| 1. |
- Algaba, Juan-Carlos, et al.
(author)
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Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
- 2021
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In: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
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Research review (peer-reviewed)abstract
- In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
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| 2. |
- Adams, C. B., et al.
(author)
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Observation of the Gamma-Ray Binary HESS J0632+057 with the HESS, MAGIC, and VERITAS Telescopes
- 2021
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In: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 923:2
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Journal article (peer-reviewed)abstract
- The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H alpha emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 +/- 4.4 days is reported, consistent with the period of 317.3 +/- 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical H alpha parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.
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| 3. |
- Malm, Camilla, et al.
(author)
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What motivates informal carers to be actively involved in research, and what obstacles to involvement do they perceive?
- 2021
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In: Research Involvement and Engagement. - : Springer Science and Business Media LLC. - 2056-7529. ; 7:1
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Journal article (peer-reviewed)abstract
- Background: Due to demographic changes and a strained public sector operating in many countries globally, informal care is increasing. Currently, at least 1.3 million adults in Sweden regularly provide help, support and/or care to a family member/significant other. With no sign of an imminent decrease in their caring activities, it is important that informal carers are considered as a key stakeholder group within research that affects them, e.g., the co-design of carer and/or dyadic support interventions. The objective of this descriptive, quantitative study was to investigate informal carers’ perceived motivations and obstacles to become involved in research. Methods: A cross-sectional survey design was adopted, using first-wave data from a panel study. The data, collected in Sweden between September 2019 and March 2020, included survey responses from 147 informal carers who were either aged 60+ years themselves or were caring for someone who was aged 60+ years. Results: Our main results showed that informal carers are, in general, interested in research. Slightly fewer were interested in becoming actively involved themselves, but older age was the only characteristic significantly associated with less interest of being actively involved. Two latent motivational dimensions emerged from the factor analysis: ‘family motivation’ and ‘the greater good motivation’. These, according to our results, almost equally valued dimensions, described the differing reasons for informal carers to become involved in research. The most common perceived obstacle was lack of time and it was reported by more women than men. Conclusion: Our study contributes with new knowledge of informal carers’ perceived motivations and obstacles regarding carer involvement in research. Paying attention to the differing motivational dimensions held by informal carers could help researchers create conditions for more inclusive and systematic participation of informal carers within research. Thereby, increasing the opportunities for research that is deemed to be of higher societal impact. IRRID (International Registered Report Identifier): RR2-10.2196/17759.
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