Validation of open-source science tools and background model construction in γ-ray astronomy

被引:32
作者
Mohrmann, L. [1 ]
Specovius, A. [1 ]
Tiziani, D. [1 ]
Funk, S. [1 ]
Malyshev, D. [1 ]
Nakashima, K. [1 ]
van Eldik, C. [1 ]
机构
[1] Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, Erwin Rommel Str 1, D-91058 Erlangen, Germany
关键词
methods: data analysis; gamma rays: general; NEBULA; FLARE;
D O I
10.1051/0004-6361/201936452
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
In classical analyses of gamma-ray data from imaging atmospheric Cherenkov telescopes (IACTs), such as the High Energy Stereoscopic System (H.E.S.S.), aperture photometry, or photon counting, is applied in a (typically circular) region of interest (RoI) encompassing the source. A key element in the analysis is to estimate the amount of background in the RoI due to residual cosmic ray-induced air showers in the data. Various standard background estimation techniques have been developed in the last decades, most of them rely on a measurement of the background from source-free regions within the observed field of view. However, in particular in the Galactic plane, source analysis and background estimation are hampered by the large number of, sometimes overlapping, gamma-ray sources and large-scale di ffuse gamma-ray emission. For complicated fields of view, a three-dimensional (3D) likelihood analysis shows the potential to be superior to classical analysis. In this analysis technique, a spectromorphological model, consisting of one or multiple source components and a background component, is fitted to the data, resulting in a complete spectral and spatial description of the field of view. For the application to IACT data, the major challenge of such an approach is the construction of a robust background model. In this work, we apply the 3D likelihood analysis to various test data recently made public by the H.E.S.S. collaboration, using the open analysis frameworks ctools and Gammapy. First, we show that, when using these tools in a classical analysis approach and comparing to the proprietary H.E.S.S. analysis framework, virtually identical high-level analysis results, such as field-of-view maps and spectra, are obtained. We then describe the construction of a generic background model from data of H.E.S.S. observations, and demonstrate that a 3D likelihood analysis using this background model yields high-level analysis results that are highly compatible with those obtained from the classical analyses. This validation of the 3D likelihood analysis approach on experimental data is an important step towards using this method for IACT data analysis, and in particular for the analysis of data from the upcoming Cherenkov Telescope Array (CTA).
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页数:22
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共 33 条
[1]   Characterising the VHE diffuse emission in the central 200 parsecs of our Galaxy with HESS [J].
Abdalla, H. ;
Abramowski, A. ;
Aharonian, F. ;
Benkhali, F. Ait ;
Akhperjanian, A. G. ;
Andersson, T. ;
Anguener, E. O. ;
Arakawa, M. ;
Arrieta, M. ;
Aubert, P. ;
Backes, M. ;
Balzer, A. ;
Barnard, M. ;
Becherini, Y. ;
Tjus, J. Becker ;
Berge, D. ;
Bernhard, S. ;
Bernloehr, K. ;
Blackwell, R. ;
Boettcher, M. ;
Boisson, C. ;
Bolmont, J. ;
Bonnefoy, S. ;
Bordas, P. ;
Bregeon, J. ;
Brun, F. ;
Brun, P. ;
Bryan, M. ;
Buechele, M. ;
Bulik, T. ;
Capasso, M. ;
Carr, J. ;
Casanova, S. ;
Cerruti, M. ;
Chakraborty, N. ;
Chaves, R. C. G. ;
Chen, A. ;
Chevalier, J. ;
Coffaro, M. ;
Colafrancesco, S. ;
Cologna, G. ;
Condon, B. ;
Conrad, J. ;
Cui, Y. ;
Davids, I. D. ;
Decock, J. ;
Degrange, B. ;
Deil, C. ;
Devin, J. ;
deWilt, P. .
ASTRONOMY & ASTROPHYSICS, 2018, 612
[2]   The HESS Galactic plane survey [J].
Abdalla, H. ;
Abramowski, A. ;
Aharonian, F. ;
Benkhali, F. Ait ;
Anguener, E. O. ;
Arakawa, M. ;
Arrieta, M. ;
Aubert, P. ;
Backes, M. ;
Balzer, A. ;
Barnard, M. ;
Becherini, Y. ;
Tjus, J. Becker ;
Berge, D. ;
Bernhard, S. ;
Bernloehr, K. ;
Blackwell, R. ;
Boettcher, M. ;
Boisson, C. ;
Bolmont, J. ;
Bonnefoy, S. ;
Bordas, P. ;
Bregeon, J. ;
Brun, F. ;
Brun, P. ;
Bryan, M. ;
Buechele, M. ;
Bulik, T. ;
Capasso, M. ;
Carrigan, S. ;
Caroff, S. ;
Carosi, A. ;
Casanova, S. ;
Cerruti, M. ;
Chakraborty, N. ;
Chaves, R. C. G. ;
Chen, A. ;
Chevalier, J. ;
Colafrancesco, S. ;
Condon, B. ;
Conrad, J. ;
Davids, I. D. ;
Decock, J. ;
Deil, C. ;
Devin, J. ;
deWilt, P. ;
Dirson, L. ;
Djannati-Atai, A. ;
Domainko, W. ;
Donath, A. .
ASTRONOMY & ASTROPHYSICS, 2018, 612
[3]   HESS observations of RX J1713.7-3946 with improved angular and spectral resolution: Evidence for gamma-ray emission extending beyond the X-ray emitting shell [J].
Abdalla, H. ;
Abramowski, A. ;
Aharonian, F. ;
Benkhali, F. Ait ;
Akhperjanian, A. G. ;
Andersson, T. ;
Anguener, E. O. ;
Arrieta, M. ;
Aubert, P. ;
Backes, M. ;
Balzer, A. ;
Barnard, M. ;
Becherini, Y. ;
Tjus, J. Becker ;
Berge, D. ;
Bernhard, S. ;
Bernloehr, K. ;
Blackwell, R. ;
Boettcher, M. ;
Boisson, C. ;
Bolmont, J. ;
Bordas, P. ;
Bregeon, J. ;
Brun, F. ;
Brun, P. ;
Bryan, M. ;
Bulik, T. ;
Capasso, M. ;
Carr, J. ;
Casanova, S. ;
Cerruti, M. ;
Chakraborty, N. ;
Chalme-Calvet, R. ;
Chaves, R. C. G. ;
Chen, A. ;
Chevalier, J. ;
Chretien, M. ;
Colafrancesco, S. ;
Cologna, G. ;
Condon, B. ;
Conrad, J. ;
Cui, Y. ;
Davids, I. D. ;
Decock, J. ;
Degrange, B. ;
Dei, C. ;
Devin, J. ;
deWilt, P. ;
Dirson, L. ;
Djannati-Atai, A. .
ASTRONOMY & ASTROPHYSICS, 2018, 612
[4]   Characterizing the γ-ray long-term variability of PKS2155 304 with HESS and Fermi-LAT [J].
Abdalla, H. ;
Abramowski, A. ;
Aharonian, F. ;
Benkhali, F. Ait ;
Akhperjanian, A. G. ;
Andersson, T. ;
Anguener, E. O. ;
Arrieta, M. ;
Aubert, P. ;
Backes, M. ;
Balzer, A. ;
Barnard, M. ;
Becherini, Y. ;
Tjus, J. Becker ;
Berge, D. ;
Bernhard, S. ;
Bernlorhr, K. ;
Blackwell, R. ;
Bottcher, M. ;
Boisson, C. ;
Bolmont, J. ;
Bordas, P. ;
Bregeon, J. ;
Brun, F. ;
Brun, P. ;
Bryan, M. ;
Bulik, T. ;
Capasso, M. ;
Carr, J. ;
Casanova, S. ;
Cerruti, M. ;
Chakraborty, N. ;
Chalme-Calvet, R. ;
Chaves, R. C. G. ;
Chen, A. ;
Chevalier, J. ;
Chretien, M. ;
Colafrancesco, S. ;
Cologna, G. ;
Condon, B. ;
Conrad, J. ;
Cui, Y. ;
Davids, I. D. ;
Decock, J. ;
Degrange, B. ;
Deil, C. ;
Devin, J. ;
deWilt, P. ;
Dirson, L. ;
Djannati-Atai, A. .
ASTRONOMY & ASTROPHYSICS, 2017, 598
[5]   Probing the extent of the non-thermal emission from the Vela X region at TeV energies with HESS [J].
Abramowski, A. ;
Acero, F. ;
Aharonian, F. ;
Akhperjanian, A. G. ;
Anton, G. ;
Balenderan, S. ;
Balzer, A. ;
Barnacka, A. ;
Becherini, Y. ;
Tjus, J. Becker ;
Bernloehr, K. ;
Birsin, E. ;
Biteau, J. ;
Bochow, A. ;
Boisson, C. ;
Bolmont, J. ;
Bordas, P. ;
Brucker, J. ;
Brun, F. ;
Brun, P. ;
Bulik, T. ;
Carrigan, S. ;
Casanova, S. ;
Cerruti, M. ;
Chadwick, P. M. ;
Charbonnier, A. ;
Chaves, R. C. G. ;
Cheesebrough, A. ;
Cologna, G. ;
Conrad, J. ;
Couturier, C. ;
Dalton, M. ;
Daniel, M. K. ;
Davids, I. D. ;
Degrange, B. ;
Deil, C. ;
deWilt, P. ;
Dickinson, H. J. ;
Djannati-Atai, A. ;
Domainko, W. ;
Drury, L. O' C. ;
Dubois, F. ;
Dubus, G. ;
Dutson, K. ;
Dyks, J. ;
Dyrda, M. ;
Egberts, K. ;
Eger, P. ;
Espigat, P. ;
Fallon, L. .
ASTRONOMY & ASTROPHYSICS, 2012, 548
[6]   VHE γ-ray emission of PKS 2155-304: spectral and temporal variability [J].
Abramowski, A. ;
Acero, F. ;
Aharonian, F. ;
Akhperjanian, A. G. ;
Anton, G. ;
de Almeida, U. Barres ;
Bazer-Bachi, A. R. ;
Becherini, Y. ;
Behera, B. ;
Benbow, W. ;
Bernloehr, K. ;
Bochow, A. ;
Boisson, C. ;
Bolmont, J. ;
Borrel, V. ;
Brucker, J. ;
Brun, F. ;
Brun, P. ;
Buehler, R. ;
Bulik, T. ;
Buesching, I. ;
Boutelier, T. ;
Chadwick, P. M. ;
Charbonnier, A. ;
Chaves, R. C. G. ;
Cheesebrough, A. ;
Chounet, L. -M. ;
Clapson, A. C. ;
Coignet, G. ;
Conrad, J. ;
Costamante, L. ;
Dalton, M. ;
Daniel, M. K. ;
Davids, I. D. ;
Degrange, B. ;
Deil, C. ;
Dickinson, H. J. ;
Djannati-Atai, A. ;
Domainko, W. ;
Drury, L. O'C. ;
Dubois, F. ;
Dubus, G. ;
Dyks, J. ;
Dyrda, M. ;
Egberts, K. ;
Eger, P. ;
Espigat, P. ;
Fallon, L. ;
Farnier, C. ;
Fegan, S. .
ASTRONOMY & ASTROPHYSICS, 2010, 520
[7]  
Acharya B. S., 2018, WSP, DOI 10.1142/10986
[8]   The Fermi Galactic Center GeV Excess and Implications for Dark Matter [J].
Ackermann, M. ;
Ajello, M. ;
Albert, A. ;
Atwood, W. B. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Bastieri, D. ;
Bellazzini, R. ;
Bissaldi, E. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonino, R. ;
Bottacini, E. ;
Brandt, T. J. ;
Bregeon ;
Bruel, P. ;
Buehler, R. ;
Burnett, T. H. ;
Cameron, R. A. ;
Caputo, R. ;
Caragiulo, M. ;
Caraveo, P. A. ;
Cavazzuti, E. ;
Cecchi, C. ;
Charles, E. ;
Chekhtman, A. ;
Chiang, J. ;
Chiappo, A. ;
Chiaro, G. ;
Ciprini, S. ;
Conrad, J. ;
Costanza, F. ;
Cuoco, A. ;
Cutini, S. ;
D'Ammando, F. ;
de Palmai, F. ;
Desiante, R. ;
Digel, S. W. ;
Di Lalla, N. ;
Di Mauro, M. ;
Di Venere, L. ;
Drell, P. S. ;
Favuzzi, C. ;
Fegan, J. ;
Ferrara, E. C. ;
Fockes, W. B. ;
Franckowiak, A. ;
Fukazawa, Y. ;
Funk, S. .
ASTROPHYSICAL JOURNAL, 2017, 840 (01)
[9]   An exceptional very high energy gamma-ray flare of PKS 2155-304 [J].
Aharonian, F. ;
Akhperjanian, A. G. ;
Bazer-Bachi, A. R. ;
Behera, B. ;
Beilicke, M. ;
Benbow, W. ;
Berge, D. ;
Bernloehr, K. ;
Boisson, C. ;
Bolz, O. ;
Borrel, V. ;
Boutelier, T. ;
Braun, I. ;
Brion, E. ;
Brown, A. M. ;
Buehler, R. ;
Buesching, I. ;
Bulik, T. ;
Carrigan, S. ;
Chadwick, P. M. ;
Clapson, A. C. ;
Chounet, L.-M. ;
Coignet, G. ;
Cornils, R. ;
Costamante, L. ;
Degrange, B. ;
Dickinson, H. J. ;
Djannati-Atai, A. ;
Domainko, W. ;
Drury, L. O'C. ;
Dubus, G. ;
Dyks, J. ;
Egberts, K. ;
Emmanoulopoulos, D. ;
Espigat, P. ;
Farnier, C. ;
Feinstein, F. ;
Fiasson, A. ;
Foerster, A. ;
Fontaine, G. ;
Funk, Seb. ;
Funk, S. ;
Fuessling, M. ;
Gallant, Y. A. ;
Giebels, B. ;
Glicenstein, J. F. ;
Glueck, B. ;
Goret, P. ;
Hadjichristidis, C. ;
Hauser, D. .
ASTROPHYSICAL JOURNAL, 2007, 664 (02) :L71-L74
[10]   Observations of the crab nebula with HESS [J].
Aharonian, F. ;
Akhperjanian, A. G. ;
Bazer-Bachi, A. R. ;
Beilicke, M. ;
Benbow, W. ;
Berge, D. ;
Bernloehr, K. ;
Boisson, C. ;
Bolz, O. ;
Borrel, V. ;
Braun, I. ;
Breitling, F. ;
Brown, A. M. ;
Buehler, R. ;
Buesching, I. ;
Carrigan, S. ;
Chadwick, P. M. ;
Chounet, L. -M. ;
Cornils, R. ;
Costamante, L. ;
Degrange, B. ;
Dickinson, H. J. ;
Djannati-Atai, A. ;
Drury, L. O'C. ;
Dubus, G. ;
Egberts, K. ;
Emmanoulopoulos, D. ;
Espigat, P. ;
Feinstein, F. ;
Ferrero, E. ;
Fiasson, A. ;
Fontaine, G. ;
Funk, Seb. ;
Funk, S. ;
Gallant, Y. A. ;
Giebels, B. ;
Glicenstein, J. F. ;
Goret, P. ;
Hadjichristidis, C. ;
Hauser, D. ;
Hauser, M. ;
Heinzelmann, G. ;
Henri, G. ;
Hermann, G. ;
Hinton, J. A. ;
Hofmann, W. ;
Holleran, M. ;
Horns, D. ;
Jacholkowska, A. ;
de Jager, O. C. .
ASTRONOMY & ASTROPHYSICS, 2006, 457 (03) :899-915