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Anderson, IN, United States

Anderson University | Date: 2005-05-24

pre-recorded CDs featuring musical performances.

Anderson University and Anderson College Inc. | Date: 1988-06-14


Aliu E.,Barnard College | Aliu E.,University of Barcelona | Archambault S.,McGill University | Archer A.,Washington University in St. Louis | And 84 more authors.
Astrophysical Journal | Year: 2015

We present the results of 71.6 hr of observations of the Geminga pulsar (PSR J0633+1746) with the VERITAS very-high-energy gamma-ray telescope array. Data taken with VERITAS between 2007 November and 2013 February were phase-folded using a Geminga pulsar timing solution derived from data recorded by the XMM-Newton and Fermi-LAT space telescopes. No significant pulsed emission above 100 GeV is observed, and we report upper limits at the 95% confidence level on the integral flux above 135 GeV (spectral analysis threshold) of 4.0 × 10-13 s-1 cm-2 and 1.7 × 10-13 s-1 cm-2 for the two principal peaks in the emission profile. These upper limits, placed in context with phase-resolved spectral energy distributions determined from 5 yr of data from the Fermi-Large Area Telescope (LAT), constrain possible hardening of the Geminga pulsar emission spectra above ∼50 GeV. © 2015. The American Astronomical Society. All rights reserved.

Aliu E.,Barnard College | Archer A.,Washington University in St. Louis | Aune T.,University of California at Los Angeles | Barnacka A.,Harvard - Smithsonian Center for Astrophysics | And 90 more authors.
Astrophysical Journal | Year: 2015

We present results from VERITAS observations of the BL Lac object PG 1553+113 spanning the years 2010, 2011, and 2012. The time-averaged spectrum, measured between 160 and 560 GeV, is well described by a power law with a spectral index of 4.33 ± 0.09. The time-averaged integral flux above 200 GeV measured for this period was (1.69 ± 0.06) × 10-11 photons cm-2 s-1, corresponding to 6.9% of the Crab Nebula flux. We also present the combined γ-ray spectrum from the Fermi Large Area Telescope and VERITAS covering an energy range from 100 MeV to 560 GeV. The data are well fit by a power law with an exponential cutoff at 101.9 ± 3.2 GeV. The origin of the cutoff could be intrinsic to PG 1553+113 or be due to the γ-ray opacity of our universe through pair production off the extragalactic background light (EBL). Given lower limits to the redshift of z > 0.395 based on optical/UV observations of PG 1553+113, the cutoff would be dominated by EBL absorption. Conversely, the small statistical uncertainties of the VERITAS energy spectrum have allowed us to provide a robust upper limit on the redshift of PG 1553+113 of z ≤ 0.62. A strongly elevated mean flux of (2.50 ± 0.14) × 10-11 photons cm-2 s-1 (10.3% of the Crab Nebula flux) was observed during 2012, with the daily flux reaching as high as (18.3% of the Crab Nebula flux) on MJD 56048. The light curve measured during the 2012 observing season is marginally inconsistent with a steady flux, giving a χ2 probability for a steady flux of 0.03%. © 2015. The American Astronomical Society. All rights reserved.

Archer A.,Washington University in St. Louis | Benbow W.,Harvard - Smithsonian Center for Astrophysics | Bird R.,University College Dublin | Buchovecky M.,University of California at Los Angeles | And 76 more authors.
Astrophysical Journal | Year: 2016

The Galactic Center ridge has been observed extensively in the past by both GeV and TeV gamma-ray instruments revealing a wealth of structure, including a diffuse component and the point sources G0.9+0.1 (a composite supernova remnant) and Sgr A∗ (believed to be associated with the supermassive black hole located at the center of our Galaxy). Previous very high energy (VHE) gamma-ray observations with the H.E.S.S. experiment have also detected an extended TeV gamma-ray component along the Galactic plane in the >300 GeV gamma-ray regime. Here we report on observations of the Galactic Center ridge from 2010 to 2014 by the VERITAS telescope array in the >2 TeV energy range. From these observations we (1) provide improved measurements of the differential energy spectrum for Sgr A∗ in the >2 TeV gamma-ray regime, (2) provide a detection in the >2 TeV gamma-ray emission from the composite SNR G0.9+0.1 and an improved determination of its multi-TeV gamma-ray energy spectrum, and (3) report on the detection of VER J1746-289, a localized enhancement of >2 TeV gamma-ray emission along the Galactic plane. © 2016. The American Astronomical Society. All rights reserved..

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