The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning
Gamma-ray astronomy through imaging atmospheric Cherenkov telescope (IACTs) has enabled the study of numerous astrophysical sources in the GeV-TeV domain. The presence of night sky background (NSB) in IACT images affects the reconstruction of the gamma-ray being observed and is usually dealt through...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/acecd9 |
| _version_ | 1797738367510642688 |
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| author | Saeeda Sajjad |
| author_facet | Saeeda Sajjad |
| author_sort | Saeeda Sajjad |
| collection | DOAJ |
| description | Gamma-ray astronomy through imaging atmospheric Cherenkov telescope (IACTs) has enabled the study of numerous astrophysical sources in the GeV-TeV domain. The presence of night sky background (NSB) in IACT images affects the reconstruction of the gamma-ray being observed and is usually dealt through image cleaning. In this work, we propose that the image cleaning approach might be adapted to the reconstruction method and NSB levels. In particular, we study the effect of NSB on source reconstruction for gamma-rays observed through IACT arrays through Monte Carlo simulations. We find that the presence of NSB can have a smoothing effect on the shower images enabling better source reconstruction under certain circumstances. We also find that there is an optimum cleaning threshold depending on the energy of the initial gamma-ray. This threshold shows very little dependence on the NSB level or core position. Based on these results, we propose and test a hybrid image cleaning method for source reconstruction. We find that this hybrid image cleaning method results in better source reconstruction when observations are made in high NSB conditions. Whereas at low NSB levels, the application of a single image cleaning threshold yields better results. We finally conclude that this implies that different image cleaning methods might be needed to best carry out source reconstructions at different NSB levels. |
| first_indexed | 2024-03-12T13:42:47Z |
| format | Article |
| id | doaj.art-193e101f579743ee80a64b56e03061f7 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T13:42:47Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-193e101f579743ee80a64b56e03061f72023-08-23T11:34:49ZengIOP PublishingNew Journal of Physics1367-26302023-01-0125808303810.1088/1367-2630/acecd9The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaningSaeeda Sajjad0https://orcid.org/0000-0002-4286-6617Department of Space Science, Institute of Space Technology , 1, Islamabad Highway, Islamabad 44000, Pakistan; Space and Astrophysics Research Lab (SARL), National Centre of GIS and Space Applications (NCGSA) , Islamabad 44000, PakistanGamma-ray astronomy through imaging atmospheric Cherenkov telescope (IACTs) has enabled the study of numerous astrophysical sources in the GeV-TeV domain. The presence of night sky background (NSB) in IACT images affects the reconstruction of the gamma-ray being observed and is usually dealt through image cleaning. In this work, we propose that the image cleaning approach might be adapted to the reconstruction method and NSB levels. In particular, we study the effect of NSB on source reconstruction for gamma-rays observed through IACT arrays through Monte Carlo simulations. We find that the presence of NSB can have a smoothing effect on the shower images enabling better source reconstruction under certain circumstances. We also find that there is an optimum cleaning threshold depending on the energy of the initial gamma-ray. This threshold shows very little dependence on the NSB level or core position. Based on these results, we propose and test a hybrid image cleaning method for source reconstruction. We find that this hybrid image cleaning method results in better source reconstruction when observations are made in high NSB conditions. Whereas at low NSB levels, the application of a single image cleaning threshold yields better results. We finally conclude that this implies that different image cleaning methods might be needed to best carry out source reconstructions at different NSB levels.https://doi.org/10.1088/1367-2630/acecd9gamma-ray astronomyimaging atmospheric Cherenkov telescopenight sky backgroundimage cleaningsource reconstruction |
| spellingShingle | Saeeda Sajjad The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning New Journal of Physics gamma-ray astronomy imaging atmospheric Cherenkov telescope night sky background image cleaning source reconstruction |
| title | The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning |
| title_full | The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning |
| title_fullStr | The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning |
| title_full_unstemmed | The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning |
| title_short | The effect of night sky background on source reconstruction in atmospheric Cherenkov telescope arrays and implications for image cleaning |
| title_sort | effect of night sky background on source reconstruction in atmospheric cherenkov telescope arrays and implications for image cleaning |
| topic | gamma-ray astronomy imaging atmospheric Cherenkov telescope night sky background image cleaning source reconstruction |
| url | https://doi.org/10.1088/1367-2630/acecd9 |
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