Bulletin of the American Physical Society
APS April Meeting 2013
Volume 58, Number 4
Saturday–Tuesday, April 13–16, 2013; Denver, Colorado
Session D14: Missions and Surveys |
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Sponsoring Units: DAP Chair: Miguel Mostafa, Colorado State University Room: Plaza Court 3 |
Saturday, April 13, 2013 3:30PM - 3:42PM |
D14.00001: The JEM-EUSO Mission Lawrence Wiencke The Extreme Universe Space Observatory (EUSO) for full-sky high energy astroparticle physics above 3x$10^{19}$ eV is planned for the Japanese Experiment Module (JEM) on the International Space Station. This extreme energy cosmic ray detector will look down on the earth's atmosphere from space to achieve an aperture at $10^{20}$ eV that exceeds the largest ground based detector by more than an order of magnitude. This pioneering instrument will also be sensitive to atmospheric optical transients, for example meteorites and ``Elves.'' The planned scientific program, the instrument, including a Global Light System for ground based calibration and the R\&D effort will be presented. The latter includes a prototype to be tested on the ground at the Telescope Array Project in 2013 and at stratospheric altitudes in a balloon launch planned for 2014 from Timmins Canada. [Preview Abstract] |
Saturday, April 13, 2013 3:42PM - 3:54PM |
D14.00002: The CALorimetric Electron Telescope (CALET): a High-Energy Astroparticle Physics Observatory on the International Space Station John Krizmanic CALET is a Japanese-led, multinational experiment that is scheduled to launch in 2014 to be attached to the Exposure Facility of the Japanese Experiment Module (JEM-EF) on the ISS. During its 5-year mission, CALET will measure the fluxes of electrons/positrons from 1 GeV to 20 TeV, gamma rays from 10 GeV to 10 TeV, and nuclei (Z=1 to 40) from 10 GeV to 1000 TeV. These measurements will address CALET's scientific goals to search for signatures of dark matter, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy, and search for nearby astrophysical sources of high-energy electrons. The main CALET instrument (CAL) is comprised of three modules: 1) two layers of segmented plastic scintillators for cosmic-ray charge identification (CHD), 2) a 3 X0-thick tungsten-scintillating fiber imaging calorimeter (IMC), and 3) and a 27 X0-thick, segmented lead-tungstate calorimeter (TASC). The IMC and TASC provide measurements of the longitudinal and lateral shower development, yielding good electron/hadron separation. CALET also includes a dedicated Gamma-ray Burst Monitor (CGBM) instrument. This talk will review the status of the mission, describe the instrument configuration and performance, and discuss the CALET cosmic radiation measurement capability. [Preview Abstract] |
Saturday, April 13, 2013 3:54PM - 4:06PM |
D14.00003: The Dark Ages Radio Explorer (DARE): What were the first objects to light up the Universe and when did they do it? Jack Burns In the NRC Astrophysics Decadal Survey, Cosmic Dawn was singled out as one of the top astrophysics priorities. Specifically, the Decadal report asked ``when and how did the first galaxies form out of cold clumps of hydrogen gas and start to shine---when was our cosmic dawn?'' This is the science objective of DARE -- to search for the first stars, galaxies, and black holes via their impact on the intergalactic medium as measured by the highly redshifted 21-cm hyperfine transition of neutral hydrogen (HI). DARE will probe redshifts of 11-35 with observed frequencies of 40-120 MHz. DARE will observe expected spectral features in the global signal of HI that correspond to stellar ignition, X-ray heating/ionization from the first accreting black holes, and the beginning of reionization. DARE will observe these spectral features with a biconical dipole antenna along with a receiver and digital spectrometer. We will place DARE in lunar orbit and take data only above the farside, a location known to be free of human-generated RFI and with a negligible ionosphere. The mission concept will be presented including initial results from an engineering prototype in western Australian which is designed to perform end-to-end validation of the instrument and our calibration techniques. [Preview Abstract] |
Saturday, April 13, 2013 4:06PM - 4:18PM |
D14.00004: The High-Altitude Water Cherenkov Observatory: First Light Thomas Weisgarber The High-Altitude Water Cherenkov (HAWC) Observatory is under construction at Sierra Negra in the state of Puebla in Mexico. Operation began in September 2012, with the first 30 out of the final 300 water Cherenkov detectors deployed and in data acquisition. The HAWC Observatory is designed to record particle air showers from gamma rays and cosmic rays with TeV energies. Though the detector is only 10\% complete, HAWC is already the world's largest water Cherenkov detector in the TeV band. In this presentation, I will summarize the performance of the detector to date and discuss preliminary observations of cosmic-ray and gamma-ray sources. I will also describe deployment plans for the remainder of the detector and outline prospects for TeV observations in the coming year. [Preview Abstract] |
Saturday, April 13, 2013 4:18PM - 4:30PM |
D14.00005: Survey and pointed mode observations with the Fermi Gamma-ray Space Telescope Julie McEnery During the first few years of the Fermi mission, the default observation mode has been an all-sky survey, optimized to provide relatively uniform coverage of the entire sky every three hours. Over 95\% of the mission has been performed in this observation mode. However, Fermi is capable of flexible survey mode patterns, and inertially pointed observations both of which allow increased coverage of selected parts of the sky. In this presentation, I will describe the types of observations that Fermi can make, the relative advantages and disadvantages of various observations, and provide guidelines to help Fermi users plan and evaluate non-standard observations. [Preview Abstract] |
Saturday, April 13, 2013 4:30PM - 4:42PM |
D14.00006: LENS: $\mu$LENS Simulations, Analysis, and Results Charles Rasco Simulations of the Low-Energy Neutrino Spectrometer prototype, $\mu$LENS, have been performed in order to benchmark the first measurements of the $\mu$LENS detector at the Kimballton Underground Research Facility (KURF). $\mu$LENS is a 6x6x6 celled scintillation lattice filled with Linear Alkylbenzene based scintillator. We have performed simulations of $\mu$LENS using the GEANT4 toolkit. We have measured various radioactive sources, LEDs, and environmental background radiation measurements at KURF using up to 96 PMTs with a simplified data acquisition system of QDCs and TDCs. In this talk we will demonstrate our understanding of the light propagation and we will compare simulation results with measurements of the $\mu$LENS detector of various radioactive sources, LEDs, and the environmental background radiation. [Preview Abstract] |
Saturday, April 13, 2013 4:42PM - 4:54PM |
D14.00007: Hard X-ray emission from Starburst Galaxies with the NuSTAR Mission Ann Hornschemeier, Megan Argo, Keith Bechtol, Steve Boggs, Finn Christensen, William Craig, Charles Hailey, Fiona Harrison, Bret Lehmer, J.-C. Leyder, Thomas Maccarone, Andrew Ptak, Daniel Stern, Tonia Venters, Daniel Wik, Andreas Zezas, William Zhang Launched in mid-2012, NuSTAR is the first focusing hard X-ray (E\textgreater 10 keV) astronomical observatory. Hard X-ray emission from star-forming galaxies arises from a population of neutron stars and stellar-mass black holes, however few starburst galaxies have been detected above 10 keV. Here we present an overview of a program to survey six normal/starburst galaxies at hard X-ray energies. As of early 2013, only the NuSTAR-Chandra-VLBA multiwavelength campaign on NGC 253 has been performed, consisting of three observational periods. The monitoring was designed to (1) sensitively isolate the locations of X-ray binaries, (2) determine the nature of the accreting compact objects via their 0.5-30 keV spectral properties, and (3) identify interesting flaring X-ray/radio sources as they make spectral state transitions due to variability in their accretion. We will also discuss upcoming observations of the rest of the sample. [Preview Abstract] |
Saturday, April 13, 2013 4:54PM - 5:06PM |
D14.00008: Search for Giant Relic Radio Lobes Straddling Classical Double Radio Galaxies Paul Wiita, S.K. Sirothia, - Gopal-Krishna The Giant Metrewave Radio Telescope (GMRT) in India is extremely sensitive and has excellent resolution at low frequencies down to 150 MHz. We are reprocessing archival GMRT data using AIPS++ to make new high dynamic range maps of known radio galaxies, primarily at 325 MHz. The goal is to search for extended synchrotron radiation often only detectable at lower frequencies. Such radiation is emitted by lower energy relativistic electrons that had been accelerated by the radio galaxy at hot-spots at the ends of jets during an earlier phase of activity. Any such discoveries would add to the fewer than 20 known Double-Double Radio Galaxies (DDRGs), which are the best tracers of recurrent activity in galactic nuclei and are one of the few ways for us to understand the duty cycle of such activity, associated with the feeding of supermassive black holes. Good maps of these sources could distinguish between the competing hot-spot and bow-shock models for the inner lobes of DDRGs. Discoveries of such relic lobes would also caution against the currently widespread use of classical double radio sources for testing cosmological models and unification schemes for active galactic nuclei since their ages and sizes would need to be reconsidered. We report our discoveries to date. [Preview Abstract] |
Saturday, April 13, 2013 5:06PM - 5:18PM |
D14.00009: Controlling for the Effects of Baryons in Cosmic Shear Constraints on Dark Energy Andrew Zentner The uncertainty introduced by the effects of baryons on the power spectrum of the convergence field is a significant theoretical error limiting forthcoming gravitational lensing surveys. A proposed method to account for baryonic effects is to include parameters that characterize dark matter halos, and to fit lensing data to these halo parameters concurrently with the cosmological parameters. We test this proposal by using this technique to model convergence power spectrum predictions from a set of cosmological simulations. We estimate biases in dark energy parameters that would be incurred if one were to fit the spectra predicted by the simulations either with no model for baryons, or with the proposed method. Neglecting baryonic effects leads to biases in dark energy parameters that are several times the statistical errors of surveys like the Dark Energy Survey. The proposed method to correct for baryonic effects renders the residual biases in dark energy equation of state parameters smaller than the statistical errors. These results suggest that this mitigation method may be applied to analyze convergence spectra from a survey like the Dark Energy Survey. For significantly larger surveys, such as the LSST or Euclid, the biases introduced by baryonic effects remain significant. [Preview Abstract] |
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