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• 1.
University of Kalmar, School of Pure and Applied Natural Sciences.
Vill kunder handla receptfria läkemedel i dagligvaruhandeln?: - En enkätundersökning2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpStudent thesis

Sammanfattning

I Sverige har det statliga apoteketsmonopolet ifrågasatts en längre tid och regeringen utreder nu möjligheten att konkurrensutsätta läkemedelsförsäljningen. Det har även föreslagits i den statliga utredningen (SOU 2008:4 del 2) att ett begränsat sortiment av OTC läkemedel (over the counter = receptfria läkemedel) ska få säljas i dagligvaruhandeln utan farmaceutiskt kompetenskrav. Vid korrekt användning och tillgång till rätt rådgivning kan OTC läkemedel vara till en stor hjälp för den enskilde individen vid egenvård och därigenom också bidra till avlastning på sjukvårdens resursers. Vid felanvändning av OTC läkemedel (över/underdosering, fel indikationsområde etc.), kan de istället få motsatt effekt. Syftet med denna enkätstudie var därför att utforska om konsumenter av OTC läkemedel i Sverige önskar få tillgång till dessa läkemedel i t ex livsmedelsbutiker, där de inte har tillgång till personlig farmaceutisk rådgivning, vidare var avsikten att undersöka hur de i dagligvaruhandeln önskade få läkemedelsinformation. I februari 2008 gjordes en enkätstudie i Västervik som inkluderade 48 deltagare varav 29 kvinnor och 19 män. Studien visade att 71 % av deltagarna hade en positiv inställning till att köpa OTC läkemedel i livsmedelsbutiker, 58 % skulle skaffa information genom läkemedelsförpackning och bipacksedel i kombination med att de tidigare använt läkemedlet. Önskan om tillgång till personlig rådgivning på inköpsstället var störst i åldern ≤ 35 år, där 38 % ansåg sig vilja det. Slutsats av studien är att majoriteten vill kunna handla OTC läkemedel i dagligvaruhandeln och information skulle de få främst från läkemedelsförpackning/bipacksedel i kombination med erfarenheter från tidigare användning.

2008:F5

• 2. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
SEARCH FOR HIGH-ENERGY MUON NEUTRINOS FROM THE "NAKED-EYE" GRB 080319B WITH THE IceCube NEUTRINO TELESCOPE2009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 701, no 2, p. 1721-1731Article in journal (Refereed)

We report on a search with the IceCube detector for high-energy muon neutrinos from GRB 080319B, one of the brightest gamma-ray bursts (GRBs) ever observed. The fireball model predicts that a mean of 0.1 events should be detected by IceCube for a bulk Lorentz boost of the jet of 300. In both the direct on-time window of 66 s and an extended window of about 300 s around the GRB, no excess was found above background. The 90% CL upper limit on the number of track-like events from the GRB is 2.7, corresponding to a muon neutrino fluence limit of 9.5 x 10(-3) erg cm(-2) in the energy range between 120 TeV and 2.2 PeV, which contains 90% of the expected events.

• 3. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
Extending the Search for Neutrino Point Sources with IceCube above the Horizon2009In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 103, no 22, p. Article ID: 221102-Article in journal (Refereed)

Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

• 4. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
First Neutrino Point-Source Results from the 22 String Icecube Detector2009In: The Astrophysical Journal Letters, ISSN 2041-8205, Vol. 701, no 1, p. L47-L51Article in journal (Refereed)

We present new results of searches for neutrino point sources in the northern sky, using data recorded in 2007-2008 with 22 strings of the IceCube detector (approximately one-fourth of the planned total) and 275.7 days of live time. The final sample of 5114 neutrino candidate events agrees well with the expected background of atmospheric muon neutrinos and a small component of atmospheric muons. No evidence of a point source is found, with the most significant excess of events in the sky at 2.2Ïƒ after accounting for all trials. The average upper limit over the northern sky for point sources of muon-neutrinos with E â€“2 spectrum is ##IMG## [http://ej.iop.org/images/1538-4357/701/1/L47/apjl318527ieqn1.gif] $E^2\,Φ _ν _μ < 1.4 \,\,\times\,\, 10^-11\; \mathrmTeV\;cm^-2\;\mathrms^-1$ , in the energy range from 3Â TeV to 3Â PeV, improving the previous best average upper limit by the AMANDA-II detector by a factor of 2.

• 5. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
Limits on a Muon Flux from Neutralino Annihilations in the Sun with the IceCube 22-String Detector2009In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, no 20, p. Article ID: 201302-Article in journal (Refereed)

A search for muon neutrinos from neutralino annihilations in the Sun has been performed with the IceCube 22-string neutrino detector using data collected in 104.3 days of live time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the weakly interacting massive particle (WIMP) proton cross sections for WIMP masses in the range 250-5000 GeV. These results are the most stringent limits to date on neutralino annihilation in the Sun.

• 6. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
Determination of the atmospheric neutrino flux and searches for new physics with AMANDA-II2009In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 79, no 10, p. Article ID: 102005-Article in journal (Refereed)

The AMANDA-II detector, operating since 2000 in the deep ice at the geographic South Pole, has accumulated a large sample of atmospheric muon neutrinos in the 100 GeV to 10 TeV energy range. The zenith angle and energy distribution of these events can be used to search for various phenomenological signatures of quantum gravity in the neutrino sector, such as violation of Lorentz invariance or quantum decoherence. Analyzing a set of 5511 candidate neutrino events collected during 1387 days of livetime from 2000 to 2006, we find no evidence for such effects and set upper limits on violation of Lorentz invariance and quantum decoherence parameters using a maximum likelihood method. Given the absence of evidence for new flavor-changing physics, we use the same methodology to determine the conventional atmospheric muon neutrino flux above 100 GeV.

• 7. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
Search for point sources of high energy neutrinos with final data from AMANDA-II2009In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 79, no 6, p. Article ID: 062001-Article in journal (Refereed)

We present a search for point sources of high energy neutrinos using 3.8 yr of data recorded by AMANDA-II during 2000-2006. After reconstructing muon tracks and applying selection criteria designed to optimally retain neutrino-induced events originating in the northern sky, we arrive at a sample of 6595 candidate events, predominantly from atmospheric neutrinos with primary energy 100 GeV to 8 TeV. Our search of this sample reveals no indications of a neutrino point source. We place the most stringent limits to date on E(-2) neutrino fluxes from points in the northern sky, with an average upper limit of E(2)Phi(nu mu)+nu(tau)<= 5.2x10(-11) TeV cm(-2) s(-1) on the sum of nu(mu) and nu(tau) fluxes, assumed equal, over the energy range from 1.9 TeV to 2.5 PeV.

• 8. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
Solar Energetic Particle Spectrum on 2006 December 13 Determined by IceTop2008In: The Astrophysical Journal Letters, Vol. 689, no 1, p. L65-L68Article in journal (Refereed)

On 2006 December 13 the IceTop air shower array at the South Pole detected a major solar particle event. By numerically simulating the response of the IceTop tanks, which are thick Cerenkov detectors with multiple thresholds deployed at high altitude with no geomagnetic cutoff, we determined the particle energy spectrum in the energy range 0.6-7.6 GeV. This is the first such spectral measurement using a single instrument with a well-defined viewing direction. We compare the IceTop spectrum and its time evolution with previously published results and outline plans for improved resolution of future solar particle spectra.

• 9. Abbasi, R.
University of Kalmar, School of Pure and Applied Natural Sciences.
The IceCube data acquisition system: Signal capture, digitization, and timestamping2009In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 601, no 3, p. 294-316Article in journal (Refereed)

IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs). detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved. (c) 2009 Elsevier B.V. All rights reserved.

• 10.
University of Kalmar, School of Pure and Applied Natural Sciences.
Hur skiljer sig traditionella från nyare generationer antipsykotika åt vad gäller biverkningen viktökning?2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpStudent thesis

Antipsykotiska läkemedel är basen för behandling av schizofreni, en psykisk sjukdom som uppträder redan hos unga människor. Symtomen vid schizofreni brukar delas in i positiva symtom (hallucinationer, vanföreställningar, paranoida tankar), negativa symtom (koncentrationssvårigheter, nedsatt språk- och tankeförmåga, minskat intresse för omgivningen, och initiativlöshet), samt kognitiva symtom (minnesproblem, problem med uppmärksamhet och koncentration).

Antipsykotiska läkemedel delas in i typiska (den äldre generationen) och atypiska (den nyare generationen) antipsykotika. För båda grupperna antipsykotiska läkemedel finns det risk för biverkningar. De vanligaste biverkningarna vid behandling med den äldre generationen antipsykotika är extrapyramidala biverkningar. En biverkning som förefaller mer specifik för de nya atypiska preparaten är viktökning, vilken även kan orsaka utveckling av många allvarliga sjukdomstillstånd.

Syftet med detta arbete var att jämföra typiska och atypiska antipsykotiska läkemedel med avseende på utveckling av viktökning.

För att få svar på min frågeställning har en litteraturstudie av fem vetenskapliga artiklar genomförts. De vetenskapliga artiklarna har hittats genom databassökningar i PubMed, medan övriga fakta har hämtats från andra källor.

Resultatet av de vetenskapliga artiklarna visar att det finns skillnader mellan traditionella och nyare generationer antipsykotika vad gäller tendens att orsaka viktökning. Med några undantag, är flera antipsykotiska läkemedel, som tillhör den nyare generationen, associerade med högre risk för utveckling av viktökning jämfört med den äldre generationen antipsykotika. Viktökning orsakas mest av klozapin, följt av olanzapin och risperidon. Quetiapin orsakar, i likhet med haloperidol, mindre viktökning.

På grund av detta faktum, forskar man numera kring orsakerna till denna skillnad för att förbättra biverkningsprofilen hos framtida antipsykotika.

2008:F2

• 11. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences. University of Kalmar, School of Pure and Applied Natural Sciences. University of Kalmar, School of Pure and Applied Natural Sciences.
The on-orbit calibration of the Fermi Large Area Telescope2009In: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 32, no 3-4, p. 193-219Article in journal (Refereed)

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. (C) 2009 Elsevier B.V. All rights reserved.

• 12. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
Detection of 16 Gamma-Ray Pulsars Through Blind Frequency Searches Using the Fermi LAT2009In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 325, no 5942, p. 840-844Article in journal (Refereed)

Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.

• 13. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI OBSERVATIONS OF GRB 090902B: A DISTINCT SPECTRAL COMPONENT IN THE PROMPT AND DELAYED EMISSION2009In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 706, no 1, p. L138-L144Article in journal (Refereed)

We report on the observation of the bright, long gamma-ray burst (GRB), GRB 090902B, by the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) instruments on-board the Fermi observatory. This was one of the brightest GRBs to have been observed by the LAT, which detected several hundred photons during the prompt phase. With a redshift of z = 1.822, this burst is among the most luminous detected by Fermi. Time-resolved spectral analysis reveals a significant power-law component in the LAT data that is distinct from the usual Band model emission that is seen in the sub-MeV energy range. This power-law component appears to extrapolate from the GeV range to the lowest energies and is more intense than the Band component, both below similar to 50 keV and above 100 MeV. The Band component undergoes substantial spectral evolution over the entire course of the burst, while the photon index of the power-law component remains constant for most of the prompt phase, then hardens significantly toward the end. After the prompt phase, power-law emission persists in the LAT data as late as 1 ks post-trigger, with its flux declining as t(-1.5). The LAT detected a photon with the highest energy so far measured from a GRB, 33.4(-3.5)(+ 2.7) GeV. This event arrived 82 s after the GBM trigger and similar to 50 s after the prompt phase emission had ended in the GBM band. We discuss the implications of these results for models of GRB emission and for constraints on models of the extragalactic background light.

• 14. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
A limit on the variation of the speed of light arising from quantum gravity effects2009In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 462, no 7271, p. 331-334Article in journal (Refereed)

A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l(Planck) approximate to 1.62 x 10(-33) cm or E-Planck = M(Planck)c(2) approximate to 1.22 x 10(19) GeV), at which quantum effects are expected to strongly affect the nature of space-time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy(1-7). Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in gamma-ray burst (GRB) light-curves(2). Here we report the detection of emission up to similar to 31GeV from the distant and short GRB090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E(Planck) on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l(Planck)/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories(3,6,7) in which the quantum nature of space-time on a very small scale linearly alters the speed of light.

• 15. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI DISCOVERY OF GAMMA-RAY EMISSION FROM NGC 12752009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 699, no 1, p. 31-39Article in journal (Refereed)

We report the discovery of high-energy (E > 100 MeV) gamma-ray emission from NGC 1275, a giant elliptical galaxy lying at the center of the Perseus cluster of galaxies, based on observations made with the Large Area Telescope (LAT) of the Fermi Gamma-ray Space Telescope. The positional center of the gamma-ray source is only approximate to 3' away from the NGC 1275 nucleus, well within the 95% LAT error circle of approximate to 5'. The spatial distribution of gamma-ay photons is consistent with a point source. The average flux and power-law photon index measured with the LAT from 2008 August 4 to 2008 December 5 are F-gamma = (2.10 +/- 0.23) x 10(-7) ph (>100 MeV) cm(-2) s(-1) and Gamma = 2.17 +/- 0.05, respectively. The measurements are statistically consistent with constant flux during the four-month LAT observing period. Previous EGRET observations gave an upper limit of F-gamma < 3.72 x 10(-8) ph (>100 MeV) cm(-2) s(-1) to the gamma-ray flux from NGC 1275. This indicates that the source is variable on timescales of years to decades, and therefore restricts the fraction of emission that can be produced in extended regions of the galaxy cluster. Contemporaneous and historical radio observations are also reported. The broadband spectrum of NGC 1275 is modeled with a simple one-zone synchrotron/synchrotron self-Compton model and a model with a decelerating jet flow.

• 16. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI/LARGE AREA TELESCOPE BRIGHT GAMMA-RAY SOURCE LIST2009In: Astrophysical Journal Supplement Series, ISSN 0067-0049, E-ISSN 1538-4365, Vol. 183, no 1, p. 46-66Article in journal (Refereed)

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 similar to 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.

• 17. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
A Population of Gamma-Ray Millisecond Pulsars Seen with the Fermi Large Area Telescope2009In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 325, no 5942, p. 848-852Article in journal (Refereed)

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.

• 18. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI LARGE AREA TELESCOPE DETECTION OF PULSED gamma-RAYS FROM THE VELA-LIKE PULSARS PSR J1048-5832 AND PSR J2229+61142009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 706, no 2, p. 1331-1340Article in journal (Refereed)

We report the detection of gamma-ray pulsations (>= 0.1GeV) from PSR J2229+ 6114 and PSR J1048-5832, the latter having been detected as a low-significance pulsar by EGRET. Data in the gamma-ray band were acquired by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, while the radio rotational ephemerides used to fold the gamma-ray light curves were obtained using the Green Bank Telescope, the Lovell telescope at Jodrell Bank, and the Parkes Telescope. The two young radio pulsars, located within the error circles of the previously unidentified EGRET sources 3EG J1048-5840 and 3EG J2227+6122, present spin-down characteristics similar to the Vela pulsar. PSR J1048-5832 shows two sharp peaks at phases 0.15 +/- 0.01 and 0.57 +/- 0.01 relative to the radio pulse confirming the EGRET light curve, while PSR J2229+ 6114 presents a very broad peak at phase 0.49 +/- 0.01. The gamma-ray spectra above 0.1 GeV of both pulsars are fit with power laws having exponential cutoffs near 3 GeV, leading to integral photon fluxes of (2.19 +/- 0.22 +/- 0.32) x 10(-7) cm(-2) s(-1) for PSR J1048-5832 and (3.77 +/- 0.22 +/- 0.44) x 10(-7) cm(-2) s(-1) for PSR J2229+6114. The first uncertainty is statistical and the second is systematic. PSR J1048-5832 is one of the two LAT sources whichwere entangled together as 3EG J1048-5840. These detections add to the growing number of young gamma-ray pulsars that make up the dominant population of GeV gamma-ray sources in the Galactic plane.

• 19. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI OBSERVATIONS OF TeV-SELECTED ACTIVE GALACTIC NUCLEI2009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 707, no 2, p. 1310-1333Article in journal (Refereed)

We report on observations of TeV-selected active galactic nuclei (AGNs) made during the first 5.5 months of observations with the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope (Fermi). In total, 96 AGNs were selected for study, each being either (1) a source detected at TeV energies (28 sources) or (2) an object that has been studied with TeV instruments and for which an upper limit has been reported (68 objects). The Fermi observations show clear detections of 38 of these TeV-selected objects, of which 21 are joint GeV-TeV sources, and 29 were not in the third EGRET catalog. For each of the 38 Fermi-detected sources, spectra and light curves are presented. Most can be described with a power law of spectral index harder than 2.0, with a spectral break generally required to accommodate the TeV measurements. Based on an extrapolation of the Fermi spectrum, we identify sources, not previously detected at TeV energies, which are promising targets for TeV instruments. Evidence for systematic evolution of the gamma-ray spectrum with redshift is presented and discussed in the context of interaction with the extragalactic background light.

• 20. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
Measurement of the Cosmic Ray e(+)+e(-) Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope2009In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, no Article number: 181101Article in journal (Refereed)

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(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-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.

• 21. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
EARLY FERMI GAMMA-RAY SPACE TELESCOPE OBSERVATIONS OF THE QUASAR 3C 454.32009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 699, no 1, p. 817-823Article in journal (Refereed)

This is the first report of Fermi Gamma-Ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope, covering 2008 July 7-October 6, indicate strong, highly variable.-ray emission with an average flux of similar to 3 x 10 (6) photons cm(-2) s(-1), for energies > 100 MeV. The gamma-ray flux is variable, with strong, distinct, symmetrically shaped flares for which the flux increases by a factor of several on a timescale of about 3 days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair production implies relativistic beaming with Doppler factor delta > 8, consistent with the values inferred from Very Long Baseline Interferometry observations of superluminal expansion (delta similar to 25). The observed gamma-ray spectrum is not consistent with a simple power law, but instead steepens strongly above similar to 2 GeV, and is well described by a broken power law with photon indices of similar to 2.3 and similar to 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high-luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2 GeV could be due to gamma-ray absorption via photon-photon pair production on the soft X-ray photon field of the host active galactic nucleus, but such an interpretation would require the dissipation region to be located very close (less than or similar to 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

• 22. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI LAT OBSERVATIONS OF LS I+61°303: FIRST DETECTION OF AN ORBITAL MODULATION IN GeV GAMMA RAYS2009In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 701, no 2, p. L123-L128Article in journal (Refereed)

This Letter presents the first results from the observations of LS I + 61 degrees 303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our results indicate variability that is consistent with the binary period, with the emission being modulated at 26.6 +/- 0.5 days. This constitutes the first detection of orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve is characterized by a broad peak after periastron, as well as a smaller peak just before apastron. The spectrum is best represented by a power law with an exponential cutoff, yielding an overall flux above 100 MeV of 0.82 +/- 0.03(stat) +/- 0.07(syst) 10(-6) ph cm(-2) s(-1), with a cutoff at 6.3 +/- 1.1(stat) +/- 0.4(syst) GeV and photon index Gamma = 2.21 +/- 0.04(stat) +/- 0.06(syst). There is no significant spectral change with orbital phase. The phase of maximum emission, close to periastron, hints at inverse Compton scattering as the main radiation mechanism. However, previous very high-energy gamma ray (>100 GeV, VHE) observations by MAGIC and VERITAS show peak emission close to apastron. This and the energy cutoff seen with Fermi suggest that the link between HE and VHE gamma rays is nontrivial.

• 23. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
DISCOVERY OF PULSATIONS FROM THE PULSAR J0205+6449 IN SNR 3C 58 WITH THE FERMI GAMMA-RAY SPACE TELESCOPE2009In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 699, no 2, p. L102-L107Article in journal (Refereed)

We report the discovery of gamma-ray pulsations (>= 0.1 GeV) from the young radio and X-ray pulsar PSR J0205 + 6449 located in the Galactic supernova remnant 3C 58. Data in the gamma-ray band were acquired by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope (formerly GLAST), while the radio rotational ephemeris used to fold gamma-rays was obtained using both the Green Bank Telescope and the Lovell telescope at Jodrell Bank. The light curve consists of two peaks separated by 0.49 +/- 0.01 +/- 0.01 cycles which are aligned with the X-ray peaks. The first gamma-ray peak trails the radio pulse by 0.08 +/- 0.01 +/- 0.01, while its amplitude decreases with increasing energy as for the other gamma-ray pulsars. Spectral analysis of the pulsed gamma-ray emission suggests a simple power law of index -2.1 +/- 0.1 +/- 0.2 with an exponential cutoff at 3.0(-0.7)(+1.1) +/- 0.4 GeV. The first uncertainty is statistical and the second is systematic. The integral gamma-ray photon flux above 0.1 GeV is (13.7 +/- 1.4 +/- 3.0) x 10(-8) cm(-2) s(-1), which implies for a distance of 3.2 kpc and assuming a broad fan-like beam a luminosity of 8.3 x 10(34) erg s(-1) and an efficiency eta of 0.3%. Finally, we report a 95% upper limit on the flux of 1.7 x 10(-8) cm(-2) s(-1) for off-pulse emission from the object.

• 24. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI/LAT OBSERVATIONS OF LS 50392009In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 706, no 1, p. L56-L61Article in journal (Refereed)

The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variability that is consistent with the binary period, with the emission being modulated with a period of 3.903 +/- 0.005 days; the first detection of this modulation at GeV energies. The light curve is characterized by a broad peak around superior conjunction in agreement with inverse Compton scattering models. The spectrum is represented by a power law with an exponential cutoff, yielding an overall flux ( 100 MeV-300 GeV) of 4.9 +/- 0.5(stat) +/- 1.8(syst) x 10(-7) photon cm(-2) s(-1), with a cutoff at 2.1 +/- 0.3(stat) +/- 1.1(syst) GeV and photon index G = 1.9 +/- 0.1(stat) +/- 0.3(syst). The spectrum is observed to vary with orbital phase, specifically between inferior and superior conjunction. We suggest that the presence of a cutoff in the spectrum may be indicative of magnetospheric emission similar to the emission seen in many pulsars by Fermi.

• 25. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
Detection of High-Energy Gamma-Ray Emission from the Globular Cluster 47 Tucanae with Fermi2009In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 325, no 5942, p. 845-848Article in journal (Refereed)

We report the detection of gamma-ray emissions above 200 megaelectron volts at a significance level of 17 sigma from the globular cluster 47 Tucanae, using data obtained with the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. Globular clusters are expected to emit gamma rays because of the large populations of millisecond pulsars that they contain. The spectral shape of 47 Tucanae is consistent with gamma-ray emission from a population of millisecond pulsars. The observed gamma-ray luminosity implies an upper limit of 60 millisecond pulsars present in 47 Tucanae.

• 26. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI LAT OBSERVATION OF DIFFUSE GAMMA RAYS PRODUCED THROUGH INTERACTIONS BETWEEN LOCAL INTERSTELLAR MATTER AND HIGH-ENERGY COSMIC RAYS2009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 703, no 2, p. 1249-1256Article in journal (Refereed)

Observations by the Large Area Telescope (LAT) on the Fermi mission of diffuse gamma-rays in a mid-latitude region in the third quadrant (Galactic longitude l from 200 degrees to 260 degrees and latitude vertical bar b vertical bar from 22 degrees to 60 degrees) are reported. The region contains no known large molecular cloud and most of the atomic hydrogen is within 1 kpc of the solar system. The contributions of gamma-ray point sources and inverse Compton scattering are estimated and subtracted. The residual gamma-ray intensity exhibits a linear correlation with the atomic gas column density in energy from 100 MeV to 10 GeV. The measured integrated gamma-ray emissivity is (1.63 +/- 0.05) x 10(-26) photons s(-1)sr(-1) H-atom(-1) and (0.66 +/- 0.02) x 10(-26) photons s(-1)sr(-1) H-atom(-1) above 100 MeV and above 300 MeV, respectively, with an additional systematic error of similar to 10%. The differential emissivity from 100 MeV to 10 GeV agrees with calculations based on cosmic ray spectra consistent with those directly measured, at the 10% level. The results obtained indicate that cosmic ray nuclei spectra within 1 kpc from the solar system in regions studied are close to the local interstellar spectra inferred from direct measurements at the Earth within similar to 10%.

• 27. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
BRIGHT ACTIVE GALACTIC NUCLEI SOURCE LIST FROM THE FIRST THREE MONTHS OF THE FERMI LARGE AREA TELESCOPE ALL-SKY SURVEY2009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 700, no 1, p. 597-622Article in journal (Refereed)

The first three months of sky-survey operation with the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope reveal 132 bright sources at |b| > 10 degrees with test statistic greater than 100 ( corresponding to about 10 sigma). Two methods, based on the CGRaBS, CRATES, and BZCat catalogs, indicate high-confidence associations of 106 of these sources with known active galactic nuclei (AGNs). This sample is referred to as the LAT Bright AGN Sample (LBAS). It contains two radio galaxies, namely, Centaurus A and NGC 1275, and 104 blazars consisting of 58 flat spectrum radio quasars (FSRQs), 42 BL Lac objects, and 4 blazars with unknown classification. Four new blazars were discovered on the basis of the LAT detections. Remarkably, the LBAS includes 10 high-energy-peaked BL Lacs (HBLs), sources which were previously difficult to detect in the GeV range. Another 10 lower-confidence associations are found. Only 33 of the sources, plus two at |b| < 10 degrees, were previously detected with Energetic Gamma-Ray Experiment Telescope( EGRET), probably due to variability. The analysis of the gamma-ray properties of the LBAS sources reveals that the average GeV spectra of BL Lac objects are significantly harder than the spectra of FSRQs. No significant correlation between radio and peak gamma-ray fluxes is observed. Blazar log N-log S distributions and luminosity functions are constructed to investigate the evolution of the different blazar classes, with positive evolution indicated for FSRQs but none for BL Lacs. The contribution of LAT blazars to the total extragalactic gamma-ray intensity is estimated.

• 28. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
FERMI LARGE AREA TELESCOPE GAMMA-RAY DETECTION OF THE RADIO GALAXY M872009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 707, no 1, p. 55-60Article in journal (Refereed)

We report the Fermi Large Area Telescope (LAT) discovery of high-energy (MeV/GeV) gamma-ray emission positionally consistent with the center of the radio galaxy M87, at a source significance of over 10 sigma in 10 months of all-sky survey data. Following the detections of Cen A and Per A, this makes M87 the third radio galaxy seen with the LAT. The faint point-like gamma-ray source has a >100 MeV flux of 2.45 (+/-0.63) x 10(-8) photons cm(-2) s(-1) (photon index = 2.26 +/- 0.13) with no significant variability detected within the LAT observation. This flux is comparable with the previous EGRET upper limit (<2.18 x 10-8 photons cm(-2) s(-1), 2 sigma), thus there is no evidence for a significant MeV/GeV flare on decade timescales. Contemporaneous Chandra and Very Long Baseline Array data indicate low activity in the unresolved X-ray and radio core relative to previous observations, suggesting M87 is in a quiescent overall level over the first year of Fermi-LAT observations. The LAT gamma-ray spectrum is modeled as synchrotron self-Compton (SSC) emission from the electron population producing the radio-to-X-ray emission in the core. The resultant SSC spectrum extrapolates smoothly from the LAT band to the historical-minimum TeV emission. Alternative models for the core and possible contributions from the kiloparsec-scale jet in M87 are considered, and cannot be excluded.

• 29. Abdo, A. A.
University of Kalmar, School of Pure and Applied Natural Sciences.
PULSED GAMMA-RAYS FROM PSR J2021+3651 WITH THE FERMI LARGE AREA TELESCOPE2009In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 700, no 2, p. 1059-1066Article in journal (Refereed)

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(-8) cm(-2) s(-1). The photon spectrum is well described by an exponentially cut-off power law of the form dF/dE = kE(-Gamma)e((-E/Ec)), 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-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(-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.

• 30. Abdo, A. A.