Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models
Observations of the time-dependent cosmic-ray Sun shadow have been proven as a valuable diagnostic for the assessment of solar magnetic field models. In this paper, seven years of IceCube data are compared to solar activity and solar magnetic field models. A quantitative comparison of solar magnetic...
| Main Authors: | , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2021
|
| Online Access: | https://hdl.handle.net/1721.1/136707 |
| _version_ | 1826204441634668544 |
|---|---|
| author | Aartsen, M. G. Abbasi, R. Ackermann, M. Adams, J. Aguilar, J. A. Ahlers, M. Ahrens, M. Alispach, C. Amin, N. M. Andeen, K. Anderson, T. Ansseau, I. Anton, G. Argüelles, C. Auffenberg, J. Axani, S. Bagherpour, H. Bai, X. Balagopal, A. V. Barbano, A. |
| author_facet | Aartsen, M. G. Abbasi, R. Ackermann, M. Adams, J. Aguilar, J. A. Ahlers, M. Ahrens, M. Alispach, C. Amin, N. M. Andeen, K. Anderson, T. Ansseau, I. Anton, G. Argüelles, C. Auffenberg, J. Axani, S. Bagherpour, H. Bai, X. Balagopal, A. V. Barbano, A. |
| author_sort | Aartsen, M. G. |
| collection | MIT |
| description | Observations of the time-dependent cosmic-ray Sun shadow have been proven as a valuable diagnostic for the assessment of solar magnetic field models. In this paper, seven years of IceCube data are compared to solar activity and solar magnetic field models. A quantitative comparison of solar magnetic field models with IceCube data on the event rate level is performed for the first time. Additionally, a first energy-dependent analysis is presented and compared to recent predictions. We use seven years of IceCube data for the moon and the Sun and compare them to simulations on data rate level. The simulations are performed for the geometrical shadow hypothesis for the moon and the Sun and for a cosmic-ray propagation model governed by the solar magnetic field for the case of the Sun. We find that a linearly decreasing relationship between Sun shadow strength and solar activity is preferred over a constant relationship at the 6.4σ level. We test two commonly used models of the coronal magnetic field, both combined with a Parker spiral, by modeling cosmic-ray propagation in the solar magnetic field. Both models predict a weakening of the shadow in times of high solar activity as it is also visible in the data. We find tensions with the data on the order of 3σ for both models, assuming only statistical uncertainties. The magnetic field model CSSS fits the data slightly better than the PFSS model. This is generally consistent with what is found previously by the Tibet AS-γ Experiment; a deviation of the data from the two models is, however, not significant at this point. Regarding the energy dependence of the Sun shadow, we find indications that the shadowing effect increases with energy during times of high solar activity, in agreement with theoretical predictions. |
| first_indexed | 2024-09-23T12:55:06Z |
| format | Article |
| id | mit-1721.1/136707 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T12:55:06Z |
| publishDate | 2021 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1367072021-11-01T14:36:57Z Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models Aartsen, M. G. Abbasi, R. Ackermann, M. Adams, J. Aguilar, J. A. Ahlers, M. Ahrens, M. Alispach, C. Amin, N. M. Andeen, K. Anderson, T. Ansseau, I. Anton, G. Argüelles, C. Auffenberg, J. Axani, S. Bagherpour, H. Bai, X. Balagopal, A. V. Barbano, A. Observations of the time-dependent cosmic-ray Sun shadow have been proven as a valuable diagnostic for the assessment of solar magnetic field models. In this paper, seven years of IceCube data are compared to solar activity and solar magnetic field models. A quantitative comparison of solar magnetic field models with IceCube data on the event rate level is performed for the first time. Additionally, a first energy-dependent analysis is presented and compared to recent predictions. We use seven years of IceCube data for the moon and the Sun and compare them to simulations on data rate level. The simulations are performed for the geometrical shadow hypothesis for the moon and the Sun and for a cosmic-ray propagation model governed by the solar magnetic field for the case of the Sun. We find that a linearly decreasing relationship between Sun shadow strength and solar activity is preferred over a constant relationship at the 6.4σ level. We test two commonly used models of the coronal magnetic field, both combined with a Parker spiral, by modeling cosmic-ray propagation in the solar magnetic field. Both models predict a weakening of the shadow in times of high solar activity as it is also visible in the data. We find tensions with the data on the order of 3σ for both models, assuming only statistical uncertainties. The magnetic field model CSSS fits the data slightly better than the PFSS model. This is generally consistent with what is found previously by the Tibet AS-γ Experiment; a deviation of the data from the two models is, however, not significant at this point. Regarding the energy dependence of the Sun shadow, we find indications that the shadowing effect increases with energy during times of high solar activity, in agreement with theoretical predictions. 2021-10-28T14:51:57Z 2021-10-28T14:51:57Z 2021-02-08 2021-02-11T09:12:34Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/136707 Phys. Rev. D 103, 042005 (2021) PUBLISHER_POLICY en http://dx.doi.org/10.1103/PhysRevD.103.042005 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Aartsen, M. G. Abbasi, R. Ackermann, M. Adams, J. Aguilar, J. A. Ahlers, M. Ahrens, M. Alispach, C. Amin, N. M. Andeen, K. Anderson, T. Ansseau, I. Anton, G. Argüelles, C. Auffenberg, J. Axani, S. Bagherpour, H. Bai, X. Balagopal, A. V. Barbano, A. Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models |
| title | Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models |
| title_full | Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models |
| title_fullStr | Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models |
| title_full_unstemmed | Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models |
| title_short | Measurements of the time-dependent cosmic-ray Sun shadow with seven years of IceCube data: Comparison with the Solar cycle and magnetic field models |
| title_sort | measurements of the time dependent cosmic ray sun shadow with seven years of icecube data comparison with the solar cycle and magnetic field models |
| url | https://hdl.handle.net/1721.1/136707 |
| work_keys_str_mv | AT aartsenmg measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT abbasir measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT ackermannm measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT adamsj measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT aguilarja measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT ahlersm measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT ahrensm measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT alispachc measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT aminnm measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT andeenk measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT andersont measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT ansseaui measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT antong measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT arguellesc measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT auffenbergj measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT axanis measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT bagherpourh measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT baix measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT balagopalav measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels AT barbanoa measurementsofthetimedependentcosmicraysunshadowwithsevenyearsoficecubedatacomparisonwiththesolarcycleandmagneticfieldmodels |