Please use this identifier to cite or link to this item:
https://hdl.handle.net/2445/221242
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DC Field | Value | Language |
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dc.contributor.author | Carretero-Castrillo, Mar | - |
dc.contributor.author | Molina, Edgar | - |
dc.contributor.author | Paredes i Poy, Josep Maria | - |
dc.contributor.author | Ribó Gomis, Marc | - |
dc.contributor.author | MAGIC Collaboration | - |
dc.date.accessioned | 2025-05-27T17:48:53Z | - |
dc.date.available | 2025-05-27T17:48:53Z | - |
dc.date.issued | 2023-02-10 | - |
dc.identifier.issn | 0031-9007 | - |
dc.identifier.uri | https://hdl.handle.net/2445/221242 | - |
dc.description.abstract | Aims. The BL Lac 1ES 2344+514 is known for temporary extreme properties characterised by a shift of the synchrotron spectral energy distribution (SED) peak energy νsynch, p above 1 keV. While those extreme states have only been observed during high flux levels thus far, additional multi-year observing campaigns are required to achieve a coherent picture. Here, we report the longest investigation of the source from radio to very high energy (VHE) performed so far, focussing on a systematic characterisation of the intermittent extreme states. Methods. We organised a monitoring campaign covering a 3-year period from 2019 to 2021. More than ten instruments participated in the observations in order to cover the emission from radio to VHE. In particular, sensitive X-ray measurements by XMM-Newton, NuSTAR, and AstroSat took place simultaneously with multi-hour MAGIC observations, providing an unprecedented constraint of the two SED components for this blazar. Results. While our results confirm that 1ES 2344+514 typically exhibits νsynch, p > 1 keV during elevated flux periods, we also find periods where the extreme state coincides with low flux activity. A strong spectral variability thus happens in the quiescent state, and is likely caused by an increase in the electron acceleration efficiency without a change in the electron injection luminosity. On the other hand, we also report a strong X-ray flare (among the brightest for 1ES 2344+514) without a significant shift of νsynch, p. During this particular flare, the X-ray spectrum is among the softest of the campaign. It unveils complexity in the spectral evolution, where the common harder-when-brighter trend observed in BL Lacs is violated. By combining Swift-XRT and Swift-UVOT measurements during a low and hard X-ray state, we find an excess of the UV flux with respect to an extrapolation of the X-ray spectrum to lower energies. This UV excess implies that at least two regions significantly contribute to the infrared/optical/ultraviolet/X-ray emission. Using the simultaneous MAGIC, XMM-Newton, NuSTAR, and AstroSat observations, we argue that a region possibly associated with the 10 GHz radio core may explain such an excess. Finally, we investigate a VHE flare, showing an absence of simultaneous variability in the 0.3−2 keV band. Using time-dependent leptonic modelling, we show that this behaviour, in contradiction to single-zone scenarios, can instead be explained by a two-component model. | - |
dc.format.extent | 8 p. | - |
dc.format.mimetype | application/pdf | - |
dc.language.iso | eng | - |
dc.publisher | American Physical Society | - |
dc.relation.isformatof | Reproducció del document publicat a: https://doi.org/10.48550/arXiv.2212.10527 | - |
dc.relation.ispartof | Physical Review Letters, 2023, vol. 130, num.6 | - |
dc.relation.uri | https://doi.org/10.48550/arXiv.2212.10527 | - |
dc.rights | (c) American Physical Society, 2023 | - |
dc.source | Articles publicats en revistes (Física Quàntica i Astrofísica) | - |
dc.subject.classification | Raigs gamma | - |
dc.subject.classification | Matèria fosca (Astronomia) | - |
dc.subject.classification | Telescopis | - |
dc.subject.other | Gamma rays | - |
dc.subject.other | Dark matter (Astronomy) | - |
dc.subject.other | Telescopes | - |
dc.title | Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC | - |
dc.type | info:eu-repo/semantics/article | - |
dc.type | info:eu-repo/semantics/publishedVersion | - |
dc.identifier.idgrec | 747472 | - |
dc.date.updated | 2025-05-27T17:48:54Z | - |
dc.rights.accessRights | info:eu-repo/semantics/openAccess | - |
Appears in Collections: | Articles publicats en revistes (Física Quàntica i Astrofísica) Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB)) |
Files in This Item:
File | Description | Size | Format | |
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857601.pdf | 3.7 MB | Adobe PDF | View/Open |
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