ORCID Profile
0000-0001-7964-974X
Current Organisation
Karlsruhe Institute of Technology
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Publisher: EDP Sciences
Date: 04-2018
DOI: 10.1051/0004-6361/201629377
Abstract: The nine-year H.E.S.S. Galactic Plane Survey (HGPS) has yielded the most uniform observation scan of the inner Milky Way in the TeV gamma-ray band to date. The sky maps and source catalogue of the HGPS allow for a systematic study of the population of TeV pulsar wind nebulae found throughout the last decade. To investigate the nature and evolution of pulsar wind nebulae, for the first time we also present several upper limits for regions around pulsars without a detected TeV wind nebula. Our data exhibit a correlation of TeV surface brightness with pulsar spin-down power Ė . This seems to be caused both by an increase of extension with decreasing Ė , and hence with time, compatible with a power law R PWN ( Ė ) ~ Ė −0.65±0.20 , and by a mild decrease of TeV gamma-ray luminosity with decreasing Ė , compatible with L 1−10 TeV ~ Ė 0.59±0.21 . We also find that the offsets of pulsars with respect to the wind nebula centre with ages around 10 kyr are frequently larger than can be plausibly explained by pulsar proper motion and could be due to an asymmetric environment. In the present data, it seems that a large pulsar offset is correlated with a high apparent TeV efficiency L 1−10 TeV ∕ Ė . In addition to 14 HGPS sources considered firmly identified pulsar wind nebulae and 5 additional pulsar wind nebulae taken from literature, we find 10 HGPS sources that are likely TeV pulsar wind nebula candidates. Using a model that subsumes the present common understanding of the very high-energy radiative evolution of pulsar wind nebulae, we find that the trends and variations of the TeV observables and limits can be reproduced to a good level, drawing a consistent picture of present-day TeV data and theory.
Publisher: EDP Sciences
Date: 02-2012
Publisher: American Astronomical Society
Date: 13-02-2014
Publisher: EDP Sciences
Date: 02-2014
Publisher: American Physical Society (APS)
Date: 30-12-2014
Publisher: Elsevier BV
Date: 03-2011
Publisher: American Physical Society (APS)
Date: 22-01-2013
Publisher: American Astronomical Society
Date: 24-04-2012
Publisher: EDP Sciences
Date: 04-2013
Publisher: EDP Sciences
Date: 02-2014
Publisher: EDP Sciences
Date: 09-2010
Publisher: Springer Science and Business Media LLC
Date: 12-2020
DOI: 10.1140/EPJC/S10052-020-08602-7
Abstract: We detail the sensitivity of the proposed liquid xenon DARWIN observatory to solar neutrinos via elastic electron scattering. We find that DARWIN will have the potential to measure the fluxes of five solar neutrino components: pp , $$^7$$ 7 Be, $$^{13}$$ 13 N, $$^{15}$$ 15 O and pep . The precision of the $$^{13}$$ 13 N, $$^{15}$$ 15 O and pep components is hindered by the double-beta decay of $$^{136}$$ 136 Xe and, thus, would benefit from a depleted target. A high-statistics observation of pp neutrinos would allow us to infer the values of the electroweak mixing angle, $$\\sin ^2\\theta _w$$ sin 2 θ w , and the electron-type neutrino survival probability, $$P_{ee}$$ P ee , in the electron recoil energy region from a few keV up to 200 keV for the first time, with relative precision of 5% and 4%, respectively, with 10 live years of data and a 30 tonne fiducial volume. An observation of pp and $$^7$$ 7 Be neutrinos would constrain the neutrino-inferred solar luminosity down to 0.2%. A combination of all flux measurements would distinguish between the high- (GS98) and low-metallicity (AGS09) solar models with 2.1–2.5 $$\\sigma $$ σ significance, independent of external measurements from other experiments or a measurement of $$^8$$ 8 B neutrinos through coherent elastic neutrino-nucleus scattering in DARWIN. Finally, we demonstrate that with a depleted target DARWIN may be sensitive to the neutrino capture process of $$^{131}$$ 131 Xe.
Publisher: EDP Sciences
Date: 06-2010
Publisher: American Astronomical Society
Date: 22-09-2014
Publisher: EDP Sciences
Date: 03-2012
Publisher: EDP Sciences
Date: 02-2014
Publisher: Oxford University Press (OUP)
Date: 02-05-2014
DOI: 10.1093/MNRAS/STU459
Publisher: EDP Sciences
Date: 30-11-2010
Publisher: EDP Sciences
Date: 04-2018
DOI: 10.1051/0004-6361/201526545
Abstract: Aim. We aim for an understanding of the morphological and spectral properties of the supernova remnant RCW 86 and for insights into the production mechanism leading to the RCW 86 very high-energy γ -ray emission. Methods. We analyzed High Energy Spectroscopic System (H.E.S.S.) data that had increased sensitivity compared to the observations presented in the RCW 86 H.E.S.S. discovery publication. Studies of the morphological correlation between the 0.5–1 keV X-ray band, the 2–5 keV X-ray band, radio, and γ -ray emissions have been performed as well as broadband modeling of the spectral energy distribution with two different emission models. Results. We present the first conclusive evidence that the TeV γ -ray emission region is shell-like based on our morphological studies. The comparison with 2–5 keV X-ray data reveals a correlation with the 0.4–50 TeV γ -ray emission. The spectrum of RCW 86 is best described by a power law with an exponential cutoff at E cut = (3.5 ± 1.2 stat ) TeV and a spectral index of Γ ≈ 1.6 ± 0.2. A static leptonic one-zone model adequately describes the measured spectral energy distribution of RCW 86, with the resultant total kinetic energy of the electrons above 1 GeV being equivalent to ~0.1% of the initial kinetic energy of a Type Ia supernova explosion (10 51 erg). When using a hadronic model, a magnetic field of B ≈ 100 μ G is needed to represent the measured data. Although this is comparable to formerly published estimates, a standard E −2 spectrum for the proton distribution cannot describe the γ -ray data. Instead, a spectral index of Γ p ≈ 1.7 would be required, which implies that ∼7 × 10 49 / n cm −3 has been transferred into high-energy protons with the effective density n cm −3 = n /1 cm −3 . This is about 10% of the kinetic energy of a typical Type Ia supernova under the assumption of a density of 1 cm −3 .
Publisher: Oxford University Press (OUP)
Date: 11-02-2014
DOI: 10.1093/MNRAS/STU139
Publisher: EDP Sciences
Date: 05-2015
Publisher: EDP Sciences
Date: 16-06-2011
Publisher: EDP Sciences
Date: 09-2012
Publisher: EDP Sciences
Date: 18-04-2012
Publisher: Oxford University Press (OUP)
Date: 08-2013
Publisher: EDP Sciences
Date: 13-02-2013
Publisher: Oxford University Press (OUP)
Date: 03-06-2014
DOI: 10.1093/MNRAS/STU826
Publisher: EDP Sciences
Date: 17-03-2011
Publisher: EDP Sciences
Date: 11-2014
Publisher: EDP Sciences
Date: 06-2013
Publisher: EDP Sciences
Date: 23-04-2014
Publisher: EDP Sciences
Date: 30-01-2015
Publisher: EDP Sciences
Date: 06-2013
Publisher: EDP Sciences
Date: 15-01-2013
Publisher: Oxford University Press (OUP)
Date: 18-11-2014
Publisher: American Physical Society (APS)
Date: 24-02-2015
Publisher: EDP Sciences
Date: 06-2012
Publisher: EDP Sciences
Date: 07-2011
Publisher: EDP Sciences
Date: 27-07-2015
Publisher: EDP Sciences
Date: 27-02-2015
Publisher: Oxford University Press (OUP)
Date: 12-06-2012
Publisher: EDP Sciences
Date: 16-11-2012
Publisher: American Astronomical Society
Date: 13-09-2012
Publisher: EDP Sciences
Date: 28-03-2014
Publisher: EDP Sciences
Date: 2012
Publisher: EDP Sciences
Date: 09-2011
Publisher: American Astronomical Society
Date: 08-06-2011
Publisher: American Physical Society (APS)
Date: 20-11-2013
Publisher: EDP Sciences
Date: 29-08-2012
Publisher: EDP Sciences
Date: 10-12-2014
Publisher: SAGE Publications
Date: 11-2015
DOI: 10.4278/AJHP.140206-QUAN-62
Abstract: To examine associations of intervention dose with weight, physical activity, glycemic control, and diet outcomes in a randomized trial of a telephone counseling intervention. Study design was a secondary analysis of intervention group. Study setting was primary care practices in a disadvantaged community in Australia. Participants were adult patients with type 2 diabetes (n = 151). Up to 27 telephone counseling calls were made during 18 months. Intervention dose was assessed as the number of calls completed (in tertile categories). Primary outcomes were weight and HbA1c, and moderate to vigorous intensity physical activity via accelerometer. Secondary outcomes were dietary energy intake and diet quality via a validated questionnaire. Analyses employed were bivariate associations of call completion with sociodemographics, and confounder-adjusted linear mixed models for associations of call completion with outcomes (multiple imputation of missing data). Only previous diagnosis of depression/anxiety had a statistically significant (p= .008) association with call completion. Call completion was significantly associated with weight loss (p .001) but not the other outcomes (p .05). Relative to low call completion, mean weight loss (as a percentage of baseline weight) was greater in the high–call completion group by −3.3% (95% confidence interval, −5.0% to −1.5%). Increased dose of intervention was associated with greater weight loss. More needs to be done to retain patients for the duration of weight loss and behavior change interventions, particularly those with diabetes and comorbid depression, who were the most difficult to engage.
Publisher: EDP Sciences
Date: 03-2013
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-01-2015
Abstract: There's a new lab for studying the origins of cosmic rays: our neighbor galaxy, the Large Magellanic Cloud. Astronomers are now making progress on this topic by examining the gamma rays that are produced when cosmic rays interact with gas or lower-energy photons. The H.E.S.S. Collaboration has detected three sources of gamma rays in a variety of forms in the galactic satellite to the Milky Way. The sources include the pulsar wind nebula of N 157B, the supernova remnant N 132D, and the superbubble 30 Dor C. Oddly, supernova 1987A was not detected. Science , this issue p. 406
Publisher: American Physical Society (APS)
Date: 18-04-2011
Publisher: American Astronomical Society
Date: 24-03-2015
Publisher: EDP Sciences
Date: 11-2013
Publisher: American Physical Society (APS)
Date: 29-12-2014
Publisher: EDP Sciences
Date: 30-03-2011
Location: No location found
No related grants have been discovered for Kathrin Valerius.