectral energy distributions (SEDs) as archival radio, optical, and X-ray data permit. While almost all FSRQs have a synchrotron-peak frequency <10{sup 14} Hz, about half of the BL Lac objects have a synchrotron-peak frequency >10{sup 15} Hz. The 2LAC represents a significant improvement relative to the first LAT AGN catalog (1LAC), with 52% more associated sources. The full characterization of the newly detected sources will require more broadband data. Various properties, such as {gamma}-ray fluxes and photon power-law spectral indices, redshifts, {gamma}-ray luminosities, variability, and archival radio luminosities and their correlations are presented and discussed for the different blazar classes. The general trends observed in 1LAC are confirmed.

  12. Development of the Model of Galactic Interstellar Emission for Standard Point-source Analysis of Fermi Large Area Telescope Data

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cuoco, A.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hayashi, K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Jogler, T.; Jóhannesson, G.; Kamae, T.; Kuss, M.; Landriu, D.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Maldera, S.; Malyshev, D.; Manfreda, A.; Martin, P.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Remy, Q.; Renault, N.; Sánchez-Conde, M.; Schaal, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Werner, M.; Wood, K. S.; Wood, M.; Zaharijas, G.; Zimmer, S.

    2016-04-01

    Most of the celestial γ rays detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope originate from the interstellar medium when energetic cosmic rays interact with interstellar nucleons and photons. Conventional point-source and extended-source studies rely on the modeling of this diffuse emission for accurate characterization. Here, we describe the development of the Galactic Interstellar Emission Model (GIEM), which is the standard adopted by the LAT Collaboration and is publicly available. This model is based on a linear combination of maps for interstellar gas column density in Galactocentric annuli and for the inverse-Compton emission produced in the Galaxy. In the GIEM, we also include large-scale structures like Loop I and the Fermi bubbles. The measured gas emissivity spectra confirm that the cosmic-ray proton density decreases with Galactocentric distance beyond 5 kpc from the Galactic Center. The measurements also suggest a softening of the proton spectrum with Galactocentric distance. We observe that the Fermi bubbles have boundaries with a shape similar to a catenary at latitudes below 20° and we observe an enhanced emission toward their base extending in the north and south Galactic directions and located within ˜4° of the Galactic Center.

  13. Fermi Large Area Telescope Observations of the Supernova Remnant GS.7-0.1

    NASA Technical Reports Server (NTRS)

    Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Ferrara, E. C.; Harding, A. K.; Hays, E.; Moiseev, A. A.; Troja, E.

    2011-01-01

    We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. An investigation of the relationship among G8.7-0.l and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.l and a lesser part located outside the western boundary of G8.7-0.l. The region of the gamma-ray emission overlaps spatially-connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 +/- 0.6 (stat) +/- 1.2 (sys) GeV, and photon indices of 2.10 +/- 0.06 (stat) +/- 0.10 (sys) below the break and 2.70 +/- 0.12 (stat) +/- 0.l4 (sys) above the break. Given the spatial association among the gamma rays, the radio emission of G8.7-0.1, and the molecular clouds, the decay of 1IoS produced by particles accelerated in the SNR and hitting the molecular clouds naturally explains the GeV gamma-ray spectrum. We also find that the GeV morphology is not well represented by the TeV emission from HESS J1804-216 and that the spectrum in the GeV band is not consistent with the extrapolation of the TeV gamma-ray spectrum. The spectral index of the TeV emission is consistent with the particle spectral index predicted by a theory that assumes energy-dependent diffusion of particles accelerated in an SNR. We discuss the possibility that the TeV spectrum originates from the interaction of particles accelerated in G8.7-0.1 with molecular clouds, and we constrain the diffusion coefficient of the particles.

  14. Fermi Large Area Telescope Observations of the Supernova Remnant GS.7-0.1

    NASA Technical Reports Server (NTRS)

    Ferrara, E. C.; Hays, E.; Troja, E.; Moiseev, A. A.

    2012-01-01

    We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. An investigation of the relationship among G8.7-0.1 and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.1 and a lesser part located outside the western boundary of G8.7-0.1. The region of the gamma-ray emission overlaps spatially-connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 +/- 0.6 (stat) +/- 1.2 (sys) GeV, and photon indices of2.10 +/- 0.06 (stat) +/- 0.10 (sys) below the break and 2.70 +/- 0.12 (stat) +/- 0.14 (sys) above the break. Given the spatial association among the gamma rays, the radio emission ofG8.7-0.1, and the molecular clouds, the decay of pions produced by particles accelerated in the SNR and hitting the molecular clouds naturally explains the GeV gamma-ray spectrum. We also find that the GeV morphology is not well represented by the TeV emission from HESS Jl804-2l6 and that the spectrum in the Ge V band is not consistent with the extrapolation of the TeV gamma-ray spectrum. The spectral index of the TeV emission is consistent with the particle spectral index predicted by a theory that assumes energy-dependent diffusion of particles accelerated in an SNR. We discuss the possibility that the TeV-spectrum originates from the interaction of particles accelerated in G8.7-0.l with molecular clouds, and we constrain the diffusion coefficient of the particles.

  15. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE CRAB PULSAR AND NEBULA

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Baring, M. G.; Bastieri, D.; Bonamente, E.; Brigida, M. E-mail: mazziotta@ba.infn.i E-mail: lemoine@cenbg.in2p3.f

    2010-01-10

    We report on gamma-ray observations of the Crab Pulsar and Nebula using 8 months of survey data with the Fermi Large Area Telescope (LAT). The high quality light curve obtained using the ephemeris provided by the Nancay and Jodrell Bank radio telescopes shows two main peaks stable in phase with energy. The first gamma-ray peak leads the radio main pulse by (281 +- 12 +- 21) mus, giving new constraints on the production site of non-thermal emission in pulsar magnetospheres. The first uncertainty is due to gamma-ray statistics, and the second arises from the rotation parameters. The improved sensitivity and the unprecedented statistics afforded by the LAT enable precise measurement of the Crab Pulsar spectral parameters: cut-off energy at E{sub c} = (5.8 +- 0.5 +- 1.2) GeV, spectral index of GAMMA = (1.97 +- 0.02 +- 0.06) and integral photon flux above 100 MeV of (2.09 +- 0.03 +- 0.18) x 10{sup -6} cm{sup -2} s{sup -1}. The first errors represent the statistical error on the fit parameters, while the second ones are the systematic uncertainties. Pulsed gamma-ray photons are observed up to approx 20 GeV which precludes emission near the stellar surface, below altitudes of around 4-5 stellar radii in phase intervals encompassing the two main peaks. A detailed phase-resolved spectral analysis is also performed: the hardest emission from the Crab Pulsar comes from the bridge region between the two gamma-ray peaks while the softest comes from the falling edge of the second peak. The spectrum of the nebula in the energy range 100 MeV-300 GeV is well described by the sum of two power laws of indices GAMMA{sub sync} = (3.99 +- 0.12 +- 0.08) and GAMMA{sub IC} = (1.64 +- 0.05 +- 0.07), corresponding to the falling edge of the synchrotron and the rising edge of the inverse Compton (IC) components, respectively. This latter, which links up naturally with the spectral data points of Cherenkov experiments, is well reproduced via IC scattering from standard magnetohydrodynamic

  16. PULSED GAMMA-RAYS FROM PSR J2021+3651 WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Bastieri, D.; Battelino, M.; Baughman, B. M.; Bogaert, G.; Bruel, P. E-mail: smith@cenbg.in2p3.fr

    2009-08-01

    We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 {+-} 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 {+-} 0.004 {+-} 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 {+-} 3 {+-} 11) x 10{sup -8} cm{sup -2} s{sup -1}. The photon spectrum is well described by an exponentially cut-off power law of the form dF/dE=kE{sup -{gamma}}e{sup (-E/E{sub c})}, where the energy E is expressed in GeV. The photon index is {gamma} = 1.5 {+-} 0.1 {+-} 0.1 and the exponential cut-off is E{sub c} = 2.4 {+-} 0.3 {+-} 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is < 10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 {+-} 4 rad m{sup -2} but a poorly constrained magnetic geometry. Re-analysis of Chandra X-ray Observatory data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.

  17. Pulsed Gamma-Rays From PSR J2021 3651 with the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, Marco; Atwood, William B.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bastieri, Denis; Battelino, Milan; Baughman, B.M.; Bechtol, K.; Bellazzini, Ronaldo; Berenji, Bijan; Bloom, Elliott D.; Bogaert, G.; Borgland, Anders W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, Thompson H.; /more authors..

    2011-11-30

    We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 {+-} 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 {+-} 0.004 {+-} 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 {+-} 3 {+-} 11) x 10{sup -8} cm{sup -2} s{sup -1}. The photon spectrum is well-described by an exponentially cut-off power law of the form dF/dE = kE{sup -{Gamma}}e{sup (-E/E{sub c})} where the energy E is expressed in GeV. The photon index is {Gamma} = 1.5 {+-} 0.1 {+-} 0.1 and the exponential cut-off is E{sub c} = 2.4 {+-} 0.3 {+-} 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is < 10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 {+-} 4 rad m{sup -2} but a poorly constrained magnetic geometry. Re-analysis of Chandra data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase-aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.

  18. Fermi Large Area Telescope Observations of the Supernova Remnant G8.7-0.1

    SciTech Connect

    Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G.A.; Cameron, R.A.; Caraveo, P.A.; /more authors..

    2012-09-14

    We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. An investigation of the relationship between G8.7-0.1 and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.1 and a lesser part located outside the western boundary of G8.7-0.1. The region of the gamma-ray emission overlaps spatially connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 {+-} 0.6 (stat) {+-} 1.2 (sys) GeV, and photon indices of 2.10 {+-} 0.06 (stat) {+-} 0.10 (sys) below the break and 2.70 {+-} 0.12 (stat) {+-} 0.14 (sys) above the break. Given the spatial association among the gamma rays, the radio emission of G8.7-0.1, and the molecular clouds, the decay of p0s produced by particles accelerated in the SNR and hitting the molecular clouds naturally explains the GeV gamma-ray spectrum. We also find that the GeV morphology is not well represented by the TeV emission from HESS J1804-216 and that the spectrum in the GeV band is not consistent with the extrapolation of the TeV gamma-ray spectrum. The spectral index of the TeV emission is consistent with the particle spectral index predicted by a theory that assumes energy-dependent diffusion of particles accelerated in an SNR. We discuss the possibility that the TeV spectrum originates from the interaction of particles accelerated in G8.7-0.1 with molecular clouds, and we constrain the diffusion coefficient of the particles.

  19. AFTERGLOW OBSERVATIONS OF FERMI LARGE AREA TELESCOPE GAMMA-RAY BURSTS AND THE EMERGING CLASS OF HYPER-ENERGETIC EVENTS

    SciTech Connect

    Cenko, S. B.; Butler, N. R.; Cobb, B. E.; Cucchiara, A.; Bloom, J. S.; Perley, D. A.; Filippenko, A. V.; Frail, D. A.; Harrison, F. A.; Haislip, J. B.; Reichart, D. E.; Ivarsen, K. M.; LaCluyze, A. P.; Berger, E.; Chandra, P.; Fox, D. B.; Prochaska, J. X.; Kasliwal, M. M.; Kulkarni, S. R.

    2011-05-01

    We present broadband (radio, optical, and X-ray) light curves and spectra of the afterglows of four long-duration gamma-ray bursts (GRBs; GRBs 090323, 090328, 090902B, and 090926A) detected by the Gamma-Ray Burst Monitor and Large Area Telescope (LAT) instruments on the Fermi satellite. With its wide spectral bandpass, extending to GeV energies, Fermi is sensitive to GRBs with very large isotropic energy releases (10{sup 54} erg). Although rare, these events are particularly important for testing GRB central-engine models. When combined with spectroscopic redshifts, our afterglow data for these four events are able to constrain jet collimation angles, the density structure of the circumburst medium, and both the true radiated energy release and the kinetic energy of the outflows. In agreement with our earlier work, we find that the relativistic energy budget of at least one of these events (GRB 090926A) exceeds the canonical value of 10{sup 51} erg by an order of magnitude. Such energies pose a severe challenge for models in which the GRB is powered by a magnetar or a neutrino-driven collapsar, but remain compatible with theoretical expectations for magnetohydrodynamical collapsar models (e.g., the Blandford-Znajek mechanism). Our jet opening angles ({theta}) are similar to those found for pre-Fermi GRBs, but the large initial Lorentz factors ({Gamma}{sub 0}) inferred from the detection of GeV photons imply {theta}{Gamma}{sub 0} {approx} 70-90, values which are above those predicted in magnetohydrodynamic models of jet acceleration. Finally, we find that these Fermi-LAT events preferentially occur in a low-density circumburst environment, and we speculate that this might result from the lower mass-loss rates of their lower-metallicity progenitor stars. Future studies of Fermi-LAT afterglows at radio wavelengths with the order-of-magnitude improvement in sensitivity offered by the Extended Very Large Array should definitively establish the relativistic energy

  20. Fermi large area telescope observations of blazar 3C 279 occultations by the sun

    SciTech Connect

    Barbiellini, G.; Bastieri, D.; Buson, S.; Bechtol, K.; Blandford, R. D.; Borgland, A. W.; Buehler, R.; Cameron, R. A.; Chiang, J.; Bellazzini, R.; Bregeon, J.; Bruel, P.; Caraveo, P. A.; Cavazzuti, E.; Ciprini, S.; Cecchi, C.; Chaves, R. C. G.; Cheung, C. C. E-mail: phdmitry@stanford.edu; and others

    2014-04-01

    Observations of occultations of bright γ-ray sources by the Sun may reveal predicted pair halos around blazars and/or new physics, such as, e.g., hypothetical light dark matter particles—axions. We use Fermi Gamma-Ray Space Telescope (Fermi) data to analyze four occultations of blazar 3C 279 by the Sun on October 8 each year from 2008 to 2011. A combined analysis of the observations of these occultations allows a point-like source at the position of 3C 279 to be detected with significance of ≈3σ, but does not reveal any significant excess over the flux expected from the quiescent Sun. The likelihood ratio test rules out complete transparency of the Sun to the blazar γ-ray emission at a 3σ confidence level.

  1. Fermi: The Gamma-Ray Large Area Space Telescope Mission Status

    NASA Technical Reports Server (NTRS)

    McEnery, Julie E

    2014-01-01

    Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of a population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

  2. A method to analyze the diffuse gamma-ray emission with the Fermi Large Area Telescope

    SciTech Connect

    Ackermann, Markus; Johannesson, Gueolaugur; Digel, Seth; Moskalenko, Igor V.; Reimer, Olaf; Porter, Troy; Strong, Andrew

    2008-12-24

    The Fermi Gamma-Ray Space Telescope with its main instrument the LAT is the most sensitive {gamma}-ray telescope in the energy region between 30 MeV and 100 GeV. One of the prime scientific goals of this mission is the measurement and interpretation of the diffuse Galactic and extragalactic {gamma}-ray emission. While not limited by photon statistics, this analysis presents several challenges: Instrumental response functions, residual background from cosmic rays as well as resolved and unresolved foreground {gamma}-ray sources have to be taken carefully into account in the interpretation of the data. Detailed modeling of the diffuse {gamma}-ray emission is being performed and will form the basis of the investigations. We present the analysis approach to be applied to the Fermi LAT data, namely the modeling of the diffuse emission components and the background contributions, followed by an all-sky maximum-likelihood fitting procedure. We also report on the performance of this method evaluated in tests on simulated Fermi LAT and real EGRET data.

  3. Large Fermi Surface of Heavy Electrons at the Border of Mott Insulating State in NiS2

    DOE PAGES

    Friedemann, S.; Chang, H.; Gamża, M. B.; ...

    2016-05-12

    One early triumph of quantum physics is the explanation why some materials are metallic whereas others are insulating. While a treatment based on single electron states is correct for most materials this approach can fail spectacularly, when the electrostatic repulsion between electrons causes strong correlations. Not only can these favor new and subtle forms of matter, such as magnetism or superconductivity, they can even cause the electrons in a half-filled energy band to lock into position, producing a correlated, or Mott insulator. The transition into the Mott insulating state raises important fundamental questions. Foremost among these is the fate ofmore » the electronic Fermi surface and the associated charge carrier mass, as the Mott transition is approached. We report the first direct observation of the Fermi surface on the metallic side of a Mott insulating transition by high pressure quantum oscillatory measurements in NiS2. We find our results point at a large Fermi surface consistent with Luttinger's theorem and a strongly enhanced quasiparticle effective mass. These two findings are in line with central tenets of the Brinkman-Rice picture of the correlated metal near the Mott insulating state and rule out alternative scenarios in which the carrier concentration vanishes continuously at the metal-insulator transition.« less

  4. Large Fermi Surface of Heavy Electrons at the Border of Mott Insulating State in NiS2

    PubMed Central

    Friedemann, S.; Chang, H.; Gamża, M. B.; Reiss, P.; Chen, X.; Alireza, P.; Coniglio, W. A.; Graf, D.; Tozer, S.; Grosche, F. M.

    2016-01-01

    One early triumph of quantum physics is the explanation why some materials are metallic whereas others are insulating. While a treatment based on single electron states is correct for most materials this approach can fail spectacularly, when the electrostatic repulsion between electrons causes strong correlations. Not only can these favor new and subtle forms of matter, such as magnetism or superconductivity, they can even cause the electrons in a half-filled energy band to lock into position, producing a correlated, or Mott insulator. The transition into the Mott insulating state raises important fundamental questions. Foremost among these is the fate of the electronic Fermi surface and the associated charge carrier mass, as the Mott transition is approached. We report the first direct observation of the Fermi surface on the metallic side of a Mott insulating transition by high pressure quantum oscillatory measurements in NiS2. Our results point at a large Fermi surface consistent with Luttinger’s theorem and a strongly enhanced quasiparticle effective mass. These two findings are in line with central tenets of the Brinkman-Rice picture of the correlated metal near the Mott insulating state and rule out alternative scenarios in which the carrier concentration vanishes continuously at the metal-insulator transition. PMID:27174799

  5. Large Fermi Surface of Heavy Electrons at the Border of Mott Insulating State in NiS2

    SciTech Connect

    Friedemann, S.; Chang, H.; Gamża, M. B.; Reiss, P.; Chen, X.; Alireza, P.; Coniglio, W. A.; Graf, D.; Tozer, S.; Grosche, F. M.

    2016-05-12

    One early triumph of quantum physics is the explanation why some materials are metallic whereas others are insulating. While a treatment based on single electron states is correct for most materials this approach can fail spectacularly, when the electrostatic repulsion between electrons causes strong correlations. Not only can these favor new and subtle forms of matter, such as magnetism or superconductivity, they can even cause the electrons in a half-filled energy band to lock into position, producing a correlated, or Mott insulator. The transition into the Mott insulating state raises important fundamental questions. Foremost among these is the fate of the electronic Fermi surface and the associated charge carrier mass, as the Mott transition is approached. We report the first direct observation of the Fermi surface on the metallic side of a Mott insulating transition by high pressure quantum oscillatory measurements in NiS2. We find our results point at a large Fermi surface consistent with Luttinger's theorem and a strongly enhanced quasiparticle effective mass. These two findings are in line with central tenets of the Brinkman-Rice picture of the correlated metal near the Mott insulating state and rule out alternative scenarios in which the carrier concentration vanishes continuously at the metal-insulator transition.

  6. Gamma-Ray Observations of the Supernova Remnant RX J0852.0-4622 with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Tanaka, T.; Allafort, A.; Ballet, J.; Funk, S.; Giordano, F.; Hewitt, J.; Lemoine-Goumard, M.; Tajima, H.; Tibolla, O.; Uchiyama, Y.

    2011-01-01

    We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.04622 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. In the Fermi-LAT data, we find a spatially extended source at the location of the SNR. The extension is consistent with the SNR size seen in other wavelengths such as X-rays and TeV gamma rays, leading to the identification of the gamma-ray source with the SNR. The spectrum is well described as a power law with a photon index of = 1.85 0.06 (stat)+0.18 0.19 (sys), which smoothly connects to the H.E.S.S. spectrum in the TeV energy band. We discuss the gamma-ray emission mechanism based on multiwavelength data. The broadband data can be fit well by a model in which the gamma rays are of hadronic origin. We also consider a scenario with inverse Compton scattering of electrons as the emission mechanism of the gamma rays. Although the leptonic model predicts a harder spectrum in the Fermi-LAT energy range, the model can fit the data considering the statistical and systematic errors.

  7. The Monster Next Door: Fermi-LAT Observations of Supernova Remnant N132D in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Castro, Daniel; Hays, Elizabeth; Acero, Fabio; Slane, Patrick; Hughes, John; Plucinsky, Paul; Fermi-LAT Collaboration Collaboration

    2017-01-01

    Supernova remnant (SNR) N132D, located in the Large Magellanic Cloud, represents a unique opportunity for the study of γ-ray emission from shock accelerated cosmic rays (CRs) in another galaxy since it stands as the first and only extra-Galactic SNR detected in γ-rays. N132D is bright in the X-ray, infrared and radio bands, as well as being detected in TeV energy γ-rays, and hence, characterizing its emission in the Fermi-LAT band allows us to build a very complete picture of the properties of the system and its progenitor, and help us understand CR acceleration in SNRs.

  8. Fermi large area telescope detection of a break in the gamma-ray spectrum of the supernova remnant Cassiopeia A

    SciTech Connect

    Yuan, Yajie; Funk, Stefan; Lande, Joshua; Tibaldo, Luigi; Jóhannesson, Gülauger; Uchiyama, Yasunobu E-mail: funk@slac.stanford.edu E-mail: uchiyama@slac.stanford.edu

    2013-12-20

    We report on observations of the supernova remnant Cassiopeia A in the energy range from 100 MeV to 100 GeV using 44 months of observations from the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope. We perform a detailed spectral analysis of this source and report on a low-energy break in the spectrum at 1.72{sub −0.89}{sup +1.35} GeV. By comparing the results with models for the gamma-ray emission, we find that hadronic emission is preferred for the GeV energy range.

  9. Large-scale behaviour of local and entanglement entropy of the free Fermi gas at any temperature

    NASA Astrophysics Data System (ADS)

    Leschke, Hajo; Sobolev, Alexander V.; Spitzer, Wolfgang

    2016-07-01

    The leading asymptotic large-scale behaviour of the spatially bipartite entanglement entropy (EE) of the free Fermi gas infinitely extended in multidimensional Euclidean space at zero absolute temperature, T = 0, is by now well understood. Here, we present and discuss the first rigorous results for the corresponding EE of thermal equilibrium states at T\\gt 0. The leading large-scale term of this thermal EE turns out to be twice the first-order finite-size correction to the infinite-volume thermal entropy (density). Not surprisingly, this correction is just the thermal entropy on the interface of the bipartition. However, it is given by a rather complicated integral derived from a semiclassical trace formula for a certain operator on the underlying one-particle Hilbert space. But in the zero-temperature limit T\\downarrow 0, the leading large-scale term of the thermal EE considerably simplifies and displays a {ln}(1/T)-singularity which one may identify with the known logarithmic enhancement at T = 0 of the so-called area-law scaling. birthday of the ideal Fermi gas.

  10. The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Britto, R. J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Carpenter, B.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Abrusco, R.; D'Ammando, F.; de Angelis, A.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Finke, J.; Focke, W. B.; Franckowiak, A.; Fuhrmann, L.; Fukazawa, Y.; Furniss, A. K.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kataoka, J.; Kawano, T.; Krauss, F.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Leto, C.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Ojha, R.; Omodei, N.; Orienti, M.; Orlando, E.; Paggi, A.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Romani, R. W.; Salvetti, D.; Schaal, M.; Schinzel, F. K.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Sokolovsky, K. V.; Spada, F.; Spandre, G.; Spinelli, P.; Stawarz, L.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, Y.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Torresi, E.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Winer, B. L.; Wood, K. S.; Zimmer, S.

    2015-09-01

    The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected between 100 MeV and 300 GeV with a Test Statistic greater than 25, between 2008 August 4 and 2012 July 31. The 3LAC includes 1591 AGNs located at high Galactic latitudes (| b| \\gt 10^\\circ ), a 71% increase over the second catalog based on 2 years of data. There are 28 duplicate associations, thus 1563 of the 2192 high-latitude gamma-ray sources of the 3FGL catalog are AGNs. Most of them (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. Based on their gamma-ray spectral properties, these sources are evenly split between flat-spectrum radio quasars (FSRQs) and BL Lacs. The most abundant detected BL Lacs are of the high-synchrotron-peaked (HSP) type. About 50% of the BL Lacs have no measured redshifts. A few new rare outliers (HSP-FSRQs and high-luminosity HSP BL Lacs) are reported. The general properties of the 3LAC sample confirm previous findings from earlier catalogs. The fraction of 3LAC blazars in the total population of blazars listed in BZCAT remains non-negligible even at the faint ends of the BZCAT-blazar radio, optical, and X-ray flux distributions, which hints that even the faintest known blazars could eventually shine in gamma-rays at LAT-detection levels. The energy-flux distributions of the different blazar populations are in good agreement with extrapolation from earlier catalogs.

  11. Riding the First-Year Roller Coaster

    ERIC Educational Resources Information Center

    Moir, Ellen

    2013-01-01

    A teacher's first year of teaching can feel like a sink-or-swim experience. Instead of making steady progress toward becoming a great teacher, in their first year, many teachers become overwhelmed by the daily demands of their own classrooms. As founder and CEO of New Teacher Center, an organization focused on understanding and meeting the…

  12. Supporting First-Year Writing Development Online

    ERIC Educational Resources Information Center

    Krause, Kerri-Lee

    2006-01-01

    It is imperative to identify the impact of technological advancements on the quality of student learning. This article reports first-year undergraduate students' perceptions of and experiences with a Web-based writing support program. Two research questions guided the study: (1) What is the nature of first-year students' interactions with…

  13. Negotiating the Curriculum: Surviving the First Year

    ERIC Educational Resources Information Center

    Poland, Molly

    2013-01-01

    Molly Poland is a first year English and Home Economics teacher who began her career in a small Far North Queensland town. In this article, she writes about her first year teaching and the last year of her degree and the challenges she faced as both teacher and student. Reading Boomer's "Negotiating the Curriculum" forced her to think a…

  14. FERMI LARGE AREA TELESCOPE DETECTION OF GRAVITATIONAL LENS DELAYED γ-RAY FLARES FROM BLAZAR B0218+357

    SciTech Connect

    Cheung, C. C.; Grove, J. E.; Larsson, S.; Scargle, J. D.; Amin, M. A.; Blandford, R. D.; Chiang, J.; Marshall, P. J.; Bulmash, D.; Ciprini, S.; Corbet, R. H. D.; Falco, E. E.; Wood, D. L.; Ajello, M.; Bastieri, D.; Chekhtman, A.; D'Ammando, F.; Giroletti, M.; Lott, B.; and others

    2014-02-20

    Using data from the Fermi Large Area Telescope (LAT), we report the first clear γ-ray measurement of a delay between flares from the gravitationally lensed images of a blazar. The delay was detected in B0218+357, a known double-image lensed system, during a period of enhanced γ-ray activity with peak fluxes consistently observed to reach >20-50 × its previous average flux. An auto-correlation function analysis identified a delay in the γ-ray data of 11.46 ± 0.16 days (1σ) that is ∼1 day greater than previous radio measurements. Considering that it is beyond the capabilities of the LAT to spatially resolve the two images, we nevertheless decomposed individual sequences of superposing γ-ray flares/delayed emissions. In three such ∼8-10 day-long sequences within a ∼4 month span, considering confusion due to overlapping flaring emission and flux measurement uncertainties, we found flux ratios consistent with ∼1, thus systematically smaller than those from radio observations. During the first, best-defined flare, the delayed emission was detailed with a Fermi pointing, and we observed flux doubling timescales of ∼3-6 hr implying as well extremely compact γ-ray emitting regions.

  15. The Fermi Large Area Telescope: Optimizing and Then Re-Optimizing the Science Return

    NASA Astrophysics Data System (ADS)

    Atwood, W. B.

    2012-01-01

    The general concepts of how to do gamma-ray observations in space were well established and vetted by the early 1990's. In particular, the success of EGRET onboard the Compton Gamma Ray Observatory whetted the appetite for a more ambitious follow on. In parallel, advances in high-energy particle detection, spurred on by plans for the Superconducting Super Collider, provided an unprecedented opportunity for space-based detectors. The GLAST concept, now Fermi-LAT, was born at SLAC in May of 1992 and the instrument was subsequently developed by an international collaboration from France, Italy, Japan, Sweden and the United States. An overview of the original design optimization of the LAT instrument, done with the goal of imposing as few limits as possible on its applications in space, is discussed (along with some of the trials and tribulations of construction along the way to launch!). Now with over 3 years of science operations experience, the lessons-learned will be reviewed and assessed against the expectations. Finally, the ongoing re-optimization of the instrument and plans for how to extend the LAT's science window into the future are discussed.

  16. Timing Gamma-ray Pulsars with the Fermi Large Area Telescope: Timing Noise and Astrometry

    NASA Astrophysics Data System (ADS)

    Kerr, M.; Ray, P. S.; Johnston, S.; Shannon, R. M.; Camilo, F.

    2015-12-01

    We have constructed timing solutions for 81 γ-ray pulsars covering more than five years of Fermi data. The sample includes 37 radio-quiet or radio-faint pulsars which cannot be timed with other telescopes. These timing solutions and the corresponding pulse times of arrival are prerequisites for further study, e.g., phase-resolved spectroscopy or searches for mode switches. Many γ-ray pulsars are strongly affected by timing noise (TN), and we present a new method for characterizing the noise process and mitigating its effects on other facets of the timing model. We present an analysis of TN over the population using a new metric for characterizing its strength and spectral shape, namely, its time-domain correlation. The dependence of the strength on ν and \\dot{ν } is in good agreement with previous studies. We find that noise process power spectra S(f) for unrecycled pulsars are steep, with strong correlations over our entire data set and spectral indices S(f)\\propto {f}-α of α ˜ 5-9. One possible explanation for these results is the occurrence of unmodeled, episodic “microglitches.” Finally, we show that our treatment of TN results in robust parameter estimation, and in particular we measure a precise timing position for each pulsar. We extensively validate our results with multi-wavelength astrometry, and using our updated position, we firmly identify the X-ray counterpart of PSR J1418-6058.

  17. Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data.

    PubMed

    Ackermann, M; Albert, A; Anderson, B; Atwood, W B; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Blandford, R D; Bloom, E D; Bonino, R; Bottacini, E; Brandt, T J; Bregeon, J; Bruel, P; Buehler, R; Caliandro, G A; Cameron, R A; Caputo, R; Caragiulo, M; Caraveo, P A; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cuoco, A; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Desiante, R; Digel, S W; Di Venere, L; Drell, P S; Drlica-Wagner, A; Essig, R; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Gomez-Vargas, G A; Grenier, I A; Guiriec, S; Gustafsson, M; Hays, E; Hewitt, J W; Horan, D; Jogler, T; Jóhannesson, G; Kuss, M; Larsson, S; Latronico, L; Li, J; Li, L; Llena Garde, M; Longo, F; Loparco, F; Lubrano, P; Malyshev, D; Mayer, M; Mazziotta, M N; McEnery, J E; Meyer, M; Michelson, P F; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Murgia, S; Nuss, E; Ohsugi, T; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Ritz, S; Sánchez-Conde, M; Schulz, A; Sehgal, N; Sgrò, C; Siskind, E J; Spada, F; Spandre, G; Spinelli, P; Strigari, L; Tajima, H; Takahashi, H; Thayer, J B; Tibaldo, L; Torres, D F; Troja, E; Vianello, G; Werner, M; Winer, B L; Wood, K S; Wood, M; Zaharijas, G; Zimmer, S

    2015-12-04

    The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass ≲100  GeV annihilating via quark and τ-lepton channels.

  18. Discovery of millisecond pulsars in radio searches of southern Fermi Large Area Telescope sources

    NASA Astrophysics Data System (ADS)

    Keith, M. J.; Johnston, S.; Ray, P. S.; Ferrara, E. C.; Saz Parkinson, P. M.; Çelik, Ö.; Belfiore, A.; Donato, D.; Cheung, C. C.; Abdo, A. A.; Camilo, F.; Freire, P. C. C.; Guillemot, L.; Harding, A. K.; Kramer, M.; Michelson, P. F.; Ransom, S. M.; Romani, R. W.; Smith, D. A.; Thompson, D. J.; Weltevrede, P.; Wood, K. S.

    2011-06-01

    Using the Parkes Radio Telescope, we have carried out deep observations of 11 unassociated gamma-ray sources. Periodicity searches of these data have discovered two millisecond pulsars, PSR J1103-5403 (1FGL J1103.9-5355) and PSR J2241-5236 (1FGL J2241.9-5236), and a long-period pulsar, PSR J1604-44 (1FGL J1604.7-4443). In addition, we searched for but did not detect any radio pulsations from six gamma-ray pulsars discovered by the Fermi satellite to a level of ˜0.04 mJy (for pulsars with a 10 per cent duty cycle). The timing of the millisecond pulsar PSR J1103-5403 has shown that its position is 9 arcmin from the centroid of the gamma-ray source. Since these observations were carried out, independent evidence has shown that 1FGL J1103.9-5355 is associated with the flat spectrum radio source PKS 1101-536. It appears certain that the pulsar is not associated with the gamma-ray source, despite the seemingly low probability of a chance detection of a radio millisecond pulsar. We consider that PSR J1604-44 is a chance discovery of a weak, long-period pulsar and is unlikely to be associated with 1FGL J1604.7-4443. PSR J2241-5236 has a spin period of 2.2 ms and orbits a very low mass companion with a 3.5-h orbital period. The relatively high flux density and low dispersion measure of PSR J2241-5236 make it an excellent candidate for high precision timing experiments. The gamma rays of 1FGL J2241.9-5236 have a spectrum that is well modelled by a power law with an exponential cut-off, and phase binning with the radio ephemeris results in a multipeaked gamma-ray pulse profile. Observations with Chandra have identified a coincident X-ray source within 0.1 arcsec of the position of the pulsar obtained by radio timing.

  19. Observations of M31 and M33 with the Fermi Large Area Telescope: A Galactic Center Excess in Andromeda?

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiaro, G.; Ciprini, S.; Costanza, F.; Cutini, S.; D’Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Favuzzi, C.; Funk, S.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Green, D.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hayashi, K.; Hou, X.; Jóhannesson, G.; Kamae, T.; Knödlseder, J.; Kong, A. K. H.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Malyshev, D.; Manfreda, A.; Martin, P.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, O.; Sánchez-Conde, M.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Tanaka, K.; Tibaldo, L.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Wang, J. C.; Wood, K. S.; Wood, M.; Zaharijas, G.; Zhou, M.

    2017-02-01

    The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in the Milky Way (MW) and in other, external, star-forming galaxies. Using 2 yr of observations with the Fermi LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit has been derived for the other nearby galaxy M33. We revisited the gamma-ray emission in the direction of M31 and M33 using more than 7 yr of LAT Pass 8 data in the energy range 0.1{--}100 {GeV}, presenting detailed morphological and spectral analyses. M33 remains undetected, and we computed an upper limit of 2.0× {10}-12 {erg} {{cm}}-2 {{{s}}}-1 on the 0.1{--}100 {GeV} energy flux (95% confidence level). This revised upper limit remains consistent with the observed correlation between gamma-ray luminosity and star formation rate tracers and implies an average CR density in M33 that is at most half of that of the MW. M31 is detected with a significance of nearly 10σ . Its spectrum is consistent with a power law with photon index {{Γ }}=2.4+/- {0.1}{stat+{syst}} and a 0.1{--}100 {GeV} energy flux of (5.6+/- {0.6}{stat+{syst}})× {10}-12 {erg} {{cm}}-2 {{{s}}}-1. M31 is detected to be extended with a 4σ significance. The spatial distribution of the emission is consistent with a uniform-brightness disk with a radius of 0.°4 and no offset from the center of the galaxy, but nonuniform intensity distributions cannot be excluded. The flux from M31 appears confined to the inner regions of the galaxy and does not fill the disk of the galaxy or extend far from it. The gamma-ray signal is not correlated with regions rich in gas or star formation activity, which suggests that the emission is not interstellar in origin, unless the energetic particles radiating in gamma rays do not originate in recent star formation. Alternative and nonexclusive interpretations are that the emission results from a population of millisecond pulsars

  20. Search for gamma-ray emission from dark matter annihilation in the large magellanic cloud with the fermi large area telescope

    NASA Astrophysics Data System (ADS)

    Buckley, Matthew R.; Charles, Eric; Gaskins, Jennifer M.; Brooks, Alyson M.; Drlica-Wagner, Alex; Martin, Pierrick; Zhao, Geng

    2015-05-01

    At a distance of 50 kpc and with a dark matter mass of ˜1 010 M⊙ , the large magellanic cloud (LMC) is a natural target for indirect dark matter searches. We use five years of data from the Fermi Large Area Telescope (LAT) and updated models of the gamma-ray emission from standard astrophysical components to search for a dark matter annihilation signal from the LMC. We perform a rotation curve analysis to determine the dark matter distribution, setting a robust minimum on the amount of dark matter in the LMC, which we use to set conservative bounds on the annihilation cross section. The LMC emission is generally very well described by the standard astrophysical sources, with at most a 1 - 2 σ excess identified near the kinematic center of the LMC once systematic uncertainties are taken into account. We place competitive bounds on the dark matter annihilation cross section as a function of dark matter particle mass and annihilation channel.

  1. Search for gamma-ray spectral lines with the Fermi Large Area Telescope and dark matter implications

    SciTech Connect

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D’Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Essig, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hayashida, M.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Inoue, Y.; Izaguirre, E.; Jogler, T.; Kamae, T.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Malyshev, D.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siegal-Gaskins, J.; Siskind, E. J.; Snyder, A.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Tinivella, M.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zaharijas, G.; Zimmer, S.

    2013-10-22

    Weakly interacting massive particles (WIMPs) are a theoretical class of particles that are excellent dark matter candidates. WIMP annihilation or decay may produce essentially monochromatic γ rays detectable by the Fermi Large Area Telescope (LAT) against the astrophysical γ -ray emission of the Galaxy. We have searched for spectral lines in the energy range 5–300 GeV using 3.7 years of data, reprocessed with updated instrument calibrations and an improved energy dispersion model compared to the previous Fermi-LAT Collaboration line searches. We searched in five regions selected to optimize sensitivity to different theoretically motivated dark matter density distributions. We did not find any globally significant lines in our a priori search regions and present 95% confidence limits for annihilation cross sections of self-conjugate WIMPs and decay lifetimes. Our most significant fit occurred at 133 GeV in our smallest search region and had a local significance of 3.3 standard deviations, which translates to a global significance of 1.5 standard deviations. We discuss potential systematic effects in this search, and examine the feature at 133 GeV in detail. We find that the use both of reprocessed data and of additional information in the energy dispersion model contributes to the reduction in significance of the linelike feature near 130 GeV relative to significances reported in other works. We also find that the feature is narrower than the LAT energy resolution at the level of 2 to 3 standard deviations, which somewhat disfavors the interpretation of the 133 GeV feature as a real WIMP signal.

  2. Anti-Semitism in First Year Composition

    ERIC Educational Resources Information Center

    Levy, Matthew; Myers, Gerald M.

    2011-01-01

    Robert Cohen, Assistant Professor English at Fairbanks University, has just completed a contentious meeting of his First Year Composition class, which had discussed a paper written by one of the students. Joe Anderson's paper contained statements that have been historically used as anti-Semitic slogans. Cohen attempted to avoid embarrassing…

  3. Sustainability and First-Year Programs

    ERIC Educational Resources Information Center

    Messineo, Melinda

    2012-01-01

    To truly impact sustainability practices, campuses need to influence the overall campus culture, including that which is fostered through first-year programs. Institutions of higher education have made a commitment to make a difference for sustainability, not only by changing curriculum, but by changing the entire institutional culture. This…

  4. Individualized Cooperative Education (First Year). Teacher Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for competencies to be taught to all Oklahoma first-year cooperative education students. Teachers of general cooperative programs (such as individualized cooperative education) may want to use the document as their basic text, but teachers in other vocational areas may prefer to use it as a supplement.…

  5. SerVermont--The First Year. 1986.

    ERIC Educational Resources Information Center

    Parsons, Cynthia

    SerVermont is a volunteer program for high school students. The program stresses public service in the community and is intended to teach students the value of personal volunteer service to their local communities. During SerVermont's first year of operation, 11 high schools were awarded minigrants to be used in developing programs in which…

  6. Twelve Steps to a Winning First Year

    ERIC Educational Resources Information Center

    Hodges, Karen

    2009-01-01

    This article offers 12 steps to jumpstart a new school librarian's career. Being the information specialist will be both challenging and rewarding as one undertakes a myriad of activities. These 12 steps will help a new school librarian's first year successful.

  7. Learning Styles in First Year Medical Students.

    ERIC Educational Resources Information Center

    Chessell, Gwen

    1986-01-01

    Reports on a study done at Aberdeen University (England) which assessed the learning styles of first-year medical students. Results indicated that these students scored higher than other students in achievement (including study methods and competitiveness) and prediction for success. Includes the instrument used. (TW)

  8. Strategies for Teaching First-Year Composition.

    ERIC Educational Resources Information Center

    Roen, Duane, Ed.; Pantoja, Veronica, Ed.; Yena, Lauren, Ed.; Miller, Susan K., Ed.; Waggoner, Eric, Ed.

    This book presents 93 essays that offer guidance, reassurance, and commentary on the many activities leading up to and surrounding classroom instruction in first-year composition. Essays in the book are written by instructors who teach in community colleges, liberal arts colleges, state university systems, and research institutions. The 14 section…

  9. The first year of routine Herschel observations

    NASA Astrophysics Data System (ADS)

    2011-06-01

    MEETING REPORT The successful completion of the first year of routine science operations of ESA's Herschel Space Observatory was marked by a Specialist Discussion Meeting of the RAS held in January 2011. A few of the early science highlights from the mission were presented. Derek Ward-Thompson and David Clements summarize.

  10. Radio Follow-up on All Unassociated Gamma-Ray Sources from the Third Fermi Large Area Telescope Source Catalog

    NASA Astrophysics Data System (ADS)

    Schinzel, Frank K.; Petrov, Leonid; Taylor, Gregory B.; Edwards, Philip G.

    2017-04-01

    The third Fermi Large Area Telescope γ-ray source catalog (3FGL) contains over 1000 objects for which there is no known counterpart at other wavelengths. The physical origin of the γ-ray emission from those objects is unknown. Such objects are commonly referred to as unassociated and mostly do not exhibit significant γ-ray flux variability. We performed a survey of all unassociated γ-ray sources found in 3FGL using the Australia Telescope Compact Array and Very Large Array in the range 4.0–10.0 GHz. We found 2097 radio candidates for association with γ-ray sources. The follow-up with very long baseline interferometry for a subset of those candidates yielded 142 new associations with active galactic nuclei that are γ-ray sources, provided alternative associations for seven objects, and improved positions for another 144 known associations to the milliarcsecond level of accuracy. In addition, for 245 unassociated γ-ray sources we did not find a single compact radio source above 2 mJy within 3σ of their γ-ray localization. A significant fraction of these empty fields, 39%, are located away from the Galactic plane. We also found 36 extended radio sources that are candidates for association with a corresponding γ-ray object, 19 of which are most likely supernova remnants or H ii regions, whereas 17 could be radio galaxies.

  11. Skills, Learning Styles and Success of First-Year Undergraduates

    ERIC Educational Resources Information Center

    Goldfinch, Judy; Hughes, Moira

    2007-01-01

    This study investigates the relationships between students' confidence in their generic skills on entry to university, their learning styles and their academic performance in first year. Research based on a large cohort of Scottish undergraduates found that students generally entered university feeling very confident that they already possessed…

  12. An Innovative Learning Model for Computation in First Year Mathematics

    ERIC Educational Resources Information Center

    Tonkes, E. J.; Loch, B. I.; Stace, A. W.

    2005-01-01

    MATLAB is a sophisticated software tool for numerical analysis and visualization. The University of Queensland has adopted Matlab as its official teaching package across large first year mathematics courses. In the past, the package has met severe resistance from students who have not appreciated their computational experience. Several main…

  13. Integrated Chemistry and Biology for First-Year College Students

    ERIC Educational Resources Information Center

    Abdella, Beth R. J.; Walczak, Mary M.; Kandl, Kim A.; Schwinefus, Jeffrey J.

    2011-01-01

    A three-course sequence for first-year students that integrates beginning concepts in biology and chemistry has been designed. The first two courses that emphasize chemistry and its capacity to inform biological applications are described here. The content of the first course moves from small to large particles with an emphasis on membrane…

  14. Nebraska wind resource assessment first year results

    SciTech Connect

    Hurley, P.J.F.; Vilhauer, R.; Stooksbury, D.

    1996-12-31

    This paper presents the preliminary results from a wind resource assessment program in Nebraska sponsored by the Nebraska Power Association. During the first year the measured annual wind speed at 40 meters ranged from 6.5 - 7.5 m/s (14.6 - 16.8 mph) at eight stations across the state. The site selection process is discussed as well as an overview of the site characteristics at the monitoring locations. Results from the first year monitoring period including data recovery rate, directionality, average wind speeds, wind shear, and turbulence intensity are presented. Results from the eight sites are qualitatively compared with other midwest and west coast locations. 5 figs., 2 tabs.

  15. SPEAR 3: the First Year of Operation

    SciTech Connect

    Hettel, R.O.; /SLAC

    2006-02-10

    The first electrons were accumulated in the newly completed 3-GeV SPEAR 3 storage ring on December 15, 2003, five days after the beginning of commissioning. By mid-January of 2004, 100 mA were stored, the maximum current allowed in the first phase of SPEAR 3 operation, and ring characterization and tuning continued until early March when the first photon beam line was opened for users. After the first year of operation the SPEAR 3 beam properties and ring performance had been extensively measured. These include micron stability using slow orbit feedback, an emittance coupling of {approx}0.1% and 50-h lifetimes. The performance of SPEAR 3 during its first year of commissioning and operation and the improvement plans are described.

  16. First Year Experience: How We Can Better Assist First-Year International Students in Higher Education

    ERIC Educational Resources Information Center

    Yan, Zi; Sendall, Patricia

    2016-01-01

    While many American colleges and universities are providing a First Year Experience (FYE) course or program for their first year students, those programs are not often customized to take into account international students' (IS) unique challenges. Using quantitative and qualitative methods, this study evaluated a FYE course that was customized for…

  17. Gamma-ray Emission from PSR J0007+7303 Using Seven Years of Fermi Large Area Telescope Observations

    NASA Astrophysics Data System (ADS)

    Li, Jian; Torres, Diego F.; de Oña Wilhelmi, Emma; Rea, Nanda; Martin, Jonatan

    2016-11-01

    Based on more than seven years of Fermi Large Area Telescope Pass 8 data, we report on a detailed analysis of the bright gamma-ray pulsar (PSR) J0007+7303. We confirm that PSR J0007+7303 is significantly detected as a point source also during the off-peak phases with a test statistic value of 262 (˜16σ). In the description of the off-peak spectrum of PSR J0007+7303, a power law with an exponential cutoff at 2.7 ± 1.2 ± 1.3 GeV (the first/second uncertainties correspond to statistical/systematic errors) is preferred over a single power law at a level of 3.5σ. The possible existence of a cutoff hints at a magnetospheric origin of the emission. In addition, no extended gamma-ray emission is detected that is compatible with either the supernova remnant (CTA 1) or the very high-energy (>100 GeV) pulsar wind nebula. A flux upper limit of 6.5 × 10-12 erg cm-2 s-1 in the energy range 10-300 GeV is reported, for an extended source assuming the morphology of the VERITAS detection. During on-peak phases, a sub-exponential cutoff is significantly preferred (˜11σ) for representing the spectral energy distribution, in both the phase-averaged and phase-resolved spectra. Three glitches are detected during the observation period and we found no flux variability at the time of the glitches or in the long-term behavior. We also report the discovery of a previously unknown gamma-ray source in the vicinity of PSR J0007+7303, Fermi J0020+7328, which we associate with the z = 1.781 quasar S5 0016+73. A concurrent analysis of this source is needed to correctly characterize the behavior of CTA 1 and it is also presented in the paper.

  18. Dark Matter Constraints from Observations of 25 Milky Way Satellite Galaxies with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Albert, A.; Anderson, B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bouvier, A.; Brandt, T. J.; Hays, E.; Perkins, J. S.

    2013-01-01

    The dwarf spheroidal satellite galaxies of the Milky Way are some of the most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are widely considered to be among the most promising targets for the indirect detection of dark matter via gamma rays. Here we report on gamma ray observations of 25 Milky Way dwarf spheroidal satellite galaxies based on 4 years of Fermi Large Area Telescope (LAT) data. None of the dwarf galaxies are significantly detected in gamma rays, and we present gamma ray flux upper limits between 500MeV and 500 GeV. We determine the dark matter content of 18 dwarf spheroidal galaxies from stellar kinematic data and combine LAT observations of 15 dwarf galaxies to constrain the dark matter annihilation cross section. We set some of the tightest constraints to date on the annihilation of dark matter particles with masses between 2 GeV and 10TeV into prototypical standard model channels. We find these results to be robust against systematic uncertainties in the LAT instrument performance, diffuse gamma ray background modeling, and assumed dark matter density profile.

  19. Constraining dark matter models from a combined analysis of Milky Way satellites with the Fermi Large Area Telescope.

    PubMed

    Ackermann, M; Ajello, M; Albert, A; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Cañadas, B; Caraveo, P A; Casandjian, J M; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Falletti, L; Favuzzi, C; Fegan, S J; Ferrara, E C; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Guiriec, S; Gustafsson, M; Hadasch, D; Hayashida, M; Hays, E; Hughes, R E; Jeltema, T E; Jóhannesson, G; Johnson, R P; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Lionetto, A M; Llena Garde, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Naumann-Godo, M; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pivato, G; Porter, T A; Profumo, S; Rainò, S; Razzano, M; Reimer, A; Reimer, O; Ritz, S; Roth, M; Sadrozinski, H F-W; Sbarra, C; Scargle, J D; Schalk, T L; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Strigari, L; Suson, D J; Tajima, H; Takahashi, H; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Troja, E; Uchiyama, Y; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Wood, M; Yang, Z; Zimmer, S; Kaplinghat, M; Martinez, G D

    2011-12-09

    Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10(-26)  cm3  s(-1) at 5 GeV to about 5×10(-23)   cm3  s(-1) at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section (∼3×10(-26)  cm3  s(-1) for a purely s-wave cross section), without assuming additional boost factors.

  20. Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bladford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Ferrara, E. C.; Gehrels, N.; Hays, E.; Scargle, J. D.; Thompson, D. J.; Troja, E.

    2011-01-01

    Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10(exp -26) cm(exp 3) / s at 5 GeV to about 5 X 10(exp -23) cm(exp 3)/ s at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section (approx 3 X 10(exp -26) cm(exp 3)/s for a purely s-wave cross section), without assuming additional boost factors.

  1. DETECTION OF THE PULSAR WIND NEBULA HESS J1825-137 WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Grondin, M.-H.; Lemoine-Goumard, M.; Hinton, J. A.; Camilo, F.; Cognard, I.; Theureau, G.; Freire, P. C. C.; Guillemot, L.; Grove, J. E.; Johnston, S.; Possenti, A.; Skilton, J. L. E-mail: lemoine@cenbg.in2p3.fr E-mail: ave@stanford.edu

    2011-09-01

    We announce the discovery of 1-100 GeV gamma-ray emission from the archetypal TeV pulsar wind nebula (PWN) HESS J1825-137 using 20 months of survey data from the Fermi-Large Area Telescope (LAT). The gamma-ray emission detected by the LAT is significantly spatially extended, with a best-fit rms extension of {sigma} = 0.{sup 0}56 {+-} 0.{sup 0}07 for an assumed Gaussian model. The 1-100 GeV LAT spectrum of this source is well described by a power law with a spectral index of 1.38 {+-} 0.12 {+-} 0.16 and an integral flux above 1 GeV of (6.50 {+-} 0.21 {+-} 3.90) x 10{sup -9} cm{sup -2} s{sup -1}. The first errors represent the statistical errors on the fit parameters, while the second ones are the systematic uncertainties. Detailed morphological and spectral analyses bring new constraints on the energetics and magnetic field of the PWN system. The spatial extent and hard spectrum of the GeV emission are consistent with the picture of an inverse Compton origin of the GeV-TeV emission in a cooling-limited nebula powered by the pulsar PSR J1826-1334.

  2. Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data.

    PubMed

    Abdollahi, S; Ackermann, M; Ajello, M; Albert, A; Atwood, W B; Baldini, L; Barbiellini, G; Bellazzini, R; Bissaldi, E; Bloom, E D; Bonino, R; Bottacini, E; Brandt, T J; Bruel, P; Buson, S; Caragiulo, M; Cavazzuti, E; Chekhtman, A; Ciprini, S; Costanza, F; Cuoco, A; Cutini, S; D'Ammando, F; de Palma, F; Desiante, R; Digel, S W; Di Lalla, N; Di Mauro, M; Di Venere, L; Donaggio, B; Drell, P S; Favuzzi, C; Focke, W B; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giordano, F; Giroletti, M; Green, D; Guiriec, S; Harding, A K; Jogler, T; Jóhannesson, G; Kamae, T; Kuss, M; Larsson, S; Latronico, L; Li, J; Longo, F; Loparco, F; Lubrano, P; Magill, J D; Malyshev, D; Manfreda, A; Mazziotta, M N; Meehan, M; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Negro, M; Nuss, E; Ohsugi, T; Omodei, N; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Principe, G; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Sgrò, C; Simone, D; Siskind, E J; Spada, F; Spandre, G; Spinelli, P; Strong, A W; Tajima, H; Thayer, J B; Torres, D F; Troja, E; Vandenbroucke, J; Zaharijas, G; Zimmer, S

    2017-03-03

    The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10^{-3}. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

  3. Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope

    SciTech Connect

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T.H.; Buson, S.; /more authors..

    2012-09-14

    Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10{sup -26} cm{sup 3} s{sup -1} at 5 GeV to about 5 x 10{sup -23} cm{sup 3} s{sup -1} at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section ({approx}3 x 10{sup -26} cm{sup 3} s{sup -1} for a purely s-wave cross section), without assuming additional boost factors.

  4. Fermi-Large Area Telescope Observations of the Exceptional Gamma-Ray Flare from 3C 279 in 2015 June

    NASA Astrophysics Data System (ADS)

    Paliya, Vaidehi S.

    2015-08-01

    An exceptional γ-ray outburst from 3C 279 was detected by the Fermi-Large Area Telescope (LAT) in 2015 June. In the energy range of 0.1-300 GeV, the highest flux measured is (39.1 ± 2.5) × 10-6 {ph} {{cm}}-2 {{{s}}}-1, which is the highest γ-ray flux ever detected from 3C 279, exceeding the previous historically brightest flare observed by EGRET in 1996. The high activity period consists of three major flares with the last one being the brightest. All but one flare show a faster rise and slower decay pattern, and at the peak of the activity, the γ-ray spectrum is found to show a clear signature of break/curvature. The obtained spectral parameters hint that the peak of the inverse Compton emission lies in the LAT energy range (around ˜1 GeV), which is in contrast to that seen during the 2013 December and 2014 April γ-ray flares of 3C 279. From the γγ pair opacity arguments, the minimum Doppler factor is estimated to be 14, and the location of the γ-ray emitting region is found to be either at the outer edge of the broad line region or farther out from it.

  5. Dark matter constraints from observations of 25 Milky Way satellite galaxies with the Fermi Large Area Telescope

    SciTech Connect

    Ackermann, M.; et al.

    2014-02-11

    The dwarf spheroidal satellite galaxies of the Milky Way are some of the most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are widely considered to be among the most promising targets for the indirect detection of dark matter via gamma rays. Here we report on gamma-ray observations of 25 Milky Way dwarf spheroidal satellite galaxies based on 4 years of Fermi Large Area Telescope (LAT) data. None of the dwarf galaxies are significantly detected in gamma rays, and we present gamma-ray flux upper limits between 500 MeV and 500 GeV. We determine the dark matter content of 18 dwarf spheroidal galaxies from stellar kinematic data and combine LAT observations of 15 dwarf galaxies to constrain the dark matter annihilation cross section. We set some of the tightest constraints to date on the the annihilation of dark matter particles with masses between 2 GeV and 10 TeV into prototypical Standard Model channels. We find these results to be robust against systematic uncertainties in the LAT instrument performance, diffuse gamma-ray background modeling, and assumed dark matter density profile.

  6. Inferred Cosmic-Ray Spectrum from Fermi Large Area Telescope γ-Ray Observations of Earth’s Limb

    SciTech Connect

    Ackermann, M.; et al.

    2014-04-17

    Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly-discovered features may offer a clue to the origin of high-energy CRs. We use the ${\\it Fermi}$ Large Area Telescope observations of the $\\gamma$-ray emission from the Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range $\\sim 90~$GeV-$6~$TeV (derived from a photon energy range $15~$GeV-$1~$TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index $2.68 \\pm 0.04$ and $2.61 \\pm 0.08$ above $\\sim 200~$GeV, respectively.

  7. Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data

    NASA Astrophysics Data System (ADS)

    Abdollahi, S.; Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bruel, P.; Buson, S.; Caragiulo, M.; Cavazzuti, E.; Chekhtman, A.; Ciprini, S.; Costanza, F.; Cuoco, A.; Cutini, S.; D'Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Donaggio, B.; Drell, P. S.; Favuzzi, C.; Focke, W. B.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Green, D.; Guiriec, S.; Harding, A. K.; Jogler, T.; Jóhannesson, G.; Kamae, T.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lubrano, P.; Magill, J. D.; Malyshev, D.; Manfreda, A.; Mazziotta, M. N.; Meehan, M.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Tajima, H.; Thayer, J. B.; Torres, D. F.; Troja, E.; Vandenbroucke, J.; Zaharijas, G.; Zimmer, S.; Fermi-LAT Collaboration

    2017-03-01

    The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10-3 . We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

  8. Optical archival spectra of blazar candidates of uncertain type in the 3rd Fermi Large Area Telescope Catalog

    NASA Astrophysics Data System (ADS)

    Álvarez Crespo, N.; Massaro, F.; D'Abrusco, R.; Landoni, M.; Masetti, N.; Chavushyan, V.; Jiménez-Bailón, E.; La Franca, F.; Milisavljevic, D.; Paggi, A.; Patiño-Álvarez, V.; Ricci, F.; Smith, Howard A.

    2016-09-01

    Despite the fact that blazars constitute the rarest class among active galactic nuclei (AGNs) they are the largest known population of associated γ-ray sources. Many of the γ-ray objects listed in the Fermi-Large Area Telescope Third Source catalog (3FGL) are classified as blazar candidates of uncertain type (BCUs), either because they show multifrequency behavior similar to blazars but lacking optical spectra in the literature, or because the quality of such spectra is too low to confirm their nature. Here we select, out of 585 BCUs in the 3FGL, 42 BCUs which we identify as probable blazars by their WISE infrared colors and which also have optical spectra that are available in the Sloan Digital Sky Survey (SDSS) and/or Six-Degree Field Galaxy Survey Database (6dFGS). We confirm the blazar nature of all of the sources. We furthermore conclude that 28 of them are BL Lacs, 8 are radio-loud quasars with flat radio spectrum and 6 are BL Lac whose emission is dominated by their host galaxy.

  9. Inferred Cosmic-Ray Spectrum from Fermi Large Area Telescope γ-Ray Observations of Earth's Limb

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Bouvier, A.; Brandt, T. J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; Dalton, M.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Di Venere, L.; do Couto e Silva, E.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hayashi, K.; Hewitt, J. W.; Horan, D.; Hou, X.; Hughes, R. E.; Inoue, Y.; Jackson, M. S.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Kawano, T.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Okumura, A.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Ritz, S.; Roth, M.; Schaal, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Strong, A. W.; Takahashi, H.; Takeuchi, Y.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Tronconi, V.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Werner, M.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Fermi LAT Collaboration

    2014-04-01

    Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the γ-ray emission from Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range ˜90 GeV-6 TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68±0.04 and 2.61±0.08 above ˜200 GeV, respectively.

  10. OBSERVATIONS OF THE YOUNG SUPERNOVA REMNANT RX J1713.7-3946 WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Baring, M. G.; Bastieri, D.; Bonamente, E.; Bouvier, A.; Brandt, T. J.; Brigida, M.; Bruel, P. E-mail: funk@slac.stanford.edu

    2011-06-10

    We present observations of the young supernova remnant (SNR) RX J1713.7-3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0.{sup 0}55 {+-} 0.{sup 0}04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7-3946. The spectrum of the source can be described by a very hard power law with a photon index of {Gamma} = 1.5 {+-} 0.1 that coincides in normalization with the steeper H.E.S.S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.

  11. Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cañadas, B.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Do Couto E Silva, E.; Drell, P. S.; Drlica-Wagner, A.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hayashida, M.; Hays, E.; Hughes, R. E.; Jeltema, T. E.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lionetto, A. M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Parent, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T. A.; Profumo, S.; Rainò, S.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Roth, M.; Sadrozinski, H. F.-W.; Sbarra, C.; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Strigari, L.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tinivella, M.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zimmer, S.; Kaplinghat, M.; Martinez, G. D.

    2011-12-01

    Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10-26cm3s-1 at 5 GeV to about 5×10-23cm3s-1 at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section (˜3×10-26cm3s-1 for a purely s-wave cross section), without assuming additional boost factors.

  12. Inferred cosmic-ray spectrum from Fermi large area telescope γ-ray observations of Earth's limb.

    PubMed

    Ackermann, M; Ajello, M; Albert, A; Allafort, A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bloom, E D; Bonamente, E; Bottacini, E; Bouvier, A; Brandt, T J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Cecchi, C; Charles, E; Chaves, R C G; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; Dalton, M; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Di Venere, L; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Gomez-Vargas, G A; Grenier, I A; Grove, J E; Guiriec, S; Gustafsson, M; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hewitt, J W; Horan, D; Hou, X; Hughes, R E; Inoue, Y; Jackson, M S; Jogler, T; Jóhannesson, G; Johnson, A S; Kamae, T; Kawano, T; Knödlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Mayer, M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nemmen, R; Nuss, E; Ohsugi, T; Okumura, A; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Ritz, S; Roth, M; Schaal, M; Schulz, A; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Takahashi, H; Takeuchi, Y; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Tronconi, V; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Werner, M; Winer, B L; Wood, K S; Wood, M; Yang, Z

    2014-04-18

    Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the γ-ray emission from Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range ∼90  GeV-6  TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68±0.04 and 2.61±0.08 above ∼200  GeV, respectively.

  13. The First Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cannon, A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Celotti, A.; Charles, E.; Chekhtman, A.; Chen, A. W.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Costamante, L.; Cotter, G.; Cutini, S.; D'Elia, V.; Dermer, C. D.; de Angelis, A.; de Palma, F.; De Rosa, A.; Digel, S. W.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Escande, L.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grandi, P.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Healey, S. E.; Hill, A. B.; Horan, D.; Hughes, R. E.; Iafrate, G.; Itoh, R.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lavalley, C.; Lemoine-Goumard, M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Malaguti, G.; Massaro, E.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; McGlynn, S.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piranomonte, S.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Ripken, J.; Ritz, S.; Rodriguez, A. Y.; Romani, R. W.; Roth, M.; Ryde, F.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sgrò, C.; Shaw, M. S.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, J.-L.; Stawarz, Ł.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Taylor, G. B.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Ubertini, P.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Villata, M.; Vitale, V.; Waite, A. P.; Wallace, E.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.

    2010-05-01

    We present the first catalog of active galactic nuclei (AGNs) detected by the Large Area Telescope (LAT), corresponding to 11 months of data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 γ-ray sources located at high Galactic latitudes (|b|>10°) that are detected with a test statistic greater than 25 and associated statistically with AGNs. Some LAT sources are associated with multiple AGNs, and consequently, the catalog includes 709 AGNs, comprising 300 BL Lacertae objects, 296 flat-spectrum radio quasars, 41 AGNs of other types, and 72 AGNs of unknown type. We also classify the blazars based on their spectral energy distributions as archival radio, optical, and X-ray data permit. In addition to the formal 1LAC sample, we provide AGN associations for 51 low-latitude LAT sources and AGN "affiliations" (unquantified counterpart candidates) for 104 high-latitude LAT sources without AGN associations. The overlap of the 1LAC with existing γ-ray AGN catalogs (LBAS, EGRET, AGILE, Swift, INTEGRAL, TeVCat) is briefly discussed. Various properties—such as γ-ray fluxes and photon power-law spectral indices, redshifts, γ-ray luminosities, variability, and archival radio luminosities—and their correlations are presented and discussed for the different blazar classes. We compare the 1LAC results with predictions regarding the γ-ray AGN populations, and we comment on the power of the sample to address the question of the blazar sequence.

  14. Recursive sequences in first-year calculus

    NASA Astrophysics Data System (ADS)

    Krainer, Thomas

    2016-02-01

    This article provides ready-to-use supplementary material on recursive sequences for a second-semester calculus class. It equips first-year calculus students with a basic methodical procedure based on which they can conduct a rigorous convergence or divergence analysis of many simple recursive sequences on their own without the need to invoke inductive arguments as is typically required in calculus textbooks. The sequences that are accessible to this kind of analysis are predominantly (eventually) monotonic, but also certain recursive sequences that alternate around their limit point as they converge can be considered.

  15. Search for gamma-ray emission from dark matter annihilation in the large magellanic cloud with the fermi large area telescope

    DOE PAGES

    Buckley, Matthew R.; Charles, Eric; Gaskins, Jennifer M.; ...

    2015-05-05

    At a distance of 50 kpc and with a dark matter mass of ~1010 M⊙, the large magellanic cloud (LMC) is a natural target for indirect dark matter searches. We use five years of data from the Fermi Large Area Telescope (LAT) and updated models of the gamma-ray emission from standard astrophysical components to search for a dark matter annihilation signal from the LMC. We perform a rotation curve analysis to determine the dark matter distribution, setting a robust minimum on the amount of dark matter in the LMC, which we use to set conservative bounds on the annihilation cross section.more » The LMC emission is generally very well described by the standard astrophysical sources, with at most a 1–2σ excess identified near the kinematic center of the LMC once systematic uncertainties are taken into account. As a result, we place competitive bounds on the dark matter annihilation cross section as a function of dark matter particle mass and annihilation channel.« less

  16. Search for gamma-ray emission from dark matter annihilation in the large magellanic cloud with the fermi large area telescope

    SciTech Connect

    Buckley, Matthew R.; Charles, Eric; Gaskins, Jennifer M.; Brooks, Alyson M.; Drlica-Wagner, Alex; Martin, Pierrick; Zhao, Geng

    2015-05-05

    At a distance of 50 kpc and with a dark matter mass of ~1010 M, the large magellanic cloud (LMC) is a natural target for indirect dark matter searches. We use five years of data from the Fermi Large Area Telescope (LAT) and updated models of the gamma-ray emission from standard astrophysical components to search for a dark matter annihilation signal from the LMC. We perform a rotation curve analysis to determine the dark matter distribution, setting a robust minimum on the amount of dark matter in the LMC, which we use to set conservative bounds on the annihilation cross section. The LMC emission is generally very well described by the standard astrophysical sources, with at most a 1–2σ excess identified near the kinematic center of the LMC once systematic uncertainties are taken into account. As a result, we place competitive bounds on the dark matter annihilation cross section as a function of dark matter particle mass and annihilation channel.

  17. Searching for dwarf spheroidal galaxies and other galactic dark matter substructures with the Fermi large area telescope

    SciTech Connect

    Drlica-Wagner, Alex

    2013-08-01

    Over the past century, it has become clear that about a quarter of the known universe is composed of an invisible, massive component termed ''dark matter''. Some of the most popular theories of physics beyond the Standard Model suggest that dark matter may be a new fundamental particle that could self-annihilate to produce γ rays. Nearby over-densities in the dark matter halo of our Milky Way present some of the most promising targets for detecting the annihilation of dark matter. We used the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope to search for γ rays produced by dark matter annihilation in Galactic dark matter substructures. We searched for γ-ray emission coincident with Milky Way dwarf spheroidal satellite galaxies, which trace the most massive Galactic dark matter substructures. We also sought to identify nearby dark matter substructures that lack all astrophysical tracers and would be detectable only through γ-ray emission from dark matter annihilation. We found no conclusive evidence for γ-ray emission from dark matter annihilation, and we set stringent and robust constraints on the dark matter annihilation cross section. While γ-ray searches for dark matter substructure are currently the most sensitive and robust probes of dark matter annihilation, they are just beginning to intersect the theoretically preferred region of dark matter parameter space. Thus, we consider future prospects for increasing the sensitivity of γ-ray searches through improvements to the LAT instrument performance and through upcoming wide- field optical surveys.

  18. Pulsed Gamma-Rays From the Millisecond Pulsar J0030+0451 with the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Axelsson, M. Baldini, L.; Ballet, J.; Barbiellini, Guido; Bastieri, Denis; Battelino, M.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, Elliott D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, Thompson H.; /more authors..

    2011-11-17

    We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma Ray Observatory. The spin-down power {dot E} = 3.5 x 10{sup 33} ergs s{sup -1} is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, respectively 0.07 {+-} 0.01 and 0.08 {+-} 0.02 wide, separated by 0.44 {+-} 0.02 in phase. The first gamma-ray peak falls 0.15 {+-} 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cut-off power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 {+-} 1.05 {+-} 1.35) x 10{sup -8} cm{sup -2} s{sup -1} with cut-off energy (1.7 {+-} 0.4 {+-} 0.5) GeV. Based on its parallax distance of (300 {+-} 90) pc, we obtain a gamma-ray efficiency L{sub {gamma}}/{dot E} {approx_equal} 15% for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

  19. DISCOVERY OF NINE GAMMA-RAY PULSARS IN FERMI LARGE AREA TELESCOPE DATA USING A NEW BLIND SEARCH METHOD

    SciTech Connect

    Pletsch, H. J.; Allen, B.; Aulbert, C.; Fehrmann, H.; Guillemot, L.; Kramer, M.; Barr, E. D.; Champion, D. J.; Eatough, R. P.; Freire, P. C. C.; Ray, P. S.; Belfiore, A.; Dormody, M.; Camilo, F.; Caraveo, P. A.; Celik, Oe.; Ferrara, E. C.; Hessels, J. W. T.; Keith, M.; Kerr, M. E-mail: guillemo@mpifr-bonn.mpg.de; and others

    2012-01-10

    We report the discovery of nine previously unknown gamma-ray pulsars in a blind search of data from the Fermi Large Area Telescope (LAT). The pulsars were found with a novel hierarchical search method originally developed for detecting continuous gravitational waves from rapidly rotating neutron stars. Designed to find isolated pulsars spinning at up to kHz frequencies, the new method is computationally efficient and incorporates several advances, including a metric-based gridding of the search parameter space (frequency, frequency derivative, and sky location) and the use of photon probability weights. The nine pulsars have spin frequencies between 3 and 12 Hz, and characteristic ages ranging from 17 kyr to 3 Myr. Two of them, PSRs J1803-2149 and J2111+ 4606, are young and energetic Galactic-plane pulsars (spin-down power above 6 Multiplication-Sign 10{sup 35} erg s{sup -1} and ages below 100 kyr). The seven remaining pulsars, PSRs J0106+4855, J0622+3749, J1620-4927, J1746-3239, J2028+3332, J2030+4415, and J2139+4716, are older and less energetic; two of them are located at higher Galactic latitudes (|b| > 10 Degree-Sign ). PSR J0106+4855 has the largest characteristic age (3 Myr) and the smallest surface magnetic field (2 Multiplication-Sign 10{sup 11} G) of all LAT blind-search pulsars. PSR J2139+4716 has the lowest spin-down power (3 Multiplication-Sign 10{sup 33} erg s{sup -1}) among all non-recycled gamma-ray pulsars ever found. Despite extensive multi-frequency observations, only PSR J0106+4855 has detectable pulsations in the radio band. The other eight pulsars belong to the increasing population of radio-quiet gamma-ray pulsars.

  20. Resolving the Extragalactic γ-Ray Background above 50 GeV with the Fermi Large Area Telescope.

    PubMed

    Ackermann, M; Ajello, M; Albert, A; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Blandford, R D; Bloom, E D; Bonino, R; Bregeon, J; Britto, R J; Bruel, P; Buehler, R; Caliandro, G A; Cameron, R A; Caragiulo, M; Caraveo, P A; Cavazzuti, E; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Cohen-Tanugi, J; Cominsky, L R; Costanza, F; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Desiante, R; Digel, S W; Di Mauro, M; Di Venere, L; Domínguez, A; Drell, P S; Favuzzi, C; Fegan, S J; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Godfrey, G; Green, D; Grenier, I A; Guiriec, S; Hays, E; Horan, D; Iafrate, G; Jogler, T; Jóhannesson, G; Kuss, M; La Mura, G; Larsson, S; Latronico, L; Li, J; Li, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Magill, J; Maldera, S; Manfreda, A; Mayer, M; Mazziotta, M N; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Negro, M; Nuss, E; Ohsugi, T; Okada, C; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Petrosian, V; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Romani, R W; Sánchez-Conde, M; Schmid, J; Schulz, A; Sgrò, C; Simone, D; Siskind, E J; Spada, F; Spandre, G; Spinelli, P; Suson, D J; Takahashi, H; Thayer, J B; Tibaldo, L; Torres, D F; Troja, E; Vianello, G; Yassine, M; Zimmer, S

    2016-04-15

    The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for the first time, the source count distribution, dN/dS, of extragalactic γ-ray sources at E>50  GeV and find that it is compatible with a Euclidean distribution down to the lowest measured source flux in the 2FHL (∼8×10^{-12}  ph cm^{-2} s^{-1}). We employ a one-point photon fluctuation analysis to constrain the behavior of dN/dS below the source detection threshold. Overall, the source count distribution is constrained over three decades in flux and found compatible with a broken power law with a break flux, S_{b}, in the range [8×10^{-12},1.5×10^{-11}]  ph cm^{-2} s^{-1} and power-law indices below and above the break of α_{2}∈[1.60,1.75] and α_{1}=2.49±0.12, respectively. Integration of dN/dS shows that point sources account for at least 86_{-14}^{+16}% of the total extragalactic γ-ray background. The simple form of the derived source count distribution is consistent with a single population (i.e., blazars) dominating the source counts to the minimum flux explored by this analysis. We estimate the density of sources detectable in blind surveys that will be performed in the coming years by the Cherenkov Telescope Array.

  1. First year results from the HAWC observatory

    NASA Astrophysics Data System (ADS)

    Casanova, Sabrina

    2017-03-01

    The High Altitude Water Cherenkov Observatory is an all-sky surveying instrument sensitive to gamma rays and cosmic rays from 100GeV to 100TeV. With its 2sr instantaneous field of view and a duty cycle of > 95%, HAWC is carrying out an unbiased survey of the Northern sky and is monitoring known flaring sources and searching for transients. HAWC operation began mid-2013 with a partially-completed detector. The array was terminated in 2015. We here summarize the status of the observatory, and highlight its first scientific results, resulting from the first year of data taking after completion of the detector. In particular, we will present the HAWC map of the sky at tens of TeV.

  2. New ALMA and Fermi/LAT Observations of the Large-scale Jet of PKS 0637‑752 Strengthen the Case Against the IC/CMB Model

    NASA Astrophysics Data System (ADS)

    Meyer, Eileen T.; Breiding, Peter; Georganopoulos, Markos; Oteo, Iván; Zwaan, Martin A.; Laing, Robert; Godfrey, Leith; Ivison, R. J.

    2017-02-01

    The Chandra X-ray observatory has discovered several dozen anomalously X-ray-bright jets associated with powerful quasars. A popular explanation for the X-ray flux from the knots in these jets is that relativistic synchrotron-emitting electrons inverse-Compton scatter cosmic microwave background (CMB) photons to X-ray energies (the IC/CMB model). This model predicts a high gamma-ray flux that should be detectable by the Fermi/Large Area Telescope (LAT) for many sources. GeV-band upper limits from Fermi/LAT for the well-known anomalous X-ray jet in PKS 0637‑752 were previously shown in Meyer et al. to violate the predictions of the IC/CMB model. Previously, measurements of the jet synchrotron spectrum, important for accurately predicting the gamma-ray flux level, were lacking between radio and infrared wavelengths. Here, we present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the large-scale jet at 100, 233, and 319 GHz, which further constrain the synchrotron spectrum, supporting the previously published empirical model. We also present updated limits from the Fermi/LAT using the new “Pass 8” calibration and approximately 30% more time on source. With these deeper limits, we rule out the IC/CMB model at the 8.7σ level. Finally, we demonstrate that complete knowledge of the synchrotron SED is critical in evaluating the IC/CMB model.

  3. Fermi at Six Months

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    An overview of the Fermi Gamma-ray Space Telescope's first 6 months in operation is provided. The Fermi Gamma-ray Space Telescope, formerly called GLAST, is a mission to measure the cosmic gamma-ray flux in the energy rage 20 MeV to more than 300 GeV, with supporting measurements for gamma-ray bursts from 8 keV to 30 MeV. It contains a Large Area Telescope capable of viewing the entire sky every 3 hours and a Gamma-ray Burst Monitor for viewing the entire unocculted sky. Since its launch on June 11, 2008 Fermi has provided information on pulsars, gamma ray bursts, relativistic jets, the active galactic nucleus, and a globular star cluster. This presentation describes Fermi's development, mission, instruments and recent findings.

  4. ISS GN and C - First Year Surprises

    NASA Technical Reports Server (NTRS)

    Begley, Michael

    2002-01-01

    Assembly of the International Space Station (ISS) began in late 1998 with the joining of the first two US and Russ ian elements. For more than two years, the outpost was served by two Russian Guidance, Navigation, and Control (GN&C) systems. The station requires orbital translation and attitude control functions for its 100+ configurations, from the nascent two-module station to the half million kilogram completed station owned and operated by seventeen nations. With the launch of the US Laboratory module in February 2001, the integration of the US GN&C system with its Russian counterpart laid the foundation for such a robust system. In its first year of combined operation, the ISS GN&C system has performed admirably, even better than many expected, but there have been surprises. Loss of command capability, loss of communication between segments, a control system force-fight, and "non-propulsive vents" that weren't - such events have repeatedly underscored the importance of thorough program integration, testing, and operation, both across subsystem boundaries and across international borders.

  5. Remembering Fermi

    SciTech Connect

    Cronin, James

    2005-03-30

    A combination of the discovery of nuclear fission and the circumstances of the 2nd World War brought Enrico Fermi to Chicago, where he led the team that produced the first controlled, self-sustained nuclear chain reaction. Following the war in 1945 Chancellor Hutchins, William Zachariasen, and Walter Bartky convinced Fermi to accept a professorship at the University of Chicago, where the Institute for Nuclear Studies was established. Fermi served as the leading figure in surely the greatest collection of scientists the world has ever seen. Fermi's tenure at Chicago was cut short by his death in 1954. My talk will concentrate on the years 1945-54. Examples of his research notebooks, his speeches, his teaching, and his correspondence will be discussed.

  6. First-Year Seminar Intervention: Enhancing First-Year Mathematics Performance at the University of Johannesburg

    ERIC Educational Resources Information Center

    Jacobs, Melanie; Pretorius, Estherna

    2016-01-01

    South Africa has opened up access to higher education over the past 20 years. The massive increase in enrolments (with almost 70% first-generation students) substantially affects progress and graduation rates in Science programmes in higher education. First-year students in Science realise that university mathematics requires knowledge and skills…

  7. Why Do First-Year Students of German Lose Motivation during their First Year at University?

    ERIC Educational Resources Information Center

    Busse, Vera

    2013-01-01

    This article explores motivational changes of first-year students enrolled on German degree courses at two major UK universities. It reports on the qualitative data obtained by a longitudinal mixed-methods study, and focuses on the interplay between students' motivation and the higher education learning environment. In particular, the article aims…

  8. Fermi Large Area Telescope Observations of High-Energy Gamma-ray Emission From Behind-the-limb Solar Flares

    NASA Astrophysics Data System (ADS)

    Omodei, Nicola; Pesce-Rollins, Melissa; Petrosian, Vahe; Liu, Wei; Rubio da Costa, Fatima; Golenetskii, Sergei; Kashapova, Larisa; Krucker, Sam; Palshin, Valentin; Fermi Large Area Telescope Collaboration

    2017-01-01

    Fermi LAT >30 MeV observations of the active Sun have increased the number of detected solar flares by almost a factor of 10 with respect to previous space observations. Of particular interest are the recent detections of three solar flares whose position behind the limb was confirmed by the STEREO-B spacecraft. These observations sample flares from active regions originating from behind both the eastern and western limbs and include an event associated with the second ground level enhancement event (GLE) of the 24th Solar Cycle. While gamma-ray emission up to tens of MeV resulting from proton interactions has been detected before from occulted solar flares, the significance of these particular events lies in the fact that these are the first detections of >100 MeV gamma-ray emission from footpoint-occulted flares. These detections present an unique opportunity to diagnose the mechanisms of high-energy emission and particle acceleration and transport in solar flares. We will present the Fermi-LAT, RHESSI and STEREO observations of these flares and discuss the various emission scenarios for these sources.

  9. Chiral non-Fermi liquids

    NASA Astrophysics Data System (ADS)

    Sur, Shouvik; Lee, Sung-Sik

    2014-07-01

    A non-Fermi liquid state without time-reversal and parity symmetries arises when a chiral Fermi surface is coupled with a soft collective mode in two space dimensions. The full Fermi surface is described by a direct sum of chiral patch theories, which are decoupled from each other in the low-energy limit. Each patch includes low-energy excitations near a set of points on the Fermi surface with a common tangent vector. General patch theories are classified by the local shape of the Fermi surface, the dispersion of the critical boson, and the symmetry group, which form the data for distinct universality classes. We prove that a large class of chiral non-Fermi liquid states exists as stable critical states of matter. For this, we use a renormalization group scheme where low-energy excitations of the Fermi surface are interpreted as a collection of (1+1)-dimensional chiral fermions with a continuous flavor labeling the momentum along the Fermi surface. Due to chirality, the Wilsonian effective action is strictly UV finite. This allows one to extract the exact scaling exponents although the theories flow to strongly interacting field theories at low energies. In general, the low-energy effective theory of the full Fermi surface includes patch theories of more than one universality classes. As a result, physical responses include multiple universal components at low temperatures. We also point out that, in quantum field theories with extended Fermi surface, a noncommutative structure naturally emerges between a coordinate and a momentum which are orthogonal to each other. We show that the invalidity of patch description for Fermi liquid states is tied with the presence of UV/IR mixing associated with the emergent noncommutativity. On the other hand, UV/IR mixing is suppressed in non-Fermi liquid states due to UV insensitivity, and the patch description is valid.

  10. Phase diagram of a one-dimensional spin-full Bose-Fermi mixture at large boson densities

    NASA Astrophysics Data System (ADS)

    Nocera, Alberto; Lutchyn, Roman M.; Feiguin, Adrian E.

    2014-03-01

    We determine the ground state phase diagram of a one dimensional Bose-Fermi Hubbard model with spin-full fermions using the Density Matrix Renormalization Group (DMRG) method. We focus on the regime with one fermion per site, and deep into the superfluid phase. We study the effects of the boson-fermion interaction on the fermionic pairing, as a function of the interaction strength, hopping, and bosonic density. We identify the regime in which fermionic superfluidity dominates, and a phase with coexisting CDW and bosonic superfluidity. At high boson densities we find a fermionic Wigner crystal coexisting with bosonic superfluidity. We analyze the structure of the Cooper pairs and the bosonic cloud that acts as the glue.

  11. Motivational Project-Based Laboratory for a Common First Year Electrical Engineering Course

    ERIC Educational Resources Information Center

    Nedic, Zorica; Nafalski, Andrew; Machotka, Jan

    2010-01-01

    Over the past few years many universities worldwide have introduced a common first year for all engineering disciplines. This is despite the opinion of many academics that large classes have negative effects on the learning outcomes of first year students. The University of South Australia is also faced with low motivation amongst engineering…

  12. Learning Communities: Foundations for First-Year Students' Development of Pluralistic Outcomes

    ERIC Educational Resources Information Center

    Soria, Krista M.; Mitchell, Tania D.

    2015-01-01

    The purpose of this study was to investigate the associations between first-year undergraduates' (n = 1,701) participation in learning communities and their development of leadership and multicultural competence. The sample included first-year students who were enrolled at six large, public research universities in 2012 and completed the Student…

  13. Maintaining Positive Attitudes toward Science and Technology in First-Year Female Undergraduates: Peril and Promise

    ERIC Educational Resources Information Center

    Machina, Kenton; Gokhale, Anu

    2010-01-01

    This study investigated attitude changes of 18-year-old first-year college students at a large state-operated institution in the USA during their initial semester in college. Attitudes of 375 students enrolled in a non-science first-year student seminar during the Fall of 2004 were measured, using a new instrument designed to focus on five…

  14. Assessing the Effectiveness of an Adventure-Based First-Year Experience Class

    ERIC Educational Resources Information Center

    Bell, Brent J.

    2012-01-01

    This study compares a first-year experience (FYE) course utilizing outdoor adventure experiences to a more traditional FYE class at a large mid-Atlantic university. This study compares the quantitative differences between responses by participants in the two classes using the First Year Initiative Survey (FYI), a measure of FYE outcomes related to…

  15. How Do Learning Communities Affect First-Year Latino Students?

    ERIC Educational Resources Information Center

    Huerta, Juan Carlos; Bray, Jennifer J.

    2013-01-01

    Do learning communities with pedagogies of active learning, collaborative learning, and integration of course material affect the learning, achievement, and persistence of first-year Latino university students? The data for this project was obtained from a survey of 1,330 first-year students in the First-Year Learning Community Program at Texas…

  16. FERMI RULES OUT THE INVERSE COMPTON/CMB MODEL FOR THE LARGE-SCALE JET X-RAY EMISSION OF 3C 273

    SciTech Connect

    Meyer, Eileen T.; Georganopoulos, Markos

    2014-01-10

    The X-ray emission mechanism in large-scale jets of powerful radio quasars has been a source of debate in recent years, with two competing interpretations: either the X-rays are of synchrotron origin, arising from a different electron energy distribution than that producing the radio to optical synchrotron component, or they are due to inverse Compton scattering of cosmic microwave background photons (IC/CMB) by relativistic electrons in a powerful relativistic jet with bulk Lorentz factor Γ ∼ 10-20. These two models imply radically different conditions in the large-scale jet in terms of jet speed, kinetic power, and maximum energy of the particle acceleration mechanism, with important implications for the impact of the jet on the large-scale environment. A large part of the X-ray origin debate has centered on the well-studied source 3C 273. Here we present new observations from Fermi which put an upper limit on the gamma-ray flux from the large-scale jet of 3C 273 that violates at a confidence greater that 99.9% the flux expected from the IC/CMB X-ray model found by extrapolation of the UV to X-ray spectrum of knot A, thus ruling out the IC/CMB interpretation entirely for this source when combined with previous work. Further, this upper limit from Fermi puts a limit on the Doppler beaming factor of at least δ < 9, assuming equipartition fields, and possibly as low as δ < 5, assuming no major deceleration of the jet from knots A through D1.

  17. Challenges for the CMS computing model in the first year

    SciTech Connect

    Fisk, I.; /Fermilab

    2009-05-01

    CMS is in the process of commissioning a complex detector and a globally distributed computing infrastructure simultaneously. This represents a unique challenge. Even at the beginning there is not sufficient analysis or organized processing resources at CERN alone. In this presentation we discuss the unique computing challenges CMS expects to face during the first year of running and how they influence the baseline computing model decisions. During the early accelerator commissioning periods, CMS will attempt to collect as many events as possible when the beam is on in order to provide adequate early commissioning data. Some of these plans involve overdriving the Tier-0 infrastructure during data collection with recovery when the beam is off. In addition to the larger number of triggered events, there will be pressure in the first year to collect and analyze more complete data formats as the summarized formats mature. The large event formats impact the required storage, bandwidth, and processing capacity across all the computing centers. While the understanding of the detector and the event selections is being improved, there will likely be a larger number of reconstruction passes and skims performed by both central operations and individual users. We discuss how these additional stresses impact the allocation of resources and the changes from the baseline computing model.

  18. High-redshift Fermi blazars

    NASA Astrophysics Data System (ADS)

    Ghisellini, G.; Tagliaferri, G.; Foschini, L.; Ghirlanda, G.; Tavecchio, F.; Della Ceca, R.; Haardt, F.; Volonteri, M.; Gehrels, N.

    2011-02-01

    With the release of the first-year Fermi catalogue, the number of blazars detected above 100 MeV lying at high redshift has been largely increased. There are 28 blazars at z > 2 in the `clean' sample. All of them are flat spectrum radio quasars. We study and model their overall spectral energy distribution in order to find the physical parameters of the jet-emitting region, and for all of them, we estimate their black hole masses and accretion rates. We then compare the jet with the accretion disc properties, setting these sources in the broader context of all the other bright γ-ray or hard X-ray blazars. We confirm that the jet power correlates with the accretion luminosity. We find that the high-energy emission peak shifts to smaller frequencies as the observed luminosity increases, according to the blazar sequence, making the hard X-ray band the most suitable for searching the most-luminous and distant blazars.

  19. Measurement of the Cosmic Ray e+ plus e- Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Bastieri, Denis; Battelino, M.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, Elliott D.; Bogaert, G.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; /more authors..

    2012-05-14

    Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m{sup 2}sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply-falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E{sup -3.0} and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.

  20. First-Year Village: Experimenting with an African Model for First-Year Adjustment and Support in South Africa

    ERIC Educational Resources Information Center

    Speckman, McGlory

    2016-01-01

    Predicated on the principles of success and contextuality, this chapter shares an African perspective on a first-year adjustment programme, known as First-Year Village, including its potential and challenges in establishing it.

  1. Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, Guido; Baring, Matthew G.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, Elliott D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, Thompson H.; Caliandro, G.A.; /more authors..

    2009-05-15

    Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search (at 3.1 GHz) in the error circle of the Energetic Gamma-Ray Experiment Telescope (EGRET) source 3EG J1027-5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of {gamma}-ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The {gamma}-ray light curve shows two sharp peaks having phase separation of 0.460 {+-} 0.004, trailing the very narrow radio pulse by 0.200 {+-} 0.003 in phase, very similar to that of other known {gamma}-ray pulsars. The measured {gamma}-ray flux gives an efficiency for the pulsar of {approx}10-20% (for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028-5819.

  2. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE ACTIVE GALAXY 4C +55.17: STEADY, HARD GAMMA-RAY EMISSION AND ITS IMPLICATIONS

    SciTech Connect

    McConville, W.; McEnery, J. E.; Ostorero, L.; Moderski, R.; Stawarz, L.; Cheung, C. C.; Ajello, M.; Monzani, M. E.; Bouvier, A.; Bregeon, J.; Donato, D.; Finke, J.; Furniss, A.; Williams, D. A.; Orienti, M.; Reyes, L. C.; Rossetti, A. E-mail: stawarz@astro.isas.jaxa.jp

    2011-09-10

    We report Fermi Large Area Telescope (LAT) observations and broadband spectral modeling of the radio-loud active galaxy 4C +55.17 (z = 0.896), formally classified as a flat-spectrum radio quasar. Using 19 months of all-sky survey Fermi-LAT data, we detect a {gamma}-ray continuum extending up to an observed energy of 145 GeV, and furthermore we find no evidence of {gamma}-ray variability in the source over its observed history. We illustrate the implications of these results in two different domains. First, we investigate the origin of the steady {gamma}-ray emission, where we re-examine the common classification of 4C +55.17 as a quasar-hosted blazar and consider instead its possible nature as a young radio source. We analyze and compare constraints on the source physical parameters in both blazar and young radio source scenarios by means of a detailed multiwavelength analysis and theoretical modeling of its broadband spectrum. Second, we show that the {gamma}-ray spectrum may be formally extrapolated into the very high energy (VHE, {>=}100 GeV) range at a flux level detectable by the current generation of ground-based Cherenkov telescopes. This enables us to place constraints on models of extragalactic background light within LAT energies and features the source as a promising candidate for VHE studies of the universe at an unprecedented redshift of z = 0.896.

  3. Anisotropic Fermi couplings due to large unquenched orbital angular momentum: Q-band (1)H, (14)N, and (11)B ENDOR of bis(trispyrazolylborate) cobalt(II).

    PubMed

    Myers, William K; Scholes, Charles P; Tierney, David L

    2009-08-05

    We report Q-band ENDOR of (1)H, (14)N, and (11)B at the g( parallel) extreme of the EPR spectrum of bis(trispyrazolylborate) cobalt(II) [Co(Tp)(2)] and two structural analogs. This trigonally symmetric, high-spin (hs) S = 3/2 Co(II) complex shows large unquenched ground-state orbital angular momentum, which leads to highly anisotropic electronic g-values (g( parallel) = 8.48, g( perpendicular) = 1.02). The large g-anisotropy is shown to result in large dipolar couplings near g( parallel) and uniquely anisotropic (14)N Fermi couplings, which arise from spin transferred to the nitrogen 2s orbital (2.2%) via antibonding interactions with singly occupied metal d(x(2)-y(2)) and d(z(2)) orbitals. Large, well-resolved (1)H and (11)B dipolar couplings were also observed. Taken in concert with our previous X-band ENDOR measurements at g( perpendicular) ( Myers, W. K.; et al. Inorg. Chem. 2008, 47, 6701-6710 ), the present data allow a detailed analysis of the dipolar hyperfine tensors of two of the four symmetry distinct protons in the parent molecule. In the substituted analogs, changes in hyperfine coupling due to altered metal-proton distances give further evidence of an anisotropic Fermi contact interaction. For the pyrazolyl 3H proton, the data indicate a 0.2 MHz anisotropic contact interaction and approximately 4% transfer of spin away from Co(II). Dipolar coupling also dominates for the axial boron atoms, consistent with their distance from the Co(II) ion, and resolved (11)B quadrupolar coupling showed approximately 30% electronic inequivalence between the B-H and B-C sp(3) bonds. This is the first comprehensive ENDOR study of any hs Co(II) species and lays the foundation for future development.

  4. Challenging and Supporting the First-Year Student: A Handbook for Improving the First Year of College

    ERIC Educational Resources Information Center

    Upcraft, M. Lee, Ed.; Gardner, John N., Ed.; Barefoot, Betsy O., Ed.

    2004-01-01

    An authoritative, comprehensive guide to the first year of college, this book includes the most current information about the policies, strategies, programs, and services designed to help first-year students make a successful transition to college and fulfill their educational and personal goals. Following the introduction, "The First Year of…

  5. German contribution to the validation of SCIAMACHY - the first year

    NASA Astrophysics Data System (ADS)

    Bramstedt, K.; Kirchhoff, B.

    2003-04-01

    An adequate validation of SCIAMACHY data products is a prerequisite for a successful completion of the SCIAMACHY mission. The German validation team, consisting of 23 different projects with more than 60 scientists, contributes with a wide range of instrument types as important part of the international validation community. A global network of ground-based stations with DOAS, FTIR, microwave instruments and ozone sondes has been build. Satellite inter-comparisons utilize the measurements of independent space-born sensors. Balloon-borne instruments participate in the Envisat Stratospheric Aircraft and Balloon validation campaigns and the German FALCON research aircraft has undertaken large flights from the Arctic to the Tropics. Here an overview of the GERMAN activities during the first year of SCIAMACHY lifetime is given.

  6. Enrico Fermi

    NASA Astrophysics Data System (ADS)

    Yang, Chen Ning

    2013-05-01

    Enrico Fermi was, of all the great physicists of the 20th century, among the most respected and admired. He was respected and admired because of his contributions to both theoretical and experimental physics, because of his leadership in discovering for mankind a powerful new source of energy, and above all, because of his personal character. He was always reliable and trustworthy. He had both of his feet on the ground all the time. He had great strength, but never threw his weight around. He did not play to the gallery. He did not practise one-up-manship. He exemplified, I always believe, the perfect Confucian gentleman...

  7. Searching for dark matter annihilation from Milky Way dwarf spheroidal galaxies with six years of Fermi Large Area Telescope data

    DOE PAGES

    Ackermann, M.

    2015-11-30

    The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. As a result, these constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DMmore » of mass ≲100 GeV annihilating via quark and τ-lepton channels.« less

  8. Searching for dark matter annihilation from Milky Way dwarf spheroidal galaxies with six years of Fermi Large Area Telescope data

    SciTech Connect

    Ackermann, M.

    2015-11-30

    The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. As a result, these constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass ≲100 GeV annihilating via quark and τ-lepton channels.

  9. High-energy gamma-ray emission from solar flares: Summary of Fermi large area telescope detections and analysis of two M-class flares

    SciTech Connect

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Bechtol, K.; Bottacini, E.; Buehler, R.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Buson, S.; Bellazzini, R.; Bregeon, J.; Bissaldi, E.; Bonamente, E.; Bouvier, A.; Brandt, T. J.; Brigida, M.; Bruel, P.; and others

    2014-05-20

    We present the detections of 18 solar flares detected in high-energy γ-rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first 4 yr of operation. This work suggests that particle acceleration up to very high energies in solar flares is more common than previously thought, occurring even in modest flares, and for longer durations. Interestingly, all these flares are associated with fairly fast coronal mass ejections (CMEs). We then describe the detailed temporal, spatial, and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying γ-ray emission over 13 hr, and the 2011 June 7 M2.5 flare, which was followed by γ-ray emission lasting for 2 hr. We compare the Fermi LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that the γ-rays are more likely produced through pion decay than electron bremsstrahlung, and we find that the energy spectrum of the proton distribution softens during the extended emission of the 2011 March 7 flare. This would disfavor a trapping scenario for particles accelerated during the impulsive phase of the flare and point to a continuous acceleration process at play for the duration of the flares. CME shocks are known for accelerating the solar energetic particles (SEPs) observed in situ on similar timescales, but it might be challenging to explain the production of γ-rays at the surface of the Sun while the CME is halfway to the Earth. A stochastic turbulence acceleration process occurring in the solar corona is another likely scenario. Detailed comparison of characteristics of SEPs and γ-ray-emitting particles for several flares will be helpful to distinguish between these two possibilities.

  10. Student Perceptions of the First Year of Veterinary Medical School.

    ERIC Educational Resources Information Center

    Powers, Donald E.

    2002-01-01

    A brief survey was conducted of nearly 900 first-year students in 14 U.S. veterinary medical schools in order to gather impressions of the first year of veterinary medical education. Although some students reported that conditions were stressful, the majority did not feel that they were inordinately so. Overall, most students were quite positive…

  11. Determining Classroom Placement for First Year English Language Learner Students

    ERIC Educational Resources Information Center

    Peña, Rodrigo H.; Maxwell, Gerri M.

    2015-01-01

    This study explores classroom placement for first year English Language Learner (ELL) students from the perspective of a dual language director and two bilingual education strategists. The study strives to interrogate classroom placement for first year ELL students whose language proficiency level is at beginning level. Through a process of coding…

  12. A First-Year Course That Teaches Research Skills

    ERIC Educational Resources Information Center

    Czarneski, Debra

    2013-01-01

    In the Fall semester of 2009, I taught a first-year course that focused on skills required to successfully complete undergraduate research. This paper will discuss the Simpson College first-year course requirements, my course goals, the graph theory topics covered, student feedback, and instructor reflection.

  13. A Mathematics Support Programme for First-Year Engineering Students

    ERIC Educational Resources Information Center

    Hillock, Poh Wah; Jennings, Michael; Roberts, Anthony; Scharaschkin, Victor

    2013-01-01

    This article describes a mathematics support programme at the University of Queensland, targeted at first-year engineering students identified as having a high risk of failing a first-year mathematics course in calculus and linear algebra. It describes how students were identified for the programme and the main features of the programme. The…

  14. Situating the Library in the First Year Experience Course

    ERIC Educational Resources Information Center

    Bissett, Susan J. C.

    2004-01-01

    John Gardner, of the National Resource Center for The First Year Experience and Students in Transition, addressed academic librarians at the ACRL meeting in Charlotte, North Carolina, in April 2003, urging librarians to become more actively involved in First Year Experience courses. Susan J. C. Bissett responds in this article, citing the…

  15. Meeting First-Year Challenges in Reading Instruction

    ERIC Educational Resources Information Center

    Noll, Brandi L.; Lenhart, Lisa A.

    2014-01-01

    The first year of teaching is often the hardest for most beginners as knowledge and skills gained from teacher preparation meet real world challenges. This article follows two teachers into their first year and describes how they adapt and align what they know about reading best practices to their local situations. Two all-too-common challenges…

  16. The First Year: Just Surviving or Thriving at an HSI

    ERIC Educational Resources Information Center

    Musoba, Glenda Droogsma; Collazo, Charlene; Placide, Sharon

    2013-01-01

    Minority retention models have identified student needs that may or may not be addressed by institutional first-year experience (FYE) programming at Hispanic-serving institutions (HSIs). Qualitatively, this study examined Hispanic and Black first-year experiences in an HSI context. Identified themes included sense of belonging, career and major…

  17. Quantitative Literacy Provision in the First Year of Medical Studies

    ERIC Educational Resources Information Center

    Frith, V.

    2011-01-01

    This article presents a description of and motivation for the quantitative literacy (numeracy) intervention in the first year of medical studies at a South African university. This intervention is a response to the articulation gap between the quantitative literacy of many first-year medical students and the demands of their curriculum.…

  18. Improving the First Year of College: Research and Practice

    ERIC Educational Resources Information Center

    Feldman, Robert S., Ed.

    2005-01-01

    The first year of college represents an enormous milestone in students' lives. Whether attending a four-year or two-year institution of higher education, living on campus or at home, or enrolled in a highly selective school or a college with an open-admissions policy, students are challenged in unique and demanding ways during their first year.…

  19. The Digital Divide and First-Year Students

    ERIC Educational Resources Information Center

    Goodfellow, Marianne; Wade, Barbara

    2007-01-01

    Current cross-campus computing initiatives demand both access and skill in employing technology as a tool for academic success. Consequently, lack of computer skills can affect first-year students' potential for success because many courses assume students are computer literate. In this study, 888 first-year students completed a…

  20. First-Year Course Requirements and Retention for Community Colleges

    ERIC Educational Resources Information Center

    Mayo, Teresa

    2013-01-01

    Community colleges educate a diverse group of students. Effective first-year programs should focus on a variety of interventions that improve learning and retention. Students have academic, intellectual, and social challenges during their community college experience. First-year orientation programs should help students adapt. This article…

  1. Diary of a First-Year Teacher of the Gifted.

    ERIC Educational Resources Information Center

    Parker, Carol

    1986-01-01

    Excerpts are presented from a teacher's diary of her first year of teaching gifted primary grade students. Principles learned over the first year include: (1) lesson planning must be flexible; (2) gifted students prefer subject matter content to brain exercises; and (3) work in the affective domain is as essential as study in the cognitive realm.…

  2. Particle pressures in fluidized beds. First year annual report

    SciTech Connect

    Campbell, C.S.; Rahman, K.; Hu, X.; Jin, C.; Potapov, A.V.

    1992-09-01

    This is an experimental project to make detailed measurements of the particle pressures generated in fluidized beds. The focus lies in two principle areas: (1) the particle pressure distribution around single bubbles rising in a two-dimensional gas-fluidized bed and (2) the particle pressures measured in liquid-fluidized beds. This first year has largely been to constructing the experiments The design of the particle pressure probe has been improved and tested. A two-dimensional gas-fluidized bed has been constructed in order to measure the particle pressure generated around injected bubbles. The probe is also being adapted to work in a liquid fluidized bed. Finally, a two-dimensional liquid fluidized bed is also under construction. Preliminary measurements show that the majority of the particle pressures are generated in the wake of a bubble. However, the particle pressures generated in the liquid bed appear to be extremely small. Finally, while not directly associated with the particle pressure studies, some NERSC supercomputer time was granted alongside this project. This is being used to make large scale computer simulation of the flow of granular materials in hoppers.

  3. The intergalactic magnetic field constrained by Fermi/Large Area Telescope observations of the TeV blazar 1ES0229+200

    NASA Astrophysics Data System (ADS)

    Tavecchio, F.; Ghisellini, G.; Foschini, L.; Bonnoli, G.; Ghirlanda, G.; Coppi, P.

    2010-07-01

    TeV photons from blazars at relatively large distances, interacting with the optical-infrared cosmic background, are efficiently converted into electron-positron pairs. The produced pairs are extremely relativistic (Lorentz factors of the order of 106- 107) and promptly lose their energy through inverse Compton scatterings with the photons of the microwave cosmic background, producing emission in the GeV band. The spectrum and the flux level of this reprocessed emission are critically dependent on the intensity of the intergalactic magnetic field, B, that can deflect the pairs diluting the intrinsic emission over a large solid angle. We derive a simple relation for the reprocessed spectrum expected from a steady source. We apply this treatment to the blazar 1ES0229+200, whose intrinsic, very hard TeV spectrum is expected to be approximately steady. Comparing the predicted reprocessed emission with the upper limits measured by the Fermi/Large Area Telescope, we constrain the value of the intergalactic magnetic field to be larger than B ~= 5 × 10-15 G, depending on the model of extragalactic background light.

  4. International Perspectives on the First-Year Experience in Higher Education. The First-Year Experience Monograph Series No. 52

    ERIC Educational Resources Information Center

    Nutt, Diane, Ed.; Calderon, Denis, Ed.

    2009-01-01

    Students around the globe have unique first-year experiences but struggle with many of the same challenges. This monograph focuses on their journeys and provides insights for educators interested in learning about how institutions across the globe provide supports to students dealing with first-year transition issues. Based on the successful…

  5. Do First-Year University Students Know What to Expect from Their First-Year Writing Intensive Course?

    ERIC Educational Resources Information Center

    O'Brien-Moran, Michael; Soiferman, L. Karen

    2010-01-01

    This study involved a one-time survey of first-year undergraduate students at a Canadian University to determine their expectations when beginning a writing intensive course (i.e., the so-called "W" course, which is required of all first-year undergraduates at the University of Manitoba.) In this study, we focused on the University's…

  6. Exploring the Evidence: Reporting Outcomes of First-Year Seminars. The First-Year Experience. Volume II. Monograph Series, Number 25.

    ERIC Educational Resources Information Center

    Barefoot, Betsy O., Ed.; Warnock, Carrie L., Ed.; Dickinson, Michael P., Ed.; Richardson, Sharon E., Ed.; Roberts, Melissa R., Ed.

    This document provides a compendium of evaluation research findings on first-year seminars at 50 institutions of higher education. Program reports are listed by type of institution: two-year institutions, small four-year institutions, mid-sized four-year institutions, and large four-year institutions. Each listing provides a brief description of…

  7. Search for gamma-ray emission from dark matter annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope

    SciTech Connect

    Caputo, Regina; Buckley, Matthew R.; Martin, Pierrick; Charles, Eric; Brooks, Alyson M.; Drlica-Wagner, Alex; Gaskins, Jennifer M.; Wood, Matthew

    2016-03-22

    The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object with relatively low astrophysical backgrounds, it is a natural target for dark matter indirect detection searches. In this work, we use six years of Pass 8 data from the Fermi Large Area Telescope to search for gamma-ray signals of dark matter annihilation in the SMC. Using data-driven fits to the gamma-ray backgrounds, and a combination of N-body simulations and direct measurements of rotation curves to estimate the SMC DM density profile, we found that the SMC was well described by standard astrophysical sources, and no signal from dark matter annihilation was detected. We set conservative upper limits on the dark matter annihilation cross section. Furthermore, these constraints are in agreement with stronger constraints set by searches in the Large Magellanic Cloud and approach the canonical thermal relic cross section at dark matter masses lower than 10 GeV in the bb¯ and τ+τ- channels.

  8. Search for gamma-ray emission from dark matter annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope

    DOE PAGES

    Caputo, Regina; Buckley, Matthew R.; Martin, Pierrick; ...

    2016-03-22

    The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object with relatively low astrophysical backgrounds, it is a natural target for dark matter indirect detection searches. In this work, we use six years of Pass 8 data from the Fermi Large Area Telescope to search for gamma-ray signals of dark matter annihilation in the SMC. Using data-driven fits to the gamma-ray backgrounds, and a combination of N-body simulations and direct measurements of rotation curves to estimate the SMC DM density profile, we found that themore » SMC was well described by standard astrophysical sources, and no signal from dark matter annihilation was detected. We set conservative upper limits on the dark matter annihilation cross section. Furthermore, these constraints are in agreement with stronger constraints set by searches in the Large Magellanic Cloud and approach the canonical thermal relic cross section at dark matter masses lower than 10 GeV in the bb¯ and τ+τ- channels.« less

  9. Gamma-Ray Emission of the Kes 73/1E 1841-045 Region Observed with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Yeung, Paul K. H.; Kong, Albert K. H.; Tam, P. H. Thomas; Hui, C. Y.; Takata, Jumpei; Cheng, K. S.

    2017-03-01

    The supernova remnant (SNR) Kes 73 and/or the magnetar 1E 1841-045 at its center can deposit a large amount of energy to the surroundings and is potentially responsible for particle acceleration. Using the data taken with the Fermi Large Area Telescope (LAT), we confirmed the presence of an extended source whose centroid position is highly consistent with this magnetar/SNR pair. Its emission is intense from 100 MeV to >100 GeV. Its LAT spectrum can be decoupled into two components, which are respectively governed by two different mechanisms. According to the young age of this system, the magnetar is seemingly a necessary and sufficient source for the downward-curved spectrum below 10 GeV, as the observed <10 GeV flux is too high for the SNR to account for. On the other hand, the SNR is reasonably responsible for the hard spectrum above 10 GeV. Further studies of this region in the TeV regime is required so that we can perform physically meaningful comparisons of the >10 GeV spectrum and the TeV spectrum.

  10. NCORP’s First Year Reviewed | Division of Cancer Prevention

    Cancer.gov

    By the numbers, the first year of NCI’s Community Oncology Research Program (NCORP) has made progress in clinical trials for prevention, control, health-related quality of life, comparative effectiveness and screening; accrual to NCI National Clinical Trials Network treatment and imaging trials; and in new areas of emphasis in cancer care delivery research and cancer disparities research. Infographic Highlight NCORP’s First Year Reviewed |

  11. Pulsar Timing with the Fermi LAT

    DTIC Science & Technology

    2010-12-01

    Pulsar Timing with the Fermi LAT Paul S. Ray∗, Matthew Kerr†, Damien Parent∗∗ and the Fermi PSC‡ ∗Naval Research Laboratory, 4555 Overlook Ave., SW...Laboratory, Washington, DC 20375, USA ‡Fermi Pulsar Search Consortium Abstract. We present an overview of precise pulsar timing using data from the Large...unbinned photon data. In addition to determining the spindown behavior of the pulsars and detecting glitches and timing noise, such timing analyses al

  12. Angular power spectrum of the diffuse gamma-ray emission as measured by the Fermi Large Area Telescope and constraints on its dark matter interpretation

    NASA Astrophysics Data System (ADS)

    Fornasa, Mattia; Cuoco, Alessandro; Zavala, Jesús; Gaskins, Jennifer M.; Sánchez-Conde, Miguel A.; Gomez-Vargas, German; Komatsu, Eiichiro; Linden, Tim; Prada, Francisco; Zandanel, Fabio; Morselli, Aldo

    2016-12-01

    The isotropic gamma-ray background arises from the contribution of unresolved sources, including members of confirmed source classes and proposed gamma-ray emitters such as the radiation induced by dark matter annihilation and decay. Clues about the properties of the contributing sources are imprinted in the anisotropy characteristics of the gamma-ray background. We use 81 months of Pass 7 Reprocessed data from the Fermi Large Area Telescope to perform a measurement of the anisotropy angular power spectrum of the gamma-ray background. We analyze energies between 0.5 and 500 GeV, extending the range considered in the previous measurement based on 22 months of data. We also compute, for the first time, the cross-correlation angular power spectrum between different energy bins. We find that the derived angular spectra are compatible with being Poissonian, i.e. constant in multipole. Moreover, the energy dependence of the anisotropy suggests that the signal is due to two populations of sources, contributing, respectively, below and above ˜2 GeV . Finally, using data from state-of-the-art numerical simulations to model the dark matter distribution, we constrain the contribution from dark matter annihilation and decay in Galactic and extra-Galactic structures to the measured anisotropy. These constraints are competitive with those that can be derived from the average intensity of the isotropic gamma-ray background.

  13. DETECTION OF THE ENERGETIC PULSAR PSR B1509-58 AND ITS PULSAR WIND NEBULA IN MSH 15-52 USING THE FERMI-LARGE AREA TELESCOPE

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Asano, K.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Baring, M. G.; Bastieri, D.; Bonamente, E.; Brigida, M. E-mail: grondin@cenbg.in2p3.f E-mail: nakamori@hp.phys.titech.ac.j

    2010-05-01

    We report the detection of high-energy {gamma}-ray emission from the young and energetic pulsar PSR B1509 - 58 and its pulsar wind nebula (PWN) in the composite supernova remnant G320.4 - 1.2 (aka MSH 15 - 52). Using 1 yr of survey data with the Fermi-Large Area Telescope (LAT), we detected pulsations from PSR B1509 - 58 up to 1 GeV and extended {gamma}-ray emission above 1 GeV spatially coincident with the PWN. The pulsar light curve presents two peaks offset from the radio peak by phases 0.96 {+-} 0.01 and 0.33 {+-} 0.02. New constraining upper limits on the pulsar emission are derived below 1 GeV and confirm a severe spectral break at a few tens of MeV. The nebular spectrum in the 1-100 GeV energy range is well described by a power law with a spectral index of (1.57 {+-} 0.17 {+-} 0.13) and a flux above 1 GeV of (2.91 {+-} 0.79 {+-} 1.35) x 10{sup -9} cm{sup -2} s{sup -1}. The first errors represent the statistical errors on the fit parameters, while the second ones are the systematic uncertainties. The LAT spectrum of the nebula connects nicely with Cherenkov observations, and indicates a spectral break between GeV and TeV energies.

  14. Observations of the gamma-ray emission from the Quiescent Sun with Fermi Large Area Telescope during the first 7 years in orbit

    NASA Astrophysics Data System (ADS)

    Rainó, S.; Giglietto, N.; Moskalenko, I.; Orlando, E.; Strong, A. W.

    2017-03-01

    The high energy gamma-ray emission from the quiescent Sun is due to the interactions of cosmic ray (CR) protons and electrons with matter and photons in the solar environment. Such interactions lead to two component gamma-ray emission: a disk-like emission due to the nuclear interactions of CR protons and nuclei in the solar atmosphere and a space extended emission due to the inverse Compton (IC) scattering of CR electrons off solar photons in the whole heliosphere. The observation of these two solar emission components may give useful information about the evolution of the solar cycle by probing two different CR components (proton and electrons) in regions not directly accessible by direct observations. We present the results of the observations of the Sun with Fermi-LAT in the first 7 years on orbit, with the exception of the flaring periods. Significantly large photon statistics and improved processing performance with respect to previous analysis allow us to explore both components of the emission in greater details and perform better comparisons of data with current models of the IC component. This allows us to probe CR electrons in the inner heliosphere which is not possible by other methods. Moreover, the longer period of observations allows us to study the variations of the emission between the maximum and the minimum of the solar cycle.

  15. Ultrafast and Ultrasensitive Gas Sensors Derived from a Large Fermi-Level Shift in the Schottky Junction with Sieve-Layer Modulation.

    PubMed

    Cheng, Ching-Cheng; Wu, Chia-Lin; Liao, Yu-Ming; Chen, Yang-Fang

    2016-07-13

    Gas sensors play an important role in numerous fields, covering a wide range of applications, including intelligent systems and detection of harmful and toxic gases. Even though they have attracted much attention, the response time on the order of seconds to minutes is still very slow. To circumvent the existing problems, here, we provide a seminal attempt with the integration of graphene, semiconductor, and an addition sieve layer forming a nanocomposite gas sensor with ultrahigh sensitivity and ultrafast response. The designed sieve layer has a suitable band structure that can serve as a blocking layer to prevent transfer of the charges induced by adsorbed gas molecules into the underlying semiconductor layer. We found that the sensitivity can be reduced to the parts per million level, and the ultrafast response of around 60 ms is unprecedented compared with published graphene-based gas sensors. The achieved high performance can be interpreted well by the large change of the Fermi level of graphene due to its inherent nature of the low density of states and blocking of the sieve layer to prevent charge transfer from graphene to the underlying semiconductor layer. Accordingly, our work is very useful and timely for the development of gas sensors with high performance for practical applications.

  16. THE FIRST DETECTION OF GeV EMISSION FROM AN ULTRALUMINOUS INFRARED GALAXY: Arp 220 AS SEEN WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Peng, Fang-Kun; Wang, Xiang-Yu; Liu, Ruo-Yu; Tang, Qing-Wen; Wang, Jun-Feng

    2016-04-20

    Cosmic rays (CRs) in starburst galaxies produce high-energy gamma-rays by colliding with the dense interstellar medium. Arp 220 is the nearest ultraluminous infrared galaxy that has star formation at extreme levels, so it has long been predicted to emit high-energy gamma-rays. However, no evidence of gamma-ray emission was found despite intense search efforts. Here we report the discovery of high-energy gamma-ray emission above 200 MeV from Arp 220 at a confidence level of ∼6.3σ using 7.5 years of Fermi Large Area Telescope observations. The gamma-ray emission shows no significant variability over the observation period and it is consistent with the quasi-linear scaling relation between the gamma-ray luminosity and total infrared luminosity for star-forming galaxies, suggesting that these gamma-rays arise from CR interactions. As the high-density medium of Arp 220 makes it an ideal CR calorimeter, the gamma-ray luminosity can be used to measure the efficiency of powering CRs by supernova (SN) remnants given a known supernova rate in Arp 220. We find that this efficiency is about 4.2 ± 2.6% for CRs above 1 GeV.

  17. DETERMINATION OF THE POINT-SPREAD FUNCTION FOR THE FERMI LARGE AREA TELESCOPE FROM ON-ORBIT DATA AND LIMITS ON PAIR HALOS OF ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Bloom, E. D.; Borgland, A. W.; Bottacini, E.; Buehler, R.; Asano, K.; Atwood, W. B.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Bastieri, D.; Bonamente, E.; Brandt, T. J.; Brigida, M.; Bruel, P. E-mail: mar0@uw.edu [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS and others

    2013-03-01

    The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to detect photons with energies from Almost-Equal-To 20 MeV to >300 GeV. The pre-launch response functions of the LAT were determined through extensive Monte Carlo simulations and beam tests. The point-spread function (PSF) characterizing the angular distribution of reconstructed photons as a function of energy and geometry in the detector is determined here from two years of on-orbit data by examining the distributions of {gamma} rays from pulsars and active galactic nuclei (AGNs). Above 3 GeV, the PSF is found to be broader than the pre-launch PSF. We checked for dependence of the PSF on the class of {gamma}-ray source and observation epoch and found none. We also investigated several possible spatial models for pair-halo emission around BL Lac AGNs. We found no evidence for a component with spatial extension larger than the PSF and set upper limits on the amplitude of halo emission in stacked images of low- and high-redshift BL Lac AGNs and the TeV blazars 1ES0229+200 and 1ES0347-121.

  18. GBM First-year Catalogs (with Some LAT GRB Catalogs as a Bonus)

    NASA Astrophysics Data System (ADS)

    Paciesas, William Simon; GBM, Fermi; LAT Collaborations

    2010-03-01

    The Fermi Gamma-ray Burst Monitor (GBM) monitors the entire unocculted sky for transient activity in the energy range from 8 keV to 40 MeV. In its first year of operation GBM's on-board trigger detected 253 gamma-ray bursts (GRBs), of which 9 were confidently detected by the LAT (a catalog of LAT upper limits for non-detected GRBs is also available). In addition, GBM triggered on 12 terrestrial gamma flashes and 168 soft gamma repeater events from four different magnetar candidates. GBM's continuous data collection over the entire sky allows continual hard X-ray monitoring of both steady and variable sources using Earth occultation and pulsed source analysis techniques. Catalogs of the GBM-detected source categories will be summarized and, if time permits, compared with relevant catalogs from other instruments such as CGRO/BATSE.

  19. Berry Fermi liquid theory

    NASA Astrophysics Data System (ADS)

    Chen, Jing-Yuan; Son, Dam Thanh

    2017-02-01

    We develop an extension of the Landau Fermi liquid theory to systems of interacting fermions with non-trivial Berry curvature. We propose a kinetic equation and a constitutive relation for the electromagnetic current that together encode the linear response of such systems to external electromagnetic perturbations, to leading and next-to-leading orders in the expansion over the frequency and wave number of the perturbations. We analyze the Feynman diagrams in a large class of interacting quantum field theories and show that, after summing up all orders in perturbation theory, the current-current correlator exactly matches with the result obtained from the kinetic theory.

  20. Factors predictive of depression in first-year college students.

    PubMed

    Brandy, Julie M; Penckofer, Sue; Solari-Twadell, Phyllis A; Velsor-Friedrich, Barbara

    2015-02-01

    Starting college is a challenging time for first-year students and is often accompanied by emotions such as depression, which can negatively affect academic performance and quality of life. This descriptive correlational study examined stress, coping, depressive symptomology, spirituality, and social support in a convenience sample of first-year students (N = 188) from two private colleges. Results indicated that 45% of students demonstrated greater than average levels of stress and 48% reported clinically significant depressive symptomology. Significant relationships existed between depressive symptoms and stress (p < 0.01) and depressive symptoms and social support (p < 0.01). Less social support was associated with more stress (p < 0.01). The results suggested that interventions targeting stress reduction in first-year students should be considered for decreasing depressive symptoms to enhance their college experience. \\

  1. SMART-1 celebrates its first year in space

    NASA Astrophysics Data System (ADS)

    2004-09-01

    scientific data have to be transferred back to Earth over large distances in space. During its cruise, SMART-1’s miniaturised payload, consisting of seven instruments weighing only 19 kilograms in total, has been tested. All instruments onboard SMART-1 were operated and performed successfully in a number of science experiments. This was excellent preparation for the next phase of the SMART-1 mission: an unprecedented scientific study of the Moon, exploring in-depth the mysteries of our Earth’s natural satellite. With all these achievements to celebrate after its first year in space, SMART-1 is now preparing for the next big milestone, the lunar capture which is expected to take place less than two months from now. Note for editors: SMART-1 was launched on 27 September 2003 from Kourou, Europe’s spaceport in French Guiana, onboard an Ariane-5 rocket. It is the first in a series of ‘Small Missions for Advanced Research in Technology’, designed to demonstrate innovative and key technologies for future deep-space science missions. In addition to its technological objectives, SMART-1 is Europe’s first lunar mission and will perform a detailed scientific study of the Moon.

  2. Multiple Assessments of a First-Year Seminar Pilot

    ERIC Educational Resources Information Center

    Barton, Andrew; Donahue, Christiane

    2009-01-01

    First-year seminars have become common at liberal arts and other colleges across the United States. An accumulating body of research appears to demonstrate that this curricular element is associated with increased retention of students and is positively correlated with graduation rates, student adjustment and involvement, student satisfaction,…

  3. Guided Planning in First-Year Student Teachers' Teaching

    ERIC Educational Resources Information Center

    Nilssen, Vivi Lisbeth

    2010-01-01

    This article focuses on a cooperating teacher in Norway and her approach to mentoring first-year student teachers in their process of planning the mathematics teaching of third-graders. The purpose of the text is to show how the cooperating teacher's mentoring assists the student teachers' performance in a teaching form that is acknowledged as…

  4. Becoming Warm Demanders: Perspectives and Practices of First Year Teachers

    ERIC Educational Resources Information Center

    Bondy, Elizabeth; Ross, Dorene D.; Hambacher, Elyse; Acosta, Melanie

    2013-01-01

    In the literature on culturally responsive pedagogy "warm demanders" are teachers who embrace values and enact practices that are central to their students' success. Few scholars have examined the experience of novice teachers who attempt to enact this stance. In this study of two first-year, female, European American teachers who attempted to be…

  5. Curriculum Guide for Marketing and Distributive Education (First Year).

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This curriculum guide consists of materials for use in teaching the first year of a two-year course in marketing and distributive education. Included in the guide are field review information, an introduction, a course outline, unit outlines for use in the first and second semesters of the course, and a bibliography. Topics addressed in the first…

  6. First-Year University Chemistry Textbooks' Misrepresentation of Gibbs Energy

    ERIC Educational Resources Information Center

    Quilez, Juan

    2012-01-01

    This study analyzes the misrepresentation of Gibbs energy by college chemistry textbooks. The article reports the way first-year university chemistry textbooks handle the concepts of spontaneity and equilibrium. Problems with terminology are found; confusion arises in the meaning given to [delta]G, [delta][subscript r]G, [delta]G[degrees], and…

  7. Law Firm: A First-Year Course on Lawyering.

    ERIC Educational Resources Information Center

    Braveman, Daan

    1989-01-01

    An experimental first-year course introducing law students to the law firm addressed: a single issue in contract law from both sides, writing as an advocate, the lawyer's role, legal research methods, the legislative process, the counseling function, the appellate process, and traditional legal writing. An interdisciplinary approach was used. (MSE)

  8. FIRST-YEAR REPORT ON THE HEGELER PROJECT READING STUDY.

    ERIC Educational Resources Information Center

    HUGHES, ANN; THOMAS, NELLIE

    IN SEPTEMBER 1964 THE HEGELER FOUNDATION CONDUCTED A WIDESCALE READING STUDY TO DETERMINE WHETHER OR NOT THE CORRELATED LANGUAGE ARTS PROGRAM BASED ON THE "OPEN COURT BASIC READERS" WOULD PRODUCE SUPERIOR RESULTS IN READING AND WRITING ACHIEVEMENT. THE FIRST-YEAR RESULTS ARE PRESENTED. THIRTY-TWO EXPERIMENTAL CLASSES AND 32 CONTROL…

  9. Promoting Conceptual Change in First Year Students' Understanding of Evaporation

    ERIC Educational Resources Information Center

    Costu, Bayram; Ayas, Alipasa; Niaz, Mansoor

    2010-01-01

    We constructed the PDEODE (Predict-Discuss-Explain-Observe-Discuss-Explain) teaching strategy, a variant of the classical POE (Predict-Observe-Explain) activity, to promote conceptual change, and investigated its effectiveness on student understanding of the evaporation concept. The sample consisted of 52 first year students in a primary science…

  10. First-Year Students' Perspectives on Intercultural Learning

    ERIC Educational Resources Information Center

    Lee, Amy; Williams, Rhiannon D.; Shaw, Marta A.; Jie, Yiyun

    2014-01-01

    Faculty can play a critical role in supporting students' intercultural development, but studies indicate that instructors report a lack of formal understanding about how to maximize this opportunity. Through the investigation of 115 first-year students' written reflections, this study provides faculty with students' perspectives on intercultural…

  11. Freshmen Marketing: A First-Year Experience with Experiential Learning

    ERIC Educational Resources Information Center

    Greene, Henry

    2011-01-01

    This paper describes an experiential learning activity designed for a New England university freshmen course, BUS101-Marketing First-Year Experience (FYE). The purpose of the activity is to teach basic principles of marketing, develop a general perspective of business, and provide FYE activities that facilitate the college transition. The specific…

  12. Linguistic Attention in Rhetorical Genre Studies and First Year Writing

    ERIC Educational Resources Information Center

    Aull, Laura

    2015-01-01

    Since Carolyn Miller's Genre as Social Action, North American Rhetorical Genre Studies (RGS) has facilitated analysis of how typified rhetorical actions constitute the contexts and communities in which writers write. In first-year writing (FYW) specifically, RGS approaches have focused on macro-level textual constructs, like the audience and…

  13. Transitions in First-Year Students' Initial Practice Orientations

    ERIC Educational Resources Information Center

    Kaufman, Roni; Segal-Engelchin, Dorit; Huss, Efrat

    2012-01-01

    This study investigates the impact of the first-year program on the initial practice orientations of 2 distinct, equal-sized clusters of entering BSW students: micro-oriented and macro-oriented students. Results indicate that the proportion of students reporting a micro-practice orientation increased from 53.2% to 62.4% between the beginning and…

  14. Accelerating Literacy Program: The First Year 1993-94.

    ERIC Educational Resources Information Center

    Smith, Ralph J.

    The 1993-94 school year was the first year of the Accelerating Literacy Program (ALP) of the Austin (Texas) Independent School District. The ALP used a grant from the Texas Education Agency to train elementary educators in the methods of a short-term reading intervention program based on the Reading Recovery/Whole Language theory. A group of 367…

  15. The First-Year Experiences of Successful Superintendents

    ERIC Educational Resources Information Center

    Roberts, Kerry; Hanna, Shellie L.; Womack, Sid T.

    2012-01-01

    These qualitative case studies give the prospective superintendent a real-life look at life on the other side of the district CEO's desk. Two dozen superintendents reflect upon their first challenges and growth opportunities that arose during that all-important first year. They tell it like it is, no sugar-coating. The experiences they listed, in…

  16. Child Nutrition Program Operations Study: First Year Report Executive Summary.

    ERIC Educational Resources Information Center

    St. Pierre, Robert; And Others

    Summarizing the first year report of a multi-year study of the Food and Nutrition Service's (Department of Agriculture) Child Nutrition Programs, this report describes the programs and methods of the study. Data were collected through telephone interviews with states and School Food Authorities (SFAs) between 1987 and 1992. Findings from 1987-1988…

  17. A Review of the AIDP Project After the First Year.

    ERIC Educational Resources Information Center

    Broadbent, William A.

    This document provides an assessment of the progress Leeward Community College has made toward fulfilling the objectives of its five-year 1.4 million dollar Advanced Institutional Development Program (AIDP) grant at the end of the first year of funding. Essentially, the objectives of the project fall into four major program areas: community…

  18. Operating Instructions: Letter to a First Year School Librarian

    ERIC Educational Resources Information Center

    Ashworth, Justin

    2006-01-01

    This article presents operational guidelines or instructions to a newly graduated librarian from library school. The author discusses some important factors to consider in the field of library work as a school librarian. He also presents seven strategies to keep in mind for a successful first year for a school librarian: (1) put people first; (2)…

  19. Psychosocial Factors Predicting First-Year College Student Success

    ERIC Educational Resources Information Center

    Krumrei-Mancuso, Elizabeth J.; Newton, Fred B.; Kim, Eunhee; Wilcox, Dan

    2013-01-01

    This study made use of a model of college success that involves students achieving academic goals and life satisfaction. Hierarchical regressions examined the role of six psychosocial factors for college success among 579 first-year college students. Academic self-efficacy and organization and attention to study were predictive of first semester…

  20. 8 Things First-Year Students Fear about College

    ERIC Educational Resources Information Center

    Shanley, Mary Kay; Johnston, Julia

    2008-01-01

    There is this little secret college-bound and first-year college students outwardly deny: They are scared sick about going off to college. In the authors' interviews with 175 college students throughout the United States for "Survival Secrets of College Students" (Barron's, 2007) students talked--sometimes painfully--about what they wished they…

  1. First Year Turkish Science Undergraduates' Understandings and Misconceptions of Light

    ERIC Educational Resources Information Center

    Yalcin, Mehmet; Altun, Sema; Turgut, Umit; Aggul, Fatma

    2009-01-01

    The present study aims to identify first year Turkish Science undergraduates' understandings and misconceptions of the concept of light and its propagation. For this purpose, an instrument composed of four open-ended questions was developed by the researchers. The diagnostic test was piloted with twenty students and modifications were made prior…

  2. First Year Engagement & Retention: A Goal-Setting Approach

    ERIC Educational Resources Information Center

    Tuffley, David; Antonio, Amy

    2013-01-01

    First year students face a daunting range of challenges as they make the transition to university life. Their experiences in the first months of university have a defining influence on their success or otherwise in their studies. The purpose of this paper is to report on the results of a case study that tests the efficacy of a student engagement…

  3. Influencers of Religious Engagement in the First Year of College

    ERIC Educational Resources Information Center

    Hartley, Harold V., III

    2006-01-01

    The purpose of this study was to identify factors that influence a deepening of students' religious engagement in the first year of college. Recent studies have challenged the findings of more than three decades of research that found attending college leads to a decline in students' religious beliefs and practices. This study extends those recent…

  4. Classroom Motivation: Strategies of First-Year Teachers.

    ERIC Educational Resources Information Center

    Newby, Timothy J.

    1991-01-01

    Motivational strategies used by 30 first year elementary school teachers and on-task behaviors of their respective students were monitored. Each teacher used several motivating strategies (concerning getting attention, emphasizing relevance, building confidence, and imposing rewards and punishments). There was a significant positive correlation…

  5. Creating, Implementing and Integrating a First-Year Statistics Requirement

    ERIC Educational Resources Information Center

    Redington, Douglas B.; Russell, R. Alan

    2012-01-01

    We present the process our institution used to create a statistics requirement for almost all incoming first-year students. From conception and planning, to hiring and acceptance by the university community, we offer lessons learned should you consider making such a shift in your own curriculum.

  6. Maternal Behavior and Infant Weight Gain in the First Year

    ERIC Educational Resources Information Center

    Worobey, John; Lopez, Maria Islas; Hoffman, Daniel J.

    2009-01-01

    Objective: To examine the relative contributions of maternal characteristics and behaviors in predicting infant weight gain over the first year of postpartum life. Design: Longitudinal study of maternal feeding style throughout infancy. Setting: A Special Supplemental Nutrition Program for Women, Infants, and Children center. Participants:…

  7. Articulatory Phonetics in the First-Year Spanish Classroom.

    ERIC Educational Resources Information Center

    Arteaga, Deborah L.

    2000-01-01

    Reconsiders the general question of the role of articulatory phonetics in the second language (L2) classroom and reviews the phonetic presentation in 10 recent first-year Spanish texts. Proposes a phonetics program based on the notion of a learners' dialect, then measures the phonetics of the textbooks against a learners' dialect. Argues against…

  8. Reflections on a Flipped Classroom in First Year Higher Education

    ERIC Educational Resources Information Center

    McCarthy, Josh

    2016-01-01

    This paper explores the efficacy of a flipped classroom model for teaching first year students three-dimensional (3D) animation, and analyses the advantages and disadvantages when compared to traditional teaching mechanisms. In 2015, within the course "Introduction to CGI" at the University of South Australia, two different tutorial…

  9. Challenges of a Successful First-Year Principal in Mexico

    ERIC Educational Resources Information Center

    Slater, Charles L.; Garcia, Jose Maria; Gorosave, Gema Lopez

    2008-01-01

    Purpose: This case study is an attempt to understand the experience of a school principal, Arnulfo. The research question is: what are the challenges of one first-year school director in Baja California, Mexico? Design/methodology/approach: Arnulfo participated in an interview and five focus groups at the Ensenada State Normal School. He kept a…

  10. Sense of Belonging and First-Year Academic Literacy

    ERIC Educational Resources Information Center

    Marshall, Steve; Zhou, Mingming; Gervan, Ted; Wiebe, Sunita

    2012-01-01

    In this article, we analyze a broad range of factors that affect the sense of belonging of undergraduate students taking a first-year academic literacy course (ALC) at a multicultural, multilingual university in Vancouver, Canada. Students who fail to meet the university's language and literacy requirements are required to pass ALC before they can…

  11. Blended Learning: The Perceptions of First-Year Geography Students

    ERIC Educational Resources Information Center

    Mitchell, Phillipa; Forer, Pip

    2010-01-01

    Focusing on "Digital Worlds", a first-year geography blended learning course at the University of Auckland, this paper gives voice to the students, examining how they perceived e-learning versus traditional learning mechanisms; how e-learning mechanisms have affected their learning behaviour; and why certain e-learning mechanisms offered…

  12. First Year Mathematics Undergraduates' Settled Images of Tangent Line

    ERIC Educational Resources Information Center

    Biza, Irene; Zachariades, Theodossios

    2010-01-01

    This study concerns 182 first year mathematics undergraduates' perspectives on the tangent line of function graph in the light of a previous study on Year 12 pupils' perspectives. The aim was the investigation of tangency images that settle after undergraduates' distancing from the notion for a few months and after their participation in…

  13. Children's Diurnal Cortisol Activity during the First Year of School

    ERIC Educational Resources Information Center

    Yang, Pei-Jung; Lamb, Michael E.; Kappler, Gregor; Ahnert, Lieselotte

    2017-01-01

    The present study examined 4- to 5-year-old British children's diurnal cortisol activity during their first year of school. The children's cortisol was measured before enrollment (baseline), upon enrollment, and both 3 and 6 months after enrollment. On each day, cortisol was sampled four times, providing information about the diurnal amount of…

  14. Realized Benefits for First-Year Student Peer Educators

    ERIC Educational Resources Information Center

    Wawrzynski, Matthew R.; Beverly, Andrew M.

    2012-01-01

    This study investigated student-learning outcomes of college peer educators whose primary responsibility or interest was to address health and safety topics on campus, such as alcohol and illicit drug use, tobacco issues, sexual health and safety issues, nutrition, and violence prevention. Participants included 69 first-year college students who…

  15. First-Year University Students' Understanding of Rate of Change.

    ERIC Educational Resources Information Center

    Bezuidenhout, Jan

    1998-01-01

    Explores first-year students' understanding of fundamental calculus concepts using written tests and interviews. Analysis of the written and verbal responses to the test items revealed significant misconceptions on which students' mathematical activities were based. Describes some of those misconceptions and errors relating to students'…

  16. Immigration Reform in Its First Year. CIS Paper 4.

    ERIC Educational Resources Information Center

    North, David S.

    This document assesses the preliminary impact of the first year of the Immigration Reform and Control Act of 1986 (IRCA). The act had three primary goals: (1) to discourage illegal immigration into the United States and to encourage the departure of recent illegal immigrants; (2) to permit the legalization of illegal immigrants who have been in…

  17. First-Year Student Aspirations: A Multinodal Analysis

    ERIC Educational Resources Information Center

    Grellier, Jane

    2014-01-01

    This article explores the aspirations of first-year university students in a particular socio-geographic context, by juxtaposing this context with those of Western universities in the 1970s. The rhizomatic analysis enables student voices and personal narratives to complement, extend and undercut the words of published researchers and of the…

  18. Teaching Visual Rhetoric in the First-Year Composition Classroom

    ERIC Educational Resources Information Center

    Welch, Kristen; Lee, Nicholas; Shuman, Dustin

    2010-01-01

    An emphasis on visual rhetoric can be incorporated into a variety of classrooms. This article illustrates teaching visual rhetoric to first-year composition students via interpretation and analysis through a trip to a local art museum for the first essay assignment and through an exploration of photography for the second essay assignment. In the…

  19. Vocational Electronics First Year Teacher's Guide and Student Workbook.

    ERIC Educational Resources Information Center

    Solanik, Chuck

    This guide is intended to help teachers give preparatory instruction in the development of basic manipulative skills, safety practices, technical knowledge, and related industrial information in order to prepare students for useful employment in the field of electronics. This first-year guide contains 6 units organized in 21 lesson plans. Each…

  20. First Year Teaching Experiences of Early Childhood Urban Teachers.

    ERIC Educational Resources Information Center

    Guyton, Edith

    The first-year teaching experiences of urban teachers were studied to conceptualize the reality faced by urban teachers and to determine the implications of the urban environment for teacher education. Subjects were four graduates of a teacher education program that gave no particular attention to the urban context beyond placement for student…

  1. Outcomes of Synergetic Peer Assessment: First-Year Experience

    ERIC Educational Resources Information Center

    Hodgson, Paula; Chan, Kitty; Liu, Justina

    2014-01-01

    Active participation in learning activities and reviewing assessment activity can facilitate learners engaged in these processes. This case study reports student experiences of the process of peer assessment with teacher guidance in a group project for a first-year nursing course with 153 students. Twenty groups of students were assigned roles in…

  2. The Work Values of First Year Spanish University Students

    ERIC Educational Resources Information Center

    Cortés-Pascual, P. A.; Cano-Escoriaza, J.; Orejudo, S.

    2014-01-01

    This study analyzes the work values of 2,951 first-year university students in Spain enrolled in degree programs within the five major areas of university studies. For our research, participants were asked to respond to a Scale of Work Values in which intrinsic, social, and pragmatic extrinsic values as well as extrinsic values related to…

  3. Literacy Development in the First Year of Schooling.

    ERIC Educational Resources Information Center

    Hill, Susan; Louden, William

    Drawing on the research study, "100 Children Go to School: Connections between Literacy Development in the Prior to School Period and the First Year of Schooling," conducted from 1996-1998 by a team made up of Susan Hill, Barbara Comber, William Louden, Judith Rivalland, and Jo-Anne Reid, this paper discusses the findings of the study,…

  4. Decreasing Authority Dependence during the First Year of College

    ERIC Educational Resources Information Center

    Magolda, Marcia B. Baxter; King, Patricia M.; Taylor, Kari B.; Wakefield, Kerri M.

    2012-01-01

    Annual interviews with 228 students at 6 diverse campuses in the Wabash National Study of Liberal Arts Education reveal 123 students' developmental growth away from authority dependence between the beginning of the first and second years of college. In the first year of college, 86% of participants relied solely on external authorities to define…

  5. Motivating First-Year University Students by Interdisciplinary Study Projects

    ERIC Educational Resources Information Center

    Koch, Franziska D.; Dirsch-Weigand, Andrea; Awolin, Malte; Pinkelman, Rebecca J.; Hampe, Manfred J.

    2017-01-01

    In order to increase student commitment from the beginning of students' university careers, the Technische Universität Darmstadt has introduced interdisciplinary study projects involving first-year students from the engineering, natural, social and history, economics and/or human sciences departments. The didactic concept includes sophisticated…

  6. First-Year Composition and the Problem of Transfer

    ERIC Educational Resources Information Center

    Kutney, Joshua Peter

    2013-01-01

    This dissertation examines recent claims that post-secondary student writers underperform because they fail to transfer the skills and knowledge taught in first-year composition courses. My analysis of the scholarship on writing transfer and investigation of the conditions of student writing at one private liberal arts college suggest that there…

  7. Helping First-Year Undergraduates Engage in Language Research

    ERIC Educational Resources Information Center

    Wyatt, Mark; Pasamar Márquez, Carmen

    2016-01-01

    Adopting an "exploratory action research" design and drawing primarily on a reflective journal and interviews, this study recounts the process of supporting first-year Applied Languages students (learning French, German and Spanish) as they started to engage in language research. Certain challenges they faced in engaging with the…

  8. Placement of Students into First-Year Writing Courses

    ERIC Educational Resources Information Center

    Elliot, Norbert; Deess, Perry; Rudniy, Alex; Joshi, Kamal

    2012-01-01

    The purpose of the present study is to examine concurrent and predictive evidence used in the validation of ACCUPLACER, a purchased test used to place first-year students into writing courses at an urban, public research university devoted to science and technology education. Concurrent evidence was determined by correlations between ACCUPLACER…

  9. Incorporating a Creative Component in First-Year Law

    ERIC Educational Resources Information Center

    Kleefeld, John C.; Farnese, Patricia L.

    2015-01-01

    For some students, law school leads to a perception of legal education as favouring technical proficiency and structural similarity over innovation and creativity, leading to disengagement in learning. To address this, we offered a creative option in two first-year law courses, worth 20% of the grade. Students who chose this option created a…

  10. Building Racial Literacy in First-Year Composition

    ERIC Educational Resources Information Center

    Sealey-Ruiz, Yolanda

    2013-01-01

    The purpose of this article is to present a case for building racial literacy in students. The author offers support for her argument by foregrounding a three-month study she conducted in her community college first-year composition (FYC) classroom. She hopes that this article will contribute to the growing body of research that emphasizes the…

  11. A 3D Approach to First Year English Education

    ERIC Educational Resources Information Center

    Zeegers, Margaret

    2013-01-01

    Purpose: The purpose of this paper is to explore the suggestive possibilities of an approach to undergraduate English teacher education that the author has called the 3D Approach--Develop professional knowledge, Display professional knowledge, Disseminate professional knowledge--in relation to a number of groups of first year pre-service teachers…

  12. High-Impact Practices and the First-Year Student

    ERIC Educational Resources Information Center

    Tukibayeva, Malika; Gonyea, Robert M.

    2014-01-01

    High-impact practices, programs, and activities where students commit considerable time and effort in different settings can help to define the first-year college experience and are likely to increase success in areas like persistence, deep learning, and self-reported gains.

  13. Some Mathematical Elements in a First-Year Seminar Course

    ERIC Educational Resources Information Center

    Pinter, Mike

    2007-01-01

    A first-year seminar general education course provides a good opportunity to search for mathematical topics associated with the popular culture represented in the course's required films and readings. We discuss mathematical connections to several books, including "Life of Pi" and "The Curious Incident of the Dog in the Night-Time," and to the…

  14. First Year ESL Students Developing Critical Thinking: Challenging the Stereotypes

    ERIC Educational Resources Information Center

    Li, Yongyan

    2013-01-01

    Reporting a case study of two high-achieving Chinese students studying at a university in Hong Kong, this paper presents evidence that poses an anti-thesis to the stereotypes of first year university students as holding naïve beliefs about learning and of "Chinese learners" as lacking in critical thinking. Many studies have examined…

  15. Reflective Journal Writing and the First-Year Experience

    ERIC Educational Resources Information Center

    Everett, Michele C.

    2013-01-01

    In recent years, great emphasis has been placed on student success and retention in higher education. To address this issue, many universities' strategic retention programs include first-year seminars. A variety of pedagogical strategies have been employed in these seminars to help students succeed personally, socially and academically. This…

  16. Assessment 101: Assessment Made Easy for First-Year Teachers

    ERIC Educational Resources Information Center

    Bailey, Jennifer; Little, Chelsea; Rigney, Rex; Thaler, Anna; Weiderman, Ken; Yorkovich, Ben

    2010-01-01

    This handbook is designed as a quick reference for first-year teachers who find themselves in an assessment driven environment with little experience to help make sense of the language, underlying philosophy, or organizational structure of the assessment system. The handbook begins with advice on developing and evaluating effective learning…

  17. Motivations for Studying Dentistry Among First-Year Dental Students

    ERIC Educational Resources Information Center

    Cohen, R.; Coburn, D.

    1977-01-01

    Reasons for choosing dentistry as a profession were analyzed among first-year dental students at the University of Toronto. An extrinsic motivation, financial reward, was found to be the most widespread, but other widely-chosen motivations were intrinsic, including working with people, stimulating work, and being autonomous. (LBH)

  18. Fermi Pulsar Analysis

    NASA Video Gallery

    This animation illustrates how analysis of Fermi data reveals new pulsars. Fermi's LAT records the precise arrival time and approximate direction of the gamma rays it detects, but to identify a pul...

  19. First year physics practicals in distance education in South Africa

    NASA Astrophysics Data System (ADS)

    Cilliers, Johanna Albertha

    Although the merits of practical work in physics is often questioned, it remains part of physics curricula word- wide. In distance education the incorporation of practical work into the curriculum is considerably complicated by the unique logistics of the setting and the high cost involved. The research reported in this thesis emanated from the need to improve the practical work module for first year physics at the University of South Africa, one of the largest distance education universities in the world. Specifically, the home-based component which, up to the commencement of the research had been entirely text-based, needed to be addressed. To this end it was necessary to identify a valid and attainable set of objectives and to determine the characteristics, abilities and needs of the students in the target group. A survey polling the viewpoints of South African physics lecturers and students about the objectives of practical work was conducted and an extensive student profile comprising a biographic, cognitive and affective component was compiled. Biographically, the target group is unique in the sense that it consists mainly of adult learners, a large percentage of whom study in a second language. The cognitive component of the profile covered aptitude, proficiency in English, mathematics and the integrated science process skills and level of cognitive development, all of which were investigated for possible influence on performance in practical work. On an affective level, students displayed a very positive attitude towards practical work, seated mainly in their need for concrete exploration of the theory. A practical work module structured around an experiential learning cycle adapted to the distance education environment was subsequently designed. The study material developed for the module comprised an interactive study guide on data processing and experimental procedure, a home experiment kit with accompanying workbook and a laboratory manual. From the

  20. M. Giroletti (INAF-IRA Bologna), M. Orienti (Univ. Bologna, INAF-IRA Bologna), C. C. Cheung (NRL/NRL) on behalf of the Fermi Large Area Telescope Collaboration

    NASA Astrophysics Data System (ADS)

    Giroletti, M.; Orienti, M.; Cheung, C. C.

    2012-09-01

    The Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope, has observed an increasing gamma-ray flux from a source positionally consistent with the blazar S3 0218+35 (also known as 2FGL J0221.0+3555, Nolan et al. 2012, ApJS, 199, 31) with radio coordinates R.A.: 35.27279 deg, Dec: +35.93715 deg (J2000, Patnaik et al. 1992, MNRAS, 254, 655).

  1. The Cosmic-Ray and Gas Content of the Cygnus Region as Measured in Gamma Rays by the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Harding, A. K.; Hays, E.; Thompson, D. J.; Troja, E.

    2011-01-01

    Context. The Cygnus region hosts a giant molecular-cloud complex which actively forms massive stars. Interactions of cosmic rays with interstellar gas and radiation fields make it shine at y-ray energies. Several gamma-ray pulsars and other energetic sources are seen in this direction. Aims. In this paper we analyse the gamma-ray emission measured by the Fermi Large Area Telescope in the energy range from 100 Me V to 100 Ge V in order to probe the gas and cosmic-ray content over the scale of the whole Cygnus complex. The gamma-ray emission on the scale of the central massive stellar clusters and from individual sources is addressed elsewhere. Methods. The signal from bright pulsars is largely reduced by selecting photons in their off-pulse phase intervals. We compare the diffuse gamma-ray emission with interstellar gas maps derived from radio/mm-wave lines and visual extinction data. and a global model of the region, including other pulsars and gamma-ray sources, is sought. Results. The integral H I emissivity above 100 MeV averaged over the whole Cygnus complex amounts to 12.06 +/- 0.11 (stat.) (+0.15 -0.84) (syst.J] x 10(exp -26) photons /s / sr / H-atom, where the systematic error is dominated by the uncertainty on the H I opacity to calculate its column densities. The integral emissivity and its spectral energy distribution are both consistent within the systematics with LAT measurements in the interstellar space near the solar system. The average X(sub co) N(H2)/W(sub co) ratio is found to be [1.68 +/- 0.05 (stat.) (H I opacity)] x 1020 molecules cm-2 (K km/s /r, consistent with other LAT measurements in the Local Arm. We detect significant gamma-ray emission from dark neutral gas for a mass corresponding to approx 40% of that traced by CO. The total interstellar mass in the Cygnus complex inferred from its gamma-ray emission amounts to 8(+5 -1) x 10(exp 6) Solar M at a distance of 1.4 kpc. Conclusions. Despite the conspicuous star formation activity and large

  2. Engagement in the First Year as a Predictor of Academic Achievement and Persistence of First-Year Students

    ERIC Educational Resources Information Center

    Schlinsog, Jimmie A.

    2010-01-01

    This study explored the relationship between engagement in educationally purposeful activities during the first year of college and academic achievement, persistence, and graduation. The study focused on the impacts of engagement on student outcomes related to academic achievement, persistence, and graduation at a comprehensive university located…

  3. Graduate Students in Transition: Assisting Students through the First Year. The First-Year Experience Monograph Series No. 50

    ERIC Educational Resources Information Center

    Tokuno, Kenneth A. Ed.

    2008-01-01

    On many campuses, graduate students are a prized resource, supporting faculty research and the undergraduate instructional mission. Yet, attrition rates among master's and doctoral students are often alarmingly high. The 50th installment of The First-Year Experience Monograph Series describes the challenges associated with entry into graduate…

  4. Transforming the First Year of College for Students of Color. The First-Year Experience Monograph Series No. 38

    ERIC Educational Resources Information Center

    Rendon, Laura I., Ed.; Garcia, Mildred, Ed.; Person, Dawn, Ed.

    2004-01-01

    "Transforming the First Year of College for Students of Color" addresses some of the unique challenges and transition issues for African-American, Latino/a, Asian-Pacific American, American Indian/Alaska Native, and multiracial college students. Chapters address specific strategies for working with these student populations to ensure their success…

  5. Involvement in Campus Activities and the Retention of First-Year College Students. The First-Year Experience Monograph Series.

    ERIC Educational Resources Information Center

    Skipper, Tracy L., Ed.; Argo, Roxanne, Ed.

    The chapters of this monograph offer insights into educationally purposeful out-of-class activities and the impact they have on the student experience. It also provides future directions for the campus activities field and identifies ways to improve the educational experience of first-year students to enhance their scholarly experience and to…

  6. Computation, Exploration, Visualisation: Reaction to MATLAB in First-Year Mathematics.

    ERIC Educational Resources Information Center

    Cretchley, Patricia; Harman, Chris; Ellerton, Nerida; Fogarty, Gerard

    This paper describes a model for effective incorporation of technology into the learning experience of a large and diverse group of students in first-semester first-year tertiary mathematics. It describes the introduction of elementary use of MATLAB, in a course offered both on-campus and at a distance. The diversity of the student group is…

  7. Social Justice, Learning Centredness and a First Year Experience Peer Mentoring Program: How Might They Connect?

    ERIC Educational Resources Information Center

    Rawlinson, Catherine; Willimot, Michael

    2016-01-01

    Peer mentoring is a powerful strategy to support students in their first year of tertiary education utilised by a large number of tertiary institutions. While social justice principles such as rights, access, and equity as outlined by Creagh, Nelson, & Clarke (2013) highlight the importance of "student centredness," Taylor (2013)…

  8. An Exploratory Factor Analysis of the Cognitive Functioning of First-Year Bachelor Students with Dyslexia

    ERIC Educational Resources Information Center

    Callens, Maaike; Tops, Wim; Stevens, Michaël; Brysbaert, Marc

    2014-01-01

    An increasing number of students with dyslexia register in higher education. As a consequence, information on their pattern of strengths and weaknesses is essential to construct adequate assessment and diagnostic protocols. In a sample of 100 first-year bachelor students with dyslexia and 100 control students, a large pool of cognitive skills were…

  9. First-Year Students' Perspectives on Reasons for and Prevention of Their Own Alcohol Overdose

    ERIC Educational Resources Information Center

    Reis, Janet

    2014-01-01

    Two hundred twenty-six first-year students enrolled at a large, public Midwest university and deemed to require an emergency transport for a potential alcohol overdose completed a brief questionnaire on the student's perceptions of why the event occurred, what might have happened to prevent the overdose situation, and personal assessment of…

  10. Professional Development and the Teaching Schools Experiment in England: Leadership Challenges in an Alliance's First Year

    ERIC Educational Resources Information Center

    Dowling, Simon

    2016-01-01

    This article reports findings from the first year of a longitudinal, mixed-methods case study of a large teaching school alliance in England. This national initiative is intended to drive improvement at system level by grouping schools around formally designated teaching schools. These "alliances" work collaboratively to share learning,…

  11. Organic methods for control of pecan weevil: Results of the first year's field trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Integrated organic tactics for control of pecan weevil were investigated in large field plot tests. The experiment was conducted at two locations: USDA-ARS Research Lab in Byron, GA and Cleveland farms in Fort Valley, GA. Results from the first year field trials indicated that organic tactics for ...

  12. Students' Perceptions of Meaningfulness in First Year Experience Courses: A Case Study

    ERIC Educational Resources Information Center

    Evans, Nancy J.

    2012-01-01

    This qualitative case study, framed by a constructivist perspective, addresses a deficit in the literature and the knowledge base of a first year experience (FYE) academic program at a large, urban university regarding freshmen perceptions of meaningfulness in their courses. Existing studies identify concepts related to meaningfulness, but do not…

  13. First-Year Students' Attitudes towards the Grand Challenges and Nanotechnology

    ERIC Educational Resources Information Center

    Lakin, Joni M.; Han, Yi; Davis, Edward

    2016-01-01

    The "Grand Challenges" for Engineering are an effort to portray engineering as a field that has profound impacts on society. This study explores the level of interest first-year engineering students had in various "Grand Challenges" and in nanotechnology topics. We administered a survey to a large sample of students enrolled in…

  14. Shifting to Active Learning: Assessment of a First-Year Biology Course in South Africa

    ERIC Educational Resources Information Center

    Downs, Colleen T.; Wilson, Amy-Leigh

    2015-01-01

    Large first-year class sizes have resulted in many lecturers adopting coping strategies consisting of direct-transmission mode teaching, reduced practical time, and assessment. Recently several strategies have been implemented in an attempt to improve student participation and active learning; however, these changes have to be facilitated and…

  15. Beyond the Tweet: Using Twitter to Enhance Engagement, Learning, and Success among First-Year Students

    ERIC Educational Resources Information Center

    West, Bettina; Moore, Hélène; Barry, Ben

    2015-01-01

    This study incorporated social media microblogging technology (Twitter) across disciplines to provide 411 first-year undergraduate students studying in large-classroom settings with opportunities to connect in real-time, both within and outside the classroom, with their professor, other students, and members of the professional community. This…

  16. The Impact of Curriculum Change on Health Sciences First Year Students' Approaches to Learning

    ERIC Educational Resources Information Center

    Walker, Rebecca; Spronken-Smith, Rachel; Bond, Carol; McDonald, Fiona; Reynolds, John; McMartin, Anna

    2010-01-01

    This study aimed to use a learning inventory (the Approaches and Study Skills Inventory for Students, ASSIST) to measure the impact of a curriculum change on students' approaches to learning in two large courses in a health sciences first year programme. The two new Human Body Systems (HUBS) courses were designed to encourage students to take a…

  17. What Account of Science Shall We Give? a Case Study of Scientists Teaching First-Year University Subjects

    ERIC Educational Resources Information Center

    Smith, Dorothy V.; Mulhall, Pamela J.; Gunstone, Richard F.; Hart, Christina E.

    2015-01-01

    This article presents a case study of four academic scientists. These academics teach in the first year of a Bachelor of Science degree at a large research-focused Australian university that has demanded and supported a greater focus on undergraduate learning. Taken as a whole, the accounts of science that the first-year academics in this case…

  18. The Relationships among Academic Attitudes, Psychological Attitudes, and the First-Semester Academic Achievement of First-Year College Students

    ERIC Educational Resources Information Center

    Reynolds, Amy L.; Weigand, Matthew J.

    2010-01-01

    This study examined the relationships among academic and psychological attitudes and academic achievement of first-year students. The College Resilience Scale, the Academic Motivation Scale, the College Self-Efficacy Inventory, and the University Environment Scale were administered to 164 first-year undergraduate students enrolled at a large RU/VH…

  19. Prior Learning in Biology at High School Does Not Predict Performance in the First Year at University

    ERIC Educational Resources Information Center

    Bone, Elisa K.; Reid, Robert J.

    2011-01-01

    Students in their first year of university face a number of transition issues that can make realising their academic potential difficult. In the sciences, first-year courses cover a large amount of material across broad subject areas, which can make them troublesome for students without background knowledge, and students need to adapt to typically…

  20. An Examination of Depressive Symptoms and Drinking Patterns in First Year College Students

    PubMed Central

    Geisner, Irene Markman; Mallett, Kimberly; Kilmer, Jason R.

    2013-01-01

    Depression and alcohol use are often found in college students, particularly during their first year. The current study assessed the interrelationship of alcohol use and specific depression symptoms. A large sample (n = 869) of first year students were invited to participate via the Internet Results indicated that specific depression symptoms correlated with alcohol consumption. Self-reported heavy, problem drinkers experienced significantly higher Beck Depression Inventory scores than all other groups. Our findings higlight the importance of screening for both alcohol use and depressed mood in college students. PMID:22545634

  1. PSR J0007+7303 IN THE CTA1 SUPERNOVA REMNANT: NEW GAMMA-RAY RESULTS FROM TWO YEARS OF FERMI LARGE AREA TELESCOPE OBSERVATIONS

    SciTech Connect

    Abdo, A. A.; Parent, D.; Wood, K. S.; Ray, P. S.; Wolff, M. T.; DeCesar, M. E.; Harding, A. K.; Gargano, F.; Giordano, F.; Coleman Miller, M.; Wood, D. L.

    2012-01-10

    One of the main results of the Fermi Gamma-Ray Space Telescope is the discovery of {gamma}-ray selected pulsars. The high magnetic field pulsar, PSR J0007+7303 in CTA1, was the first ever to be discovered through its {gamma}-ray pulsations. Based on analysis of two years of Large Area Telescope (LAT) survey data, we report on the discovery of {gamma}-ray emission in the off-pulse phase interval at the {approx}6{sigma} level. The emission appears to be extended at the {approx}2{sigma} level with a disk of extension {approx}0.{sup 0}6. level. The flux from this emission in the energy range E {>=} 100 MeV is F{sub 100} = (1.73 {+-} 0.40{sub stat} {+-} 0.18{sub sys}) Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1} and is best fitted by a power law with a photon index of {Gamma} = 2.54 {+-} 0.14{sub stat} {+-} 0.05{sub sys}. The pulsed {gamma}-ray flux in the same energy range is F{sub 100} = (3.95 {+-} 0.07{sub stat} {+-} 0.30{sub sys}) Multiplication-Sign 10{sup -7} photons cm{sup -2} s{sup -1} and is best fitted by an exponentially cutoff power-law spectrum with a photon index of {Gamma} = 1.41 {+-} 0.23{sub stat} {+-} 0.03{sub sys} and a cutoff energy E{sub c} = 4.04 {+-} 0.20{sub stat} {+-} 0.67{sub sys} GeV. We find no flux variability either at the 2009 May glitch or in the long-term behavior. We model the {gamma}-ray light curve with two high-altitude emission models, the outer gap and slot gap, and find that the preferred model depends strongly on the assumed origin of the off-pulse emission. Both models favor a large angle between the magnetic axis and observer line of sight, consistent with the nondetection of radio emission being a geometrical effect. Finally, we discuss how the LAT results bear on the understanding of the cooling of this neutron star.

  2. Microwave signatures of first-year and multiyear sea ice

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Nordberg, P.; Schmugge, T. J.; Wilheit, T. T.; Campbell, W. J.

    1972-01-01

    A combination of remote sensing from an aircraft and simultaneous surface measurements have confirmed the feasibility of identifying old and new sea ice according to its emission of thermal radiation at wavelengths between 0.3 and 3 cm. Emissivity of first-year thick ice with a surface temperature of about 260 K is 0.95 or greater for wavelengths between 0.81 and 11 cm; the emissivity of multiyear ice is 0.8 at 0.81 cm and 0.95 at 11 cm, increasing monotonically in this wave length interval. The ease with which multiyear ice can be distinguished from first-year ice using a passive microwave radiometer is demonstrated by comparing mosaics prepared both from photographs and images of 1.55 cm radiation.

  3. Women at the Naval Academy: The First Year of Integration

    DTIC Science & Technology

    1978-02-01

    traditionalism of males of the Class of 1980I toward rights and roles of women in society was evaluated as a function of level of contact with female plebes. A...6pinions about shipboard and other military roles for women . Upperclassmen were # most resistant to the integration of Annapolis (19% were neutral or... women as groups had tended to compete in the first year of integration.__ Excessive publicity -and male resentment were cited by tost female plepes (67

  4. New generation Arctic Drilling System: Overview of first year's performance

    SciTech Connect

    Loh, J.K.S.; Cusack, K.P.; Stamberg, J.C.

    1984-05-01

    This paper is a follow-up to OTC 4481: - Kulluk - An Arctic Exploratory Drilling Unit, presented at the 1983 OTC. A comparison between the original design basis of the rig and the first year's operational results is presented. The items compared are the towing performance, mooring system performance, the hull structure, and the drilling system. The towing and mooring system comparisons cover both open water and ice conditions. Ice management by icebreakers and logistics problems are reviewed.

  5. Institute for Computational Mechanics in Propulsion (ICOMP) first year summary

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Institute for Computational Mechanics in Propulsion (ICOMP) in Cleveland, Ohio, is operated jointly by Case Western Reserve University and the NASA Lewis Research Center. The purpose of ICOMP is to develop techniques to improve problem-solving capabilities in all aspects of computational mechanics related to propulsion. The Institute began operation in 1985. Described are the events leading to its formation, its organization and method of operation, and the technical activities of the first year.

  6. Conformal Fermi Coordinates

    SciTech Connect

    Dai, Liang; Pajer, Enrico; Schmidt, Fabian E-mail: Enrico.pajer@gmail.com

    2015-11-01

    Fermi Normal Coordinates (FNC) are a useful frame for isolating the locally observable, physical effects of a long-wavelength spacetime perturbation. Their cosmological application, however, is hampered by the fact that they are only valid on scales much smaller than the horizon. We introduce a generalization that we call Conformal Fermi Coordinates (CFC). CFC preserve all the advantages of FNC, but in addition are valid outside the horizon. They allow us to calculate the coupling of long- and short-wavelength modes on all scales larger than the sound horizon of the cosmological fluid, starting from the epoch of inflation until today, by removing the complications of the second order Einstein equations to a large extent, and eliminating all gauge ambiguities. As an application, we present a calculation of the effect of long-wavelength tensor modes on small scale density fluctuations. We recover previous results, but clarify the physical content of the individual contributions in terms of locally measurable effects and ''projection'' terms.

  7. Patterns of Substance Use Across the First Year of College and Associated Risk Factors

    PubMed Central

    Cho, Seung Bin; Llaneza, Danielle C.; Adkins, Amy E.; Cooke, Megan; Kendler, Kenneth S.; Clark, Shaunna L.; Dick, Danielle M.

    2015-01-01

    Starting college is a major life transition. This study aims to characterize patterns of substance use across a variety of substances across the first year of college and identify associated factors. We used data from the first cohort (N = 2056, 1240 females) of the “Spit for Science” sample, a study of incoming freshmen at a large urban university. Latent transition analysis was applied to alcohol, tobacco, cannabis, and other illicit drug uses measured at the beginning of the fall semester and midway through the spring semester. Covariates across multiple domains – including personality, drinking motivations and expectancy, high school delinquency, peer deviance, stressful events, and symptoms of depression and anxiety – were included to predict the patterns of substance use and transitions between patterns across the first year. At both the fall and spring semesters, we identified three subgroups of participants with patterns of substance use characterized as: (1) use of all four substances; (2) alcohol, tobacco, and cannabis use; and (3) overall low substance use. Patterns of substance use were highly stable across the first year of college: most students maintained their class membership from fall to spring, with just 7% of participants in the initial low substance users transitioning to spring alcohol, tobacco, and cannabis users. Most of the included covariates were predictive of the initial pattern of use, but covariates related to experiences across the first year of college were more predictive of the transition from the low to alcohol, tobacco, and cannabis user groups. Our results suggest that while there is an overall increase in alcohol use across all students, college students largely maintain their patterns of substance use across the first year. Risk factors experienced during the first year may be effective targets for preventing increases in substance use. PMID:26578984

  8. The First Fermi Gamma-ray Burst Monitor (GBM) Terrestrial Gamma-ray Flash (TGF) Catalog

    NASA Astrophysics Data System (ADS)

    Briggs, M. S.; Connaughton, V.; Stanbro, M.; Zhang, B.; Bhat, N.; Fishman, G. J.; Roberts, O.; Fitzpatrick, G.; McBreen, S.; Grove, J. E.; Chekhtman, A.

    2014-12-01

    We present summary results from the first catalog of Terrestrial Gamma-ray Flashes (TGFs) detected with the Gamma-ray Burst Monitor (GBM) on the Fermi Space Telescope. The catalog is expected to contain about 2600 TGFs and will be released both online, to conveniently provide the community with TGF parameters, and as a publication. Since the launch of Fermi in 2008 the TGF detection sensitivity of GBM has been improved several times, both in the flight software and in ground analysis. Starting in 2010 July individual photons were downloaded for portions of the orbits, enabling an off-line search that found weaker and shorter TGFs. Since 2012 November 26 this telemetry mode has been extended to continuous coverage -- in the first year of this data mode 841 TGFs were detected. The TGF sample is reliable, with cosmic rays rejected using data both from Fermi GBM and from the Large Area Telescope on Fermi. The online catalog will include times (UTC and solar), spacecraft geographic positions, durations, count intensities and other parameters (e.g., see the Bayesian Block analysis by O. Roberts). There will be separate tables for bright TGFs detected by the flight software and Terrestrial Electron Beams (TEBs).

  9. Predictors of implantable cardioverter defibrillator shocks during the first year.

    PubMed

    Dougherty, Cynthia M; Hunziker, Jim

    2009-01-01

    The purpose of this study was to predict implantable cardioverter defibrillator (ICD) shocks using demographic and clinical characteristics in the first year after implantation for secondary prevention of cardiac arrest. A prospective design was used to follow 168 first-time ICD recipients over 12 months. Demographic and clinical data were obtained from medical records at the time of ICD insertion. Implantable cardioverter defibrillator shock data were obtained from ICD interrogation reports at hospital discharge, 3, 6, and 12 months. Logistic regression was used to predict ever receiving an ICD shock using background characteristics. Patients received an ICD for secondary prevention of sudden cardiac arrest, they were 64.1 years old, 89% were white, 77% were male, with a mean (SD) ejection fraction of 33.7% (14.1%). The cumulative percentage of ever receiving an ICD shock was 33.3% over 1 year. Three variables predicted shocks in the first year: history of chronic obstructive pulmonary disease (COPD) (odds ratio [OR], 4.42; 95% confidence interval [CI], 1.2-16.4; P = .03), history of congestive heart failure (OR, 3.55; 95% CI, 1.4-9.3; P = .01), and documented ventricular tachycardia (VT) at the time of ICD implant (OR, 10.05; 95% Cl, 1.8-55.4; P = .01). High levels of anxiety approached significance (OR = 2.82; P = .09). The presence of COPD, congestive heart failure, or VT at ICD implant was a significant predictor of receiving an ICD shock in the first year after ICD implantation. Because ICD shocks are distressing, painful, and associated with greater mortality, healthcare providers should focus attention on prevention of shocks by controlling VT, careful management of HF symptoms, reduction of the use of short acting beta agonist medications in COPD, and perhaps recognizing and treating high levels of anxiety.

  10. Surviving and Thriving Your First Year in Private Practice.

    PubMed

    Schwab, Elizabeth Falk

    2016-11-01

    Taking the leap toward a career as a private practice owner is daunting. When in the initial stages of starting a private practice, I searched for current advice from an audiologist who had recently confronted the same challenges I was about to face. Because of the limited information available, I documented my process in hopes of providing an overview of my startup experience to help others. Included is a timeline of startup tasks and a sample budget to use as a reference. In this chapter, I share my experiences, both the positives and the negatives, and tips with the goal of helping you survive and thrive in your first year in private practice.

  11. [Video-laparoscopic cholecystectomy: first years of experience].

    PubMed

    Guadagno, P; Caracò, C; Candela, G; Conzo, G; Santini, L

    1995-01-01

    Laparoscopic cholecystectomy is became the elective operation in the treatment of symptomatic lithiasis of gallbladder, and it represent the surgical choice in 96% of cases. The authors on the base of their first years experience analyzes the results of literature with particular reference to the complications, like lesion of principal biliary tract and of other organs or vessels, underlining how the right selection of patients can be reduce morbidity. In this direction the subdivision of contraindication, in relative and absolute, already described in literature, represent an obliged chose to respect the mini-invasive principle which laparoscopic technique mean.

  12. Sustained Parenting and College Drinking in First-Year Students

    PubMed Central

    Turrisi, Rob; Ray, Anne E.

    2014-01-01

    Research indicates that for many students excessive drinking in college is a continuation of high school drinking tendencies. However, there have been limited theory-driven, systematic interventions targeting students so as to prevent alcohol misuse in their transition to college. Almost all current prevention approaches tend to be focused on younger populations and college-drinking interventions are typically delivered to students when they are already on campus. These analyses draw from a novel program of research involving parents of college freshmen based on the work of Turrisi et al. and focuses on examining: (1) the relationship between parenting and student drinking tendencies during the transitional period between high school and college and into the first year of college, and (2) the mediation process by which sustained parenting throughout the first year is related to college-drinking outcomes and consequences so as to inform future intervention efforts. The empirical evidence from this study suggests that sustained parental efforts have a beneficial effect on reducing high-risk drinking and preventing harm even at this late stage of late adolescent/early adult development. PMID:20213752

  13. Alcohol and cocaine use among first-year college students.

    PubMed

    Canterbury, R J; Gressard, C F; Vieweg, W V; Grossman, S J; Westerman, P S; McKelway, R B

    1991-01-01

    We surveyed 1528 first-year students at the University of Virginia, 1 month after their arrival on campus, who had used alcohol at some time in their lives. Our survey was designed to identify alcohol and cocaine use, and related psychosocial patterns. Men drank more and more often than women. Our data suggest that body weight should be considered in defining those who drink heavily and often. We define 'frequent heavy drinking' as five or more drinks in a row each week for men and three to four drinks or more in a row each week for women. Frequent heavy drinkers, cocaine users, and students with psychosocial problems appeared disproportionately among students planning to join fraternities and sororities. Although first-year students used cocaine infrequently, its users followed the patterns of frequent heavy drinkers. We believe efforts to correct alcohol and cocaine misuse by college students should be directed, in part, at social organizations such as Greek-letter societies. Also, we must attend to psychosocial features that predispose to alcohol and cocaine misuse.

  14. Homogeneous Atomic Fermi Gases

    NASA Astrophysics Data System (ADS)

    Mukherjee, Biswaroop; Yan, Zhenjie; Patel, Parth B.; Hadzibabic, Zoran; Yefsah, Tarik; Struck, Julian; Zwierlein, Martin W.

    2017-03-01

    We report on the creation of homogeneous Fermi gases of ultracold atoms in a uniform potential. In the momentum distribution of a spin-polarized gas, we observe the emergence of the Fermi surface and the saturated occupation of one particle per momentum state: the striking consequence of Pauli blocking in momentum space for a degenerate gas. Cooling a spin-balanced Fermi gas at unitarity, we create homogeneous superfluids and observe spatially uniform pair condensates. For thermodynamic measurements, we introduce a hybrid potential that is harmonic in one dimension and uniform in the other two. The spatially resolved compressibility reveals the superfluid transition in a spin-balanced Fermi gas, saturation in a fully polarized Fermi gas, and strong attraction in the polaronic regime of a partially polarized Fermi gas.

  15. PTSD symptom courseduring the first year of college

    PubMed Central

    Read, Jennifer P.; Bachrach, Rachel L.; Wright, Aidan G.C.; Colder, Craig R.

    2015-01-01

    In this study we examined patterns of transition in posttraumatic stress symptoms over the first year of college. We also examined two factors that might predict these transitions, trauma exposure and alcohol involvement. Matriculating students (N=944; 65% female) completed assessments of PTSD, trauma exposure, and alcohol use and consequences multiple times in their freshman year. Three symptom classes (No Symptoms, Moderate Symptoms, and Severe Symptoms) were identified. Examination of transitions from one status to another was conducted with latent transition analysis (LTA). These models revealed considerable variability in the course of PTSD symptoms. The most common pattern was resolution, yet a significant portion of students showed other patterns. Symptom worsening was more commonly observed in the second semester. Trauma exposure had a deleterious effect on PTSD symptom change trajectories, as did alcohol involvement, though less consistently so. Interventions that focus on the timing and correlates of symptom progression may benefit college students with posttraumatic distress. PMID:26828977

  16. Wabash River coal gasification repowering project -- first year operation experience

    SciTech Connect

    Troxclair, E.J.; Stultz, J.

    1997-12-31

    The Wabash River Coal Gasification Repowering Project (WRCGRP), a joint venture between Destec Energy, Inc. and PSI Energy, Inc., began commercial operation in November of 1995. The Project, selected by the United States Department of Energy (DOE) under the Clean Coal Program (Round IV) represents the largest operating coal gasification combined cycle plant in the world. This Demonstration Project has allowed PSI Energy to repower a 1950`s vintage steam turbine and install a new syngas fired combustion turbine to provide 262 MW (net) of electricity in a clean, efficient manner in a commercial utility setting while utilizing locally mined high sulfur Indiana bituminous coal. In doing so, the Project is also demonstrating some novel technology while advancing the commercialization of integrated coal gasification combined cycle technology. This paper discusses the first year operation experience of the Wabash Project, focusing on the progress towards achievement of the demonstration objectives.

  17. First-Year College Students' Conflict with Religion and Science

    NASA Astrophysics Data System (ADS)

    Martin-Hansen, Lisa Michelle

    2008-04-01

    This study took place during a First Year Seminar course where 20 incoming college freshmen studied the central topic of the nature of science within the context of biological evolution. The instructor researched students’ understandings in the nature of science as they progressed through the course by examining a variety of qualitative and quantitative data including class writings, pre- and post-test selected items from the VOSTS (Views on Science-Technology-Society), and interviews. The intended outcomes of the course were to reduce the number of student misconceptions in the nature of science and to ease student apprehension when learning about evolution. Data were analyzed to determine whether students were moving toward a more generally accepted idea of the nature of science or toward another type of misconception.

  18. First year results of the High Altitude Water Cherenkov observatory

    NASA Astrophysics Data System (ADS)

    Carramiñana, Alberto

    2016-10-01

    The High Altitude Water Cherenkov (HAWC) γ-ray observatory is a wide field of view (1.8 Sr) and high duty cycle (> 95% up-time) detector of unique capabilities for the study of TeV gamma-ray sources. Installed at an altitude of 4100m in the Northern slope of Volcan Sierra Negra, Puebla, by a collaboration of about thirty institutions of Mexico and the United States, HAWC has been in full operations since March 2015, surveying 2/3 of the sky every sidereal day, monitoring active galaxies and mapping sources in the Galactic Plane to a detection level of 1 Crab per day. This contribution summarizes the main results of the first year of observations of the HAWC γ-ray observatory.

  19. THE OREGON HEALTH INSURANCE EXPERIMENT: EVIDENCE FROM THE FIRST YEAR*

    PubMed Central

    Finkelstein, Amy; Taubman, Sarah; Wright, Bill; Bernstein, Mira; Gruber, Jonathan; Newhouse, Joseph P.; Allen, Heidi; Baicker, Katherine

    2012-01-01

    In 2008, a group of uninsured low-income adults in Oregon was selected by lottery to be given the chance to apply for Medicaid. This lottery provides an opportunity to gauge the effects of expanding access to public health insurance on the health care use, financial strain, and health of low-income adults using a randomized controlled design. In the year after random assignment, the treatment group selected by the lottery was about 25 percentage points more likely to have insurance than the control group that was not selected. We find that in this first year, the treatment group had substantively and statistically significantly higher health care utilization (including primary and preventive care as well as hospitalizations), lower out-of-pocket medical expenditures and medical debt (including fewer bills sent to collection), and better self-reported physical and mental health than the control group. PMID:23293397

  20. A longitudinal study of stress in first-year dental students.

    PubMed

    Silverstein, Sarah T; Kritz-Silverstein, Donna

    2010-08-01

    This study examines the association of stress with performance and health in first-year dental students and changes in the amount and sources of stress over one year. Students at four U.S. dental schools completed the Dental Environment Stress (DES) scale, Perceived Stress Scale (PSS), stress rating, and demographic questions at the start of their first year of school (baseline), 11.7 weeks, and one year later when first-year GPA, illnesses, health ratings, and symptom frequency were also assessed. Overall, 296 (186 men, 110 women) responded at baseline and after one year; 205 responded all three times. Stress scores were negatively correlated with GPA (DES, p=.006; PSS, p=.04; stress rating, p=.002) and with physical and emotional health ratings (p's< or =.002), but positively associated with illness (p<.05), symptoms (p<.0001), and symptom frequency (p's<.05). Stress was higher after one year (p's<.001) and varied by school (p<.0001). Women (p<.01), younger (p<.003), and single students (p<.03) had higher stress at baseline, but after one year, there were no differences by gender, age, or marital status. Ratings for items on the Dental Environment Stress scale related to schoolwork were high at baseline and increased further by one year (p's< or =.0001); items related to school atmosphere had low ratings initially with large increases over time (p's<.0001). In conclusion, stress increases over time in first-year dental students and is related to detrimental effects on performance and health. Variation between schools may reflect different teaching methods. Changes in sources of stress may reflect the different contributions of anticipatory and situational stress over time. First-year dental students may benefit from stress reduction programs.

  1. Figures and First Years: Examining first-year Calculus I student ability to incorporate figures into technical reports

    NASA Astrophysics Data System (ADS)

    Antonacci, Nathan; Rogers, Michael; Pfaff, Thomas

    This three-year study focused on first-year Calculus I students and their abilities to incorporate figures into technical reports. Students were handed guidelines as part of their Multidisciplinary Sustainability Education Module meant to aid them in crafting effective figures. Figure-specific questionnaires were added in the class to gain insight into the quantitative literacy skills students possessed both before starting their course and after its completion. Reviews of the figures in 78 technical reports written by 106 students showed repeated failure to refer to figures in discussion sections and use them in evidence-based arguments. Analysis of quantitative literacy skills revealed that the students could both read and interpret figures, suggesting that issues with literacy were not the main contributor to the sub-par graphs.

  2. Performance of battery charge controllers: First year test report

    SciTech Connect

    Dunlop, J. ); Bower, W. ); Harrington, S. )

    1991-01-01

    The results of the first year of an evaluation of charge controllers for stand-alone photovoltaic (PV) systems are presented. The objectives of the test program are to positively influence the development of battery charge controllers for stand-alone PV applications and to develop design and application criteria that will improve PV system reliability and battery performance. Future goals are to expand the evaluation program to include various battery technologies and controller algorithms. Also, the information is being communicated to manufacturers to aid in the design of more effective and reliable charge controllers for PV systems. Eight different models of small (nominal 10 amp) charge controllers are being subjected to a comprehensive evaluation. These evaluations include operational tests in identical stand-alone PV systems and environmental and electrical cycling tests. Selected custom tests are also performed on the controllers to determine the response to transients, installation requirements and system design compatibilities. Data presented in this paper include measured electrical characteristics of the controllers, temperature effects on set points, and operational performance in PV systems both in the lab and in the field. A comparison is presented for four different charge controller algorithms which include array-shunt, series-interrupting, series-linear constant-voltage and series-linear-multistep constant-current. 9 refs., 11 figs., 2 tabs.

  3. Program plan, and request for reprogramming first year funds

    SciTech Connect

    Not Available

    1993-02-10

    In June of 1992, the U. S. Department of Energy (DOE) awarded assistance Medical University of South Carolina (MUSC) for the Environmental Hazards Assessment Program, The first year of the program is primarily a planning year. We have aggressively pursued input into the EHAP program to begin to understand where our efforts fit within other efforts underway nationally. We have also begun some direct activities at MUSC to begin the program. Part of this report is devoted to informing DOE of what we have accomplished so far this year. In our efforts to plan, we have identified several changes in emphasis for the program. These changes affect the original plan in terms of projected milestones and budget allocations. Part of this report describes these changes and describes the proposed changes to the budget. We are not requesting additional funds for this year. Simply, we are requesting some change in allocations to budget categories. Therefore, our report to DOE is a combination status report, program plan, and request for reallocation of budget.

  4. A wellness program for first year medical students.

    PubMed

    McGrady, Angele; Brennan, Julie; Lynch, Denis; Whearty, Kary

    2012-12-01

    Entering medical students experience distress symptoms due to the demands of the intensive curriculum, adjustment to new environments and increased responsibilities. The purpose of this controlled, randomized study was to determine the effects of a structured wellness program on measures of anxiety, depression and frequency of acute illness in 449 first year medical students. The effects of eight sessions of stress management were compared to a wait list control group. High risk students were identified based on scores on psychological inventories and number of recent life events (WLE). Results showed that depression, anxiety scores and frequency of acute illness were higher in women than in men, and were higher in students with multiple life events. Significant decreases were observed in depression in the intervention group students when WLE was the covariate (p = .045). Further, the high risk group showed consistently lower depression scores after the intervention compared to high risk wait list controls (p = .003), and these changes were maintained at the end of school year. There were no significant changes in anxiety or frequency of acute illness. Wellness programs can be implemented in medical school and may be particularly useful for entering students with elevated psychological distress.

  5. Prevalence of oral Candida in the first year of life.

    PubMed

    Stecksén-Blicks, C; Granström, E; Silfverdal, S A; West, C E

    2015-09-01

    Colonisation of the gastrointestinal tract is influenced by primary microbial exposure and bioactive factors in breastmilk. The aim was to explore the prevalence of oral Candida in the first year of life in relation to selected exposures. Oral Candida was studied in 100 healthy infants at 4 and 8 weeks, 3, 6 and 12 months of age and related to delivery mode, birth weight, infant health and feeding, antibiotics, antimycotics, steroids and probiotics in mother and infant, living conditions, maternal smoking and infections The association between lactoferrin and antisecretory factor in breastmilk and maternal serum haemoglobin, transferrin, and ferritin levels in relation to oral Candida was also explored. About 11% to 15% of the infants had oral Candida at the respective age. Colonisation was fairly stable until 6 months of age. There was no conclusive impact of the investigated exposures at entry. Infants with a furry pet at home had a lower frequency of Candida at 3 months, (P < 0.05) whereas all but one colonised infant had older siblings at 12 months (P < 0.01). Lactoferrin in breastmilk was negatively associated with colonisation at 6 months of age. It is concluded that 11 to 15% had oral Candida. Exposure to furry pets and siblings impacted oral Candida.

  6. Michigan Oncology Medical Home Demonstration Project: first-year results.

    PubMed

    Kuntz, Gordon; Tozer, Jane M; Snegosky, Jeff; Fox, John; Neumann, Kurt

    2014-09-01

    Launched in May 2012, the Michigan Oncology Medical Home Demonstration Project is an innovative multipractice oncology medical home model supported by payment reform. In the first year of the project, four oncology practices (29 physicians) participated and enrolled 85 patients receiving chemotherapy for a cancer diagnosis (96 new chemotherapy starts). By creating an oncology medical home for patients, the project reduced costs associated with unnecessary emergency room visits and inpatient admissions, with an average estimated cost savings of $550 per patient, while also enhancing payments to providers. The total estimated cost savings for year 1 was $46,228. In addition to the financial savings realized through reductions in emergency room visits and hospitalizations, the program also demonstrated that participating practices had high adherence to national and practice-selected guidelines, instituted advance care planning, and provided effective and standardized symptom management. The results are promising and provide evidence that community oncology practices will embrace the transformation to a patient-centered model with properly aligned incentives and administrative assistance.

  7. Childcare patterns of mothers of twins during the first year.

    PubMed

    Robin, M; Corroyer, D; Casati, I

    1996-05-01

    This study aims to describe the ways in which mothers of twins organize their childcare activities during the first year after a twin birth and to determine what factors might affect these mothering practices. The mother's physical and psychological state, support and help from the father and others in the surroundings, and the type of twinship were among the factors studied. Data on the organization of feeding, sleeping and waking routines were gathered from 51 families. A correspondence analysis and a cluster analysis showed that twin mothering practices can be described along two dimensions: individualized care vs collective care, and level of organization of daily routines. The mother's state of fatigue only partially accounts for the different types of maternal behavior. Likewise, the presence of several caregivers does not lead to greater individualization in care routines. Nor does there seem to be a clear link between the type of maternal behaviour and the type of twinship. The discussion deals with the mother's emotional investment, her personal capacity for adjusting to the "triadic motherhood' process, and the nature of the father's involvement in that process. Another consideration is the impact of the type of childcare pattern on twin development.

  8. Case studies of first-year critical science teachers

    NASA Astrophysics Data System (ADS)

    Love, Kurt A.

    Brent Davis and Dennis Sumara (1997) performed a study of themselves and another professor who took a sabbatical to work in an elementary school for a year. Their intentions, as professors focused on cognition, was to create a change in teaching practices throughout the school that aligned more closely with social cognitive research. However, their experiences did not go as planned. Each found that he could not just simply bring their philosophies into their classrooms independent of the sociocultural context of the school. They found very quickly that none of them could act as fully autonomous agents. They described their experiences as being part of the sociocultural fabric of the school because each of their teaching practices changed in ways that they did not anticipate and in ways that were not philosophically aligned. However, they also found that this was a two-way relationship. They were not describing completely deterministic experiences. Davis and Sumara described observing colleagues changing their practices in ways that did incorporate some of the philosophies that they espoused during their tenure at the elementary school. They explain their experience as one where they were pushed and pulled by the sociocultural context and they also pushed and pulled on the sociocultural context. This dissertation focuses on three first-year science teachers (a 4 th grade teacher and two high school science teachers) who identified as wanting to bring critical, feminist, and ecojustice perspectives into their teaching practices. Each enacts these practices much differently in the context of the sociocultural contexts of their own schools, and often changed their teaching practices in ways that seemed to more closely align with those contexts. Each of the three dealt with external and internal hegemonic pressures that caused them to align more closely with their contexts. The philosophical foundations of their sociocultural contexts were manifested externally through

  9. How we Know: Spectroscopy in the First Year and Beyond

    NASA Astrophysics Data System (ADS)

    Ooms, Kristopher J.

    2015-06-01

    Chemical educators face the never ending challenge of showing students that the content written in their textbook arises from a rich interplay of experimentation, imagination and a desire to understand and impact the world. We have found that asking three simple questions - What do we know, How do we know it, Why do we care - is an effective strategy to guide the content and pedagogy within our chemistry classes. Of these three questions What we know is the most thoroughly covered and with the growing use of rich context teaching, the Why we care is becoming more central to our chemistry teaching. How are we doing on telling students How we know? Spectroscopy is at the core of our ability to answer questions about how we know things about the molecular world. Yet the teaching of spectroscopy is not a central part of student's early chemistry learning, often being left to the later stages of degrees and courses. For example, a brief look at common North American general chemistry text books reveals almost no discussion of spectroscopic techniques and their centrality to understanding chemistry. In this talk I will discuss efforts to bring spectroscopy into the first year course and some of the repercussions this has for the whole chemistry undergraduate curriculum. The goal is to make students better aware of where the ideas in chemistry arise from, the strengths and weaknesses of spectroscopic experiments, and how our models of the molecular world are built on rigorous experimentation.

  10. Use of Sleep Aids During the First Year of Life

    PubMed Central

    Burnham, Melissa M.; Goodlin-Jones, Beth L.; Gaylor, Erika E.; Anders, Thomas F.

    2005-01-01

    Objective. In an attempt to foster self-soothing during the night, a novel sleep aid infused with maternal odor was introduced to 4 groups of infants ranging in age from 3 to 12 months. Infants’ use of parent-provided sleep aids also was examined. Methodology. Nighttime sleep and waking behaviors were videotaped for 2 consecutive nights on 3 occasions over a 3-month interval. Using all-night video recording, the study examined the infant’s use of a novel sleep aid and parent-provided sleep aids during sleep onset and after nighttime awakenings. Results. Results indicated that infants of different ages differed in the types of sleep aids used when falling asleep either at the beginning of the night or after awakenings in the middle of the night. More 3-month-olds used their thumbs/fingers/hands, whereas more 6-month-olds used soft objects. The 6-month-olds were most likely to use the novel sleep aid. Almost all of the infants at all 4 ages used some type of object during the night. Intra-individual analyses showed that infants tended to change their pattern of sleep aid use over the 3-month study period. Conclusions. The data provide evidence that infants during the first year of life use sleep aids frequently and interchangeably rather than a specific favorite object. PMID:11927702

  11. The First-Year Seminar: Designing, Implementing, and Assessing Courses to Support Student Learning and Success: Volume Five: Assessing the First-Year Seminar

    ERIC Educational Resources Information Center

    Friedman, Daniel B.

    2012-01-01

    "The First-Year Seminar: Designing, Implementing, and Assessing Courses to Support Student Learning and Success," a five-volume series, is designed to assist educators who are interested in launching a first-year seminar or revamping an existing program. Each volume examines a different aspect of first-year seminar design or…

  12. Correlates of smokeless tobacco use among first year college students

    PubMed Central

    Spangler, John; Song, Eunyoung; Pockey, Jessica; Sutfin, Erin L; Reboussin, Beth A; Wagoner, Kimberly; Wolfson, Mark

    2014-01-01

    Objective Smokeless tobacco (SLT) use is associated with specific adverse health effects. Knowledge of student tobacco use, including SLT, may guide inquiry into other risky health behaviors, and provide opportunities for health education of students. Design An incentivized email invitation to complete a web-based survey was sent to students at 11 colleges and universities in North Carolina and Virginia. Methods In autumn 2010, emails were sent to all first-year students (n=29,536) at 11 colleges and universities in North Carolina and Virginia, inviting them to participate in a brief web-based survey to be used to establish a cohort for the parent study evaluating tobacco use over 4 years. Survey items elicited demographic characteristics, tobacco use and other health behaviors. Results A total of 10,520 (36%) students responded. Past 30 day smoking and SLT use were 12% and 3%, respectively. Logistic regression analysis revealed that male gender (Adjusted Odds Ratio [AOR] = 11.6, 95% Confidence Interval [CI] = 8.16–16.59); current smoking (AOR = 5.5, 95% CI = 4.21–7.10), ever use of alcoholic energy drinks (AOR = 4.8, 95% CI = 3.63–6.43), and ≥ 5 days vs. < 3 days of physical activity a week (AOR = 1.5, 95% CI = 1.07–2.01) predicted risk of past 30 day SLT use. Conclusion While SLT use is relatively uncommon, knowledge of significant correlations between student tobacco use, including SLT and other risky health behaviors, might guide clinicians' inquiry and provide opportunities for health education of students. PMID:25484378

  13. Journey to Motherhood in the First Year After Child Birth

    PubMed Central

    Javadifar, Nahid; Majlesi, Fereshteh; Nikbakht, Alireza; Nedjat, Saharnaz; Montazeri, Ali

    2016-01-01

    Objective: Child bearing is a period of psychological challenges that must be viewed in a social context. This study reports the maternal transition from the perspective of Iranian first-time mothers in the first year after childbirth. Materials and methods: Qualitative method was chosen for explanation of mothers’ individual experiences of motherhood.26 first-time mothers (aged 18-35 years old with various socio-economic status) who had delivered between 0-1 year prior to the interviews participated in the study.Data were collected through in-depth semi-structured interviews and interview transcripts were analyzed using the constant comparison method. Results: The core category was called "Regaining advanced balance." There were several themes within this category: "internal conflicts", "encounter and interaction" and "internalization". They felt unpreparedness, lack of control over their lives, incomplete maternal feelings and unstable relation to their husbands and others. Within the first postpartum days and weeks a sort of attachment develops between mother and child as the mother starts to attain a better understanding of maternal feelings; she begins to accept the child as an independent identity and reconstructs herself. As the attachment to child deepens, the mother feels control over the affairs. She realizes a kind of development and integration in herself which specifically stems from becoming a mother and attempts to strengthen family bonds. Conclusion: Through the expression of new mothers’ experiences toward motherhood, healthcare providers can reach a better perception of the emotional and psychological changes as well as the various aspects of mothers’ acceptance of their maternal role and helps a better preparation and presentation of effective training programs for mothers and families. PMID:28101116

  14. Large Fermi energy modulation in graphene transistors with high-pressure O{sub 2}-annealed Y{sub 2}O{sub 3} topgate insulators

    SciTech Connect

    Kanayama, Kaoru; Nagashio, Kosuke Nishimura, Tomonori; Toriumi, Akira

    2014-02-24

    We demonstrate a considerable suppression of the low-field leakage through a Y{sub 2}O{sub 3} topgate insulator on graphene by applying high-pressure O{sub 2} at 100 atm during post-deposition annealing (HP-PDA). Consequently, the quantum capacitance measurement for the monolayer graphene reveals the largest Fermi energy modulation (E{sub F} = ∼0.52 eV, i.e., the carrier density of ∼2 × 10{sup 13} cm{sup −2}) in the solid-state topgate insulators reported so far. HP-PDA is the robust method to improve the electrical quality of high-k insulators on graphene.

  15. Fermi's Conundrum: Proliferation and Closed Societies

    NASA Astrophysics Data System (ADS)

    Teller, Wendy; Westfall, Catherine

    2007-04-01

    On January 1, 1946 Emily Taft Douglas, a freshman Representative at Large for Illinois, sent a letter to Enrico Fermi. She wanted to know whether, if atomic energy was used for peaceful purposes, it might be possible to clandestinely divert some material for bombs. Douglas first learned about the bomb not quite five months before when Hiroshima was bombed. Even though she was not a scientist she identified a key problem of the nuclear age. Fermi responded with requirements to allow peaceful uses of atomic energy and still outlaw nuclear weapons. First, free interchange of information between people was required, and second, people who reported possible violations had to be protected. Fermi had lived in Mussolini's Italy and worked under the war time secrecy restrictions of the Manhattan Project. He was not optimistic that these conditions could be met. This paper discusses how Douglas came to recognize the proliferation issue and what led Fermi to his solution and his pessimism about its practicality.

  16. Fermi Surface of the Most Dilute Superconductor

    NASA Astrophysics Data System (ADS)

    Lin, Xiao; Zhu, Zengwei; Fauqué, Benoît; Behnia, Kamran

    2013-04-01

    The origin of superconductivity in bulk SrTiO3 is a mystery since the nonmonotonous variation of the critical transition with carrier concentration defies the expectations of the crudest version of the BCS theory. Here, employing the Nernst effect, an extremely sensitive probe of tiny bulk Fermi surfaces, we show that, down to concentrations as low as 5.5×1017cm-3, the system has both a sharp Fermi surface and a superconducting ground state. The most dilute superconductor currently known therefore has a metallic normal state with a Fermi energy as little as 1.1 meV on top of a band gap as large as 3 eV. The occurrence of a superconducting instability in an extremely small, single-component, and barely anisotropic Fermi surface implies strong constraints for the identification of the pairing mechanism.

  17. GAMMA-RAY OBSERVATIONS OF THE MICROQUASARS CYGNUS X-1, CYGNUS X-3, GRS 1915+105, AND GX 339–4 WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Bodaghee, Arash; Tomsick, John A.; Pottschmidt, Katja; Rodriguez, Jérôme; Pooley, Guy G.

    2013-10-01

    Detecting gamma-rays from microquasars is a challenging but worthwhile endeavor for understanding particle acceleration and the jet mechanism and for constraining leptonic/hadronic emission models. We present results from a likelihood analysis on timescales of 1 day and 10 days of ∼4 yr worth of gamma-ray observations (0.1-10 GeV) by Fermi-LAT of Cyg X-1, Cyg X-3, GRS 1915+105, and GX 339–4. Our analysis reproduced all but one of the previous gamma-ray outbursts of Cyg X-3 as reported with Fermi or AGILE, plus five new days on which Cyg X-3 is detected at a significance of ∼5σ that are not reported in the literature. In addition, Cyg X-3 is significantly detected on 10 day timescales outside of known gamma-ray flaring epochs, which suggests that persistent gamma-ray emission from Cyg X-3 has been detected for the first time. For Cyg X-1 we find three low-significance excesses (∼3-4σ) on daily timescales that are contemporaneous with gamma-ray flares reported (also at low significance) by AGILE. Two other microquasars, GRS 1915+105 and GX 339–4, are not detected, and we derive 3σ upper limits of 2.3 × 10{sup –8} photons cm{sup –2} s{sup –1} and 1.6 × 10{sup –8} photons cm{sup –2} s{sup –1}, respectively, on the persistent flux in the 0.1-10 GeV range. These results enable us to define a list of the general conditions that are necessary for the detection of gamma-rays from microquasars.

  18. Fermi LARGE AREA TELESCOPE DETECTION OF TWO VERY-HIGH-ENERGY (E > 100 GeV) γ-RAY PHOTONS FROM THE z = 1.1 BLAZAR PKS 0426–380

    SciTech Connect

    Tanaka, Y. T.; Mizuno, T.; Cheung, C. C.; Dermer, C. D.; Inoue, Y.; Stawarz, Ł.; Ajello, M.; Wood, D. L.; Chekhtman, A.; Fukazawa, Y.; Ohno, M.; Paneque, D.; Thompson, D. J.

    2013-11-01

    We report the Fermi Large Area Telescope (LAT) detection of two very-high-energy (VHE, E > 100 GeV) γ-ray photons from the directional vicinity of the distant (redshift, z = 1.1) blazar PKS 0426–380. The null hypothesis that both the 134 and 122 GeV photons originate from unrelated sources can be rejected at the 5.5σ confidence level. We therefore claim that at least one of the two VHE photons is securely associated with PKS 0426–380, making it the most distant VHE emitter known to date. The results are in agreement with recent Fermi-LAT constraints on the extragalactic background light (EBL) intensity, which imply a z ≅ 1 horizon for ≅ 100 GeV photons. The LAT detection of the two VHE γ-rays coincided roughly with flaring states of the source, although we did not find an exact correspondence between the VHE photon arrival times and the flux maxima at lower γ-ray energies. Modeling the γ-ray continuum of PKS 0426–380 with daily bins revealed a significant spectral hardening around the time of the first VHE event detection (LAT photon index Γ ≅ 1.4) but on the other hand no pronounced spectral changes near the detection time of the second one. This combination implies a rather complex variability pattern of the source in γ-rays during the flaring epochs. An additional flat component is possibly present above several tens of GeV in the EBL-corrected Fermi-LAT spectrum accumulated over the ∼8 month high state.

  19. Fermi Galactic Center Zoom

    NASA Video Gallery

    This animation zooms into an image of the Milky Way, shown in visible light, and superimposes a gamma-ray map of the galactic center from NASA's Fermi. Raw data transitions to a view with all known...

  20. Fermi, Szilard and Trinity

    ERIC Educational Resources Information Center

    Anderson, Herbert L.

    1974-01-01

    The final installment of the author's recollections of his work with physicists Enrico Fermi, Leo Szilard and others in developing the first controlled nuclear chain reaction and in preparing the test explosion of the first atomic bomb. (GS)

  1. Fermi/LAT Observations of Swift/BAT Seyfert Galaxies: On the Contribution of Radio-Quiet Active Galactic Nuclei to the Extragalactic gamma-Ray Background

    NASA Technical Reports Server (NTRS)

    Teng, Stacy H.; Mushotzky, Richard F.; Sambruna, Rita M.; Davis, David S.; Reynolds, Christopher S.

    2011-01-01

    We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R(sub X,BAT) where radio-loud objects have logR(sub X,BAT) > -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be approx.2x10(exp -11) photons/sq cm/s, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the gamma-ray (1-100 GeV) luminosity of < approx.3x10(exp 41) erg/s. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

  2. Predicting Community College Student Success by Participation in a First-Year Experience Course

    ERIC Educational Resources Information Center

    Gardner, Andy Franklin

    2013-01-01

    A first-year experience is a collaborative effort of many initiatives, with varying names that have the greatest impact on student success during the first year of college. A first-year experience course, a feature of the first-year experience, is an intervention program designed to increase student academic performance and integration (Braxton…

  3. Understanding and Using the Fermi Science Tools

    NASA Astrophysics Data System (ADS)

    Asercion, Joseph; Fermi Science Support Center

    2017-01-01

    The Fermi Science Support Center (FSSC) provides information, documentation, and tools for the analysis of Fermi science data, including both the Large-Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). Source and binary versions of the Fermi Science Tools can be downloaded from the FSSC website, and are supported on multiple platforms. An overview document, the Cicerone, provides details of the Fermi mission, the science instruments and their response functions, the science data preparation and analysis process, and interpretation of the results. Analysis Threads and a reference manual available on the FSSC website provide the user with step-by-step instructions for many different types of data analysis: point source analysis - generating maps, spectra, and light curves, pulsar timing analysis, source identification, and the use of python for scripting customized analysis chains. We present an overview of the structure of the Fermi science tools and documentation, and how to acquire them. We also provide examples of standard analyses, including tips and tricks for improving Fermi science analysis.

  4. Understanding and Using the Fermi Science Tools

    NASA Astrophysics Data System (ADS)

    Asercion, Joseph; Fermi Science Support Center Team

    2016-01-01

    The Fermi Science Support Center (FSSC) provides information, documentation, and tools for the analysis of Fermi science data, including both the Large-Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). Source and binary versions of the Fermi Science Tools can be downloaded from the FSSC website, and are supported on multiple platforms. An overview document, the Cicerone, provides details of the Fermi mission, the science instruments and their response functions, the science data preparation and analysis process, and interpretation of the results. Analysis Threads and a reference manual available on the FSSC website provide the user with step-by-step instructions for many different types of data analysis: point source analysis - generating maps, spectra, and light curves, pulsar timing analysis, source identification, and the use of python for scripting customized analysis chains. We present an overview of the structure of the Fermi science tools and documentation, and how to acquire them. We also provide examples of standard analyses, including tips and tricks for improving Fermi science analysis.

  5. Deep Inelastic Scattering results from the first year of HERA operation

    SciTech Connect

    Magill, S.R.

    1993-12-31

    The first year of operation of the HERA electron-proton collider has resulted in Deep Inelastic Scattering (DIS) Physics results from both the H1 and ZEUS experiments. Reported here are the H1 and ZEUS measurements of the proton structure function F{sub 2} at higher Q{sup 2} and lower x than previously reported from fixed target experiments. Also included are the results of QCD studies on hadronic final states and jets, and the observation of high Q{sup 2} charged current events from both experiments. Finally, the observation of events with large rapidity gaps by the ZEUS collaboration is also reported.

  6. Aura MLS Cloud Measurements: First-Year Results

    NASA Technical Reports Server (NTRS)

    Jiang, Jonathan H.; Wu, Dong L.

    2005-01-01

    Aura MLS provides the first vertical upper tropospheric cloud profiling from space, enabling global survey of the vertical structure of cloud systems, with seasonal and geographical variations, needed to evaluate the way clouds are parameterized in global models, thereby contributing to the understanding of cloud-climate feedbacks, and improved weather and climate predictions. The vertical structure of cloud systems is fundamentally important for understanding how clouds affect both their regional and large-scale atmospheric and radiative environments. The regional cloud profiles provide a critical tests of important parameterizations that enable the calculation of radiative flux profiles and heating rates throughout the atmospheric column, which in turn also regulates the water and energy cycles in the upper troposphere

  7. Service-Learning and the First-Year Experience: Preparing Students for Personal Success and Civic Responsibility. The First-Year Experience Monograph Series.

    ERIC Educational Resources Information Center

    Zlotkowski, Edward, Ed.

    This collection presents essays on service-learning and its role in the education of first-year college students. Following a preface by John N. Gardner and an introduction by Edward Zlotkowski, the chapters of section 1, "Making the Case for Service-Learning in the First Year of College," are: (1) "High School Service-Learning and the Preparation…

  8. Examining the Academic Performance and Retention of First-Year Students in Living-Learning Communities and First-Year Experience Courses

    ERIC Educational Resources Information Center

    Purdie, John R., II; Rosser, Vicki J.

    2011-01-01

    Institutional data were used to examine the grades and retention of first-year students in 2 types of living learning communities--Academic Theme Floors (ATFs) and Freshman Interest Groups (FIGs)--and a First-Year Experience (FYE) course. Multiple regression revealed students in FIGs earned nominally higher GPAs (standardized [beta] = 0.02, p less…

  9. A Mechanistic Approach to Cross-Domain Perceptual Narrowing in the First Year of Life

    PubMed Central

    Hadley, Hillary; Rost, Gwyneth C.; Fava, Eswen; Scott, Lisa S.

    2014-01-01

    Language and face processing develop in similar ways during the first year of life. Early in the first year of life, infants demonstrate broad abilities for discriminating among faces and speech. These discrimination abilities then become tuned to frequently experienced groups of people or languages. This process of perceptual development occurs between approximately 6 and 12 months of age and is largely shaped by experience. However, the mechanisms underlying perceptual development during this time, and whether they are shared across domains, remain largely unknown. Here, we highlight research findings across domains and propose a top-down/bottom-up processing approach as a guide for future research. It is hypothesized that perceptual narrowing and tuning in development is the result of a shift from primarily bottom-up processing to a combination of bottom-up and top-down influences. In addition, we propose word learning as an important top-down factor that shapes tuning in both the speech and face domains, leading to similar observed developmental trajectories across modalities. Importantly, we suggest that perceptual narrowing/tuning is the result of multiple interacting factors and not explained by the development of a single mechanism. PMID:25521763

  10. Eight new Milky Way companions discovered in first-year Dark Energy Survey data

    DOE PAGES

    Bechtol, K.

    2015-06-30

    We report the discovery of eight new Milky Way companions inmore » $$\\sim 1800\\;{\\mathrm{deg}}^{2}$$ of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (MV from $-2.2$ to $$-7.4\\;\\mathrm{mag}$$), physical sizes ($$10-170\\;\\mathrm{pc}$$), and heliocentric distances ($$30-330\\;\\mathrm{kpc}$$). Based on the low surface brightnesses, large physical sizes, and/or large Galactocentric distances of these objects, several are likely to be new ultra-faint satellite galaxies of the Milky Way and/or Magellanic Clouds. We introduce a likelihood-based algorithm to search for and characterize stellar over-densities, as well as identify stars with high satellite membership probabilities. As a result, we also present completeness estimates for detecting ultra-faint galaxies of varying luminosities, sizes, and heliocentric distances in the first-year DES data.« less

  11. Eight new Milky Way companions discovered in first-year Dark Energy Survey data

    SciTech Connect

    Bechtol, K.

    2015-06-30

    We report the discovery of eight new Milky Way companions in $\\sim 1800\\;{\\mathrm{deg}}^{2}$ of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (MV from $-2.2$ to $-7.4\\;\\mathrm{mag}$), physical sizes ($10-170\\;\\mathrm{pc}$), and heliocentric distances ($30-330\\;\\mathrm{kpc}$). Based on the low surface brightnesses, large physical sizes, and/or large Galactocentric distances of these objects, several are likely to be new ultra-faint satellite galaxies of the Milky Way and/or Magellanic Clouds. We introduce a likelihood-based algorithm to search for and characterize stellar over-densities, as well as identify stars with high satellite membership probabilities. As a result, we also present completeness estimates for detecting ultra-faint galaxies of varying luminosities, sizes, and heliocentric distances in the first-year DES data.

  12. The First Year of Robotic Science with MINERVA

    NASA Astrophysics Data System (ADS)

    McCrady, Nate; Johnson, John A.; Wright, Jason; Wittenmyer, Robert; Eastman, Jason; Beatty, Thomas G.; Bottom, Michael; Johnson, Samson

    2016-01-01

    Detection of low-mass exoplanets orbiting Sun-like stars requires high cadence, long time-baseline observations that are impossible to obtain on shared large telescopes. MINERVA is a dedicated observatory for exoplanet detection that consists of four robotic 0.7-meter PlaneWave telescopes located at Whipple Observatory on Mt Hopkins, Arizona. First light science began in May 2015 with photometric monitoring of transit and microlensing events. The four telescopes can observe different targets, or provide simultaneous multi-color light curves of a single event. We will add a purpose-built, temperature-stabilized, high precision iodine cell spectrometer from Callaghan Innovation in 2016 to facilitate velocimetric search for low-mass exoplanets around nearby stars. The flexibility of the MINERVA array provides a natural avenue for educational and public outreach activities. One telescope in the array can break formation to observe targets from a queue or respond to remote operations from astronomy courses at a partner institution. MINERVA is a collaboration among Harvard U., Penn State U., U. Montana, and U. New South Wales.

  13. FermiGrid

    SciTech Connect

    Yocum, D.R.; Berman, E.; Canal, P.; Chadwick, K.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Sharma, N.; Timm, S.; /Fermilab

    2007-05-01

    As one of the founding members of the Open Science Grid Consortium (OSG), Fermilab enables coherent access to its production resources through the Grid infrastructure system called FermiGrid. This system successfully provides for centrally managed grid services, opportunistic resource access, development of OSG Interfaces for Fermilab, and an interface to the Fermilab dCache system. FermiGrid supports virtual organizations (VOs) including high energy physics experiments (USCMS, MINOS, D0, CDF, ILC), astrophysics experiments (SDSS, Auger, DES), biology experiments (GADU, Nanohub) and educational activities.

  14. Highlights from the first year of Odin observations

    NASA Astrophysics Data System (ADS)

    Hjalmarson, Å.; Frisk, U.; Olberg, M.; Bergman, P.; Bernath, P.; Biver, N.; Black, J. H.; Booth, R. S.; Buat, V.; Crovisier, J.; Curry, C. L.; Dahlgren, M.; Encrenaz, P. J.; Falgarone, E.; Feldman, P. A.; Fich, M.; Florén, H. G.; Fredrixon, M.; Gerin, M.; Gregersen, E. M.; Hagström, M.; Harju, J.; Hasegawa, T.; Horellou, C.; Johansson, L. E. B.; Kyrölä, E.; Kwok, S.; Larsson, B.; Lecacheux, A.; Liljeström, T.; Lindqvist, M.; Liseau, R.; Llewellyn, E. J.; Mattila, K.; Mégie, G.; Mitchell, G. F.; Murtagh, D.; Nyman, L.-Å.; Nordh, H. L.; Olofsson, A. O. H.; Olofsson, G.; Olofsson, H.; Pagani, L.; Persson, G.; Plume, R.; Rickman, H.; Ristorcelli, I.; Rydbeck, G.; Sandqvist, Aa.; von Schéele, F.; Serra, G.; Torchinsky, S.; Tothill, N. F.; Volk, K.; Wiklind, T.; Wilson, C. D.; Winnberg, A.; Witt, G.

    2003-05-01

    Key Odin operational and instrumental features and highlights from our sub-millimetre and millimetre wave observations of H2O, H218O, NH3, 15NH3 and O2 are presented, with some insights into accompanying Odin Letters in this A&A issue. We focus on new results where Odin's high angular resolution, high frequency resolution, large spectrometer bandwidths, high sensitivity or/and frequency tuning capability are crucial: H2O mapping of the Orion KL, W3, DR21, S140 regions, and four comets; H2O observations of Galactic Centre sources, of shock enhanced H2O towards the SNR IC443, and of the candidate infall source IRAS 16293-2422; H218O detections in Orion KL and in comet Ikeya-Zhang; sub-mm detections of NH3 in Orion KL (outflow, ambient cloud and bar) and ρ Oph, and very recently, of 15NH3 in~Orion KL. Simultaneous sensitive searches for the 119 GHz line of O2 have resulted in very low abundance limits, which are difficult to accomodate in chemical models. We also demonstrate, by means of a quantitative comparison of Orion KL H2O results, that the Odin and SWAS observational data sets are very consistently calibrated. Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes), and the Centre National d'études Spatiales (CNES, France). The Swedish Space Corporation (SSC) has been the prime industrial contractor, and is also responsible for the satellite operation from its Odin Mission Control Centre at SSC in Solna and its Odin Control Centre at ESRANGE near Kiruna in northern Sweden. See also the SNSB Odin web page: http://www.snsb.se/eng_odin_intro.shtml

  15. Wilkinson Microwave Anisotropy Probe (WMAP) First Year Observations: TE Polarization

    NASA Technical Reports Server (NTRS)

    Kogut, A.; Spergel, D. N.; Barnes, C.; Bennett, C. L.; Halpern, M.; Hinshaw, G.; Jarosik, N.; Limon, M.; Meyer, S. S.; Page, L.; Oegerle, William (Technical Monitor)

    2001-01-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the full sky in Stokes I, Q, and U parameters at frequencies 23, 33, 41, 61, and 94 GHz. We detect correlations between the temperature and polarization maps significant at more than 10 standard deviations. The correlations are inconsistent with instrument noise and are significantly larger than the upper limits established for potential systematic errors. The correlations are present in all WAMP frequency bands with similar amplitude from 23 to 94 GHz, and are consistent with a superposition of a CMB signal with a weak foreground. The fitted CMB component is robust against different data combinations and fitting techniques. On small angular scales (theta less than 5 deg), the WMAP data show the temperature-polarization correlation expected from adiabatic perturbations in the temperature power spectrum. The data for l greater than 20 agree well with the signal predicted solely from the temperature power spectra, with no additional free parameters. We detect excess power on large angular scales (theta greater than 10 deg) compared to predictions based on the temperature power spectra alone. The excess power is well described by reionization at redshift 11 is less than z(sub r) is less than 30 at 95% confidence, depending on the ionization history. A model-independent fit to reionization optical depth yields results consistent with the best-fit ACDM model, with best fit value t = 0.17 +/- 0.04 at 68% confidence, including systematic and foreground uncertainties. This value is larger than expected given the detection of a Gunn-Peterson trough in the absorption spectra of distant quasars, and implies that the universe has a complex ionization history: WMAP has detected the signal from an early epoch of reionization.

  16. Mental Well-Being in First Year Medical Students: A Comparison by Race and Gender

    PubMed Central

    Hardeman, Rachel R.; Przedworski, Julia M.; Burke, Sara E.; Burgess, Diana J.; Phelan, Sean M.; Dovidio, John F.; Nelson, Dave; Rockwood, Todd; van Ryn, Michelle

    2015-01-01

    Purpose In this study, authors sought to characterize race and gender disparities in mental health in a national sample of first year medical students early in their medical school experience. Method This study used cross-sectional baseline data of Medical Student CHANGES, a large national longitudinal study of a cohort of medical students surveyed in the winter of 2010. Authors ascertained respondents via the American Association of Medical Colleges questionnaire, a third-party vendor-compiled list, and referral sampling. Results A total of 4732 first year medical students completed the baseline survey; of these, 301 were African American and 2890 were White. Compared to White students and after adjusting for relevant covariates, African American students had a greater risk of being classified as having depressive (relative risk (RR)=1.59 [95 % confidence interval, 1.37–2.40]) and anxiety symptoms (RR=1.66 [1.08–2.71]). Women also had a greater risk of being classified as having depressive (RR=1.36 [1.07–1.63]) and anxiety symptoms (RR−1.95 [1.39–2.84]). Conclusions At the start of their first year of medical school, African American and female medical students were at a higher risk for depressive symptoms and anxiety than their White and male counterparts, respectively. The findings of this study have practical implications as poor mental and overall health inhibit learning and success in medical school, and physician distress negatively affects quality of clinical care. PMID:26413458

  17. A technical writing programme implemented in a first-year engineering course at KU Leuven

    NASA Astrophysics Data System (ADS)

    Heylen, Christel; Vander Sloten, Jos

    2013-12-01

    Technical communication and technical writing are important skills for the daily work-life of every engineer. In the first-year engineering programme at KU Leuven, a technical writing programme is implemented within the project-based course 'Problem Solving and Engineering Design'. This paper describes a case study for implementing a writing programme based on active learning methods and situated learning in large classes. The programme consists of subsequent cycles of instructions, learning by doing and reflection on received feedback. In addition, a peer-review assignment, together with an interactive lecture using clicking devices, is incorporated within the assignments of the second semester. A checklist of desired writing abilities makes it easier to grade the large number of papers. Furthermore, this ensures that all staff involved in the evaluation process uses the same criteria to grade and for providing feedback.

  18. Large-Scale Campus Computer Technology Implementation: Lessons from the First Year.

    ERIC Educational Resources Information Center

    Nichols, Todd; Frazer, Linda H.

    The purpose of the Elementary Technology Demonstration Schools (ETDS) Project, funded by IBM and Apple, Inc., was to demonstrate the effectiveness of technology in accelerating the learning of low achieving at-risk students and enhancing the education of high achieving students. The paper begins by giving background information on the district,…

  19. Prediction of College Major Persistence Based on Vocational Interests, Academic Preparation, and First-Year Academic Performance

    ERIC Educational Resources Information Center

    Allen, Jeff; Robbins, Steven B.

    2008-01-01

    We hypothesized that college major persistence would be predicted by first-year academic performance and an interest-major composite score that is derived from a student's entering major and two work task scores. Using a large data set representing 25 four-year institutions and nearly 50,000 students, we randomly split the sample into an…

  20. Evaluation of a Peer Mentoring Program for a Mature Cohort of First-Year Undergraduate Paramedic Students

    ERIC Educational Resources Information Center

    Hryciw, Deanne H.; Tangalakis, Kathy; Supple, Briony; Best, Gill

    2013-01-01

    The purpose of this study was to evaluate the effectiveness of a peer-assisted study session (PASS) program for a large class of Bachelor of Health Science (Paramedic) students. This cohort was made up predominantly of mature aged students who have not undertaken any study for many years. Within a bioscience first-year core subject, student…

  1. A Case Study of Factors That Influenced the Attrition or Retention of Two First-Year Special Education Teachers

    ERIC Educational Resources Information Center

    Grant, Marquis C.

    2017-01-01

    The issue of attrition and retention has been a chronic problem in the field of education for decades. School districts across the United States are experiencing shortages of qualified special education teachers largely due to high turnover rates, with many of these teachers electing not to return after their first year of teaching. In fact,…

  2. Identifying the Strengths, Needs, and Barriers to Student Success for First Generation, Low-Income, First Year College Students

    ERIC Educational Resources Information Center

    Hayes, Linda A.

    2013-01-01

    This participatory action research needs assessment was to empower the students in a large urban research university to explore and to identify the strengths of the program, to identify the needs, and to identify the barriers to student success during their first year of college. Using qualitative methods of Group Level Interviews (GLA) and…

  3. Writing Hope, Self-Regulation, and Self-Efficacy as Predictors of Writing Ability in First-Year College Students

    ERIC Educational Resources Information Center

    Sieben, Nicole

    2013-01-01

    Using a social cognitive theory framework, this single-subject, correlational study examined to what extent writing self-regulation, writing efficacy, hope, and writing hope predicted first-year college students' writing abilities. Past research reveals that a large part of teaching students to be successful in completing writing tasks is related…

  4. Improving Student Performance in a First-Year Geography Course: Examining the Importance of Computer-Assisted Formative Assessment

    ERIC Educational Resources Information Center

    Wilson, Kathi; Boyd, Cleo; Chen, Liwen; Jamal, Sarosh

    2011-01-01

    The main objective of this paper is to examine the effectiveness of computer-assisted formative assessment in a large, first-year undergraduate geography course. In particular, the paper evaluates the impact of computer-assisted multiple-choice practice tests on student performance in the course as well as student opinions of this type of…

  5. Reading, Learning, and Growing: An Examination of the Benefits of Common Book Programs for First-Year Students' Development

    ERIC Educational Resources Information Center

    Soria, Krista M.

    2015-01-01

    Despite the continued growth of common book reading programs on college and university campuses, little is known about the benefits of such programs on first-year students' development. Using a multi-institutional survey of undergraduates attending six large, public universities (n = 1,237), the present study examined relationships between…

  6. They Do Not Buy It: Exploring the Extent to Which Entering First-Year Students View Themselves as Customers

    ERIC Educational Resources Information Center

    Saunders, Daniel B.

    2015-01-01

    While a number of scholars have discussed the pervasiveness of the conceptualization of students as customers, to date there has been limited reliable research examining the extent to which students actually view themselves as customers. Using a survey that was administered to a census of entering first-year students at a large public research…

  7. Feelings and Performance in the First Year at University: Learning-Related Emotions as Predictors of Achievement Outcomes in Mathematics and Statistics

    ERIC Educational Resources Information Center

    Niculescu, Alexandra C.; Templelaar, Dirk; Leppink, Jimmie; Dailey-Hebert, Amber; Segers, Mien; Gijselaers, Wim

    2015-01-01

    Introduction: This study examined the predictive value of four learning-related emotions--Enjoyment, Anxiety, Boredom and Hopelessness for achievement outcomes in the first year of study at university. Method: We used a large sample (N = 2337) of first year university students enrolled over three consecutive academic years in a mathematics and…

  8. Using Multiple Sources of Data to Gauge Outcome Differences between Academic-Themed and Transition-Themed First-Year Seminars

    ERIC Educational Resources Information Center

    Zerr, Ryan J.; Bjerke, Elizabeth

    2016-01-01

    Students in two different types of first-year experience seminar courses at a moderately sized public university were compared using a large variety of measures--both direct and indirect. One of these first-year experience types was a three-credit academic-themed course offered in sections with variable content; the other was a two-credit…

  9. Readiness and Expectations Questionnaire: A Cross-Cultural Measurement Instrument for First-Year University Students

    ERIC Educational Resources Information Center

    Jansen, Ellen; Andre, Stefanie; Suhre, Cor

    2013-01-01

    The readiness and expectations questionnaire (REQ) assesses first-year students' expectations and preparedness for their first year in university. This measurement instrument is useful for educational policy and curriculum development; it can also be used to predict the outcomes of the first year of college. This instrument was initially developed…

  10. Understanding Weight Management Perceptions in First-Year College Students Using the Health Belief Model

    ERIC Educational Resources Information Center

    Das, Bhibha M.; Evans, Ellen M.

    2014-01-01

    Objective: To examine weight management barriers, using the Health Belief Model, in first-year college students. Participants: First-year college students (n = 45), with data collected in April, May, and November 2013. Methods: Nominal group technique sessions (n = 8) were conducted. Results: First-year students recognize benefits to weight…

  11. Engaging and Empowering First-Year Students through Curriculum Design: Perspectives from the Literature

    ERIC Educational Resources Information Center

    Bovill, Catherine; Bulley, Cathy J.; Morss, Kate

    2011-01-01

    There is an increasing value being placed on engaging and empowering first-year students and first-year curriculum design is a key driver and opportunity to ensure early enculturation into successful learning at university. This paper summarises the literature on first-year curriculum design linked to student engagement and empowerment. We present…

  12. The Impact of First-Year Seminars on College Students' Life-Long Learning Orientations

    ERIC Educational Resources Information Center

    Padgett, Ryan D.; Keup, Jennifer R.; Pascarella, Ernest T.

    2013-01-01

    Using longitudinal data from the Wabash National Study of Liberal Arts Education, this study measured the impact of first-year seminars on college students' life-long learning orientations. The findings suggest that first-year seminars enhance students' life-long learning orientations and that the effect of first-year seminars is mediated through…

  13. Information Literacy in the Lab: Graduate Teaching Experiences in First-Year Biology

    ERIC Educational Resources Information Center

    Lantz, Catherine

    2016-01-01

    The author interviewed 10 graduate teaching assistants leading lab sessions for first-year biology about how they introduce students to scientific literature. Qualitative data analysis of the interview transcripts revealed that both first-year students and graduate teaching assistants (many of whom are first-year teachers) struggle with…

  14. The First Year at University: Giving Social Capital a Sporting Chance

    ERIC Educational Resources Information Center

    Budgen, Fiona; Main, Susan J.; Callcot, Deborah; Hamlet, Brenda

    2014-01-01

    The first year of university has been identified as an area of interest and concern for several decades because, for many students, their first year at university is also their last. The researchers developed a program based on a Sports Education model to influence the engagement and retention of first year students. The program sought to build…

  15. First-Year Students' Expectations of Conduct and Consequence: A Case Study

    ERIC Educational Resources Information Center

    Crance Gutmann, Gina-Lyn

    2008-01-01

    Research on first-year students' expectations about college has explored areas of academic and social expectations, but not first-year college students' expectations about judicial conduct and consequence. The purpose of this study was to empirically explore two questions: what are first year students' expectations about campus conduct and…

  16. An Interdisciplinary Study of the SARS Virus: A One-Semester First-Year Seminar

    ERIC Educational Resources Information Center

    Ealy, Julie; Dorward, Adrienne

    2005-01-01

    The rationale for the first-year seminar is to introduce freshmen to the university. The basic components of a first-year seminar are academic integrity, skill development, a sense of community, active and collaborative learning strategies, and technology. All freshmen must take a first-year seminar that consists primarily of freshmen, although…

  17. Fermi TGF detection map

    NASA Video Gallery

    Fermi’s Gamma-ray Burst Monitor detected 130 TGFs from August 2008 to the end of 2010. Thanks to instrument tweaks, the team has been able to improve the detection rate to several TGFs per week. ...

  18. Interaction quenches of Fermi gases

    SciTech Connect

    Uhrig, Goetz S.

    2009-12-15

    It is shown that the jump in the momentum distribution of Fermi gases evolves smoothly for small and intermediate times once an interaction between the fermions is suddenly switched on. The jump does not vanish abruptly. The loci in momentum space where the jumps occur are those of the noninteracting Fermi sea. No relaxation of the Fermi surface geometry takes place.

  19. Understanding and Using the Fermi Science Tools

    NASA Astrophysics Data System (ADS)

    Asercion, Joseph; Fermi Science Support Center

    2015-01-01

    The Fermi Science Support Center (FSSC) provides information, documentation, and tools for the analysis of Fermi science data, including both the Large-Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). Source and binary versions of the Fermi Science Tools can be downloaded from the FSSC website, and are supported on multiple platforms. An overview document, the Cicerone, provides details of the Fermi mission, the science instruments and their response functions, the science data preparation and analysis process, and interpretation of the results. Analysis Threads provide the user with step-by-step instructions for many different types of data analysis: point source analysis - generating maps, spectra, and light curves, pulsar timing analysis, source identification, and the use of python for scripting customized analysis chains. The reference manual gives details of the options available for each tool. We present an overview of the structure of the Fermi science tools and documentation, and how to acquire them. We also provide information on recent updates incorporated in the Science Tools as well as upcoming changes that will be included in the upcoming release of the Science Tools in early 2015.

  20. Maintaining Positive Attitudes toward Science and Technology in First-Year Female Undergraduates: Peril and promise

    NASA Astrophysics Data System (ADS)

    Machina, Kenton; Gokhale, Anu

    2010-03-01

    This study investigated attitude changes of 18-year-old first-year college students at a large state-operated institution in the USA during their initial semester in college. Attitudes of 375 students enrolled in a non-science first-year student seminar during the Fall of 2004 were measured, using a new instrument designed to focus on five attitude constructs especially relevant to female engagement with science and technology (S & T). The authors found that students whose seminar included visits with S & T professionals, plus at least four weeks of context-based S & T content, maintained modestly positive attitudes toward S & T. Students whose seminars included the science content but not the visits from professionals also maintained relatively positive attitudes, except that the females became less accepting of female participation in S & T. Notably, females enrolled in seminars that did not include any of these interventions declined significantly in all five attitudes toward S & T, even though 95% of these students were simultaneously enrolled in required introductory natural science courses. Thus, introducing context-based science content into the curriculum appears to be helpful in maintaining positive attitudes toward S & T in 18-year-old US female college students, while more traditional natural science pedagogy is associated with attitude decline in these students. This result is socially significant because females continue to be under-represented in several S & T fields at the level of first university degree, in many regions of the world.

  1. Can infant lung function predict respiratory morbidity during the first year of life in preterm infants?

    PubMed

    Proietti, Elena; Riedel, Thomas; Fuchs, Oliver; Pramana, Isabelle; Singer, Florian; Schmidt, Anne; Kuehni, Claudia; Latzin, Philipp; Frey, Urs

    2014-06-01

    Compared with term-born infants, preterm infants have increased respiratory morbidity in the first year of life. We investigated whether lung function tests performed near term predict subsequent respiratory morbidity during the first year of life and compared this to standard clinical parameters in preterms. The prospective birth cohort included randomly selected preterm infants with and without bronchopulmonary dysplasia. Lung function (tidal breathing and multiple-breath washout) was measured at 44 weeks post-menstrual age during natural sleep. We assessed respiratory morbidity (wheeze, hospitalisation, inhalation and home oxygen therapy) after 1 year using a standardised questionnaire. We first assessed the association between lung function and subsequent respiratory morbidity. Secondly, we compared the predictive power of standard clinical predictors with and without lung function data. In 166 preterm infants, tidal volume, time to peak tidal expiratory flow/expiratory time ratio and respiratory rate were significantly associated with subsequent wheeze. In comparison with standard clinical predictors, lung function did not improve the prediction of later respiratory morbidity in an individual child. Although associated with later wheeze, noninvasive infant lung function shows large physiological variability and does not add to clinically relevant risk prediction for subsequent respiratory morbidity in an individual preterm.

  2. Introducing first year students to interprofessionalism: Exploring professional identity in the "enterprise culture": a Foucauldian analysis.

    PubMed

    DeMatteo, Dale J; Reeves, Scott

    2013-01-01

    This paper explores the experiences of, and thoughts on, interprofessional learning and care of first year health science students at a large Canadian university within a broad socioeconomic context. We apply discourse analysis to survey data collected to evaluate an introductory interprofessional event involving first year students from a variety of health professions. Follow-up focus-group interviews were conducted to gain greater understanding of student issues and concerns emerging from the survey, providing a second source of data. A significant paper entitled, "Education, enterprise culture and the entrepreneurial self: A Foucauldian perspective" by Peters (2001) provides an historical and theoretical framework for this paper. Peters notes the changing nature of professionalism and global crises in public institutions under neoliberalism as governments divest themselves of social responsibility, shifting it onto individuals through increased privatization and focus on entrepreneurialism. In exploring the thoughts and experiences of students through the historical lens of a shifting professional discourse and changing cultural and political environment, a unique view of professionalism and this interprofessional project comes to light. Reflective of the paradigm shift that Peters documents, there was evidence of students "internalizing" responsibility for a sustainable health care system through acquisition of interprofessional knowledge and behaviours.

  3. Rat Kidney Cancers Determined by Dietary Ochratoxin A in the First Year of Life

    PubMed Central

    2016-01-01

    An experiment to explore renal carcinogenic efficacy of male rat exposure to dietary ochratoxin A (OTA) only in the first year of life has been made in comparison to lifetime exposure. Ten months exposure to OTA at 300 µg/kg b.w. was sufficient to cause high incidence of tumours which became apparent clinically after a latency of up to a year. As a putative model for human kidney cancer, the study shows a silent organ-specific carcinogenic effect through protracted exposure up to middle age and focused probably on very few nephrons. So far, tumourigenesis has not been recognised until in the last quarter of natural rat life, but for OTA, rat renal carcinogenesis requires both long exposure and only during the first year of normal longevity. The present findings offer an experimental framework within which systematic histopathology during tumourigenesis might show whether findings of mechanistic studies in key focal neoplasms can reasonably be applied to OTA as a putative renal carcinogen for idiopathic kidney cancer in humans. Already, the rat tumours mimic those occurring spontaneously in the Eker rat, and there is disparity between the large necessary OTA exposure in the rat and the trace amounts of OTA consumed by humans. In all such complex considerations it is important to adhere rigorously to established principles of disease epidemiology. PMID:28326281

  4. Statistics and topology of the COBE differential microwave radiometer first-year sky maps

    NASA Astrophysics Data System (ADS)

    Smoot, G. F.; Tenorio, L.; Banday, A. J.; Kogut, A.; Wright, E. L.; Hinshaw, G.; Bennett, C. L.

    1994-12-01

    We use statistical and topological quantities to test the Cosmic Background Explorer (COBE) Differential Microwave Radiometer (DMR) first-year sky maps against the hypothesis that the observed temperature fluctuations reflect Gaussian initial density perturbations with random phases. Recent papers discuss specific quantities as discriminators between Gaussian and non-Gaussian behavior, but the treatment of instrumental noise on the data is largely ignored. The presence of noise in the data biases many statistical quantities in a manner dependent on both the noise properties and the unknown cosmic microwave background temperature field. Appropriate weighting schemes can minimize this effect, but it cannot be completely eliminated. Analytic expressions are presented for these biases, and Monte Carlo simulations are used to assess the best strategy for determining cosmologically interesting information from noisy data. The genus is a robust discriminator that can be used to estimate the power-law quadrupole-normalized amplitude, Qrms-PS, independently of the two-point correlation function. The genus of the DMR data is consistent with Gaussian initial fluctuations with Qrms-PS = (15.7 +/- 2.2) - (6.6 +/- 0.3)(n - 1) micro-K, where n is the power-law index. Fitting the rms temperature variations at various smoothing angles gives Qrms-PS = 13.2 +/- 2.5 micro-K and n = 1.7(+0.3(-0.6)). While consistent with Gaussian fluctuations, the first year data are only sufficient to rule out strongly non-Gaussian distributions of fluctuations.

  5. Exploring the association of Fermi sources with young stellar objects

    NASA Astrophysics Data System (ADS)

    Munar-Adrover, P.; Paredes, J. M.; Romero, G. E.

    2011-11-01

    Massive protostars have associated bipolar outflows which can produce strong shocks when interact with the surrounding medium. In these conditions particle acceleration at relativistic velocities can occur leading to gamma ray emission, as some theoretical models predict. To identify young stellar objects (YSO) that may emit gamma rays we have crossed the Fermi First Year Catalog with some catalogs of known YSOs, and we have conducted Montecarlo simulations to find the probability of chance coincidence. With this crossing we obtained a list of YSOs spatially coincident with Fermi sources that may show gamma ray emission. Our results indicate that about 70% of the candidates should be gamma-ray sources with a confidence of 5 sigma. We have studied the coincidences one by one to check the viability of these YSOs as potential counterparts of Fermi sources and plan further detailed observations of few of them.

  6. A phenomenographic study of students' experiences with transition from pre-college engineering programs to first-year engineering

    NASA Astrophysics Data System (ADS)

    Salzman, Noah

    Recent national dialogues on the importance of preparing more students for careers in Science, Technology, Engineering, and Mathematics has driven the development of formal and informal learning opportunities for children and adolescents to explore engineering. Despite the growth of these programs, relatively little research exists on how participation in these programs affects students who choose to pursue further study in engineering. The present study addressed this gap through an exploration of the different ways that First-Year Engineering students experience the transition from pre-college engineering to undergraduate engineering studies. Given the focus of this research on students' experiences, phenomenography was chosen to explore the phenomenon of transition from pre-college to first-year engineering at a large, public Midwestern university. This facilitated understanding the range of variation in the ways that students experienced this transition. Twenty-two students with different amounts of participation in a variety of different engineering programs were selected to be interviewed using a purposeful maximum variation sampling strategy. The interviews were guided by a semi-structured interview protocol that encouraged the participants to reflect on their pre-college engineering experiences, their experiences in First-Year Engineering, and the transition between the two domains. The interviews were analyzed using phenomenographic methods to develop an outcome space consisting of five qualitatively different but related ways of experiencing the transition from pre-college to First-Year Engineering. These categories of description included Foreclosure, Frustration, Tedium, Connection, and Engaging Others. With the exception of the first category which was characterized by a lack of passion and commitment to engineering, the remaining four categories formed a hierarchical relationship representing increasing integration in First-Year Engineering. The

  7. Upgrading Fermi Without Traveling to Space

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-02-01

    The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has received an upgrade that increased its sensitivity by a whopping 40% and nobody had to travel to space to make it happen! The difference instead stems from remarkable improvement to the software used to analyze Fermi-LATs data, and it has resulted in a new high-energy map of our sky.Animation (click to watch!) comparing the Pass 7 to the Pass 8 Fermi-LAT analysis, in a region in the constellation Carina. Pass 8 provides more accurate directions for incoming gamma rays, so more of them fall closer to their sources, creating taller spikes and a sharper image. [NASA/DOE/Fermi LAT Collaboration]Pass 8Fermi-LAT has been surveying the whole sky since August 2008. It detects gamma-ray photons by converting them into electron-positron pairs and tracking the paths of these charged particles. But differentiating this signal from the charged cosmic rays that also pass through the detector with a flux that can be 10,000 times larger! is a challenging process. Making this distinction and rebuilding the path of the original gamma ray relies on complex analysis software.Pass 8 is a complete reprocessing of all data collected by Fermi-LAT. The software has gone through many revisions before now, but this is the first revision that has taken into account all of the experience that the Fermi team has gained operating the LAT in its orbital environment.The improvements made in Pass 8 include better background rejection of misclassified charged particles, improvements to the point spread function and effective area of the detector, and an extension of the effective energy range from below 100 MeV to beyond a few hundred GeV. The changes made in Pass 8 have increased the sensitivity of Fermi-LAT by an astonishing 40%.Map of the High-Energy SkySky map of the sources in the 2FHL catalog, classified by their most likely association. Click for a better look! [Ackermann et al. 2016]The first result from the

  8. First-Year Results of an Obesity Prevention Program at The Dow Chemical Company

    PubMed Central

    Goetzel, Ron Z.; Baker, Kristin M.; Short, Meghan E.; Pei, Xiaofei; Ozminkowski, Ronald J.; Wang, Shaohung; Bowen, Jennie D.; Roemer, Enid C.; Craun, Beth A.; Tully, Karen J.; Baase, Catherine M.

    2010-01-01

    Objective To examine first-year results from a workplace environmental obesity prevention program at The Dow Chemical Company. Methods A quasi-experimental cohort study was conducted among employees at nine treatment worksites (n=8,013) who received environmental weight management interventions and three control worksites (n=2,269). Changes in employees’ weight, body mass index (BMI), and other health risks were examined using chi-square and t-tests. Results After one year, a modest treatment effect was observed for weight and BMI largely because the control group subjects gained weight; however, no effect was observed for overweight and obesity prevalence. Other risk factors (tobacco use, high blood pressure, and systolic and diastolic blood pressure values) decreased significantly, although blood glucose (high risk prevalence and values) increased. Conclusions Environmental changes to the workplace can achieve modest improvements in employees’ health risks, including weight and BMI measures, in one year. PMID:19209033

  9. Developing and validating test items for first-year computer science courses

    NASA Astrophysics Data System (ADS)

    Vahrenhold, Jan; Paul, Wolfgang

    2014-10-01

    We report on the development, validation, and implementation of a collection of test items designed to detect misconceptions related to first-year computer science courses. To this end, we reworked the development scheme proposed by Almstrum et al. (SIGCSE Bulletin 38(4):132-145, 2006) to include students' artifacts and to simultaneously incorporate think-aloud interviews and flash tests. We also investigated to what extent the practical efficiency of detecting certain misconceptions could be increased without significantly affecting the sensitivity of the instrument, and present positive and negative results regarding this goal. The results of a first transfer and implementation study suggest that it is indeed possible to use the test items in a large-scale practical setting - both as diagnostic instruments and as interventions.

  10. Limits on three-point correlations in the COBE DMR first-year anisotropy maps

    NASA Technical Reports Server (NTRS)

    Hinshaw, G.; Kogut, A.; Gorski, K. M.; Banday, A. J.; Bennett, C. L.; Lineweaver, C.; Lubin, P.; Smoot, G. F.; Wright, E. L.

    1994-01-01

    We compute the three-point temperature correlation function of the Cosmic Background Explorer (COBE) Differential Microwave Radiometer (DMR) first-year sky maps to search for non-Gaussian temperature fluctuations. The level of fluctuations seen in the computed correlation function are too large to be attributable solely to instrument noise. However the fluctuations are consistent with the level expected to result from a superposition of istrument noise and sky signal arising from a Gaussian power-law model of initial fluctuations, with a quadrupole normalized amplitude of 17 micro K and a power-law spectral index n = 1. We place limits on the amplitude of intrinsic three-point correlations with a variety of predicted functional forms.

  11. Dynamics and Stabilization of the Human Gut Microbiome during the First Year of Life.

    PubMed

    Bäckhed, Fredrik; Roswall, Josefine; Peng, Yangqing; Feng, Qiang; Jia, Huijue; Kovatcheva-Datchary, Petia; Li, Yin; Xia, Yan; Xie, Hailiang; Zhong, Huanzi; Khan, Muhammad Tanweer; Zhang, Jianfeng; Li, Junhua; Xiao, Liang; Al-Aama, Jumana; Zhang, Dongya; Lee, Ying Shiuan; Kotowska, Dorota; Colding, Camilla; Tremaroli, Valentina; Yin, Ye; Bergman, Stefan; Xu, Xun; Madsen, Lise; Kristiansen, Karsten; Dahlgren, Jovanna; Wang, Jun; Jun, Wang

    2015-05-13

    The gut microbiota is central to human health, but its establishment in early life has not been quantitatively and functionally examined. Applying metagenomic analysis on fecal samples from a large cohort of Swedish infants and their mothers, we characterized the gut microbiome during the first year of life and assessed the impact of mode of delivery and feeding on its establishment. In contrast to vaginally delivered infants, the gut microbiota of infants delivered by C-section showed significantly less resemblance to their mothers. Nutrition had a major impact on early microbiota composition and function, with cessation of breast-feeding, rather than introduction of solid food, being required for maturation into an adult-like microbiota. Microbiota composition and ecological network had distinctive features at each sampled stage, in accordance with functional maturation of the microbiome. Our findings establish a framework for understanding the interplay between the gut microbiome and the human body in early life.

  12. Growing up our way: the first year of life in remote Aboriginal Australia.

    PubMed

    Kruske, Sue; Belton, Suzanne; Wardaguga, Molly; Narjic, Concepta

    2012-06-01

    In this study, we attempted to explore the experiences and beliefs of Aboriginal families as they cared for their children in the first year of life. We collected family stories concerning child rearing, development, behavior, health, and well-being between each infant's birth and first birthday. We found significant differences in parenting behaviors and child-rearing practices between Aboriginal groups and mainstream Australians. Aboriginal parents perceived their children to be autonomous individuals with responsibilities toward a large family group. The children were active agents in determining their own needs, highly prized, and included in all aspects of community life. Concurrent with poverty, neocolonialism, and medical hegemony, child-led parenting styles hamper the effectiveness of health services. Hence, until the planners of Australia's health systems better understand Aboriginal knowledge systems and incorporate them into their planning, we can continue to expect the failure of government and health services among Aboriginal communities.

  13. Chern-Simons theories with fundamental matter: A brief review of large N results including Fermi-Bose duality and the S-matrix

    NASA Astrophysics Data System (ADS)

    Wadia, Spenta R.

    2016-10-01

    We begin with a few words about Salam’s contribution to the growth of String Theory in India. In the technical talk we review results in SU(N) Chern-Simons plus vector matter theories in 2+1 dim in the large N limit. The dressing of charged matter by Chern-Simons gauge fields leads to anyons that interpolate between fermions and bosons and lead to a duality symmetry between fermionic and bosonic theories. The S-matrix (defined in the large N limit) besides exhibiting this duality, also exhibits novel properties due to the presence of anyons. The S-matrix is not analytic, like in Aharonov-Bohm scattering, and satisfies modified crossing symmetry relations.

  14. Fermi Gamma-Ray Space Telescope Science Overview

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2010-01-01

    After more than 2 years of science operations, the Fermi Gamma-ray Space Telescope continues to survey the high-energy sky on a daily basis. In addition to the more than 1400 sources found in the first Fermi Large Area Telescope Catalog (I FGL), new results continue to emerge. Some of these are: (1) Large-scale diffuse emission suggests possible activity from the Galactic Center region in the past; (2) a gamma-ray nova was found, indicating particle acceleration in this binary system; and (3) the Crab Nebula, long thought to be a steady source, has varied in the energy ranges seen by both Fermi instruments.

  15. NASA's Fermi Shows How Active Galaxies Can Be

    NASA Video Gallery

    Active galaxies called blazars make up the largest class of objects detected by Fermi's Large Area Telescope (LAT). Massive black holes in the hearts of these galaxies fire particle jets in our dir...

  16. Behavioral assessment of language brain processing in the first year of life.

    PubMed

    Guzzetta, Francesco

    2014-09-01

    An up-to-date review of the behavioral assessments of language development in the first year of life is reported. After recalling the anatomical bases of the early development of the auditory system, the different stages of language development during the first year of life are considered: discrimination, transition and perception. The different kinds of behavioral assessment during the course of the first year are then described by stressing their indications and limitations.

  17. Greenhouse gas emissions from an abandoned peatland in central Belarus during the first year of rewetting

    NASA Astrophysics Data System (ADS)

    Chuvashova, H.; Minke, M.; Burlo, A.; Thiele, A.; Augustin, J.; Yarmashuk, T.; Tichonov, V.; Liashchynskaya, N.; Kuzmin, Vl.

    2012-04-01

    Peatland restoration by inundation of drained fen grasslands can lead to very high methane emissions in the first years (M. Hahn-Schöfl et al, 2011). Due to a lack of other studies on the GHG emissions of fen forbs and meadows during the first years after flooding there is the worry to create methane plants by restoring such sites. Within the BMU-ICI financed project "Restoring Peatlands and applying Concepts for Sustainable Managements in Belarus - Climate Change Mitigation with Economic and Biodiversity Benefits" we selected the mesotrophic fen Bartenikha as a typical petland for central Belarus as study site. The peatland Bartenikha was drained in 1990 and used for peat extraction till 1999. Subsequently the peatland got abandoned and a meadow dominated by Agrostis stolonifera emerged in its SW part. In September 2010 the meadow was unexpectedly flooded by the beaver and the forbs died. During one year the water level changed from nearly 10 cm below surface to nearly 50 cm above surface. In 2011 only detritus was left from the former vegetation, but new species, beside some Chara, were still not established. We studied the effect of rewetting on the emission of carbon dioxide and methane during the period from September 2010 till September 2011 using the closed chamber method. Methane release during autumn, winter and early spring was still low. Substantially higher emissions of Methane are observed since June with highest rates in July when the water level was lower than usually, i.e. 20 cm above the surface and the temperature was high. In total Methane emissions per year were lower as expected. Carbon dioxide release was low during the whole year because of high water level but a dependence of emissions on temperature was detected. Altogether greenhouse gas emissions from the rewetted peatland were not high in the first year of flooding. Hahn-Schöfl M, Zak D., Minke M., Gelbrecht J., Augustin J., and Freibauer A. Organic sediment formed during inundation of

  18. A Student Evaluation of Molecular Modeling in First Year College Chemistry.

    ERIC Educational Resources Information Center

    Ealy, Julie B.

    1999-01-01

    Evaluates first-year college students' perceptions of molecular modeling. Examines the effectiveness, integration with course content, interests, benefits, advantages, and disadvantages of molecular modeling. (Author/CCM)

  19. Designing a New Physics Laboratory Programme for First-Year Engineering Students.

    ERIC Educational Resources Information Center

    Kirkup, L.; Johnson, S.; Hazel, E.; Cheary, R. W.; Green, D. C.; Swift, P.; Holliday, W.

    1998-01-01

    Explores the issue of physics laboratory work for engineering students and discusses the design, implementation, and evaluation of a laboratory program developed for first year engineering students. (DDR)

  20. Predicting success among first-year engineering students at the Rand Afrikaans University.

    PubMed

    Maree, Jacobus G; Pretorius, Anlia; Eiselen, Riëtte J

    2003-10-01

    160 first-year students in the Engineering Faculty at the Rand Afrikaans University completed the Study Orientation Questionnaire in Mathematics and the Senior Aptitude Test Advanced. 100 students who passed and 40 who failed the first year scored significantly differently on three subtests, Calculations, Study attitude in mathematics, and Problem-solving behaviour in mathematics. Step-wise linear regression showed a combination of three fields, namely, Calculations, Study attitude in mathematics, and Mathematics anxiety, contributed significantly (R2=25.8%) towards predicting the first-year aggregate score of first-year engineering students.

  1. DISCOVERY OF PULSED gamma-RAYS FROM PSR J0034-0534 WITH THE FERMI LARGE AREA TELESCOPE: A CASE FOR CO-LOCATED RADIO AND gamma-RAY EMISSION REGIONS

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P. E-mail: Tyrel.J.Johnson@nasa.go E-mail: Christo.Venter@nwu.ac.z

    2010-04-01

    Millisecond pulsars (MSPs) have been firmly established as a class of gamma-ray emitters via the detection of pulsations above 0.1 GeV from eight MSPs by the Fermi Large Area Telescope (LAT). Using 13 months of LAT data, significant gamma-ray pulsations at the radio period have been detected from the MSP PSR J0034-0534, making it the ninth clear MSP detection by the LAT. The gamma-ray light curve shows two peaks separated by 0.274 +- 0.015 in phase which are very nearly aligned with the radio peaks, a phenomenon seen only in the Crab pulsar until now. The >=0.1 GeV spectrum of this pulsar is well fit by an exponentially cutoff power law with a cutoff energy of 1.8 +- 0.6 +- 0.1 GeV and a photon index of 1.5 +- 0.2 +- 0.1, first errors are statistical and second are systematic. The near-alignment of the radio and gamma-ray peaks strongly suggests that the radio and gamma-ray emission regions are co-located and both are the result of caustic formation.

  2. Socioeconomic Outcomes in Adults Malnourished in the First Year of Life: A 40-Year Study

    PubMed Central

    Bryce, Cyralene; Waber, Deborah P.; Zichlin, Miriam L.; Fitzmaurice, Garret M.; Eaglesfield, David

    2012-01-01

    OBJECTIVE: Lifelong functional, adaptive, and economic outcomes of moderate to severe infantile malnutrition are not well known. We assessed social status and income at midlife in a cohort of Barbadian adults, hospitalized for protein-energy malnutrition (PEM) during the first year of life, with good nutrition and health thereafter, in the context of a 40-year longitudinal case-control study. We also examined to what extent childhood IQ mediated any group differences. METHODS: Educational achievement, occupational status, and standard of living were assessed by the Hollingshead scales and a site-specific Ecology Questionnaire in Barbadian adults (aged 37–43 years) with a history of malnutrition (n = 80) and a matched healthy control group (n = 63), classmates of the index cases. Malnutrition effects, adjusted for childhood standard of living, were estimated by longitudinal multiple regression analyses, with and without childhood IQ, in the models. RESULTS: PEM predicted poorer socioeconomic outcomes with medium to large effect sizes (0.50–0.94), but childhood IQ substantially attenuated the magnitude of these effects (adjusted effect sizes: 0.17–0.34). The gap in weekly household income between the PEM and control groups increased substantially over the life span (P < .001). CONCLUSIONS: Moderate to severe PEM during the first year of life with adequate nutrition and health care thereafter is associated with significant depression of socioeconomic outcomes in adulthood, mediated in part by cognitive compromise in affected individuals. This finding underscores the potential long-term economic burden of infant malnutrition, which is of major concern given the continued high prevalence of malnutrition worldwide. PMID:22732170

  3. Statistics and topology of the COBE differential microwave radiometer first-year sky maps

    NASA Technical Reports Server (NTRS)

    Smoot, G. F.; Tenorio, L.; Banday, A. J.; Kogut, A.; Wright, E. L.; Hinshaw, G.; Bennett, C. L.

    1994-01-01

    We use statistical and topological quantities to test the Cosmic Background Explorer (COBE) Differential Microwave Radiometer (DMR) first-year sky maps against the hypothesis that the observed temperature fluctuations reflect Gaussian initial density perturbations with random phases. Recent papers discuss specific quantities as discriminators between Gaussian and non-Gaussian behavior, but the treatment of instrumental noise on the data is largely ignored. The presence of noise in the data biases many statistical quantities in a manner dependent on both the noise properties and the unknown cosmic microwave background temperature field. Appropriate weighting schemes can minimize this effect, but it cannot be completely eliminated. Analytic expressions are presented for these biases, and Monte Carlo simulations are used to assess the best strategy for determining cosmologically interesting information from noisy data. The genus is a robust discriminator that can be used to estimate the power-law quadrupole-normalized amplitude, Q(sub rms-PS), independently of the two-point correlation function. The genus of the DMR data is consistent with Gaussian initial fluctuations with Q(sub rms-PS) = (15.7 +/- 2.2) - (6.6 +/- 0.3)(n - 1) micro-K, where n is the power-law index. Fitting the rms temperature variations at various smoothing angles gives Q(sub rms-PS) = 13.2 +/- 2.5 micro-K and n = 1.7(sup (+0.3) sub (-0.6)). While consistent with Gaussian fluctuations, the first year data are only sufficient to rule out strongly non-Gaussian distributions of fluctuations.

  4. Looking for the Northern Fermi Bubble with HAWC

    NASA Astrophysics Data System (ADS)

    Ayala, Hugo; Zhou, Hao; Huentemeyer, Petra; HAWC Collaboration

    2016-03-01

    The Fermi Bubbles were discovered in the GeV gamma-ray data from the Fermi Telescope in 2010. They extend up to 55° above and below the Galactic Center forming two large and homogeneous regions of spectrally hard gamma-ray emission. Understanding the mechanisms which produce the observed hard spectrum will help understand the origin of the Fermi Bubbles. Both hadronic and leptonic models can describe the spectrum of the bubbles, though the leptonic model can explain similar structures observed in microwave data from the WMAP and Planck satellites. Recent publications show that the spectrum of the Fermi Bubbles is well described by a power law with an exponential cutoff between 100MeV to 500GeV. Observing the Fermi Bubbles at higher gamma-ray energies will help constrain their spectrum. A steeper cutoff will favor a leptonic model. The High Altitude Water Cherenkov (HAWC) Observatory, located 4100m above sea level in Mexico, is designed to measure high-energy gamma rays between 100GeV to 100TeV. With a large field of view and good sensitivity to spatially extended sources, HAWC is the ground-based observatory best suited to detect extended regions like the Fermi Bubbles. We present a search for emission from the Fermi Bubble visible to HAWC.

  5. Exploring Collaboratively Written L2 Texts among First-Year Learners of German in Google Docs

    ERIC Educational Resources Information Center

    Abrams, Zsuzsanna

    2016-01-01

    Grounded in research on collaborative writing and computer-mediated writing the present study examines the computer-mediated collaborative writing process among first-year learners of German as a second language (L2) at a US university. The data come from 28 first-year learners of German at a US university, who wrote hypothesized endings to a…

  6. Quantitative Evaluation of a First Year Seminar Program: Relationships to Persistence and Academic Success

    ERIC Educational Resources Information Center

    Jenkins-Guarnieri, Michael A.; Horne, Melissa M.; Wallis, Aaron L.; Rings, Jeffrey A.; Vaughan, Angela L.

    2015-01-01

    In the present study, we conducted a quantitative evaluation of a novel First Year Seminar (FYS) program with a coordinated curriculum implemented at a public, four-year university to assess its potential role in undergraduate student persistence decisions and academic success. Participants were 2,188 first-year students, 342 of whom completed the…

  7. The Effects of Patient Contact upon First-Year Dental Students: A Study of Changing Perceptions.

    ERIC Educational Resources Information Center

    Branch, Roger G.; And Others

    This study attempted to determine the effects of early patient contact through clinic experience upon the perceptions and attitudes of first year dental students. Questionnaires were administered at the beginning and end of students' first year in an innovative and new dental school where they were introduced to clinic experience within the first…

  8. From Tinkering to Meddling: Notes on Engaging First Year Art Theory Students

    ERIC Educational Resources Information Center

    Messham-Muir, Kit

    2012-01-01

    This paper considers the two-year-long process of redesigning Art Theory: Modernism, the initial core art theory course at The University of Newcastle in Australia, with the aim of increasing the academic engagement of first year fine art students. First year students are particularly vulnerable to dropping out if they feel disengaged from the…

  9. Investigating First Year Elementary Mathematics Teacher Education Students' Knowledge of Prism

    ERIC Educational Resources Information Center

    Bozkurt, Ali; Koc, Yusuf

    2012-01-01

    The purpose of this study was to investigate first year elementary mathematics teacher education students' knowledge of prism. For this goal, the participants were asked to define the geometric concept of prism. The participants were 158 first year elementary mathematics teacher education students from a public university in Southern Turkey. The…

  10. Impacting Information Literacy Learning in First-Year Seminars: A Rubric-Based Evaluation

    ERIC Educational Resources Information Center

    Lowe, M. Sara; Booth, Char; Stone, Sean; Tagge, Natalie

    2015-01-01

    The authors conducted a rubric assessment of information literacy (IL) skills in research papers across five undergraduate first-year seminar programs to explore the question "What impact does librarian intervention in first-year courses have on IL performance in student work?" Statistical results indicate that students in courses with…

  11. Supporting the Development of Persistence: Strategies for Teachers of First Year Undergraduate Students

    ERIC Educational Resources Information Center

    Huntly, Helen; Donovan, Jenny

    2009-01-01

    The first year of university study has a major impact on later participation and performance. Transitioning to university from school or other contexts requires first year students to become self-directed learners, entering an environment with minimal constraints and expectations of self-motivation and individual effort. In 1991, Costa named the…

  12. Perceptions of Teachers in Their First Year of School Restructuring: Failure to Make Adequate Yearly Progress

    ERIC Educational Resources Information Center

    Moser, Sharon

    2010-01-01

    The 2007-2008 school year marked the first year Florida's Title I schools that did not made Adequate Yearly Progress (AYP) for five consecutive years entered into restructuring as mandated by the "No Child Left Behind Act" of 2001. My study examines the perceptions of teacher entering into their first year of school restructuring due to…

  13. First-Year Students' Use of Social Network Sites to Reduce the Uncertainty of Anticipatory Socialization

    ERIC Educational Resources Information Center

    Anderson, Isolde K.; Lerstrom, Alan; Tintle, Nathan

    2014-01-01

    This study surveyed 399 incoming first-year students at two colleges in the Midwest on their use of social network sites before college entry and its impact on various dimensions of the first-year experience. Significant correlations were found for two pairs of variables: (a) students who used social network sites before arriving on campus…

  14. Interventions to Improve Teaching and Learning in First Year Mathematics Courses

    ERIC Educational Resources Information Center

    Engelbrecht, Johann; Harding, Ansie

    2015-01-01

    In keeping with the national mandate of increasing graduates in the sciences in South Africa, a concerted effort in improving the first year experience becomes imperative. First year mathematics courses commonly provide the base knowledge necessary for progression in different degree programmes at university. Success in mathematics courses…

  15. Effects of Identity Processing Styles on Academic Achievement of First Year University Students

    ERIC Educational Resources Information Center

    Seabi, Joseph; Payne, Jarrod

    2013-01-01

    Purpose: Academic achievement of first year university students in the international arena, as well as in South Africa, has been a point of concern for all stakeholders because of high failure and dropout rates. The purpose of this paper is to investigate the effects of identity processing styles on academic achievement in first year university…

  16. The Effect of Secondary School Study Skills Preparation on First-Year University Achievement

    ERIC Educational Resources Information Center

    Jansen, Ellen P. W. A.; Suhre, Cor J. M.

    2010-01-01

    Although many studies have revealed the importance of study skills for students' first-year performance and college retention, the extent of the impact of study skills preparation on students' academic achievement is less clear. This paper explores the impact of pre-university study skills preparation on students' first-year study experiences,…

  17. Blended Learning Environments: Using Social Networking Sites to Enhance the First Year Experience

    ERIC Educational Resources Information Center

    McCarthy, Joshua

    2010-01-01

    This study explores blending virtual and physical learning environments to enhance the experience of first year by immersing students into university culture through social and academic interaction between peers. It reports on the progress made from 2008 to 2009 using an existing academic platform, the first year design elective course…

  18. A Passion for Service? Motivations for Volunteerism among First-Year College Students

    ERIC Educational Resources Information Center

    Stroup, John T.; Dodson, Kyle; Elias, Kaitlyn; Gewirtzman, Andrea

    2015-01-01

    This study addressed the links between first-year college students' motivations to volunteer, gender, and past volunteering practices. We surveyed 149 first-year students using items from the Volunteer Functions Inventory (Clary et al., 1998). The results of a series of one-way ANOVAs determined significant differences in motivations when…

  19. Achieving and Sustaining Institutional Excellence for the First Year of College

    ERIC Educational Resources Information Center

    Barefoot, Betsy O.; Gardner, John N.; Cutright, Marc; Morris, Libby V.; Schroeder, Charles C.; Schwartz, Stephen W.; Siegel, Michael J.; Swing, Randy L.

    2005-01-01

    In 2002, the Policy Center on the First Year of College (supported by The Pew Charitable Trusts, The Atlantic Philanthropies, and Lumina Foundation for Education) sponsored a project to recognize colleges and universities as "Institutions of Excellence" in their design and execution of the first year. Thirteen colleges and…

  20. An Investigation of First-Year Engineering Student and Instructor Perspectives of Learning Analytics Approaches

    ERIC Educational Resources Information Center

    Knight, David B.; Brozina, Cory; Novoselich, Brian

    2016-01-01

    This paper investigates how first-year engineering undergraduates and their instructors describe the potential for learning analytics approaches to contribute to student success. Results of qualitative data collection in a first-year engineering course indicated that both students and instructors\temphasized a preference for learning analytics…

  1. Academic Achievement in First-Year University: Who Maintains Their High School Average?

    ERIC Educational Resources Information Center

    Wintre, Maxine Gallander; Dilouya, Barry; Pancer, S. Mark; Pratt, Michael W.; Birnie-Lefcovitch, Shelly; Polivy, Janet; Adams, Gerald

    2011-01-01

    The present study investigates the characteristics which differentiate between first-year university students who maintain their high school averages (Maintainers: n = 165) and those whose averages decrease at least one letter grade (Decliners: n = 435). The 600 students entered first year at one of six Canadian Universities, which varied in size…

  2. Supporting Students in the Margins: Establishing a First-Year Experience for LGBTQA Students

    ERIC Educational Resources Information Center

    Squire, Dian; Norris, Lauren

    2014-01-01

    This paper describes the creation of a comprehensive First-Year Experience program for lesbian, gay, bisexual, transgender, queer, and ally (LGBTQA) students. Background information on First-Year Experience programs, LGBTQA populations, and the benefits of providing this program are described. The authors discuss how to plan and implement this…

  3. Measuring, Monitoring and Managing the Psychological Well-Being of First Year University Students

    ERIC Educational Resources Information Center

    Cooke, Richard; Bewick, Bridgette M.; Barkham, Michael; Bradley, Margaret; Audin, Kerry

    2006-01-01

    This paper profiles the psychological well-being of students in their initial year of university. There were three aims: to measure the impact of arrival at university on the psychological well-being of first year students, to monitor (i.e. profile) the shape of psychological well-being across the first year, and to investigate how students manage…

  4. The Value of a First-Year Seminar: International Students' Insights in Retrospect

    ERIC Educational Resources Information Center

    Andrade, Maureen S.

    2009-01-01

    Higher education institutions in the United States commonly offer first-year seminars to assist students with their transition to college. Seminars are one of several types of first-year interventions based on findings from persistence research identifying variables affecting student success. Diverse student populations such as international…

  5. First Year Symposium: One College's Response to the Perceived "Deficit" in Civic Education

    ERIC Educational Resources Information Center

    Roidt, Joseph; DeNicolo, Martin; Kittle, Amy; Osborne, Katherine; Saindon, Brent

    2016-01-01

    This essay outlines a unique program developed at Davis & Elkins College: the First Year Symposium. Responding to concerns about the lack of civic engagement in America's youth and the call for colleges and universities to develop strategic plans for addressing democratic learning, the First Year Symposium is a required class for all…

  6. Challenges in the First Year of Teaching: Lessons Learned in an Elementary Education Resident Teacher Program

    ERIC Educational Resources Information Center

    Gourneau, Bonni

    2014-01-01

    It is well known that the first years of teaching are a challenge for all beginning teachers. According to the National Commission on Teaching and America's Future's study (2010) first-year teacher attrition has been steadily increasing and many leave the profession even before they are proficient educators who know how to work with colleagues to…

  7. Embedding Information Literacy in a First-Year Business Undergraduate Course

    ERIC Educational Resources Information Center

    Price, Robin; Becker, Karen; Clark, Lynette; Collins, Sue

    2011-01-01

    This article reports on a project to embed information literacy skills development in a first-year undergraduate business course at an Australian university. In accordance with prior research suggesting that first-year students are over-confident about their skills, the project used an optional online quiz to allow students to pre-test their…

  8. Career Self-Appraisals and Educational Aspirations of Diverse First-Year College Students

    ERIC Educational Resources Information Center

    Gasser, Courtney E.

    2013-01-01

    This study examined the career, social, and academic self-appraisals and educational aspirations of first-year college students of diverse racial/ethnic backgrounds. Participants included 72 first-year students of Black, Asian, and White ethnicities. Career self-appraisals were significantly different for Black and Asian students when compared to…

  9. Improving the Retention of First-Year College Students: A Temporal Model of Assessment and Intervention

    ERIC Educational Resources Information Center

    Beck, Hall P.; Davidson, William B.

    2015-01-01

    This investigation sought to determine when colleges should conduct assessments to identify first-year students at risk of dropping out. Thirty-five variables were used to predict the persistence of 2,024 first-year students from four universities in the southeastern United States. The predictors were subdivided into groups according to when they…

  10. Peer and Self-Assessment in the First Year of University

    ERIC Educational Resources Information Center

    Nulty, Duncan D.

    2011-01-01

    This paper reviews the literature about peer and self-assessment in university courses from the point of view of their use, and the suitability of their use, in the first year of university study. The paper is divided into three parts. The first part argues that although first-year students are involved in many of the studies that report on the…

  11. First-Year Teachers' Support Networks: Intentional Professional Networks and Diverse Professional Allies

    ERIC Educational Resources Information Center

    Baker-Doyle, Kira J.

    2012-01-01

    In this article the author describes a mixed-methods study of first-year urban teachers' social support networks. Social Network Analysis (SNA) data on the support networks of 24 first-year teachers provided a background context and framework for the case study analysis of 4 of the teachers. Findings of the analysis identified 2 important networks…

  12. The Multimedia CD as a New Approach to First-Year Reading Programs

    ERIC Educational Resources Information Center

    Sanger, Kerran L.; Ramsey, Janet E.; Merberg, Eileen Naughton

    2008-01-01

    Buffalo State College's search for a text for its common first-year reading program ended not in the selection of a book but in the creation of a multimedia CD. The CD guides discussion in first-year classrooms throughout the year, resulting in a meaningful intellectual experience for the school's diverse mix of students, faculty, and staff. The…

  13. Teaching Students with Learning Disabilities: Perceptions of a First-Year Teacher.

    ERIC Educational Resources Information Center

    Busch, Todd W.; Pederson, Kari; Espin, Christine A.; Weissenburger, Jacalyn W.

    2001-01-01

    This article reports perceptions of a first-year teacher of students with learning disabilities. First-year challenges are described, as well as views on assessment, accountability, and inclusion. Recommendations are made for new teachers and steps that teacher educators, school administrators, and experienced teachers can take to ensure the…

  14. The First Year Out: Understanding American Teens after High School. Morality and Society Series

    ERIC Educational Resources Information Center

    Clydesdale, Tim

    2007-01-01

    Wild parties, late nights, and lots of sex, drugs, and alcohol. Many assume these are the things that define an American teenager's first year after high school. But the reality is really quite different. As Tim Clydesdale reports in "The First Year Out", teenagers generally manage the increased responsibilities of everyday life immediately after…

  15. From Tununak to Beaufort: Taking a Critical Inquiry Stance as a First Year Teacher

    ERIC Educational Resources Information Center

    Fecho, Bob; Price, Kim; Read, Chris

    2004-01-01

    In this article, the authors show how two first year teachers a continent apart--Kim in the village of Tununak on the Bering Sea in Alaska and Chris in Beaufort, South Carolina, on the Atlantic Ocean--were able to take inquiry stances on their classrooms. In particular, through analysis of e-mails written in Chris' and Kim's first years of…

  16. Financial Aid and First-Year Collegiate GPA: A Regression Discontinuity Approach

    ERIC Educational Resources Information Center

    Curs, Bradley R.; Harper, Casandra E.

    2012-01-01

    Using a regression discontinuity design, we investigate whether a merit-based financial aid program has a causal effect on the first-year grade point average of first-time out-of-state freshmen at the University of Oregon. Our results indicate that merit-based financial aid has a positive and significant effect on first-year collegiate grade point…

  17. Intellectual Curiosity in Action: A Framework to Assess First-Year Seminars in Liberal Arts Settings

    ERIC Educational Resources Information Center

    Kolb, Kenneth H.; Longest, Kyle C.; Barnett, Jenna C.

    2014-01-01

    Fostering students' intellectual curiosity is a common goal of first-year seminar programs--especially in liberal arts settings. The authors propose an alternative method to assess this ambiguous, value-laden concept. Relying on data gathered from pre- and posttest in-depth interviews of 34 students enrolled in first-year seminars, they construct…

  18. Challenging the First Year of College: Old Models and New Imperatives

    ERIC Educational Resources Information Center

    Mills, Shala A.; Mehaffy, George L.

    2016-01-01

    This chapter argues that the first year of college needs to be reconsidered. The authors offer, as an alternative, a new kind of course, one created by groups of faculty members from different campuses, multidisciplinary in focus, delivered in a blended format, focused on civic outcomes, and intended primarily for first-year students.

  19. "MathePraxis"--Connecting First-Year Mathematics with Engineering Applications

    ERIC Educational Resources Information Center

    Harterich, Jorg; Kiss, Christine; Rooch, Aeneas; Monnigmann, Martin; Darup, Moritz Schulze; Span, Roland

    2012-01-01

    First-year engineering students often complain about their mathematics courses as the significance of the difficult and abstract calculus to their field of study remains unclear. We report on the project "MathePraxis", a feasibility study which was designed as a means to give first-year students some impression about the use of…

  20. How Do Beginning Administrators Navigate through Their First Year of the Middle School Principalship?

    ERIC Educational Resources Information Center

    Cryer, James D.

    2009-01-01

    In an effort to understand the positive and negative experiences that principals encounter as they navigate through their first year of administrative duties at the middle school level, this research study examined what events happened during their first year that encouraged the individual to stay in the position or discouraged the individual to…

  1. Institutional Factors That Positively Impact First-Year Students' Sense of Well-Being

    ERIC Educational Resources Information Center

    Harmening, Debra S.; Jacob, Stacy A.

    2015-01-01

    This qualitative case study conducted at a single institution in the Midwest examines how institutional context and environment impact college students' sense of well-being. Twenty-seven first-year students participated in one to two hour, in-depth interviews where they talked about their first-year experiences, their concepts of well-being, and…

  2. Reinventing First-Year Composition at the First Land-Grant University: A Cautionary Tale.

    ERIC Educational Resources Information Center

    Graham, Margaret Baker; Birmingham, Elizabeth; Zachry, Mark

    1997-01-01

    Examines the restructuring of first-year composition at Iowa State University. Discusses the exodus of tenure-track faculty from first-year composition in the late 1970's and early 1980's; why upper administration is now mandating tenure-track faculty's return; why the department of English is cooperating; and potential risks in cooperating or not…

  3. Stand age affects fertilizer nitrogen response in first-year corn following alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amount of N that alfalfa (Medicago sativa L.) provides to subsequent first-year corn (Zea mays L.) depends, in part, on the age of alfalfa at termination. Our objective was to determine how alfalfa stand age affects N availability and fertilizer N requirements for first-year corn. Fertilizer N w...

  4. The Impact of Mentor Leadership Styles on First-Year Adult Student Retention

    ERIC Educational Resources Information Center

    Smith Staley, Charlesetta

    2012-01-01

    This quantitative study explored the leadership styles of mentors for retained first-year adult students to analyze whether the prevalent style had a higher impact on first-year adult student retention. The Multifactor Leadership Questionnaire (MLQ) 5x was used to collect data on the mentors' leadership styles from the perspective of retained…

  5. Novices "In Story": What First-Year Teachers' Narratives Reveal about the Shady Corners of Teaching

    ERIC Educational Resources Information Center

    Orland-Barak, Lily; Maskit, Ditza

    2011-01-01

    In a national contest of story writing in Israel, first-year teachers from all educational sectors were invited to write a story that mirrors their first year of teaching experience. The narrative analysis of the stories sheds light on the hostile and adverse sides of teaching, surfacing novices' sense of impotence in their capacity to act. The…

  6. Making the Grade: Understanding Learning and Grade Orientations of First-Year Students

    ERIC Educational Resources Information Center

    Purcell, Jennifer M.

    2009-01-01

    First-year undergraduate students enter college with varying expectations, motivations, and goals and are being bombarded with messages about the importance of grades, sometimes to the detriment of learning. This descriptive, cross-sectional study employs LOGO II to describe the learning and grade orientations of first-year students and identify…

  7. One-Year Prevalence Rates of Major Depressive Disorder in First-Year University Students

    ERIC Educational Resources Information Center

    Price, E. Lisa; McLeod, Peter J.; Gleich, Stephen S.; Hand, Denise

    2006-01-01

    First-year university students may be more at risk for experiencing Major Depressive Disorder (MDD) than the general population given associated risk factors of this age range. A two-phase procedure was used to estimate the one-year prevalence rate of MDD and comorbid Major Anxiety Disorders among first-year university students at a small Canadian…

  8. An Investigation into the Understanding and Skills of First-Year Electrical Engineering Students

    ERIC Educational Resources Information Center

    Smaill, C. R.; Rowe, G. B.; Godfrey, E.; Paton, R. O.

    2012-01-01

    In response to demands from industry and the profession for more graduates, first-year engineering numbers have grown considerably over the last decade, matched by an increasing diversity of academic backgrounds. In order to support first-year students effectively, and ensure the courses they take remain appropriately pitched, the academic…

  9. Students with Autism Spectrum Disorders (ASD): The First-Year Postsecondary Educational Experience

    ERIC Educational Resources Information Center

    Shook Torres, Elizabeth

    2014-01-01

    This study utilized a qualitative case study interview methodology to explore the transition to postsecondary education and first-year postsecondary educational experiences of four students with Autism Spectrum Disorders (ASD). This research provided a comprehensive understanding of the first-year postsecondary educational experience of the…

  10. "Freeing Students to Do Their Best": Examining Writing in First-Year Seminars

    ERIC Educational Resources Information Center

    Thaiss, Chris; Moloney, Kara; Chaozon-Bauer, Pearl

    2016-01-01

    First-Year Seminars (FYS) are among the high-impact practices described by AAC&U. We studied the long-standing First-Year Seminar Program at our public research university for the ways in which writing assignments--individualized for each seminar--help faculty and students achieve program objectives in critical and analytical thinking, the…

  11. Engaging with Higher Education Academic Support: A First Year Student Teacher Transition Model

    ERIC Educational Resources Information Center

    Penn-Edwards, Sorrel; Donnison, Sharn

    2011-01-01

    The need for a redefinition of first year experience in higher education is advocated with the aid of two models, which, although focused on a sample of Australian pre-service teaching students, is proposed as generalisable across the first year. Introduction to the mores of higher education is generally supported by teaching institutions during…

  12. Developing the Inner Teacher: Guiding the Reflective Practice of First Year Preservice Teachers

    ERIC Educational Resources Information Center

    Penn-Edwards, Sorrel; Donnison, Sharn; Albion, Lisa

    2016-01-01

    First year Australian Initial Teacher Education students are at a high risk of not completing their studies, particularly in the transition into their tertiary studies in first year, and then if achieving graduation, many are likely to leave the profession in the early years. While the reasons vary, it is known that early departure from a career…

  13. Peer Mentoring to Develop Psychological Literacy in First-Year and Graduating Students

    ERIC Educational Resources Information Center

    Burton, Lorelle J.; Chester, Andrea; Xenos, Sophie; Elgar, Karen

    2013-01-01

    First- and final-year undergraduate students have unique transition issues. To support both the transition of first-year students into the program, and the transition of third-year students out of the program and into the workforce or further study, a face-to-face peer mentoring program was embedded into the first-year psychology curricula at RMIT…

  14. A Study of the Mentoring Program for First Year School Superintendents in Missouri

    ERIC Educational Resources Information Center

    Woolsey, Tina

    2013-01-01

    Mentoring first-year superintendents in Missouri began as an informal process with the pairing of a veteran superintendent (mentor) with a first-year superintendent (protege) by the Missouri Association of School Administrators (MASA). The adoption of the Career Continuous Professional Certification by the Missouri State Board of Education…

  15. The Readiness of High School Students to Pursue First Year Physics

    ERIC Educational Resources Information Center

    Ramnarain, U.; Molefe, P.

    2012-01-01

    A high failure rate at first year physics is often attributed to the lack of readiness of high school students to pursue such studies. This research explores this issue and reports on the perceptions of five physics lecturers at a South African university on the preparedness of high school students for first year physics. Qualitative data was…

  16. First-Year College Students' Strengths Awareness and Perceived Leadership Development

    ERIC Educational Resources Information Center

    Soria, Krista M.; Roberts, Julia E.; Reinhard, Alex P.

    2015-01-01

    The purpose of this study was to examine whether first-year college students' strengths awareness is associated with their perceived leadership development. The institution in this study offered all first-year students the Clifton StrengthsFinder assessment and strengths-related programming. The results of hierarchical regression analysis of two…

  17. Adjustment to College in Nonresidential First-Year Students: The Roles of Stress, Family, and Coping

    ERIC Educational Resources Information Center

    Gefen, Dalia R.; Fish, Marian C.

    2013-01-01

    This study explored factors related to college adjustment in nonresidential first-year students. It was hypothesized that stress, family functioning, and coping strategies would predict academic, personal-emotional, and social adjustment in addition to institutional attachment. The sample comprised 167 first-year college students (ages 18-23)…

  18. 2006 National Survey of First-Year Seminars: Continuing Innovations in the Collegiate Curriculum. The First-Year Experience Monograph Series No. 51

    ERIC Educational Resources Information Center

    Tobolowsky, Barbara F.

    2008-01-01

    Since 1988, the National Resource Center has conducted a national survey every three years to gather information about the nature and extent of first-year seminars on American college campuses. The findings from the 2006 survey administration have been reorganized to make it easier to find information of interest with major chapters focusing on…

  19. Fulfilling the Promise of the Community College: Increasing First-Year Student Engagement and Success. The First-Year Experience Monograph Series Number 56

    ERIC Educational Resources Information Center

    Brown, Thomas, Ed.; King, Margaret C., Ed.; Stanley, Patricia, Ed.

    2011-01-01

    For the past three decades, American higher education has paid increasing attention to the beginning college experience--to ensuring that entering students make a successful transition to college. Yet, much of the extant research and practice literature focuses on the experience of first-year students entering four-year colleges and universities.…

  20. Using Hybridization and Specialization to Enhance the First-Year Experience in Community Colleges: A National Picture of High-Impact Practices in First-Year Seminars

    ERIC Educational Resources Information Center

    Young, Dallin George; Keup, Jennifer R.

    2016-01-01

    This chapter draws from national data to explore unique attributes of first-year seminars in community college contexts as well as high-impact practices that are often connected to them. Findings point to areas of opportunity for practice and directions for future research to better understand how community colleges can be poised to meet the…

  1. The 2003 National Survey of First-Year Seminars: Continuing Innovations in the Collegiate Curriculum. The First-Year Experience Monograph Series No. 41

    ERIC Educational Resources Information Center

    Tobolowsky, Barbara F.

    2005-01-01

    This volume reports on the sixth triennial National Survey of First-Year Seminar. Data from more than 600 colleges and universities are analyzed to offer information on the structure, content, and administration of these courses. Changes to the survey capture new information on innovative course practices including using undergraduates as…

  2. A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students

    PubMed Central

    Jordan, Tuajuanda C.; Burnett, Sandra H.; Carson, Susan; Caruso, Steven M.; Clase, Kari; DeJong, Randall J.; Dennehy, John J.; Denver, Dee R.; Dunbar, David; Elgin, Sarah C. R.; Findley, Ann M.; Gissendanner, Chris R.; Golebiewska, Urszula P.; Guild, Nancy; Hartzog, Grant A.; Grillo, Wendy H.; Hollowell, Gail P.; Hughes, Lee E.; Johnson, Allison; King, Rodney A.; Lewis, Lynn O.; Li, Wei; Rosenzweig, Frank; Rubin, Michael R.; Saha, Margaret S.; Sandoz, James; Shaffer, Christopher D.; Taylor, Barbara; Temple, Louise; Vazquez, Edwin; Ware, Vassie C.; Barker, Lucia P.; Bradley, Kevin W.; Jacobs-Sera, Deborah; Pope, Welkin H.; Russell, Daniel A.; Cresawn, Steven G.; Lopatto, David; Bailey, Cheryl P.; Hatfull, Graham F.

    2014-01-01

    ABSTRACT Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates students’ interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training. PMID:24496795

  3. Degenerate Fermi gas perturbations at standard background cosmology

    SciTech Connect

    Bernardini, A.E.; Perico, E.L.D. E-mail: elduarte@ifi.unicamp.br

    2011-01-01

    The hypothesis of a tiny fraction of the cosmic inventory evolving cosmologically as a degenerate Fermi gas test fluid at some dominant cosmological background is investigated. Our analytical results allow for performing preliminary computations to the evolution of perturbations for relativistic and non-relativistic test fluids. The density fluctuation, δ, the fluid velocity divergence, θ, and an explicit expression for the dynamics of the shear stress, σ, are obtained for a degenerate Fermi gas in the background regime of radiation. Extensions to the dominance of matter and to the ΛCDM cosmological background are also investigated and lessons concerning the formation of large structures of degenerate Fermi gas are depicted.

  4. FermiGrid - experience and future plans

    SciTech Connect

    Chadwick, K.; Berman, E.; Canal, P.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Timm, S.; Yocum, D.; /Fermilab

    2007-09-01

    Fermilab supports a scientific program that includes experiments and scientists located across the globe. In order to better serve this community, Fermilab has placed its production computer resources in a Campus Grid infrastructure called 'FermiGrid'. The FermiGrid infrastructure allows the large experiments at Fermilab to have priority access to their own resources, enables sharing of these resources in an opportunistic fashion, and movement of work (jobs, data) between the Campus Grid and National Grids such as Open Science Grid and the WLCG. FermiGrid resources support multiple Virtual Organizations (VOs), including VOs from the Open Science Grid (OSG), EGEE and the Worldwide LHC Computing Grid Collaboration (WLCG). Fermilab also makes leading contributions to the Open Science Grid in the areas of accounting, batch computing, grid security, job management, resource selection, site infrastructure, storage management, and VO services. Through the FermiGrid interfaces, authenticated and authorized VOs and individuals may access our core grid services, the 10,000+ Fermilab resident CPUs, near-petabyte (including CMS) online disk pools and the multi-petabyte Fermilab Mass Storage System. These core grid services include a site wide Globus gatekeeper, VO management services for several VOs, Fermilab site authorization services, grid user mapping services, as well as job accounting and monitoring, resource selection and data movement services. Access to these services is via standard and well-supported grid interfaces. We will report on the user experience of using the FermiGrid campus infrastructure interfaced to a national cyberinfrastructure--the successes and the problems.

  5. FERMI-LAT Observations of Galatic Transients

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2010-01-01

    This slide presentation reviews the use of the Large Area Telescope on the Fermi Observatory observations of Galactic Transients. LAT all-sky monitoring is producing spectacular results for the GeV transient sky: (1) New blazars and unidentified transients (2) Probing the jet of the Cygnus X-3 microquasar (3) Discovery of gamma rays from V407 Cygni nova (4) Fast high-energy gamma-ray flares from the Crab Nebula.

  6. Becoming a science teacher: First year teachers' approaches to learning about teaching

    NASA Astrophysics Data System (ADS)

    Loughran, John

    1992-12-01

    This paper discusses some of the issues arising from the first year of a longitudinal study into the career development of science teachers. It deals with the influences on, and approaches to, teaching by first year science teachers. Eighteen science graduates who had completed a Diploma in Education in 1990, were interviewed about their first year's teaching experiences. The participants explored issues ranging from the influences on their approach to teaching, student learning, determinants of a good lesson, the role of pre-service teacher training, and teaching as a career.

  7. A Dual-Process Examination of Alcohol-Related Consequences Among First-Year College Students

    PubMed Central

    Mallett, Kimberly A.; Turrisi, Rob; Cleveland, Michael J.; Scaglione, Nichole M.; Reavy, Racheal; Sell, Nichole M.; Varvil-Weld, Lindsey

    2015-01-01

    Objective: Despite showing reductions in college student drinking, interventions have shown some inconsistency in their ability to successfully decrease consequences. With the goal of improving prevention efforts, the purpose of this study was to examine the role of consequence-specific constructs, in addition to drinking, that influence students’ experiences with alcohol-related problems. The study examined how drinking and protective behaviors mediated the relationships between students’ willingness to experience consequences, intentions to avoid them, and four categories of alcohol-related problems (physiological, social, sexual, and academic). Method: First-year college student drinkers (n = 2,024) at a large northeastern university completed surveys during the fall and spring of their freshman year. Results: As expected, different patterns of associations emerged for physiological and nonphysiological consequences. When physiological consequences (e.g., hangover, vomiting) were examined, drinking significantly mediated the effect of willingness on the consequences. Drinking-specific protective behaviors indirectly influenced consequences through drinking behaviors whereas general protective behaviors did not. When nonphysiological (e.g., social, sexual, academic) consequences were examined, drinking and general protective behaviors emerged as significant mediators of the effects of willingness and intentions on the consequences, whereas drinking-specific protective behaviors did not. Conclusions: The results suggest that prevention efforts (e.g., personalized feedback) could be tailored to address specific types of protective behaviors as well as specific types of consequences frequently experienced by college students. PMID:26562594

  8. Psychological and sociocultural adjustment of first-year international students: Trajectories and predictors.

    PubMed

    Hirai, Reiko; Frazier, Patricia; Syed, Moin

    2015-07-01

    Despite the increasing number of international students in U.S. universities, the temporal course of international students' adjustment has not been adequately tested, and only 1 study to date has examined multiple trajectories of adjustment. Therefore, the first goal of the current study was to explore multiple trajectories of adjustment among first-year international students using a broader range of adjustment measures (i.e., psychological distress, positive psychological adjustment, sociocultural adjustment). The second goal was to identify important predictors of trajectories. A wide range of individual and interpersonal predictor variables was examined, including academic stress and perceived control over academic stress, personality, social relationships, and language-related factors. Undergraduate and graduate international students in their first semester at a large midwestern university participated in this 5-wave longitudinal study (N = 248) that spanned 1 academic year. Multiple trajectories emerged, and the trajectories varied across the 3 adjustment measures. Average trajectories masked the trajectories of small groups of students who maintained or increased in terms of adjustment difficulties across outcomes. Contrary to popular theories, the U-shape adjustment trajectory (characterized by initial euphoria, distress, and then recovery) did not emerge. The most consistent predictors of adjustment trajectories were perceived present control over academic stress and Neuroticism.

  9. Dietary changes and food intake in the first year after breast cancer treatment.

    PubMed

    Vance, Vivienne; Campbell, Sharon; McCargar, Linda; Mourtzakis, Marina; Hanning, Rhona

    2014-06-01

    Understanding dietary habits of women after breast cancer is a critical first step in developing nutrition guidelines that will support weight management and optimal health in survivorship; however, limited data are available. The objective of this study was to describe changes in diet among breast cancer survivors in the first year after treatment, and to evaluate these changes in the context of current dietary intake. Changes in diet were assessed in 28 early stage breast cancer survivors, using a self-reported survey in which women identified changes in food intake since their diagnosis. Current dietary intake was estimated from 3-day food records and described relative to current recommendations. The majority of women reported changes in diet after diagnosis, most common being an increase in vegetables/fruit and fish, lower intake of red meat, and reduced alcohol. Many women reported that these changes were initiated during active treatment. Dietary changes were largely consistent with current recommendations for cancer prevention; however, some women were still above the guidelines for total and saturated fat, and many were below recommendations for vegetables/fruit, milk/alternatives, calcium, and vitamin D. Evidence that some women are willing and able to initiate positive changes in diet early in the treatment trajectory suggests that early intervention may be effective in promoting dietary habits that will assist with weight management and overall health. Data on current dietary intake highlights several possible targets for dietary intervention in this population.

  10. OzDES multifibre spectroscopy for the Dark Energy Survey: first-year operation and results

    NASA Astrophysics Data System (ADS)

    Yuan, Fang; Lidman, C.; Davis, T. M.; Childress, M.; Abdalla, F. B.; Banerji, M.; Buckley-Geer, E.; Carnero Rosell, A.; Carollo, D.; Castander, F. J.; D'Andrea, C. B.; Diehl, H. T.; Cunha, C. E.; Foley, R. J.; Frieman, J.; Glazebrook, K.; Gschwend, J.; Hinton, S.; Jouvel, S.; Kessler, R.; Kim, A. G.; King, A. L.; Kuehn, K.; Kuhlmann, S.; Lewis, G. F.; Lin, H.; Martini, P.; McMahon, R. G.; Mould, J.; Nichol, R. C.; Norris, R. P.; O'Neill, C. R.; Ostrovski, F.; Papadopoulos, A.; Parkinson, D.; Reed, S.; Romer, A. K.; Rooney, P. J.; Rozo, E.; Rykoff, E. S.; Sako, M.; Scalzo, R.; Schmidt, B. P.; Scolnic, D.; Seymour, N.; Sharp, R.; Sobreira, F.; Sullivan, M.; Thomas, R. C.; Tucker, D.; Uddin, S. A.; Wechsler, R. H.; Wester, W.; Wilcox, H.; Zhang, B.; Abbott, T.; Allam, S.; Bauer, A. H.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Burke, D. L.; Carrasco Kind, M.; Covarrubias, R.; Crocce, M.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Maia, M. A. G.; Makler, M.; Marshall, J.; Miller, C. J.; Miquel, R.; Ogando, R.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Walker, A. R.

    2015-09-01

    The Australian Dark Energy Survey (OzDES) is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim is to measure redshifts of approximately 2500 Type Ia supernovae host galaxies over the redshift range 0.1 < z < 1.2, and derive reverberation-mapped black hole masses for approximately 500 active galactic nuclei and quasars over 0.3 < z < 4.5. This treasure trove of data forms a major part of the spectroscopic follow-up for the Dark Energy Survey for which we are also targeting cluster galaxies, radio galaxies, strong lenses, and unidentified transients, as well as measuring luminous red galaxies and emission line galaxies to help calibrate photometric redshifts. Here, we present an overview of the OzDES programme and our first-year results. Between 2012 December and 2013 December, we observed over 10 000 objects and measured more than 6 000 redshifts. Our strategy of retargeting faint objects across many observing runs has allowed us to measure redshifts for galaxies as faint as mr = 25 mag. We outline our target selection and observing strategy, quantify the redshift success rate for different types of targets, and discuss the implications for our main science goals. Finally, we highlight a few interesting objects as examples of the fortuitous yet not totally unexpected discoveries that can come from such a large spectroscopic survey.

  11. A Person-Centered Approach to Understanding Negative Reinforcement Drinking Among First Year College Students

    PubMed Central

    Holt, Laura J.; Armeli, Stephen; Tennen, Howard; Austad, Carol S.; Raskin, Sarah A.; Fallahi, Carolyn R.; Wood, Rebecca; Rosen, Rivkah I.; Ginley, Meredith K.; Pearlson, Godfrey D.

    2016-01-01

    The current study used a person-centered approach (i.e. latent class analysis) to identify distinct types of college student drinkers based on the predictions of motivational, social learning, and stress and coping theories of maladaptive drinking. A large sample (N=844; 53% female) of first-year undergraduates from two institutions, public and private, who reported consuming one or more drinks in the last three months completed measures of depression, anxiety, positive alcohol-outcome expectancies, negative life events, social support, drinking motives, drinking level and drinking-related problems. Latent class analysis revealed a small subgroup of individuals (n=81, 9%) who conformed to the anticipated high risk profile; specifically, this group demonstrated high levels of negative affect, coping motives, alcohol consumption and drinking-related problems. However, additional groups emerged that showed patterns inconsistent with the proposed vulnerability profile (e.g., high negative affect, positive expectancies, and life stress, but relatively low drinking levels). Findings from our person-centered approach showing the presence of groups both consistent and inconsistent with the predictions of motivational, social learning, and stress and coping theories highlight the need to identify and target certain college students for prevention and intervention of negative affect-related drinking. PMID:24064193

  12. OzDES multifibre spectroscopy for the Dark Energy Survey: First-year operation and results

    SciTech Connect

    Yuan, Fang

    2015-07-29

    The Australian Dark Energy Survey (OzDES) is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim is to measure redshifts of approximately 2500 Type Ia supernovae host galaxies over the redshift range 0.1 < z < 1.2, and derive reverberation-mapped black hole masses for approximately 500 active galactic nuclei and quasars over 0.3 < z < 4.5. This treasure trove of data forms a major part of the spectroscopic follow-up for the Dark Energy Survey for which we are also targeting cluster galaxies, radio galaxies, strong lenses, and unidentified transients, as well as measuring luminous red galaxies and emission line galaxies to help calibrate photometric redshifts. Here, we present an overview of the OzDES programme and our first-year results. Between 2012 December and 2013 December, we observed over 10 000 objects and measured more than 6 000 redshifts. Our strategy of retargeting faint objects across many observing runs has allowed us to measure redshifts for galaxies as faint as mr = 25 mag. We outline our target selection and observing strategy, quantify the redshift success rate for different types of targets, and discuss the implications for our main science goals. In conclusion, we highlight a few interesting objects as examples of the fortuitous yet not totally unexpected discoveries that can come from such a large spectroscopic survey.

  13. Targeting Critical Thinking Skills in a First-Year Undergraduate Research Course †

    PubMed Central

    Carson, Susan

    2015-01-01

    TH!NK is a new initiative at NC State University focused on enhancing students’ higher-order cognitive skills. As part of this initiative, I explicitly emphasized critical and creative thinking in an existing bacteriophage discovery first-year research course. In addition to the typical activities associated with undergraduate research such as review of primary literature and writing research papers, another strategy employed to enhance students’ critical thinking skills was the use of discipline-specific, real-world scenarios. This paper outlines a general “formula” for writing scenarios, as well as several specific scenarios created for the described course. I also present how embedding aspects of the scenarios in reviews of the primary literature enriched the activity. I assessed student gains in critical thinking skills using a pre-/posttest model of the Critical Thinking Assessment Test (CAT), developed by Tennessee Technological University. I observed a positive gain trend in most of the individual skills assessed in the CAT, with a statistically significant large effect on critical thinking skills overall in students in the test group. I also show that a higher level of critical thinking skills was demonstrated in research papers written by students who participated in the scenarios compared with similar students who did not participate in the scenario activities. The scenario strategy described here can be modified for use in biology and other STEM disciplines, as well as in diverse disciplines in the social sciences and humanities. PMID:26753022

  14. OzDES multifibre spectroscopy for the Dark Energy Survey: First-year operation and results

    DOE PAGES

    Yuan, Fang

    2015-07-29

    The Australian Dark Energy Survey (OzDES) is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim is to measure redshifts of approximately 2500 Type Ia supernovae host galaxies over the redshift range 0.1 < z < 1.2, and derive reverberation-mapped black hole masses for approximately 500 active galactic nuclei and quasars over 0.3 < z < 4.5. This treasure trove of data forms a major part of the spectroscopic follow-up for the Dark Energy Survey for which we are also targeting cluster galaxies, radio galaxies, strong lenses, and unidentified transients, as well as measuring luminous red galaxiesmore » and emission line galaxies to help calibrate photometric redshifts. Here, we present an overview of the OzDES programme and our first-year results. Between 2012 December and 2013 December, we observed over 10 000 objects and measured more than 6 000 redshifts. Our strategy of retargeting faint objects across many observing runs has allowed us to measure redshifts for galaxies as faint as mr = 25 mag. We outline our target selection and observing strategy, quantify the redshift success rate for different types of targets, and discuss the implications for our main science goals. In conclusion, we highlight a few interesting objects as examples of the fortuitous yet not totally unexpected discoveries that can come from such a large spectroscopic survey.« less

  15. Interprofessional education for first year psychology students: career plans, perceived relevance and attitudes.

    PubMed

    Roberts, Lynne D; Forman, Dawn

    2015-05-01

    Undergraduate psychology students have been largely excluded from interprofessional education (IPE) initiatives. In contrast to many health professions, undergraduate psychology students do not engage in work placements as part of their degree, and many enter careers outside the health care context. However, the collaborative skills gained through an IPE experience may well be beneficial to students who work in this wider context. This research examines whether undergraduate psychology students' views of IPE vary according to their planned career directions, and if so, whether the perceived relevance of IPE mediates the relationships. A sample of 188 Australian university undergraduate psychology students completed an online questionnaire following completion of a first-year IPE health sciences program. Path analysis indicated that psychology students' attitudes towards IPE are associated with both professional identification and practitioner orientation, fully mediated through the perceived relevance of IPE to future career and study plans. Stronger professional identification and practitioner orientation were associated with greater perceived relevance and more positive and less negative attitudes towards IPE. Placing a stronger emphasis on the generalizability of IP skills taught may increase students' awareness of the relevance outside of the health context, reducing disengagement of students planning alternative careers.

  16. Targeting Critical Thinking Skills in a First-Year Undergraduate Research Course.

    PubMed

    Carson, Susan

    2015-12-01

    TH!NK is a new initiative at NC State University focused on enhancing students' higher-order cognitive skills. As part of this initiative, I explicitly emphasized critical and creative thinking in an existing bacteriophage discovery first-year research course. In addition to the typical activities associated with undergraduate research such as review of primary literature and writing research papers, another strategy employed to enhance students' critical thinking skills was the use of discipline-specific, real-world scenarios. This paper outlines a general "formula" for writing scenarios, as well as several specific scenarios created for the described course. I also present how embedding aspects of the scenarios in reviews of the primary literature enriched the activity. I assessed student gains in critical thinking skills using a pre-/posttest model of the Critical Thinking Assessment Test (CAT), developed by Tennessee Technological University. I observed a positive gain trend in most of the individual skills assessed in the CAT, with a statistically significant large effect on critical thinking skills overall in students in the test group. I also show that a higher level of critical thinking skills was demonstrated in research papers written by students who participated in the scenarios compared with similar students who did not participate in the scenario activities. The scenario strategy described here can be modified for use in biology and other STEM disciplines, as well as in diverse disciplines in the social sciences and humanities.

  17. A person-centered approach to understanding negative reinforcement drinking among first year college students.

    PubMed

    Holt, Laura J; Armeli, Stephen; Tennen, Howard; Austad, Carol S; Raskin, Sarah A; Fallahi, Carolyn R; Wood, Rebecca; Rosen, Rivkah I; Ginley, Meredith K; Pearlson, Godfrey D

    2013-12-01

    The current study used a person-centered approach (i.e. latent profile analysis) to identify distinct types of college student drinkers based on the predictions of motivational, social learning, and stress and coping theories of maladaptive drinking. A large sample (N=844; 53% female) of first-year undergraduates from two institutions, public and private, who reported consuming one or more drinks in the last three months completed measures of depressive and anxiety symptoms, positive alcohol-outcome expectancies, negative life events, social support, drinking motives, drinking level and drinking-related problems. Latent profile analysis revealed a small subgroup of individuals (n=81, 9%) who conformed to the anticipated high-risk profile; specifically, this group demonstrated high levels of negative affect, coping motives, drinks per week, and drinking-related problems. However, additional groups emerged that showed patterns inconsistent with the proposed vulnerability profile (e.g., high negative affect, positive expectancies, and negative life events, but relatively low drinking levels). Findings from our person-centered approach showing the presence of groups both consistent and inconsistent with the predictions of motivational, social learning, and stress and coping theories highlight the need to identify and target certain college students for prevention and intervention of negative affect-related drinking.

  18. The Fermi Paradox Is Neither Fermi's Nor a Paradox

    NASA Astrophysics Data System (ADS)

    Gray, Robert H.

    2015-03-01

    The so-called Fermi paradox claims that if technological life existed anywhere else, we would see evidence of its visits to Earth-and since we do not, such life does not exist, or some special explanation is needed. Enrico Fermi, however, never published anything on this topic. On the one occasion he is known to have mentioned it, he asked 'where is everybody?'- apparently suggesting that we don't see extraterrestrials on Earth because interstellar travel may not be feasible, but not suggesting that intelligent extraterrestrial life does not exist, or suggesting its absence is paradoxical. The claim 'they are not here; therefore they do not exist' was first published by Michael Hart, claiming that interstellar travel and colonization of the galaxy would be inevitable if intelligent extraterrestrial life existed, and taking its absence here as proof that it does not exist anywhere. The Fermi paradox appears to originate in Hart's argument, not Fermi's question. Clarifying the origin of these ideas is important, because the Fermi paradox is seen by some as an authoritative objection to searching for evidence of extraterrestrial intelligence-cited in the U. S. Congress as a reason for killing NASA's SETI program on one occasion-but evidence indicates that it misrepresents Fermi's views, misappropriates his authority, deprives the actual authors of credit, and is not a valid paradox. Keywords: Astrobiology, SETI, Fermi paradox, extraterrestrial life

  19. Photochemical Reactions of Tris (Oxalato) Iron (III): A First-Year Chemistry Experiment.

    ERIC Educational Resources Information Center

    Baker, A. D.; And Others

    1980-01-01

    Describes a first-year chemistry experiment that illustrates the fundamental concepts of a photoinduced reaction. Qualitative and quantitative parts of the photoreduction of potassium ferrioxalate are detailed. (CS)

  20. New Frontiers for Student Affairs Professionals: Teaching and the First-Year Experience

    ERIC Educational Resources Information Center

    Hunter, Mary Stuart; Murray, Kathleen A.

    2007-01-01

    The first-year experience movement opens a window of opportunity for student affairs professionals to extend their educational endeavors into the classroom, thus allowing entrance into segments of campus once reserved exclusively for faculty.