Astrophysics and Astronomy Commons^™

A Photometric Redshift Of Z = 1.8+0.4 -.3 For The Agile Grb 080514b, A. Rossi, A. De Ugarte Postigo, P. Ferrero, D. A. Kann, S. Klose, S. Schulze, J. Greiner, P. Schady, R. Filgas, E. E. Gonsalves, A. Küpcü Yolda¸S, T. Krühler, G. Szokoly, A. Yolda¸S, P. M.J. Afonso, C. Clemens, J. S. Bloom, D. A. Perley, J. P.U. Fynbo, A. J. Castro-Tirado, J. Gorosabel, P. Kubánek, Adria Updike, D. H. Hartmann, A. Giuliani, S. T. Holland, L. Hanlon, M. Bremer, J. French, G. Melady, D. A. García-Hernández

Arts & Sciences Faculty Publications

The AGILE gamma-ray burst GRB 080514B is the first detected to have emission above 30 MeV and an optical afterglow. However, no spectroscopic redshift for this burst is known.We report on our ground-based optical/NIR and millimeter follow-up observations of this event at several observatories, including the multi-channel imager GROND on La Silla, supplemented by Swift UVOT and Swift XRT data. The spectral energy distribution (SED) of the optical/NIR afterglow is found to decline sharply bluewards to the UV bands, which can be utilized in estimating the redshift. Fitting the SED from the Swift UVOT uvw2 band to the H band, …

The Rapidly Flaring Afterglow Of The Very Bright And Energetic Grb 070125, Adria Updike, Josh B. Haislip, Melissa C. Nysewander, Andrew S. Fruchter, D. Alexander Kann, Sylvio Klose, Peter A. Milne, G. Grant Williams, Weikang Zheng, Carl W. Hergenrother, Jason X. Prochaska, Jules P. Halpern, Nestor Mirabal, John R. Thorstensen, Alexander J. Van Der Horst, Rhaana L.C. Starling, Judith L. Racusin, David N. Burrows, N. P.M. Kuin, Peter W.A. Roming, Eric Bellm, Kevin Hurley, Weidong Li, Alexei V. Filippenko, Cullen Blake, Dan Starr, Emilio E. Falco, Warren R. Brown, Xinyu Dai, Jinsong Deng, Liping Xin, Yulei Qiu, Jianyan Wei, Yuji Urata, Domenico Nanni, Elisabetta Maiorano, Eliana Palazzi, Guiseppe Greco, Corrado Bartolini, Adriano Guarnieri, Adalberto Piccioni, Graziella Pizzichini, Federica Terra, Kuntal Misra, B. C. Bhatt, G. C. Anupama, X. Fan, L. Jiang, Ralph A.M.J. Wijers, Daniel E. Reichart, Hala A. Eid, Ginger Bryngelson, Jason Puls, R. C. Goldthwaite, Dieter H. Hartmann

Arts & Sciences Faculty Publications

No abstract provided.

Multiwavelength Analysis Of The Intriguing Grb 061126: The Reverse Shock Scenario And Magnetization, A. Gomboc, S. Kobayashi, C. Guidorzi, A. Melandri, V. Mangano, B. Sbarufatti, C. G. Mundell, P. Schady, R. J. Smith, Adria Updike, D. A. Kann, K. Misra, E. Rol, A. Pozanenko, A. J. Castro-Tirado, G. C. Anupama, D. Bersier, M. F. Bode, D. Carter, P. Curran, A. Fruchter, J. Graham, D. H. Hartmann, M. Ibrahimov, A. Levan, A. Monfardini, C. J. Mottram, P. T. O’Brien, P. Prema, D. K. Sahu, I. A. Steele, N. R. Tanvir, K. Wiersema

Arts & Sciences Faculty Publications

No abstract provided.

Precision Measurements Of The Neutron Electric Form Factor At High Momentum Transfers, Ameya Suresh Kolarkar

University of Kentucky Doctoral Dissertations

The neutron, although electrically neutral, is composed of elementary charged particles and as a result, possesses a charge distribution within. The charge distribution can be studied by measuring a quantity called the neutron electric form factor, Gⁿ_E. Experiment E02-013 at Jefferson Lab’s Hall A measured Gⁿ_E at high four-momentum transfer values of Q2 = 1.2, 1.7, 2.5 and 3.4 (GeV/c)² in double polarized semi-exclusive ³He(e, e'n) scattering in quasi-elestic kinematics by measuring the transverse asymmetry A_T of the cross section.

The neutron electric form factor is essential to …

Charge Density Wave Polarization Dynamics, Luis Alejandro Ladino Gaspar

University of Kentucky Doctoral Dissertations

We have studied the charge density wave (CDW) repolarization dynamics in blue bronze (K_0.3MoO₃) by applying symmetric bipolar square-wave voltages of different frequencies to the sample and measuring the changes in infrared transmittance, proportional to CDW strain. The frequency dependence of the electro-transmittance was fit to a modified harmonic oscillator response and the evolution of the parameters as functions of voltage, position, and temperature are discussed. We found that resonance frequencies decrease with distance from the current contacts, indicating that the resulting delays are intrinsic to the CDW with the strain effectively flowing from the contact. …

Next-To-Leading Order Evolution Of Color Dipoles, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

The small-x deep inelastic scattering in the saturation region is governed by the nonlinear evolution of Wilson-line operators. In the leading logarithmic approximation it is given by the Balitsky-Kovchegov equation for the evolution of color dipoles. In the next-to-leading order the Balitsky-Kovchegov equation gets contributions from quark and gluon loops as well as from the tree gluon diagrams with quadratic and cubic nonlinearities. We calculate the gluon contribution to the small-x evolution of Wilson lines (the quark part was obtained earlier).

Beating The Spin-Down Limit On Gravitational Wave Emission From The Crab Pulsar, B. P. Abbott, R. Abbott, R. Adhikari, Mario C. Diaz, Roberto Grosso, Kazuhiro Hayama, Soumya Mohanty, Soma Mukherjee, Joseph D. Romano, Robert Stone

Physics & Astronomy Faculty Publications

We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret …

The Crab Nebula's Dynamical Age As Measured From Its Northern Filamentary Jet, G. C. Rudie, R. A. Fesen, T. Yamada

Dartmouth Scholarship

We present a deep [O III] 4959,5007 image of the northern filamentary jet in the Crab Nebula taken with the 8.2m Subaru telescope. Using this image and an image taken with the KPNO 4m in 1988 (Fesen & Staker 1993), we have computed proper motions for 35 locations in the jet. The results suggest that when compared to the main body of the remnant, the jet experienced less outward acceleration from the central pulsar's rapidly expanding synchrotron nebula. The jet's apparent expansion rate yields an undecelerated explosion date for the Crab Nebula of 1055 plus or minus 24 C.E., a …

The Pulsation Modes Of The Pre-White Dwarf Pg 1159-035, Jörge E.S. Costa, Matt A. Wood, Thomas J. Ahrens

Aerospace, Physics, and Space Science Faculty Publications

Context. PG 1159-035 , a pre-white dwarf with Teff ≃ 140 000 K, is the prototype of both two classes: the PG 1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained with the Whole Earth Telescope (WET) showed a rich frequency spectrum allowing the identification of 122 pulsation modes. Analyzing the periods of pulsation, it is possible to measure the stellar mass, the rotational period and the inclination of the rotation axis, to estimate an upper limit for the magnetic field, and even to obtain information about the inner stratification of the star. …

Study Of The Solar Anisotropy Of Cosmic Ray Primaries Of About 200 Gev Energy With The L3+C Muon Detector, G Baksay, L Baksay, K Dehmelt, M Hohlmann, Z Szillasi, I Vodopianov, The L3 Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Context. Primary cosmic rays experience multiple deflections in the non-uniform galactic and heliospheric magnetic fields which may generate anisotropies. Aims. A study of anisotropies in the energy range between 100 and 500 GeV is performed. This energy range is not yet well explored. Methods. The L3 detector at the CERN electron-positron collider, LEP, is used for a study of the angular distribution of atmospheric muons with energies above 20 GeV. This distribution is used to investigate the isotropy of the time-dependent intensity of the primary cosmic-ray flux with a Fourier analysis. Results. A small deviation from isotropy at energies around …

Quantitative Constraints On The Transport Properties Of Hot Partonic Matter From Semi-Inclusive Single High Transverse Momentum Pion Suppression In Au+Au Collisions At √Snn = 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

The PHENIX experiment has measured the suppression of semi-inclusive single high-transverse-momentum π0's in Au+Au collisions at √sNN = 200 GeV. The present understanding of this suppression is in terms of energy loss of the parent (fragmenting) parton in a dense color-charge medium. We have performed a quantitative comparison between various parton energy-loss models and our experimental data. The statistical point-to-point uncorrelated as well as correlated systematic uncertainties are taken into account in the comparison. We detail this methodology and the resulting constraint on the model parameters, such as the initial color-charge density dNg/dy, the medium transport coefficient q, or the …

Transverse Momentum And Centrality Dependence Of Dihadron Correlations In Au+Au Collisions At Snn=200 Gev: Jet Quenching And The Response Of Partonic Matter, Andrew Marshall Adare, Gyöngyi Baksay, László Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Azimuthal angle (Δ) correlations are presented for charged hadrons from dijets for 0.4

Dihadron Azimuthal Correlations In Au+Au Collisions At √Snn=200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

Azimuthal angle (Δϕ) correlations are presented for a broad range of transverse momentum (0.4

Charged Hadron Multiplicity Fluctuations In Au+Au And Cu+Cu Collisions From √Snn=22.5 To 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at √sNN=62.4 and 200 GeV, and Cu+Cu collisions at √sNN=22.5,62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for nondynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions …

High-Energy Electron Beams Launched Into Space By Thunderstorms, Joseph R. Dwyer, Brian W. Grefenstette, David M. Smith

Aerospace, Physics, and Space Science Faculty Publications

Using CGRO/BATSE data, a possible new source of high-energy electrons and positrons in the earth's inner magnetosphere is presented. These particles are generated within the upper atmosphere by Compton scattering and pair-production of gamma-rays originating from near the tropopause as Terrestrial Gamma-ray Flashes (TGFs). Once created, these energetic electrons and positrons follow the geomagnetic field into the inner magnetosphere where they can be detected in low-earth orbit, either near the TGF magnetic foot point or at the conjugate point several thousand kilometers away. Approximately 17% of CGRO/BATSE events previously identified as terrestrial gamma-ray flashes are, in fact, such electrons and …

Hubble Space Telescope Near-Infrared Snapshot Survey Of 3cr Radio Source Counterparts. Ii. An Atlas And Inventory Of The Host Galaxies, Mergers, And Companions, David J. E. Floyd, Eric Perlman

Aerospace, Physics, and Space Science Faculty Publications

We present the second part of an H-band (1.6 μm) "atlas" of z < 0.3 3CR radio galaxies, using the Hubble Space Telescope Near Infrared Camera and Multi-Object Spectrometer (HST NICMOS2). We present new imaging for 21 recently acquired sources and host galaxy modeling for the full sample of 101 (including 11 archival) - an 87% completion rate. Two different modeling techniques are applied, following those adopted by the galaxy morphology and the quasar host galaxy communities. Results are compared and found to be in excellent agreement, although the former breaks down in the case of sources with strong active galactic nuclei (AGNs). Companion sources are tabulated, and the presence of mergers, tidal features, dust disks, and jets are cataloged. The tables form a catalog for those interested in the structural and morphological dust-free host galaxy properties of the 3CR sample, and for comparison with morphological studies of quiescent galaxies and quasar host galaxies. Host galaxy masses are estimated and found to typically lie at around 2 × 1011 M⊙. In general, the population is found to be consistent with the local population of quiescent elliptical galaxies, but with a longer tail to low Sérsic index, mainly consisting of low-redshift (z < 0.1) and low-radio-power (FR I) sources. A few unusually disky FR II host galaxies are picked out for further discussion. Nearby external sources are identified in the majority of our images, many of which we argue are likely to be companion galaxies or merger remnants. The reduced NICMOS data are now publicly available from our Web site.

The Extreme Outburst Of Ex Lup In 2008: Optical Spectra And Light Curve, Ágnes Kóspál, P. Németh, Péter Ábrahám, Mária Kun, Arne A. Henden, Albert F. Jones

Aerospace, Physics, and Space Science Faculty Publications

EX Lup is the prototype of EXors, a class of pre-main sequence eruptive variables, exhibiting unpredictable brightenings lasting some months (Herbig, 1977; Herbig et al., 2001; Herbig, 2007). According to the current picture, eruptions of pre-main sequence stars are caused by enhanced accretion (Hartmann & Kenyon, 1996). In quiescent phase, EX Lup has typically V 13 mag, while in outburst, it may brighten by 1{4 mag. The last known are-up happened in 2002 (Herbig, 2007). As was announced by Jones (2008), EX Lup has been in outburst again since at least 2008 January 15. Based on visual estimates, the star …

The Warps Survey. Vii. The Warps-Ii Cluster Catalog, Donald J. Horner, Eric S. Perlman, Harald Ebeling, Laurence R. Jones, Caleb A. Scharf, Gary Wegner, Matthew Malkan, Ben Maughan

Aerospace, Physics, and Space Science Faculty Publications

We present the galaxy cluster catalog from the second, larger phase of the Wide Angle ROSAT Pointed Survey (WARPS), an X-ray selected survey for high-redshift galaxy clusters. WARPS is among the largest deep X-ray cluster surveys and is being used to study the properties and evolution of galaxy clusters. The WARPS-II sample contains 125 clusters serendipitously detected in a survey of 301 ROSAT PSPC pointed observations and covers a sky area of 56.7 deg2. Of these 125 clusters, 53 have not been previously reported in the literature. We have nearly complete spectroscopic follow-up of the clusters, which range in redshift …

Beating The Spin-Down Limit On Gravitational Wave Emission From The Crab Pulsar, B. Abbott, R. Abbott, R. Adhikari, P. Ajith, B. Allen, G. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. A. Arain, M. Araya, H. Armandula, P. Armor, Y. Aso, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, M. Bastarrika, K. Bayer, J. Betzwieser, P. T. Beyersdorf, I. A. Bilenko, Tiffany Z. Summerscales

Faculty Publications

We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret …