Publications

2000
Dingus BL, Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Dorfan DE, Ellsworth RW, Evans D, Falcone A, et al. Milagro: A TeV gamma-ray monitor of the Northern Hemisphere Sky, in American Institute of Physics Conference Series. Vol 510. ; 2000 :642–645.
Dingus BL, Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Ellsworth RW, Evans D, Falcone A, Fleysher L, et al. Milagro: A TeV observatory for gamma-ray bursts, in Gamma-ray Bursts, 5th Huntsville Symposium. Vol 526. ; 2000 :751–755.
Kappadath SC, Altice PP, Cherry ML, Guzik TG, Stacy JG, Macri J, McConnell ML, Ryan JM, Band DL, Matteson JL, et al. Minute-of-Arc Resolution Gamma ray Imaging Experiment-MARGIE, in American Institute of Physics Conference Series. Vol 510. ; 2000 :779–783.
Smith AJ, Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Dingus BL, Dorfan DE, Ellsworth RW, Evans D, et al. Results from the Milagrito experiment, in American Institute of Physics Conference Series. Vol 515. ; 2000 :441–447.
Young CA, Connors A, Bennett K, Collmar W, Hermsen W, Kippen RM, Kolaczyk ED, Kuiper L, McConnell M, Miller R, et al. Spectra of a recent bright burst measured by CGRO-COMPTEL: GRB 990123, in Gamma-ray Bursts, 5th Huntsville Symposium. Vol 526. ; 2000 :170–174.
Schönfelder V, Bennett K, Blom JJ, Bloemen H, Collmar W, Connors A, Diehl R, Hermsen W, Iyudin A, Kippen RM, et al. Summary of the first COMPTEL source catalogue, in American Institute of Physics Conference Series. Vol 510. ; 2000 :596–600.
Ryan JM, Arndt M, Lockwood JA, McConnell ML, Miller R, Young CA, Diehl R, Rank G, Schoenfelder V, Bennett K, et al. COMPTEL Gamma-Ray Observations of the C4 Solar Flare on 20 January 2000, in AAS/Solar Physics Division Meeting #31. Vol 32. ; 2000 :847–847.
McEnery JE, Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Dingus BL, Dorfan DE, Ellsworth RW, Evans D, et al. Evidence for TeV emission from GRB 970417a, in Gamma-ray Bursts, 5th Huntsville Symposium. Vol 526. ; 2000 :240–244.
Miller RS, Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Dingus BL, Dorfan DE, Ellsworth RW, Evans D, et al. First results of a study of TeV emission from GRBs in Milagrito, in American Institute of Physics Conference Series. Vol 510. ; 2000 :543–547.
McConnell ML, Ryan JM, Collmar W, Schönfelder V, Steinle H, Strong AW, Bloemen H, Hermsen W, Kuiper L, Bennett K, et al. Spectral Variability of Cygnus X-1 at Energies Above 1 MeV, in AAS/High Energy Astrophysics Division #5. Vol 32. ; 2000 :1233–1233.
McConnell ML, Macri JR, Ryan J, Larson K, Hamel LA, Bernard G, Pomerleau C, Tousignant O, Leroux J-C, Jordanov VT. Three-dimensional imaging and detection efficiency performance of orthogonal coplanar CZT strip detectors, in SPIE Proceedings. ; 2000. Publisher's VersionAbstract
We report on recent three-dimensional imaging performance and detection efficiency measurements obtained with 5 mm thick prototype CdZnTe detectors fabricated with orthogonal coplanar anode strips. In previous work, we have shown that detectors fabricated using this design achieve both very good energy resolution and sub-millimeter spatial resolution with fewer electronic channels than are required for pixel detectors. As electron-only devices, like pixel detectors, coplanar anode strip detectors can be fabricated in the thickness required to be effective imagers for photons with energies in excess of 500 keV. Unlike conventional double-sided strip detectors, the coplanar anode strip detectors require segmented contacts and signal processing electronics on only one surface. The signals can be processed to measure the total energy deposit and the photon interaction location in three dimensions. The measurements reported here provide a quantitative assessment of the detection capabilities of orthogonal coplanar anode strip detectors.
O Neill TJ, Bhattacharya D, Dixon DD, Polson M, White RS, Zych AD, Ryan J, McConnell M, Macri J, Samimi J, et al. The TIGRE gamma-ray telescope, in American Institute of Physics Conference Series. Vol 510. ; 2000 :804–808.
Arndt MB, Connors A, McConnell M, Ryan JM, Suleiman R, Young CA, Bennett K, Rank G, Schönfelder V. X-Ray and Gamma Ray Measurements of the 15 November 1991 Solar Flare, in High Energy Solar Physics Workshop - Anticipating Hess!. Vol 206. ; 2000 :451–451.
McEnery JE, Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Dingus BL, Dorfan DE, Ellsworth RW, Evans D, et al. First Results of a Study of TeV Emission from GRBs in Milagrito . American Institute of Physics Conference Proceedings [Internet]. 2000;515 :243. Publisher's VersionAbstract

Milagrito, a detector sensitive to gamma-rays at TeV energies, monitored the northern sky during the period February 1997 through May 1998. With a large field of view and high duty cycle, this instrument was used to perform a search for TeV counterparts to gamma-ray bursts. Within the Milagrito field of view 54 gamma-ray bursts at keV energies were observed by the Burst And Transient Satellite Experiment (BATSE) aboard the Compton Gamma-Ray Observatory. This paper describes the results of a preliminary analysis to search for TeV emission correlated with BATSE detected bursts. Milagrito detected an excess of events coincident both spatially and temporally with GRB 970417a, with chance probability \$2.8 \times 10^-5\$ within the BATSE error radius. No other significant correlations were detected. Since 54 bursts were examined the chance probability of observing an excess with this significance in any of these bursts is \$1.5 \times 10^-3\$. The statistical aspects and physical implications of this result are discussed.

Collmar W, Schoenfelder V, Strong AW, Bloemen H, Hermsen W, McConnell M, Ryan J, Bennett K. COMPTEL Time-Averaged All-Sky Point Source Analysis . 26th International Cosmic Ray Conference [Internet]. 2000;5 :316-319. Publisher's VersionAbstract

We use all COMPTEL data from the beginning of the CGRO mission (April '91) up to the end of CGRO Cycle 6 (November '97) to carry out all-sky point source analyses in the four standard COMPTEL energy bands for different time periods. We apply our standard maximum-likelihood method to generate all-sky significance and flux maps for point sources by subtracting off the diffuse emission components via model fitting. In addition, fluxes of known sources have been determined for individual CGRO Phases/Cycles to generate lightcurves with a time resolution of the order of one year. The goal of the analysis is to derive quantitative results – significances, fluxes, light curves – of our brightest and most significant sources such as 3C 273, and to search for additional new COMPTEL sources, showing up in time-averaged maps only.

Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Dingus BL, Dorfan DE, Ellsworth RW, Evans D, Falcone A, et al. Evidence for TeV emission from GRB 970417a. ASTROPHYSICAL JOURNAL [Internet]. 2000;533 :L119–L122. Publisher's Version
Atkins TMCR, Benbow W, Berley D, Chen ML, Coyne DG, Dingus BL, Dorfan DE, Ellsworth RW, Evans D, Falcone A, et al. Evidence for TeV Emission from GRB 970417a. ArXiv Astrophysics e-prints. 2000.
Schonfelder V, Bennett K, Blom JJ, Bloemen H, Collmar W, Connors A, Diehl R, Hermsen W, Iyudin A, Kippen RM, et al. The first COMPTEL source catalogue. ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES [Internet]. 2000;143 :145–179. Publisher's Version
McConnell ML, Ryan JM, Collmar W, Schonfelder V, Steinle H, Strong AW, Bloemen H, Hermsen W, Kuiper L, Bennett K, et al. A high-sensitivity measurement of the MeV gamma-ray spectrum of Cygnus X-1. ASTROPHYSICAL JOURNAL [Internet]. 2000;543 :928–937. Publisher's Version
Atkins R, Benbow W, Berley D, Chen ML, Coyne DG, Delay RS, Dingus BL, Dorfan DE, Ellsworth RW, Espinoza C, et al. Milagrito, a TeV air-shower array. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT [Internet]. 2000;449 :478–499. Publisher's Version

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