Saved in:
| Main Authors: | , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2510.15465 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866909852649914368 |
|---|---|
| author | Wierzcholska, Alicja Siejkowski, Hubert |
| author_facet | Wierzcholska, Alicja Siejkowski, Hubert |
| contents | X-ray observations are essential to achieve a deeper understanding of the broadband emission mechanism in blazars. Here, we present a long-term spectral and temporal analysis of X-ray and optical observations of 1E 0229+200 collected with the Neil Gehrels Swift Observatory from 2008 to 2024, complemented by hard X-ray observations from the Nuclear Spectroscopic Telescope Array NuSTAR. The blazar 1ES 0229+200 is a high-frequency, peaked BL Lac object, known for its exceptionally hard very high-energy (VHE) $γ$-ray spectrum extending up to 10 TeV. In August 2021, NuSTAR observed the source in a low X-ray state, revealing a concave spectral shape with a distinct upturn around 25 keV. This feature contrasts with previous observations performed with NuSTAR and Swift-BAT, which showed no such spectral upturn. Previous observations of 1ES 0229+200 and broadband SED (spectral energy distribution) modelling suggest that its X-ray emission extends beyond 100 keV without a significant cutoff. The newly detected spectral upturn may indicate a transition between the synchrotron and inverse Compton components or could be linked to photohadronic processes involving high-energy neutrinos. We discuss the implications of this finding in the context of blazar spectral energy distributions, particularly the potential existence of a third SED bump in the kiloelectronvolt to megaelectronvolt range. The observed spectral features support the hypothesis that 1ES 0229+200 could be a source of high-energy neutrino emission. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2510_15465 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Disentangling two spectral components in the X-ray emission of the blazar 1ES 0229+200 Wierzcholska, Alicja Siejkowski, Hubert High Energy Astrophysical Phenomena X-ray observations are essential to achieve a deeper understanding of the broadband emission mechanism in blazars. Here, we present a long-term spectral and temporal analysis of X-ray and optical observations of 1E 0229+200 collected with the Neil Gehrels Swift Observatory from 2008 to 2024, complemented by hard X-ray observations from the Nuclear Spectroscopic Telescope Array NuSTAR. The blazar 1ES 0229+200 is a high-frequency, peaked BL Lac object, known for its exceptionally hard very high-energy (VHE) $γ$-ray spectrum extending up to 10 TeV. In August 2021, NuSTAR observed the source in a low X-ray state, revealing a concave spectral shape with a distinct upturn around 25 keV. This feature contrasts with previous observations performed with NuSTAR and Swift-BAT, which showed no such spectral upturn. Previous observations of 1ES 0229+200 and broadband SED (spectral energy distribution) modelling suggest that its X-ray emission extends beyond 100 keV without a significant cutoff. The newly detected spectral upturn may indicate a transition between the synchrotron and inverse Compton components or could be linked to photohadronic processes involving high-energy neutrinos. We discuss the implications of this finding in the context of blazar spectral energy distributions, particularly the potential existence of a third SED bump in the kiloelectronvolt to megaelectronvolt range. The observed spectral features support the hypothesis that 1ES 0229+200 could be a source of high-energy neutrino emission. |
| title | Disentangling two spectral components in the X-ray emission of the blazar 1ES 0229+200 |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2510.15465 |