Publications


The second data release of the INT Photometric Ha Survey of the Northern Galactic Plane (IPHAS DR2)

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 444 (2014) 3230-3257

G Barentsen, HJ Farnhill, JE Drew, EA Gonzalez-Solares, R Greimel, MJ Irwin, B Miszalski, C Ruhland, P Groot, A Mampaso, SE Sale, AA Henden, A Aungwerojwit, MJ Barlow, PJ Carter, RLM Corradi, JJ Drake, J Eisloeffel, J Fabregat, BT Gaensicke, NPG Fusillo, S Greiss, AS Hales, S Hodgkin, L Huckvale, J Irwin, R King, C Knigge, T Kupfer, E Lagadec, DJ Lennon, JR Lewis, M Mohr-Smith, RAH Morris, T Naylor, QA Parker, S Phillipps, S Pyrzas, R Raddi, GHA Roelofs, P Rodriguez-Gil, L Sabin, S Scaringi, D Steeghs, J Suso, R Tata, YC Unruh, J van Roestel, K Viironen, JS Vink, NA Walton, NJ Wright, AA Zijlstra


Radially global $δf$ computation of neoclassical phenomena in a tokamak pedestal

ArXiv (2013)

M Landreman, FI Parra, PJ Catto, DR Ernst, I Pusztai

Conventional radially-local neoclassical calculations become inadequate if the radial gradient scale lengths of the H-mode pedestal become as small as the poloidal ion gyroradius. Here, we describe a radially global $\delta f$ continuum code that generalizes neoclassical calculations to allow stronger gradients. As with conventional neoclassical calculations, the formulation is time-independent and requires only the solution of a single sparse linear system. We demonstrate precise agreement with an asymptotic analytic solution of the radially global kinetic equation in the appropriate limits of aspect ratio and collisionality. This agreement depends crucially on accurate treatment of finite orbit width effects.


Distribution of slow and fast rotators in the Fornax cluster

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 441 (2014) 274-288

N Scott, RL Davies, RCW Houghton, M Cappellari, AW Graham, KA Pimbblet


The Gaia-ESO Survey: processing FLAMES-UVES spectra

ASTRONOMY & ASTROPHYSICS 565 (2014) ARTN A113

GG Sacco, L Morbidelli, E Franciosini, E Majorca, S Randich, A Modigliani, G Gilmore, M Asplund, J Binney, P Bordfacio, J Drew, S Feltzing, A Ferguson, R Jeffries, G Micela, I Negueruela, T Prusti, H-W Rix, A Vallenari, E Alfaro, CA Prieto, C Babusiaux, T Bensby, R Blomme, A Bragaglia, E Flaccomio, P Francois, N Hambly, M Irwin, S Koposov, A Korn, A Lanzafame, F Pancino, A Recio-Blanco, R Smiljanic, S Van Eck, N Walton, M Bergemann, MT Costado, P de Laverny, U Heiter, V Hill, A Hourihane, R Jackson, P Jofre, J Lewis, K Lind, C Lardo, L Magrini, T Masseron, L Prisinzano, C Worley


Equivalence of two independent calculations of the higher order guiding center Lagrangian

PHYSICS OF PLASMAS 21 (2014) ARTN 104506

FI Parra, I Calvo, JW Burby, J Squire, H Qin


Energy Reconstruction Methods in the IceCube Neutrino Telescope

ArXiv (2013)

I Collaboration, MG Aartsen, R Abbasi, M Ackermann, J Adams, JA Aguilar, M Ahlers, D Altmann, C Arguelles, J Auffenberg, X Bai, M Baker, SW Barwick, V Baum, R Bay, JJ Beatty, JB Tjus, K-H Becker, S BenZvi, P Berghaus, D Berley, E Bernardini, A Bernhard, DZ Besson, G Binder, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, L Brayeur, H-P Bretz, AM Brown, R Bruijn, J Casey, M Casier, D Chirkin, A Christov, B Christy, K Clark, L Classen, F Clevermann, S Coenders, S Cohen, DF Cowen, AHC Silva, M Danninger, J Daughhetee, JC Davis, M Day, CD Clercq, SD Ridder, P Desiati, KDD Vries, MD With, T DeYoung, JCD' iaz-Vélez, M Dunkman, R Eagan, B Eberhardt, B Eichmann, J Eisch, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, S Flis, A Franckowiak, K Frantzen, T Fuchs, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, G Golup, JG Gonzalez, JA Goodman, D Góra, DT Grandmont, D Grant, P Gretskov, JC Groh, A Groß, C Ha, AH Ismail, P Hallen, A Hallgren, F Halzen, K Hanson, D Hebecker, D Heereman, D Heinen, K Helbing, R Hellauer, S Hickford, GC Hill, KD Hoffman, R Hoffmann, A Homeier, K Hoshina, F Huang, W Huelsnitz, PO Hulth, K Hultqvist, S Hussain, A Ishihara, S Jackson, E Jacobi, J Jacobsen, K Jagielski, GS Japaridze, K Jero, O Jlelati, B Kaminsky, A Kappes, T Karg, A Karle, M Kauer, JL Kelley, J Kiryluk, J Kläs, SR Klein, J-H Köhne, G Kohnen, H Kolanoski, L Köpke, C Kopper, S Kopper, DJ Koskinen, M Kowalski, M Krasberg, A Kriesten, K Krings, G Kroll, J Kunnen, N Kurahashi, T Kuwabara, M Labare, H Landsman, MJ Larson, M Lesiak-Bzdak, M Leuermann, J Leute, J Lünemann, O Macías, J Madsen, G Maggi, R Maruyama, K Mase, HS Matis, F McNally, K Meagher, M Merck, T Meures, S Miarecki, E Middell, N Milke, J Miller, L Mohrmann, T Montaruli, R Morse, R Nahnhauer, U Naumann, H Niederhausen, SC Nowicki, DR Nygren, A Obertacke, S Odrowski, A Olivas, A Omairat, A O'Murchadha, L Paul, JA Pepper, CPDL Heros, C Pfendner, D Pieloth, E Pinat, J Posselt, PB Price, GT Przybylski, M Quinnan, L Rädel, M Rameez, K Rawlins, P Redl, R Reimann, E Resconi, W Rhode, M Ribordy, M Richman, B Riedel, S Robertson, JP Rodrigues, C Rott, T Ruhe, B Ruzybayev, D Ryckbosch, SM Saba, H-G Sander, M Santander, S Sarkar, K Schatto, F Scheriau, T Schmidt, M Schmitz, S Schoenen, S Schöneberg, A Schönwald, A Schukraft, L Schulte, O Schulz, D Seckel, Y Sestayo, S Seunarine, R Shanidze, C Sheremata, MWE Smith, D Soldin, GM Spiczak, C Spiering, M Stamatikos, T Stanev, NA Stanisha, A Stasik, T Stezelberger, RG Stokstad, A Stößl, EA Strahler, R Ström, NL Strotjohann, GW Sullivan, H Taavola, I Taboada, A Tamburro, A Tepe, S Ter-Antonyan, G Tešić, S Tilav, PA Toale, MN Tobin, S Toscano, M Tselengidou, E Unger, M Usner, S Vallecorsa, NV Eijndhoven, AV Overloop, JV Santen, M Vehring, M Voge, M Vraeghe, C Walck, T Waldenmaier, M Wallraff, C Weaver, M Wellons, C Wendt, S Westerhoff, B Whelan, N Whitehorn, K Wiebe, CH Wiebusch, DR Williams, H Wissing, M Wolf, TR Wood, K Woschnagg, DL Xu, XW Xu, JP Yanez, G Yodh, S Yoshida, P Zarzhitsky, J Ziemann, S Zierke, M Zoll

Accurate measurement of neutrino energies is essential to many of the scientific goals of large-volume neutrino telescopes. The fundamental observable in such detectors is the Cherenkov light produced by the transit through a medium of charged particles created in neutrino interactions. The amount of light emitted is proportional to the deposited energy, which is approximately equal to the neutrino energy for $\nu_e$ and $\nu_\mu$ charged-current interactions and can be used to set a lower bound on neutrino energies and to measure neutrino spectra statistically in other channels. Here we describe methods and performance of reconstructing charged-particle energies and topologies from the observed Cherenkov light yield, including techniques to measure the energies of uncontained muon tracks, achieving average uncertainties in electromagnetic-equivalent deposited energy of $\sim 15\%$ above 10 TeV.


A 3D extinction map of the northern Galactic plane based on IPHAS photometry

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 443 (2014) 2907-2922

SE Sale, JE Drew, G Barentsen, HJ Farnhill, R Raddi, MJ Barlow, J Eisloeffel, JS Vink, P Rodriguez-Gil, NJ Wright


Equilibration dynamics and conductivity of warm dense hydrogen

PHYSICAL REVIEW E 90 (2014) ARTN 013104

U Zastrau, P Sperling, A Becker, T Bornath, R Bredow, T Doeppner, S Dziarzhytski, T Fennel, LB Fletcher, E Forster, C Fortmann, SH Glenzer, S Goede, G Gregori, M Harmand, V Hilbert, B Holst, T Laarmann, HJ Lee, T Ma, JP Mithen, R Mitzner, CD Murphy, M Nakatsutsumi, P Neumayer, A Przystawik, S Roling, M Schulz, B Siemer, S Skruszewicz, J Tiggesbaeumker, S Toleikis, T Tschentscher, T White, M Woestmann, H Zacharias, R Redmer


How do galaxies build up their spin in the cosmic web?

ArXiv (2014)

C Welker, Y Dubois, J Devriendt, C Pichon, S Peirani

Using the Horizon-AGN simulation we find a mass dependent spin orientation trend for galaxies: the spin of low-mass, rotation-dominated, blue, star-forming galaxies are preferentially aligned with their closest filament, whereas high-mass, velocity dispersion- supported, red quiescent galaxies tend to possess a spin perpendicular to these filaments. We explore the physical mechanisms driving galactic spin swings and quantify how much mergers and smooth accretion re-orient them relative to their host filaments and impact their shape. In particular, we analyze the effect of dispersion and morphology of galaxies and discuss potential tracers for prospective surveys.


The ATLAS(3D) project - XXV. Two-dimensional kinematic analysis of simulated galaxies and the cosmological origin of fast and slow rotators

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 444 (2014) 3357-3387

T Naab, L Oser, E Emsellem, M Cappellari, D Krajnovic, RM McDermid, K Alatalo, E Bayet, L Blitz, M Bois, F Bournaud, M Bureau, A Crocker, RL Davies, TA Davis, PT de Zeeuw, P-A Duc, M Hirschmann, PH Johansson, S Khochfar, H Kuntschner, R Morganti, T Oosterloo, M Sarzi, N Scott, P Serra, G van de Ven, A Weijmans, LM Young


Proton-driven plasma wakefield acceleration: A path to the future of high-energy particle physics

Plasma Physics and Controlled Fusion 56 (2014)

R Assmann, R Bingham, R Bingham, T Bohl, C Bracco, B Buttenschön, A Butterworth, A Caldwell, S Chattopadhyay, S Chattopadhyay, S Chattopadhyay, S Chattopadhyay, S Cipiccia, S Cipiccia, E Feldbaumer, RA Fonseca, RA Fonseca, B Goddard, M Gross, O Grulke, E Gschwendtner, J Holloway, J Holloway, C Huang, D Jaroszynski, S Jolly, P Kempkes, N Lopes, N Lopes, K Lotov, K Lotov, J Machacek, SR Mandry, SR Mandry, JW McKenzie, M Meddahi, BL Militsyn, N Moschuering, P Muggli, Z Najmudin, TCQ Noakes, PA Norreys, PA Norreys, E Öz, A Pardons, A Petrenko, A Petrenko, A Pukhov, K Rieger, O Reimann, H Ruhl, E Shaposhnikova, LO Silva, A Sosedkin, A Sosedkin, R Tarkeshian, RMGN Trines, T Tückmantel, J Vieira, J Vieira, H Vincke, M Wing, G Xia, G Xia

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN - the AWAKE experiment - has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator. © 2014 IOP Publishing Ltd.


The ATLAS(3D) project - XXVII. Cold gas and the colours and ages of early-type galaxies

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 444 (2014) 3408-3426

LM Young, N Scott, P Serra, K Alatalo, E Bayet, L Blitz, M Bois, F Bournaud, M Bureau, AF Crocker, M Cappellari, RL Davies, TA Davis, PT de Zeeuw, P-A Duc, E Emsellem, S Khochfar, D Krajnovic, H Kuntschner, RM McDermid, R Morganti, T Naab, T Oosterloo, M Sarzi, A-M Weijmans


Modelling gamma-ray photon emission and pair production in high-intensity laser-matter interactions

Journal of Computational Physics 260 (2014) 273-285

CP Ridgers, CP Ridgers, CP Ridgers, JG Kirk, R Duclous, TG Blackburn, CS Brady, K Bennett, TD Arber, AR Bell, AR Bell

In high-intensity (>1021 Wcm -2) laser-matter interactions gamma-ray photon emission by the electrons can strongly affect the electron's dynamics and copious numbers of electron-positron pairs can be produced by the emitted photons. We show how these processes can be included in simulations by coupling a Monte Carlo algorithm describing the emission to a particle-in-cell code. The Monte Carlo algorithm includes quantum corrections to the photon emission, which we show must be included if the pair production rate is to be correctly determined. The accuracy, convergence and energy conservation properties of the Monte Carlo algorithm are analysed in simple test problems. © 2013 Elsevier Inc.


Phase-space Lagrangian derivation of electrostatic gyrokinetics in general geometry (vol 53, 045001, 2011)

PLASMA PHYSICS AND CONTROLLED FUSION 56 (2014) ARTN 099501

FI Parra, I Calvo


Erratum: Long-wavelength limit of gyrokinetics in a turbulent tokamak and its intrinsic ambipolarity (Plasma Phys. Control. Fusion (2012) 54 (115007))

Plasma Physics and Controlled Fusion 56 (2014)

I Calvo, FI Parra, FI Parra


High energy conversion efficiency in laser-proton acceleration by controlling laser-energy deposition onto thin foil targets

Applied Physics Letters 104 (2014)

CM Brenner, CM Brenner, APL Robinson, K Markey, RHH Scott, RJ Gray, M Rosinski, O Deppert, J Badziak, D Batani, JR Davies, SM Hassan, KL Lancaster, K Li, IO Musgrave, PA Norreys, PA Norreys, J Pasley, J Pasley, M Roth, HP Schlenvoigt, C Spindloe, M Tatarakis, T Winstone, J Wolowski, D Wyatt, P McKenna, D Neely

An all-optical approach to laser-proton acceleration enhancement is investigated using the simplest of target designs to demonstrate application-relevant levels of energy conversion efficiency between laser and protons. Controlled deposition of laser energy, in the form of a double-pulse temporal envelope, is investigated in combination with thin foil targets in which recirculation of laser-accelerated electrons can lead to optimal conditions for coupling laser drive energy into the proton beam. This approach is shown to deliver a substantial enhancement in the coupling of laser energy to 5-30 MeV protons, compared to single pulse irradiation, reaching a record high 15% conversion efficiency with a temporal separation of 1 ps between the two pulses and a 5 μm-thick Au foil. A 1D simulation code is used to support and explain the origin of the observation of an optimum pulse separation of ∼1 ps. © 2014 Author(s).


Performance of the K-band multi-object spectrograph (KMOS) on the ESO VLT

GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY V 9147 (2014)

R Sharples, R Bender, AA Berbel, R Bennett, N Bezawada, R Castillo, M Cirasuolo, P Clark, G Davidson, R Davies, R Davies, M Dubbeldam, A Fairley, G Finger, NF Schreiber, R Genzel, R Haefner, A Hess, I Jung, I Lewis, D Montgomery, J Murray, B Muschielok, J Pirard, S Ramsey, P Rees, J Richter, D Robertson, I Robson, S Rolt, R Saglia, I Saviane, J Schlichter, L Schmidtobreik, A Segovia, A Smette, M Tecza, S Todd, M Wegner, E Wiezorrek


Evidence for a glassy state in strongly driven carbon.

Scientific reports 4 (2014) 5214-

CR Brown, DO Gericke, M Cammarata, BI Cho, T Döppner, K Engelhorn, E Förster, C Fortmann, D Fritz, E Galtier, SH Glenzer, M Harmand, P Heimann, NL Kugland, DQ Lamb, HJ Lee, RW Lee, H Lemke, M Makita, A Moinard, CD Murphy, B Nagler, P Neumayer, KU Plagemann, R Redmer, D Riley, FB Rosmej, P Sperling, S Toleikis, SM Vinko, J Vorberger, S White, TG White, K Wünsch, U Zastrau, D Zhu, T Tschentscher, G Gregori

Here, we report results of an experiment creating a transient, highly correlated carbon state using a combination of optical and x-ray lasers. Scattered x-rays reveal a highly ordered state with an electrostatic energy significantly exceeding the thermal energy of the ions. Strong Coulomb forces are predicted to induce nucleation into a crystalline ion structure within a few picoseconds. However, we observe no evidence of such phase transition after several tens of picoseconds but strong indications for an over-correlated fluid state. The experiment suggests a much slower nucleation and points to an intermediate glassy state where the ions are frozen close to their original positions in the fluid.


AMS-02 data confronts acceleration of cosmic ray secondaries in nearby sources

ArXiv (2014)

P Mertsch, S Sarkar

We revisit the model proposed earlier to account for the observed increase in the positron fraction in cosmic rays with increasing energy, in the light of new data from the Alpha Magnetic Spectrometer (AMS-02) experiment. The model accounts for the production and acceleration of secondary electrons and positrons in nearby supernova remnants which results in an additional, harder component that becomes dominant at high energies. By fitting this to AMS-02 data we can calculate the expected concomitant rise of the boron-to-carbon ratio, as well as of the fraction of antiprotons. If these predictions are confirmed by the forthcoming AMS-02 data it would conclusively rule out all other proposed explanations, in particular dark matter annihilations or decays.


FINGERPRINTS OF GALACTIC LOOP I ON THE COSMIC MICROWAVE BACKGROUND

ASTROPHYSICAL JOURNAL LETTERS 789 (2014) ARTN L29

H Liu, P Mertsch, S Sarkar