Search

Your search keyword '"Gallant, P."' showing total 2,953 results
Start Over Author "Gallant, P."
2,953 results on '"Gallant, P."'

202. Absolute Decay Counting of 146147Sm and 146147Sm for Early Solar System Chronology

Author

Kim, G. B., Borg, L. E., Boyd, S. T. P., Cantor, R. H., Despotopulos, J. D., Drury, O. B., Friedrich, S., Gallant, A., Hines, N. R., Jacobs, A., Jovanovic, I., Kmak, K. N., Kavner, A. R. L., Kim, Y. H., Kunz, P., Kwiatkowski, A., Kwon, D. H., Lee, D., Murböck, T., Scielzo, N. D., Shollenberger, Q. R., Sio, C. K. I., Thomas, K. J., Wooddy, T., and Walls, C.

Published
2022
Full Text
View/download PDF

206. MAKSIM KUANTITAS DAN MAKSIM KUALITAS SERTA IMPLIKATURNYA PADA TAYANGAN MATA NAJWA EPISODE 'IRONI HARI-HARI INI'

Author

Dyah Pratiwi and Gallant Kurnia Assidik

Subjects
Theory and practice of education, LB5-3640, Languages and literature of Eastern Asia, Africa, Oceania, PL1-8844
Abstract

This study aims to describe the observance of maxims of quantity and maxims of quality, describe violations of maxims of quantity and maxims of quality, and describe the implicatures found in Mata Najwa's episode of "Ironi Hari-Hari Ini". The research data is in the form of utterances spoken by the resource person and also the presenter, namely, Najwa Shihab. Sources of data obtained by watching the show and making a transcript of the data. The data collection technique used is listening, free involvement, conversation and notes. Analysis of research data was carried out with interactive analysis techniques. While the validity of the data is done by data triangulation. The results showed that the process of compliance and violation of the maxim of quantity and maxim of quality as well as their implicatures in the Mata Najwa episode of "Ironi Hari-Hari Ini" included: (1) obedience to the maxim of quantity was 28.1%; (2) compliance with maxim of quality as much as 7.8%; (3) the violation of the maxim of quantity is 25%; (4) violation of maxim of quality as much as 10.9%; (5) conventional implicature as much as 17.1%; (6) non-conventional implicatures as much as 10.9%. With the background of the different sources, this is one of the reasons for the many compliances and violations of maxims that were found. Keywords: Implicature; Maxim of Quality; Maxim of Quantity; Najwa Eyes.

Published
2022
Full Text
View/download PDF

207. Structural basis for specific inhibition of the deubiquitinase UCHL1

Author

Christian Grethe, Mirko Schmidt, Gian-Marvin Kipka, Rachel O’Dea, Kai Gallant, Petra Janning, and Malte Gersch

Subjects
Science
Abstract

The deubiquitinase UCHL1 has been linked to cancer invasiveness and neurodegeneration yet its molecular roles have remained poorly defined. Here the authors reveal the structural basis for how UCHL1 can be specifically inhibited and how chemogenomic probes can be used to dissect its functions in living cells.

Published
2022
Full Text
View/download PDF

208. Synthesis and Characterization of 2-(((2,7-Dihydroxynaphthalen-1-yl)methylene)amino)-3′,6′-bis(ethylamino)-2′,7′-dimethylspiro[isoindoline-1,9′-xanthen]-3-one and Colorimetric Detection of Uranium in Water

Author

Rahisa Mohammed, Peace Ogadi, Dennis M. Seth, Amrutaa Vibho, Sarah K. Gallant, and Rory Waterman

Subjects
Schiff base, ligand, colorimetric analysis, Inorganic chemistry, QD146-197
Abstract

2-(((2,7-Dihydroxynaphthalen-1-yl)methylene)amino)-3′,6′-bis(ethylamino)-2′,7′-dimethylspiro[isoindoline-1,9′-xanthen]-3-one was synthesized using Rhodamine 6G hydrazide (prepared using literature methods) and commercially available 2,7-dihydroxynaphthalene-1-carbaldehyde via imine condensation. Structural characterization was performed using FT-IR, 1H-NMR, 13C-NMR, X-ray, and HRMS. This Schiff base shows promise as a ligand for the colorimetric analysis of uranium in water.

Published
2023
Full Text
View/download PDF

209. Impact of California Statute on Naloxone Availability and Opioid Overdose Rates

Author

Tara L. Gallant, BA, Andrew R. Gilbert, BS, Sina Zargham, BA, Michael F. Di Lorenzo, MS, Jose L. Puglisi, PhD, Zachary R. Nicholas, MD, and Valerie A. Gerriets, PhD

Subjects
Naloxone, CA AB1535, California pharmacies, opioid overdose, harm reduction, Public aspects of medicine, RA1-1270
Abstract

Introduction: Ensuring that people at risk of overdosing on opioids have easy access to naloxone is an essential part of the fight against the opioid crisis. This study evaluates the impact of the 2016 California law (CA AB1535) permitting pharmacies to dispense this life-saving medication without a physician's prescription. Methods: California counties were categorized on the basis of population density (rural, suburban, urban), rate of opioid-related deaths by population density (high, medium, low), and rate of opioid prescriptions by population density (high, medium, low). Ten diverse pharmacies from each category were selected for inclusion. In a brief 1-minute interview conducted between July and August 2021, pharmacists from 146 California pharmacies were surveyed regarding their knowledge of CA AB1535, their practice of dispensing naloxone without a physician's prescription, and whether they normally stock naloxone. Chi-square tests were used to compare responses. Results: Although almost all pharmacies interviewed (94%) were aware of the law and most of them (64%) dispensed naloxone without a physician's prescription, few statistically significant differences were found between surveyed categories. There were no significant relationships between naloxone availability at pharmacies and overdose death rates. Conclusions: Our results suggest that the number of California pharmacies dispensing naloxone without a physician's prescription has continued to increase since the implementation of CA AB1535. However, despite increased access to naloxone at pharmacies, opioid overdose rates have continued to rise since 2016, indicating the need for a multifaceted harm reduction approach.

Published
2023
Full Text
View/download PDF

210. Prevention of mental illness within public health: An analysis of progress via systematic literature review and a pathway forward

Author

Randall Waechter, Cassandra Gallant, Kristen De Wilde, Gabrielle Arens, Taylor Brady, Jasmin Custodio, Yusuke Wakita, Barbara Landon, Yvonne Boateng, Nadeem Parthab, and Anjali Bhagat

Subjects
Public health, Prevention, Mental health, Mental illness, Maternal-child health, Medicine
Abstract

Primary prevention is the cornerstone of public health. Prevention is especially important for chronic diseases of significant burden such as mental illnesses because many of them have limited treatment options, an onset in childhood or in adolescence, and are linked to adverse childhood experiences requiring a focus on early childhood and maternal-child health (MCH). Despite this need, there appears to be a paucity of research into prevention of mental illnesses within public health. To confirm this, we performed a systematic literature review to quantify the proportion of articles in public health that focus on prevention of mental illness versus intervention for these illnesses after their onset, and the proportion of published articles within MCH that focus on mental health. Between November 2019 and August 2021, we reviewed 211,794 published articles from 147 Scimago-ranked English public health journals with no limit on year of publication. As hypothesized, a very small portion (2.2%) of mental health articles included primary prevention and a small portion of MCH articles (7.8%) included mental health. These results are consistent with the existence of a research gap in mental illness prevention within the public health field. Given the early onset of mental illness, the importance of early childhood experiences in the later development of mental illness, and the importance of the social-emotional connection between mother and child for building resilience, public health professionals must incorporate evidence from the field of MCH to develop and assess more primary prevention programs for mental illness.

Published
2023
Full Text
View/download PDF

211. Surgical Management and Outcomes of Pediatric Congenital Head and Neck Teratomas: A Scoping Review

Author

Siddharth Patel, Ansley J. Kunnath, Jean‐Nicolas Gallant, and Ryan H. Belcher

Subjects
congenital teratoma, cervical teratoma, head and neck, Otorhinolaryngology, RF1-547, Surgery, RD1-811
Abstract

Abstract Objective To perform a scoping review to characterize postoperative outcomes of pediatric patients (ages 0‐18) with a history of congenital head and neck teratomas. Data Sources PubMed, EMBASE, Web of Science, Cochrane, Clinicaltrails.gov. Review Methods A search of multiple databases was performed. Studies were included if they detailed the surgical management and outcomes of pediatric patients with a history of congenital head and neck teratomas. Results One hundred and eight studies totaling 137 patients were identified. The median gestational age at birth was 37 weeks. Respiratory distress, prompting emergent endotracheal intubation or tracheostomy, was present in most patients (58%). The ex utero intrapartum treatment (EXIT) procedure was utilized for 21 (15%) patients. The teratomas were resected after a median duration of 4 days from birth. The most common postsurgical complications were vocal cord paralysis (3%), hemorrhage (2%), and tracheomalacia (2%). Death occurred perioperatively in 2 patients (2%). Twenty‐six patients (19%) required additional surgery, and 5 patients (4%) needed adjuvant chemotherapy. Patients were monitored for a median duration of 24 months with a recurrence rate of 6%. Four recurrent cases (50%) had intracranial extension, and 88% of the recurrent cases were mature teratomas at initial histopathological diagnosis. Conclusion Most patients with congenital head and neck teratomas require emergent airway management perinatally. Excisional and surgical complications are rare, and most patients are cured of their disease with a single operation. Recurrent teratomas tend to have an intracranial extension and are likely to be of mature pathology at the time of initial diagnosis.

Published
2023
Full Text
View/download PDF

212. Antibiotic-induced socio-sexual behavioral deficits are reversed via cecal microbiota transplantation but not androgen treatment

Author

Stephanie Salia, Yellow Martin, Francine F. Burke, Leah A. Myles, Lauren Jackman, Katherine Halievski, Francis R. Bambico, and Ashlyn Swift-Gallant

Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Recent evidence has demonstrated a sex-specific role of the gut microbiome on social behavior such as anxiety, possibly driven by a reciprocal relationship between the gut microbiome and gonadal hormones. For instance, gonadal hormones drive sex differences in gut microbiota composition, and certain gut bacteria can produce androgens from glucocorticoids. We thus asked whether the gut microbiome can influence androgen-dependent socio-sexual behaviors. We first treated C57BL/6 mice with broad-spectrum antibiotics (ABX) in drinking water to deplete the gut microbiota either transiently during early development (embryonic day 16-postnatal day [PND] 21) or in adulthood (PND 60–85). We hypothesized that if ABX interferes with androgens, then early ABX would interfere with critical periods for sexual differentiation of brain and thus lead to long-term decreases in males' socio-sexual behavior, while adult ABX would interfere with androgens’ activational effects on behavior. We found that in males but not females, early and adult ABX treatment decreased territorial aggression, and adult ABX also decreased sexual odor preference. We then assessed whether testosterone and/or cecal microbiota transplantation (CMT) via oral gavage could prevent ABX-induced socio-sexual behavioral deficits in adult ABX-treated males. Mice were treated with same- or other-sex control cecum contents or with testosterone for two weeks. While testosterone was not effective in rescuing any behavior, we found that male CMT restored both olfactory preference and aggression in adult ABX male mice, while female CMT restored olfactory preference but not aggression. These results suggest sex-specific effects of the gut microbiome on socio-sexual behaviors, independent of androgens.

Published
2023
Full Text
View/download PDF

213. On-line installation of the Superallowed Transition Beta-Neutrino Decay Ion Coincidence Trap

Author

Brodeur M., Bardayan D.W., Bruce O., Bualuan R., Burdette D.P., Clark J.A., Gallant A.T., Gan D., Guillet D., Houff A.M., Kolata J.J., Liu B., O’Malley P.D., Porter W.S., Quick C., Rivero F., Savard G., von Seeger W.W., Valverde A.A., and Zite R.

Subjects
Physics, QC1-999
Abstract

The Cabibbo-Kobayashi-Maskawa quark mixing matrix currently does not satisfy unitarity at the 2σ-level. This could be the result of an inaccurate value of one or both of its largest matrix elements Vus and Vud. In the case of Vud, the most precise measurement is obtained from the f t-value measurements of superallowed beta-transitions between 0+ states. The accuracy of this determination can, in turn, be tested by extracting Vud in other transitions including superallowed transitions between mirror nuclei. The Superallowed Transition Beta-Neutrino Decay Ion Coincidence Trap (St. Benedict) is currently under construction at the Nuclear Science Laboratory of the University of Notre Dame to perform such a determination, with the goal of shedding more light on this tension with unitarity. St. Benedict will take a radioactive ion beam produced by TwinSol, thermalize it in a large volume gas catcher, then transport it in two separate differentially-pumped volumes using a radio-frequency (RF) carpet and a radio-frequency quadrupole (RFQ) ion guide before injecting it in an RFQ trap to create cool ion bunches for injection in the measurement Paul trap. In this paper, we detail the installation of the beam preparation components of St. Benedict, and present the results of the first RIBs successfully stopped and extracted from its gas catcher.

Published
2024
Full Text
View/download PDF

214. Sea surface temperature driven modulation of decadal co-variability in mean and extreme precipitation

Author

Mustapha Adamu, Shayne McGregor, and Ailie J E Gallant

Subjects
decadal variability, sea surface temperature, climate modeling, climate extremes, rainfall, stochastic variability, Environmental technology. Sanitary engineering, TD1-1066, Environmental sciences, GE1-350, Science, Physics, QC1-999
Abstract

This study investigates the role that sea surface temperature (SST) variability plays in modulating the relationship between decadal-scale mean precipitation and monthly-scale extreme precipitation using the Australian Community Climate and Earth System Simulator Earth System model (ACCESS ESM1.5) climate model. The model large ensemble successfully reproduces the observed strong co-variability between monthly mean rainfall and wet extreme rainfall, defined as monthly rainfall totals above the 95th percentile. Removing SST variability in the ACCESS ESM1.5 model significantly weakens the co-variability between mean and wet extremes over most of the globe, showing that SSTs play a key role in modulating this co-variability. The study identifies Pacific and Atlantic SST patterns as the main drivers of the decadal scale co-variability in mean and extreme wet precipitation. On the other hand, observations and model results show that co-variability between mean and dry extremes is generally weaker than for wet extremes, with highly regional signals. Model experiments also show that SST variability plays a weaker role in modulating the co-variability between the mean precipitation and dry extremes as compared to wet extremes. These results suggest that stochastic atmospheric variability plays a stronger role in generating dry precipitation extremes compared SST forcing.

Published
2024
Full Text
View/download PDF

215. Knowledge Gaps and Bridges: The Relationship between the Awareness of General Patient Rights and the Awareness of Minors’ Patient Rights in the Netherlands

Author

Charelity Adu-Gallant, Jaan Toelen, Judith Sluiter-Post, David De Coninck, and Peter de Winter

Subjects
patient rights, minors, age-based framework, medical decision-making, consent, self-determination, Pediatrics, RJ1-570
Abstract

The major focus of this research is the level of awareness among Dutch parents of general patient rights in relation to minors’ patient rights. Moreover, this study is intended to highlight the most effective strategies to increase the awareness of general and minor patient rights in the Netherlands. A survey was conducted among 1010 Dutch parents aged between 35 and 55 years who had at least one child. In this study, we described the relationship between the knowledge among parents of general patient rights and their understanding of the patient rights of minors. A significant connection was found between the knowledge levels of general patient rights and the knowledge levels of the patient rights of minors (p < 0.05 [95% CI: 0.019–0.183]). While age and sex (male/female) did not appear to be significant confounders in this association, the educational background of the participants may have played a role. This study provides comprehensive insights into the association between the knowledge of general patient rights and the patient rights of minors among Dutch parents. Furthermore, this study points out that there is a need for focused educational interventions to address specific areas of misunderstanding or uncertainty.

Published
2024
Full Text
View/download PDF

217. The unified maximum a posteriori (MAP) framework for neuronal system identification

Author

Wu, Michael C. -K., Deniz, Fatma, Prenger, Ryan J., and Gallant, Jack L.

Subjects
Quantitative Biology - Neurons and Cognition
Abstract

The functional relationship between an input and a sensory neuron's response can be described by the neuron's stimulus-response mapping function. A general approach for characterizing the stimulus-response mapping function is called system identification. Many different names have been used for the stimulus-response mapping function: kernel or transfer function, transducer, spatiotemporal receptive field. Many algorithms have been developed to estimate a neuron's mapping function from an ensemble of stimulus-response pairs. These include the spike-triggered average, normalized reverse correlation, linearized reverse correlation, ridge regression, local spectral reverse correlation, spike-triggered covariance, artificial neural networks, maximally informative dimensions, kernel regression, boosting, and models based on leaky integrate-and-fire neurons. Because many of these system identification algorithms were developed in other disciplines, they seem very different superficially and bear little relationship with each other. Each algorithm makes different assumptions about the neuron and how the data is generated. Without a unified framework it is difficult to select the most suitable algorithm for estimating the neuron's mapping function. In this review, we present a unified framework for describing these algorithms called maximum a posteriori estimation (MAP). In the MAP framework, the implicit assumptions built into any system identification algorithm are made explicit in three MAP constituents: model class, noise distributions, and priors. Understanding the interplay between these three MAP constituents will simplify the task of selecting the most appropriate algorithms for a given data set. The MAP framework can also facilitate the development of novel system identification algorithms by incorporating biophysically plausible assumptions and mechanisms into the MAP constituents., Comment: affiliations changed

Published
2018

218. Particle Transport within the Pulsar Wind Nebula HESS J1825-137

Author

Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Armand, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chand, T., Chandra, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Drury, L. O'C., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kraus, M., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schutte, H., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, R. M., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Zywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Aims: We present a detailed view of the pulsar wind nebula (PWN) HESS J1825-137. We aim to constrain the mechanisms dominating the particle transport within the nebula, accounting for its anomalously large size and spectral characteristics. Methods: The nebula is studied using a deep exposure from over 12 years of H.E.S.S. I operation, together with data from H.E.S.S. II improving the low energy sensitivity. Enhanced energy-dependent morphological and spatially-resolved spectral analyses probe the Very High Energy (VHE, E > 0.1 TeV) gamma-ray properties of the nebula. Results: The nebula emission is revealed to extend out to 1.5 degrees from the pulsar, ~1.5 times further than previously seen, making HESS J1825--137, with an intrinsic diameter of ~100 pc, potentially the largest gamma-ray PWN currently known. Characterisation of the nebula's strongly energy-dependent morphology enables the particle transport mechanisms to be constrained. A dependence of the nebula extent with energy of R $\propto$ E^\alpha with \alpha = -0.29 +/- 0.04 (stat) +/- 0.05 (sys) disfavours a pure diffusion scenario for particle transport within the nebula. The total gamma-ray flux of the nebula above 1~TeV is found to be (1.12 +/- 0.03 (stat) +/- 0.25 (sys)) $\times 10^{-11}$ cm$^{-2}$ s$^{-1}$, corresponding to ~64% of the flux of the Crab Nebula. Conclusions: HESS J1825-137 is a PWN with clear energy-dependent morphology at VHE gamma-ray energies. This source is used as a laboratory to investigate particle transport within middle-aged PWNe. Deep observations of this highly spatially-extended PWN enable a spectral map of the region to be produced, providing insights into the spectral variation within the nebula., Comment: 20 pages, 10 figures, 5 tables, accepted for publication by Astronomy and Astrophysics

Published
2018
Full Text
View/download PDF

219. VHE $\gamma$-ray discovery and multi-wavelength study of the blazar 1ES 2322-409

Author

Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Armand, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chandra, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Drury, L. O'C., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Martí-Devesa, G. Guillem, Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spanier, F., Specovius, A., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Wörnlein, A., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

A hotspot at a position compatible with the BL Lac object 1ES 2322-409 was serendipitously detected with H.E.S.S. during observations performed in 2004 and 2006 on the blazar PKS 2316-423. Additional data on 1ES 2322-409 were taken in 2011 and 2012, leading to a total live-time of 22.3h. Point-like very-high-energy (VHE; E>100GeV) $\gamma$-ray emission is detected from a source centred on the 1ES 2322-409 position, with an excess of 116.7 events at a significance of 6.0$\sigma$. The average VHE $\gamma$-ray spectrum is well described with a power law with a photon index $\Gamma=3.40\pm0.66_{\text{stat}}\pm0.20_{\text{sys}}$ and an integral flux $\Phi(E>200GeV) = (3.11\pm0.71_{\rm stat}\pm0.62_{\rm sys})\times10^{-12} cm^{-2} s^{-1}$, which corresponds to 1.1$\%$ of the Crab nebula flux above 200 GeV. Multi-wavelength data obtained with Fermi LAT, Swift XRT and UVOT, RXTE PCA, ATOM, and additional data from WISE, GROND and Catalina, are also used to characterise the broad-band non-thermal emission of 1ES 2322-409. The multi-wavelength behaviour indicates day-scale variability. Swift UVOT and XRT data show strong variability at longer scales. A spectral energy distribution (SED) is built from contemporaneous observations obtained around a high state identified in Swift data. A modelling of the SED is performed with a stationary homogeneous one-zone synchrotron-self-Compton (SSC) leptonic model. The redshift of the source being unknown, two plausible values were tested for the modelling. A systematic scan of the model parameters space is performed, resulting in a well-constrained combination of values providing a good description of the broad-band behaviour of 1ES 2322-409., Comment: Accepted for publication in MNRAS. 13 pages, 8 figures

Published
2018
Full Text
View/download PDF

220. Searches for gamma-ray lines and `pure WIMP' spectra from Dark Matter annihilations in dwarf galaxies with H.E.S.S

Author

Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Armand, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chandra, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Drury, L. O'C., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spanier, F., Specovius, A., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, R. M., White, R., Wierzcholska, A., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., Żywucka, N., Cirelli, M., Panci, P., Sala, F., Silk, J., and Taoso, M.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

Dwarf spheroidal galaxies are among the most promising targets for detecting signals of Dark Matter (DM) annihilations. The H.E.S.S. experiment has observed five of these systems for a total of about 130 hours. The data are re-analyzed here, and, in the absence of any detected signals, are interpreted in terms of limits on the DM annihilation cross section. Two scenarios are considered: i) DM annihilation into mono-energetic gamma-rays and ii) DM in the form of pure WIMP multiplets that, annihilating into all electroweak bosons, produce a distinctive gamma-ray spectral shape with a high-energy peak at the DM mass and a lower-energy continuum. For case i), upper limits at 95\% confidence level of about $\langle \sigma v \rangle \lesssim 3 \times 10^{-25}$ cm$^3$ s$^{-1}$ are obtained in the mass range of 400 GeV to 1 TeV. For case ii), the full spectral shape of the models is used and several excluded regions are identified, but the thermal masses of the candidates are not robustly ruled out., Comment: Accepted for publication in JCAP. 18 pages, 7 figures

Published
2018
Full Text
View/download PDF

221. Xu: An Automated Query Expansion and Optimization Tool

Author

Gallant, Morgan, Isah, Haruna, Zulkernine, Farhana, and Khan, Shahzad

Subjects
Computer Science - Computation and Language, Computer Science - Information Retrieval
Abstract

The exponential growth of information on the Internet is a big challenge for information retrieval systems towards generating relevant results. Novel approaches are required to reformat or expand user queries to generate a satisfactory response and increase recall and precision. Query expansion (QE) is a technique to broaden users' queries by introducing additional tokens or phrases based on some semantic similarity metrics. The tradeoff is the added computational complexity to find semantically similar words and a possible increase in noise in information retrieval. Despite several research efforts on this topic, QE has not yet been explored enough and more work is needed on similarity matching and composition of query terms with an objective to retrieve a small set of most appropriate responses. QE should be scalable, fast, and robust in handling complex queries with a good response time and noise ceiling. In this paper, we propose Xu, an automated QE technique, using high dimensional clustering of word vectors and Datamuse API, an open source query engine to find semantically similar words. We implemented Xu as a command line tool and evaluated its performances using datasets containing news articles and human-generated QEs. The evaluation results show that Xu was better than Datamuse by achieving about 88% accuracy with reference to the human-generated QE., Comment: Accepted to IEEE COMPSAC 2019

Published
2018
Full Text
View/download PDF

222. X-ray spectral variability of blazars using principal component analysis

Author

Gallant, Dennis, Gallo, Luigi C., and Parker, Michael L.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Principal Component Analysis (PCA) is applied to a variety of blazars to examine X-ray spectral variability. Data from nine different objects are analysed in two ways: long-term, which examines variability trends across years or decades, and short-term, which looks at variability within a single observation. The results are then compared to simulated spectra in order to identify the physical components that they correspond to. It is found that long-term variability for all objects is dominated by changes in a single power law component. The primary component is responsible for more than 84 per cent of the variability in every object, while the second component is responsible for at least 3 per cent. Small differences in the shapes of these components can be used to predict qualities such as the degree to which spectral parameters are varying relative to one another, and correlations between spectral hardness and flux. Short-term variability is less clear-cut, with no obvious physical analogue for some of the PCA results. We discuss the simulation process, and specifically remark on the consequences of the breakdown of the linearity assumption of PCA and how it manifests in the real data. We conclude that PCA is a useful tool for analysing variability, but only if its underlying assumptions and limitations are understood., Comment: 13 pages, 7 figures, accepted for publication in MNRAS

Published
2018
Full Text
View/download PDF

223. The $\gamma$-ray spectrum of the core of Centaurus A as observed with H.E.S.S. and Fermi-LAT

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Armand, C., Arrieta, M., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Donath, A., Drury, L. O'C., Dyks, J., Edwards, T., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Seyffert, A. S., Shafi, N., Shilon, I., Simoni, K. Shiningayamwe. R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., Żywucka, N., collaboration, Fermi-LAT, Magill, J. D., Buson, S., Cheung, C. C., Perkins, J. S., and Tanaka, Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Centaurus A (Cen A) is the nearest radio galaxy discovered as a very-high-energy (VHE; 100 GeV-100 TeV) $\gamma$-ray source by the High Energy Stereoscopic System (H.E.S.S.). It is a faint VHE $\gamma$-ray emitter, though its VHE flux exceeds both the extrapolation from early Fermi-LAT observations as well as expectations from a (misaligned) single-zone synchrotron-self Compton (SSC) description. The latter satisfactorily reproduces the emission from Cen A at lower energies up to a few GeV. New observations with H.E.S.S., comparable in exposure time to those previously reported, were performed and eight years of Fermi-LAT data were accumulated to clarify the spectral characteristics of the $\gamma$-ray emission from the core of Cen A. The results allow us for the first time to achieve the goal of constructing a representative, contemporaneous $\gamma$-ray core spectrum of Cen A over almost five orders of magnitude in energy. Advanced analysis methods, including the template fitting method, allow detection in the VHE range of the core with a statistical significance of 12$\sigma$ on the basis of 213 hours of total exposure time. The spectrum in the energy range of 250 GeV-6 TeV is compatible with a power-law function with a photon index $\Gamma=2.52\pm0.13_{\mathrm{stat}}\pm0.20_{\mathrm{sys}}$. An updated Fermi-LAT analysis provides evidence for spectral hardening by $\Delta\Gamma\simeq0.4\pm0.1$ at $\gamma$-ray energies above $2.8^{+1.0}_{-0.6}$ GeV at a level of $4.0\sigma$. The fact that the spectrum hardens at GeV energies and extends into the VHE regime disfavour a single-zone SSC interpretation for the overall spectral energy distribution (SED) of the core and is suggestive of a new $\gamma$-ray emitting component connecting the high-energy emission above the break energy to the one observed at VHE energies., Comment: Accepted for publication in A&A, Abstract abridged for arXiv submission

Published
2018
Full Text
View/download PDF

224. First Ground-based Measurement of Sub-20 GeV to 100 GeV $\gamma$-rays from the Vela Pulsar with H.E.S.S. II

Author

Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Arm, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Ch, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Drury, L. O'C., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., López-Coto, R., Lypova, I., Malyshev, D., Mar, V., Marcowith, A., Mariaud, C., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spanier, F., Specovius, A., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, R. M., White, R., Wierzcholska, A., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., Żywucka, N., Kerr, M., Johnston, S., and Shannon, R. M.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report on the measurement and investigation of pulsed high-energy $\gamma$-ray emission from the Vela pulsar, PSR B0833$-$45, based on 40.3 hours of observations with the largest telescope of H.E.S.S., CT5, in monoscopic mode, and on 8 years of data obtained with the Fermi-LAT. A dedicated very-low-threshold event reconstruction and analysis pipeline was developed and, together with the CT5 telescope response model, was validated using the Fermi-LAT data as reference. A pulsed $\gamma$-ray signal at a significance level of more than $15\sigma$ is detected from the P2 peak of the Vela pulsar light curve. Of a total of 15835 events, more than 6000 lie at an energy below 20 GeV, implying a significant overlap between H.E.S.S. II-CT5 and the Fermi-LAT. While the investigation of the pulsar light curve with the LAT confirms characteristics previously known up to 20 GeV, in the tens of GeV energy range, CT5 data show a change in the pulse morphology of P2, i.e., an extreme sharpening of its trailing edge, together with the possible onset of a new component at 3.4$\sigma$ significance level. Assuming a power-law model for the P2 spectrum, an excellent agreement is found for the photon indices ($\Gamma \simeq$ 4.1) obtained with the two telescopes above 10 GeV and an upper bound of 8% is derived on the relative offset between their energy scales. Using both instruments data, it is however shown that the spectrum of P2 in the 10-100 GeV has a pronounced curvature, i.e. a confirmation of the sub-exponential cutoff form found at lower energies with the LAT. This is further supported by the weak evidence for an emission above 100 GeV obtained with CT5. In contrast, converging indications are found from both CT5 and LAT data for the emergence of a hard component above 50 GeV in the leading wing (LW2) of P2, which possibly extends beyond 100 GeV., Comment: Accepted for publication in A&A. 16 Pages, 9 figures (slightly language edited version)

Published
2018
Full Text
View/download PDF

225. The starburst galaxy NGC 253 revisited by H.E.S.S. and Fermi-LAT

Author

Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Armand, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chandra, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., de Wilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Drury, L. O'C., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, N., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spanier, F., Specovius, A., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Wörnlein, A., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

(Abridged) Context. NGC 253 is one of only two starburst galaxies found to emit $\gamma$-rays from hundreds of MeV to multi-TeV energies. Accurate measurements of the very-high-energy (VHE) (E $>$ 100 GeV) and high-energy (HE) (E $>$ 60 MeV) spectra are crucial to study the underlying particle accelerators and cosmic-ray interaction and transport. Aims. The measurement of the VHE $\gamma$-ray emission of NGC 253 published in 2012 by H.E.S.S. was limited by large systematic uncertainties. Here, a measurement of the $\gamma$-ray spectrum of NGC 253 is investigated in both HE and VHE $\gamma$-rays. Methods. The data of H.E.S.S. observations are reanalysed using an updated calibration and analysis chain. The $Fermi$-LAT analysis employs more than 8 years of data processed using pass 8. The cosmic-ray particle population is evaluated from the combined HE--VHE $\gamma$-ray spectrum using NAIMA. Results. The VHE $\gamma$-ray energy spectrum is best fit by a power-law with a flux normalisation of $(1.34\,\pm\,0.14^{\mathrm{stat}}\,\pm\,0.27^{\mathrm{sys}}) \times 10^{-13} \mathrm{cm^{-2} s^{-1} TeV^{-1}}$ at 1 TeV -- about 40 \% above, but compatible with the value obtained in Abramowski et al. (2012). The spectral index $\Gamma = 2.39 \pm 0.14^{\mathrm{stat}} \pm 0.25^{\mathrm{sys}}$ is slightly softer than but consistent with the previous measurement. At energies above $\sim$3 GeV the HE spectrum is consistent with a power-law ranging into the VHE part of the spectrum measured by H.E.S.S. Conclusions. Two scenarios for the starburst nucleus are tested, in which the gas in the starburst nucleus acts as a target for hadronic cosmic rays. In these two models, the level to which NGC\,253 acts as a calorimeter is estimated to a range of $f_{\rm cal} = 0.1$ to $1$ while accounting for the measurement uncertainties., Comment: Accepted by A&A, 8 pages, 2 figures, 2 tables

Published
2018
Full Text
View/download PDF

226. Search for $\gamma$-ray line signals from dark matter annihilations in the inner Galactic halo from ten years of observations with H.E.S.S

Author

Collaboration, H. E. S. S., Abdallah, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Caroff, S., Carosi, A., Carr, J., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Domainko, W., Donath, A., Drury, L. O'C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Eger, P., Emery, G., Ernenwein, J. P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Giebels, B., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Janiak, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Komin, N., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. P., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. P., Leser, E., Liu, R., Lohse, T., Lorentz, M., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schandri, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Zywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Spectral lines are among the most powerful signatures for dark matter (DM) annihilation searches in very-high-energy $\gamma$-rays. The central region of the Milky Way halo is one of the most promising targets given its large amount of DM and proximity to Earth. We report on a search for a monoenergetic spectral line from self-annihilations of DM particles in the energy range from 300 GeV to 70 TeV using a two-dimensional maximum likelihood method taking advantage of both the spectral and spatial features of signal versus background. The analysis makes use of Galactic Center (GC) observations accumulated over ten years (2004 - 2014) with the H.E.S.S. array of ground-based Cherenkov telescopes. No significant $\gamma$-ray excess above the background is found. We derive upper limits on the annihilation cross section $\langle\sigma v\rangle$ for monoenergetic DM lines at the level of $\sim4\times10^{-28}$ cm$^{3}$s$^{-1}$ at 1 TeV, assuming an Einasto DM profile for the Milky Way halo. For a DM mass of 1 TeV, they improve over the previous ones by a factor of six. The present constraints are the strongest obtained so far for DM particles in the mass range 300 GeV - 70 TeV. Ground-based $\gamma$-ray observations have reached sufficient sensitivity to explore relevant velocity-averaged cross sections for DM annihilation into two $\gamma$-ray photons at the level expected from the thermal relic density for TeV DM particles., Comment: Accepted by Phys. Rev. Lett. Includes Supplemental Material. 8+4 pages, 3+3 figures, 2 tables

Published
2018
Full Text
View/download PDF

227. H.E.S.S. discovery of very high energy gamma-ray emission from PKS 0625-354

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Akhperjanian, A. G., Andersson, T., Angüner, E. O., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Bulik, T., Capasso, M., Carr, J., Casanova, S., Cerruti, M., Chakraborty, N., Chalme-Calvet, R., Chaves, R. C. G., Chen, A., Chevalier, J., Chrétien, M., Colafrancesco, S., Cologna, G., Condon, B., Conrad, J., Cui, Y., Davids, I. D., Decock, J., Degrange, B., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Domainko, W., Donath, A., Drury, L. O'C., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Edwards, T., Egberts, K., Eger, P., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, S., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J. F., Gottschall, D., Goyal, A., Grondin, M. -H., Hadasch, D., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hinton, J. A., Hofmann, W., Hoischen, C., Holler, M., Horns, D., Ivascenko, A., Jacholkowska, A., Jamrozy, M., Janiak, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jogler, T., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kerszberg, D., Khélifi, B., Kieffer, M., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krayzel, F., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. -P., Lefaucheur, J., Lefranc, V., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., de Naurois, M., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Öttl, S., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Romoli, C., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Salek, D., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Simoni, R., Sol, H., Spanier, F., Spengler, G., Spies, F., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zabalza, V., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

PKS 0625-354 (z=0.055) was observed with the four H.E.S.S. telescopes in 2012 during 5.5 hours. The source was detected above an energy threshold of 200 GeV at a significance level of 6.1$\sigma$. No significant variability is found in these observations. The source is well described with a power-law spectrum with photon index $\Gamma =2.84 \pm 0.50_{stat} \pm 0.10_{syst}$ and normalization (at $E_0$=1.0 TeV) $N_0(E_0)=(0.58 \pm 0.22_{stat} \pm 0.12_{syst})\times10^{-12}$ TeV$^{-1}$cm$^{-2}$s$^{-1}$. Multi-wavelength data collected with Fermi-LAT, Swift-XRT, Swift-UVOT, ATOM and WISE are also analysed. Significant variability is observed only in the Fermi-LAT $\gamma$-ray and Swift-XRT X-ray energy bands. Having a good multi-wavelength coverage from radio to very high energy, we performed a broadband modelling from two types of emission scenarios. The results from a one zone lepto-hadronic, and a multi-zone leptonic models are compared and discussed. On the grounds of energetics, our analysis favours a leptonic multi-zone model. Models associated to the X-ray variability constraint supports previous results suggesting a BL Lac nature of PKS 0625-354, with, however, a large-scale jet structure typical of a radio galaxy., Comment: 13 pages, 6 figures, accepted for publication in MNRAS

Published
2018
Full Text
View/download PDF

228. Population study of Galactic supernova remnants at very high $\gamma$-ray energies with H.E.S.S.

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Donath, A., Drury, L. O'C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fernandez, D., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Giebels, B., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. -P., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., deNaurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., OBrien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Safi-Harb, S., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Shell-type supernova remnants (SNRs) are considered prime candidates for the acceleration of Galactic cosmic rays (CRs) up to the knee of the CR spectrum at $\mathrm{E} \approx \mathrm{3}\times \mathrm{10}^\mathrm{15}$ eV. Our Milky Way galaxy hosts more than 350 SNRs discovered at radio wavelengths and at high energies, of which 220 fall into the H.E.S.S. Galactic Plane Survey (HGPS) region. Of those, only 50 SNRs are coincident with a H.E.S.S source and in 8 cases the very high-energy (VHE) emission is firmly identified as an SNR. The H.E.S.S. GPS provides us with a legacy for SNR population study in VHE $\gamma$-rays and we use this rich data set to extract VHE flux upper limits from all undetected SNRs. Overall, the derived flux upper limits are not in contradiction with the canonical CR paradigm. Assuming this paradigm holds true, we can constrain typical ambient density values around shell-type SNRs to $n\leq 7~\textrm{cm}^\textrm{-3}$ and electron-to-proton energy fractions above 10~TeV to $\epsilon_\textrm{ep} \leq 5\times 10^{-3}$. Furthermore, comparisons of VHE with radio luminosities in non-interacting SNRs reveal a behaviour that is in agreement with the theory of magnetic field amplification at shell-type SNRs., Comment: 20 pages, 11 figures, 4 tables. Accepted for publication in A&A

Published
2018
Full Text
View/download PDF

229. Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Domainko, W., Donath, A., Drury, L. O'C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Eger, P., Emery, G., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Giebels, B., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. -P., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schandri, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Context. Recently, the high-energy (HE, 0.1-100 GeV) $\gamma$-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic $\gamma$-ray binary. Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) $\gamma$-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Energy spectra are obtained for the orbit-averaged data set, and for the orbital phase bin around the VHE maximum. Results. VHE $\gamma$-ray emission is detected with a statistical significance of 6.4 $\sigma$. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the $1-10$ TeV energy range is $(1.4 \pm 0.2) \times 10^{35}$ erg/s. A luminosity of $(5 \pm 1) \times 10^{35}$ erg/s is reached during 20% of the orbit. HE and VHE $\gamma$-ray emissions are anti-correlated. LMC P3 is the most luminous $\gamma$-ray binary known so far., Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&A

Published
2018
Full Text
View/download PDF

230. A search for new supernova remnant shells in the Galactic plane with H.E.S.S

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Akhperjanian, A. G., Andersson, T., Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Carr, J., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Coffaro, M., Colafrancesco, S., Cologna, G., Condon, B., Conrad, J., Cui, Y., Davids, I. D., Decock, J., Degrange, B., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Domainko, W., Donath, A., Drury, L. O'C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Eger, P., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, S., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J. F., Gottschall, D., Goyal, A., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Janiak, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jogler, T., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. -P., Lefaucheur, J., Lefranc, V., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Öttl, S., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Richter, S., Rieger, F., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Salek, D., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Simoni, R., Sol, H., Spanier, F., Spengler, G., Spies, F., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stycz, K., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zabalza, V., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Żywucka, N., Bamba, A., Fukui, Y., Sano, H., and Yoshiike, S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

A search for new supernova remnants (SNRs) has been conducted using TeV gamma-ray data from the H.E.S.S. Galactic plane survey. As an identification criterion, shell morphologies that are characteristic for known resolved TeV SNRs have been used. Three new SNR candidates were identified in the H.E.S.S. data set with this method. Extensive multiwavelength searches for counterparts were conducted. A radio SNR candidate has been identified to be a counterpart to HESS J1534-571. The TeV source is therefore classified as a SNR. For the other two sources, HESS J1614-518 and HESS J1912+101, no identifying counterparts have been found, thus they remain SNR candidates for the time being. TeV-emitting SNRs are key objects in the context of identifying the accelerators of Galactic cosmic rays. The TeV emission of the relativistic particles in the new sources is examined in view of possible leptonic and hadronic emission scenarios, taking the current multiwavelength knowledge into account., Comment: Accepted for publication in A&A, 24 pages, 13 figures. Minor corrections in v2

Published
2018
Full Text
View/download PDF

231. The Representation of Semantic Information Across Human Cerebral Cortex During Listening Versus Reading Is Invariant to Stimulus Modality

Author

Deniz, Fatma, Nunez-Elizalde, Anwar O, Huth, Alexander G, and Gallant, Jack L

Subjects
Neurosciences, Behavioral and Social Science, Basic Behavioral and Social Science, Clinical Research, 1.2 Psychological and socioeconomic processes, Underpinning research, 1.1 Normal biological development and functioning, Mental health, Neurological, Acoustic Stimulation, Adult, Auditory Perception, Cerebral Cortex, Comprehension, Female, Humans, Magnetic Resonance Imaging, Male, Models, Neurological, Photic Stimulation, Reading, Semantics, Visual Perception, BOLD, cross-modal representations, fMRI, listening, reading, semantics, Medical and Health Sciences, Psychology and Cognitive Sciences, Neurology & Neurosurgery
Abstract

An integral part of human language is the capacity to extract meaning from spoken and written words, but the precise relationship between brain representations of information perceived by listening versus reading is unclear. Prior neuroimaging studies have shown that semantic information in spoken language is represented in multiple regions in the human cerebral cortex, while amodal semantic information appears to be represented in a few broad brain regions. However, previous studies were too insensitive to determine whether semantic representations were shared at a fine level of detail rather than merely at a coarse scale. We used fMRI to record brain activity in two separate experiments while participants listened to or read several hours of the same narrative stories, and then created voxelwise encoding models to characterize semantic selectivity in each voxel and in each individual participant. We find that semantic tuning during listening and reading are highly correlated in most semantically selective regions of cortex, and models estimated using one modality accurately predict voxel responses in the other modality. These results suggest that the representation of language semantics is independent of the sensory modality through which the semantic information is received.SIGNIFICANCE STATEMENT Humans can comprehend the meaning of words from both spoken and written language. It is therefore important to understand the relationship between the brain representations of spoken or written text. Here, we show that although the representation of semantic information in the human brain is quite complex, the semantic representations evoked by listening versus reading are almost identical. These results suggest that the representation of language semantics is independent of the sensory modality through which the semantic information is received.

Published
2019

232. Plagiarism or not? investigation of Turnitin®‐detected similarity hits in biology laboratory reports

Author

Gallant, Tricia Bertram, Picciotto, Madeleine, Bozinovic, Goran, and Tour, Ella

Subjects
Biochemistry and Cell Biology, Biological Sciences, Biology, Humans, Laboratories, Plagiarism, Software, Students, Writing, source incorporation, laboratory reports, undergraduate laboratory courses, similarity-matching software, Curriculum and Pedagogy, Education, Biochemistry and cell biology
Abstract

In undergraduate biology laboratory courses, laboratory reports can be a useful tool for teaching scientific writing, integration of source material, and information literacy; however, these teaching objectives are at times undermined by students' plagiarism. Laboratory instructors often use similarity-matching software to detect plagiarism in laboratory reports, yet similarity hits detected with such software remain poorly characterized. In the upper division molecular biology laboratory course described here, Turnitin® routinely detected dozens of similarity hits in laboratory reports. To determine whether this abundance of similarity hits was indicative of widespread plagiarism, we analyzed similarity hits detected in 255 laboratory reports written by 135 students. Only a small minority of Turnitin® similarity matches were problematic, but over half of the laboratory reports contained at least one problem with incorporation of scientific sources (e.g., laboratory manual and scientific articles). We identified four common types of such writing problems: patchwriting, technical parroting, copying, and falsification of sources. In 18% of the laboratory reports, we detected an alarmingly superficial use of primary literature. Most of the source incorporation problems did not rise to the level of plagiarism. As a result of this study, we recommend changes in scientific writing instruction and a transition to laboratories providing more authentic research experiences. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):370-379, 2019.

Published
2019

233. Plagiarism or not? investigation of Turnitin®-detected similarity hits in biology laboratory reports.

Author

Bertram Gallant, Tricia, Picciotto, Madeleine, Bozinovic, Goran, and Tour, Ella

Subjects
Humans, Biology, Students, Writing, Software, Plagiarism, Laboratories, laboratory reports, similarity-matching software, source incorporation, undergraduate laboratory courses, Education, Curriculum and Pedagogy, Biochemistry and Cell Biology
Abstract

In undergraduate biology laboratory courses, laboratory reports can be a useful tool for teaching scientific writing, integration of source material, and information literacy; however, these teaching objectives are at times undermined by students' plagiarism. Laboratory instructors often use similarity-matching software to detect plagiarism in laboratory reports, yet similarity hits detected with such software remain poorly characterized. In the upper division molecular biology laboratory course described here, Turnitin® routinely detected dozens of similarity hits in laboratory reports. To determine whether this abundance of similarity hits was indicative of widespread plagiarism, we analyzed similarity hits detected in 255 laboratory reports written by 135 students. Only a small minority of Turnitin® similarity matches were problematic, but over half of the laboratory reports contained at least one problem with incorporation of scientific sources (e.g., laboratory manual and scientific articles). We identified four common types of such writing problems: patchwriting, technical parroting, copying, and falsification of sources. In 18% of the laboratory reports, we detected an alarmingly superficial use of primary literature. Most of the source incorporation problems did not rise to the level of plagiarism. As a result of this study, we recommend changes in scientific writing instruction and a transition to laboratories providing more authentic research experiences. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):370-379, 2019.

Published
2019

234. ALG11-CDG syndrome: Expanding the phenotype.

Author

Haanpää, Maria, Ng, Bobby, Gallant, Natalie, Freeze, Hudson, Muller, Eric, Brown, Candida, Kimonis, Virginia, and Singh, Kathryn

Subjects
ALG11, CDG, GP130, LLO, intellectual disability, Adolescent, Alleles, Biomarkers, Child, Preschool, Congenital Disorders of Glycosylation, Electroencephalography, Female, Genetic Association Studies, Genetic Predisposition to Disease, Glycosylation, Humans, Magnetic Resonance Imaging, Male, Mannosyltransferases, Mutation, Pedigree, Phenotype, Tomography, X-Ray Computed
Abstract

ALG11-Congenital Disorder of Glycosylation (ALG11-CDG, also known as congenital disorder of glycosylation type Ip) is an inherited inborn error of metabolism due to abnormal protein and lipid glycosylation. We describe two unrelated patients with ALG11-CDG due to novel mutations, review the literature of previously described affected individuals, and further expand the clinical phenotype. Both affected individuals reported here had severe psychomotor disabilities and epilepsy. Their fibroblasts synthesized truncated precursor glycan structures, consistent with ALG11-CDG, while also showing hypoglycosylation of a novel biomarker, GP130. Surprisingly, one patient presented with normal transferrin glycosylation profile, a feature that has not been reported previously in patients with ALG11-CDG. Together, our data expand the clinical and mutational spectrum of ALG11-CDG.

Published
2019

235. A multi‐analyte cell‐free DNA–based blood test for early detection of hepatocellular carcinoma

Author

Nan Lin, Yongping Lin, Jianfeng Xu, Dan Liu, Diange Li, Hongyu Meng, Maxime A. Gallant, Naoto Kubota, Dhruvajyoti Roy, Jason S. Li, Emmanuel C. Gorospe, Morris Sherman, Robert G. Gish, Ghassan K. Abou‐Alfa, Mindie H. Nguyen, David J. Taggart, Richard A. Van Etten, Yujin Hoshida, and Wei Li

Subjects
Diseases of the digestive system. Gastroenterology, RC799-869
Abstract

Abstract The limited performance of guideline‐recommended abdominal ultrasound and serum alpha‐fetoprotein (AFP) highlights the urgent, unmet need for new biomarkers for more accurate detection of early hepatocellular carcinoma (HCC). To this end, we have conducted a prospective clinical validation study to evaluate the performance of the HelioLiver Test, a multi‐analyte blood test combining cell‐free DNA methylation patterns, clinical variables, and protein tumor markers. A blinded, multicenter validation study was performed with 247 subjects, including 122 subjects with HCC and 125 control subjects with chronic liver disease. The performance of the HelioLiver Test was compared with AFP and the GALAD score as established HCC surveillance blood tests. The performance of the HelioLiver Test (area under the receiver operating characteristic curve [AUROC] = 0.944) was superior to both AFP (AUROC = 0.851; p < 0.0001) and GALAD (AUROC = 0.899; p < 0.0001). Using a prespecified diagnostic algorithm, the HelioLiver Test showed sensitivities of 85% (95% confidence interval [CI], 78%–90%) for HCC of any stage and 76% (95% CI, 60%–87%) for early stage (American Joint Committee on Cancer [AJCC] I and II) HCC. In contrast, AFP (≥20 ng/mL) alone and the GALAD score (≥−0.63) showed lower sensitivities of 62% (95% CI, 54%–70%) and 75% (95% CI, 67%‐82%) for HCC overall, and 57% (95% CI, 40%–71%) and 65% (95% CI, 49%–79%) for early stage (AJCC I and II) HCC, respectively. The specificities of the HelioLiver Test (91%; 95% CI, 85%–95%), AFP (97%; 95% CI, 92%–99%), and the GALAD score (94%; 95% CI, 88%–97%) were similar for control subjects. The HelioLiver Test showed superior performance for HCC detection compared to with both AFP and the GALAD score and warrants further evaluation in HCC surveillance settings.

Published
2022
Full Text
View/download PDF

236. Impact of respiratory syncytial virus in an open bay neonatal intensive care unit

Author

Minisha Morris, Annette Vasandani, Yvonne Estrada, Malik Merchant, Annie Garcia, John Duran, Melissa Gallant, and Adonica Benesh

Subjects
Infectious and parasitic diseases, RC109-216, Public aspects of medicine, RA1-1270
Abstract

Background: Respiratory syncytial virus, RSV, is a respiratory virus that causes cold-like symptoms in adults. In infants and young children, RSV can cause severe illnesses such as bronchiolitis or pneumonia. We describe a successful response to a laboratory-confirmed RSV outbreak in a 21-bed open-pod neonatal intensive care unit (NICU) at a level 2 trauma hospital. Methods: After 2 of the 3 initial neonates were diagnosed with hospital-onset RSV, an outbreak investigation began on November 16, 2022. Following the results, testing was expanded to all neonates in the NICU. The clinical case was defined as a hospitalized neonate with laboratory confirmation of RSV by RSV antigen screen or polymerase chain reaction (PCR) detection on the Biofire respiratory panel. Outbreak resolution was determined by utilizing a viral test for the remaining positive neonates after the 2-week incubation period from the last identified positive neonate. Results: On day 1 of the investigation, 6 of 18 neonates were identified as positive for RSV. The initial 12 negative neonates received a prophylactic dose of palivizumab. Due to the increase in positive neonates, enhanced infection prevention and control measures were immediately implemented. These measures included the immediate closure of the NICU for new transfers, placing all positive neonates in a single-bay cohort in the NICU, implementing contact and droplet precautions, minimizing shared staff, increasing environmental cleaning, and using dedicated equipment. With awareness of the increased community occurrence of RSV, additional measures were taken to monitor adherence to infection prevention and control measures by staff and visitors entering the NICU, including daily symptom screening. Visitation was restricted to block scheduling to monitor the number of individuals in the NICU. Once we obtained the complete conversion of the initial neonate cohort, the additional focus shifted to maintaining the enhanced precautions until all neonate laboratory tests were negative. The NICU was successfully reopened once the remaining 3 positive neonates received no growth on their viral culture. Conclusions: The quick and effective response from a multidisciplinary team allowed a successful intervention to mitigate the identified outbreak. This investigation highlights the importance of enhanced infection prevention and control practices during increased community spread. Future efforts focus on educating staff and visitors on appropriate measures to decrease transmission risks.

Published
2023
Full Text
View/download PDF

237. Identifying and addressing the impacts of the COVID-19 pandemic on school-based immunisation programmes in the Canadian Maritimes: a mixed methods study protocol

Author

Jeanna Parsons Leigh, Audrey Steenbeek, Janet A Curran, Allyson J Gallant, and Scott A Halperin

Subjects
Medicine
Abstract

Introduction The COVID-19 pandemic highlighted the importance of keeping up to date on routine vaccinations. Throughout the pandemic, many routine vaccine programmes in Canada were paused or cancelled, including school-based immunisation programmes (SBIP). This resulted in decreased coverage for many vaccine-preventable diseases. While the effects of the pandemic on SBIP have been described in other provinces, its effects in the Maritime region (ie, Nova Scotia, New Brunswick and Prince Edward Island) have yet to be understood. We aim to determine how these programmes were affected by COVID-19 and associated public health measures in the Canadian Maritimes by (1) identifying and describing usual and interim catch-up programmes; (2) exploring stakeholders’ perceptions of SBIP through interviews; and (3) designing recommendations with stakeholders to address gaps in SBIP and vaccine coverage.Methods and analysis A sequential, explanatory mixed methods study design will be used to address the objectives during the study period (September 2022–December 2023). First, an environmental scan will describe changes to SBIP and vaccine coverage over a period of five school years (2018/2019–2022/2023). Findings will inform semistructured interviews (n=65) with key stakeholders (eg, health officials, healthcare providers, school officials and parents and adolescents) to explore perceptions of SBIP and changes in parental vaccine hesitancy during the pandemic. These data will be integrated to design recommendations to support SBIP during two stakeholder engagement meetings. Analysis will be guided by the behaviour change wheel, a series of complementary tools and frameworks to simplify behaviour diagnosis and analysis in public health research.Ethics and dissemination Ethics approval for this study has been obtained from Dalhousie University’s Health Sciences Research Ethics Board (Ref: 2022-6395). Informed consent will be obtained from participants prior to participating in an interview or stakeholder engagement meeting. Study findings will be disseminated through conference presentations, publications and infographics.

Published
2023
Full Text
View/download PDF

238. Convergent validity and inter-rater reliability of a lower-limb multimodal physical function assessment in community-dwelling older adults

Author

Myles W. O’Brien, Heather F. Neyedli, Laurent Bosquet, Brianna Leadbetter, Alex Smith, Francois Gallant, Pamela Tanguay, Mathieu Bélanger, and Said Mekari

Subjects
timed up-and-go, lower limb, convergent validity, physical function, healthy aging, Geriatrics, RC952-954.6
Abstract

Introduction: Lower-limb physical function declines with age and contributes to a greater difficulty in performing activities of daily living. Existing assessments of lower-limb function assess one dimension of movement in isolation or are not time-efficient, which discourages their use in community and clinical settings. We aimed to address these limitations by assessing the inter-rater reliability and convergent validity of a new multimodal functional lower-limb assessment (FLA).Methods: FLA consists of five major functional movement tasks (rising from a chair, walking gait, stair ascending/descending, obstacle avoidance, and descending to a chair) performed consecutively. A total of 48 community-dwelling older adults (32 female participants; age: 71 ± 6 years) completed the FLA as well as timed up-and-go, 30-s sit-to-stand, and 6-min walk tests.Results: Slower FLA time was correlated with a slower timed up-and-go test (ρ = 0.70), less sit-to-stand repetitions (ρ = −0.65), and a shorter distance in the 6-min walk test (ρ = −0.69; all, p < 0.001). Assessments by two raters were not different (12.28 ± 3.86 s versus 12.29 ± 3.83 s, p = 0.98; inter-rater reliability ρ = 0.993, p < 0.001) and were statistically equivalent (via equivalence testing). Multiple regression and relative weights analyses demonstrated that FLA times were most predicted by the timed up-and-go performance [adjusted R2 = 0.75; p < 0.001; raw weight 0.42 (95% CI: 0.27, 0.53)].Discussion: Our findings document the high inter-rater reliability and moderate-strong convergent validity of the FLA. These findings warrant further investigation into the predictive validity of the FLA for its use as an assessment of lower-limb physical function among community-dwelling older adults.

Published
2023
Full Text
View/download PDF

239. Women judges in transitional justice and their impact on trials on cases of sexual and gender-based violence committed as war crimes

Author

Anna Adamska-Gallant

Subjects
genre, responsabilité, violences sexuelles et sexistes, crimes de guerre, femme juge, Social history and conditions. Social problems. Social reform, HN1-995
Abstract

Unfortunately, sexual and gender-based violence (SGBV) against women and men who are identified as enemies very often appears as a tool of war. For a long time, SGBV-related atrocities were not perceived as an element of combat, thus they were not investigated as war crimes. None of the war criminals prosecuted in the Nurnberg and Tokyo trials was ever charged with crimes that specifically targeted women, despite overwhelming evidence of mass-scale rapes committed during World War II by their subordinates. Only in 2000, the Women's International War Crimes Tribunal on Japan's Military Sexual Slavery was established to hear cases of women forced into sexual slavery by the Japanese Imperial Army more than 50 years earlier.The perception of the SGBV crimes in armed conflicts has considerably changed because of the mass atrocities committed in Bosnia and Hercegovina and in Rwanda. Women who as victims of the sexual violence dared to talk about their suffering, played the crucial role in changing the general attitude towards SGBV crime committed during the war. Simultaneously, the composition of international prosecution and judiciary included numerous female prosecutors and judges.It may be argued if judge's characteristic, personal experience, or gender indeed or to what extent influence judicial decisions. Some fundamental questions related to the judge's gender remain without an answer: Would the gender of judges impact the quality of fact-finding in SGBV as a war crime? Would a female judge assess the evidence more thoroughly than a male judge? Would a SGBV victim's well-being be better protected by a judge of the same gender? Would the risk of a victim's re-traumatisation be lower if the trial was handled by a judge of the same gender as the victim? And finally: would the risk of a victim's re-traumatisation be lower if a judge of the same gender as the victim handled the trial? All these questions seem particularly relevant in the context of the new wave of war crimes SGBV cases resulting from the war in Ukraine.

Published
2023
Full Text
View/download PDF

240. Assessing Quantitative Modelling Practices, Metamodelling, and Capability Confidence of Biology Undergraduate Students

Author

Dauer, Joseph, Mayes, Robert, Rittschof, Kent, and Gallant, Bryon

Abstract

Quantitative modelling plays an important role as biology increasingly deals with big data sets, relies on modelling to understand system dynamics, makes predictions about impacts of changes, and revises our understanding of system interactions. An assessment of quantitative modelling in biology was administered to students (n = 612) in undergraduate biology courses at two universities to provide a picture of student ability in quantitative reasoning within biology and to determine how capable those students felt about this ability. A Rasch analysis was used to construct linear measures and provide validity evidence for the assessment and to examine item statistics on the same scale as student ability measures. Students overall had greater ability in quantitative literacy than in quantitative interpretation of models or modelling. There was no effect of class standing (Freshmen, Sophomore, etc.) on student performance. The assessment showed that students who participated felt confidence in their ability to quantitatively model biological phenomena, even while their performance on ability questions were low. Collectively modelling practices were correlated with students' metamodelling knowledge and not correlated with students' modelling capability confidence. Biology instructors who incorporate the process of modelling into their courses may see improved abilities of students to perform on quantitative modelling tasks.

Published
2021
Full Text
View/download PDF

242. EELGRASS BED MAPPING WITH MULTISPECTRAL UAV IMAGERY IN ATLANTIC CANADA

Author

B. Leblon, A. LaRocque, E. Gallant, K. Clyne, and A. Douglas

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

Eelgrass (Zostera marina L.) is a marine angiosperm that grows throughout coastal regions in Atlantic Canada. This study aimed to assess the capability of UAV multispectral imagery to map the presence of eelgrass beds within two estuaries in Atlantic Canada (Souris River and Richibucto River). The images were mosaicked using Agisoft and calibrated in reflectance. The corrected images were classified using a non-parametric supervised classifier (Random Forests). The input features of the classification were the UAV band reflectance and associated bathymetric ratios and vegetation indices. The resulting maps were compared with sonar data. The overall validation accuracy for presence/absence was 91.30% with the Souris image and 86.92%% with the Richibucto images. The limitations of the study are also presented.

Published
2022
Full Text
View/download PDF

243. Barriers to and strategies to address COVID-19 testing hesitancy: a rapid scoping review

Author

Mark Embrett, S. Meaghan Sim, Hilary A. T. Caldwell, Leah Boulos, Ziwa Yu, Gina Agarwal, Rhiannon Cooper, Allyson J. Gallant AJ, Iwona A. Bielska, Jawad Chishtie, Kathryn Stone, Janet Curran, and Andrea Tricco

Subjects
Covid-19, Testing, Testing hesitancy, Health policy, Social determinants of health, Equity, Public aspects of medicine, RA1-1270
Abstract

Abstract Background Testing is a foundational component of any COVID-19 management strategy; however, emerging evidence suggests that barriers and hesitancy to COVID-19 testing may affect uptake or participation and often these are multiple and intersecting factors that may vary across population groups. To this end, Health Canada’s COVID-19 Testing and Screening Expert Advisory Panel commissioned this rapid review in January 2021 to explore the available evidence in this area. The aim of this rapid review was to identify barriers to COVID-19 testing and strategies used to mitigate these barriers. Methods Searches (completed January 8, 2021) were conducted in MEDLINE, Scopus, medRxiv/bioRxiv, Cochrane and online grey literature sources to identify publications that described barriers and strategies related to COVID-19 testing. Results From 1294 academic and 97 grey literature search results, 31 academic and 31 grey literature sources were included. Data were extracted from the relevant papers. The most cited barriers were cost of testing; low health literacy; low trust in the healthcare system; availability and accessibility of testing sites; and stigma and consequences of testing positive. Strategies to mitigate barriers to COVID-19 testing included: free testing; promoting awareness of importance to testing; presenting various testing options and types of testing centres (i.e., drive-thru, walk-up, home testing); providing transportation to testing centres; and offering support for self-isolation (e.g., salary support or housing). Conclusion Various barriers to COVID-19 testing and strategies for mitigating these barriers were identified. Further research to test the efficacy of these strategies is needed to better support testing for COVID-19 by addressing testing hesitancy as part of the broader COVID-19 public health response.

Published
2022
Full Text
View/download PDF

244. HiIDDD: a high-throughput imaging pipeline for the quantitative detection of DNA damage in primary human immune cells

Author

Kelsey Gallant, Arsun Bektas, Mary Kaileh, Ana Lustig, Luigi Ferrucci, Gianluca Pegoraro, and Tom Misteli

Subjects
Medicine, Science
Abstract

Abstract DNA damage is a prominent biomarker for numerous diseases, including cancer, as well as for the aging process. Detection of DNA damage routinely relies on traditional microscopy or cytometric methods. However, these techniques are typically of limited throughput and are not ideally suited for large-scale longitudinal and population studies that require analysis of large sample sets. We have developed HiIDDD (High-throughput Immune cell DNA Damage Detection), a robust, quantitative and single-cell assay that measures DNA damage by high-throughput imaging using the two major DNA damage markers 53BP1 and $$\upgamma$$ γ -H2AX. We demonstrate sensitive detection with low inter-assay variability of DNA damage in various types of freshly isolated and cryopreserved primary human immune cells, including CD4 + and CD8 + T cells, B cells and monocytes. As proof of principle, we demonstrate parallel batch processing of several immune cell types from multiple donors. We find common patterns of DNA damage in multiple immune cell types of donors of varying ages, suggesting that immune cell properties are specific to individuals. These results establish a novel high-throughput assay for the evaluation of DNA damage in large-scale studies.

Published
2022
Full Text
View/download PDF

245. Health system impacts of SARS-CoV − 2 variants of concern: a rapid review

Author

Justine Dol, Leah Boulos, Mari Somerville, Lynora Saxinger, Alexander Doroshenko, Stephanie Hastings, Bearach Reynolds, Allyson Gallant, Hwayeon Danielle Shin, Helen Wong, Daniel Crowther, Marilyn Macdonald, Ruth Martin-Misener, Holly McCulloch, Andrea C. Tricco, and Janet A. Curran

Subjects
SARS-CoV − 2, Variants of concern, Health system impact, Rapid review, Public aspects of medicine, RA1-1270
Abstract

Abstract Background As of November 25th 2021, four SARS-CoV − 2 variants of concern (VOC: Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), and Delta (B.1.617.2)) have been detected. Variable degrees of increased transmissibility of the VOC have been documented, with potential implications for hospital and health system capacity and control measures. This rapid review aimed to provide a synthesis of evidence related to health system responses to the emergence of VOC worldwide. Methods Seven databases were searched up to September 27, 2021, for terms related to VOC. Titles, abstracts, and full-text documents were screened independently by two reviewers. Data were extracted independently by two reviewers using a standardized form. Studies were included if they reported on at least one of the VOC and health system outcomes. Results Of the 4877 articles retrieved, 59 studies were included, which used a wide range of designs and methods. Most of the studies reported on Alpha, and all except two reported on impacts for capacity planning related to hospitalization, intensive care admissions, and mortality. Most studies (73.4%) observed an increase in hospitalization, but findings on increased admission to intensive care units were mixed (50%). Most studies (63.4%) that reported mortality data found an increased risk of death due to VOC, although health system capacity may influence this. No studies reported on screening staff and visitors or cohorting patients based on VOC. Conclusion While the findings should be interpreted with caution as most of the sources identified were preprints, evidence is trending towards an increased risk of hospitalization and, potentially, mortality due to VOC compared to wild-type SARS-CoV − 2. There is little evidence on the need for, and the effect of, changes to health system arrangements in response to VOC transmission.

Published
2022
Full Text
View/download PDF

246. Development, evaluation, and implementation of an online pain assessment training program for staff in rural long-term care facilities: a case series approach

Author

Natasha Gallant, Thomas Hadjistavropoulos, Emily M. Winters, Emma K. Feere, and Abigail Wickson-Griffiths

Subjects
Dementia, Implementation Science, Long-Term Care, Online Training, Pain, Rural Settings, Geriatrics, RC952-954.6
Abstract

Abstract Background Pain among long-term care (LTC) residents, and especially residents with dementia, is often underassessed and this underassessment has been attributed, in part, to gaps in front-line staff education. Furthermore, although evidence-based clinical guidelines for pain assessment in LTC are available, pain assessment protocols are often inconsistently implemented and, when they are implemented, it is usually within urban LTC facilities located in large metropolitan centers. Implementation science methodologies are needed so that changes in pain assessment practices can be integrated in rural facilities. Thus, our purpose was to evaluate an online pain assessment training program and implement a standardized pain assessment protocol in rural LTC environments. Methods During the baseline and implementation periods, we obtained facility-wide pain-related quality indicators from seven rural LTC homes. Prior to implementing the protocol, front-line staff completed the online training program. Front-line staff also completed a set of self-report questionnaires and semi-structured interviews prior to and following completion of the online training program. Results Results indicated that knowledge about pain assessment significantly increased following completion of the online training program. Implementation of the standardized protocol resulted in more frequent pain assessments on admission and on a weekly basis, although improvements in the timeliness of follow-up assessments for those identified as having moderate to severe pain were not as consistent. Directed content analysis of semi-structured interviews revealed that the online training program and standardized protocol were well-received despite a few barriers to effective implementation. Conclusions In conclusion, we demonstrated the feasibility of the remote delivery of an online training program and implementation of a standardized protocol to address the underassessment of pain in rural LTC facilities.

Published
2022
Full Text
View/download PDF

247. Predicting Severe Sepsis Using Text from the Electronic Health Record

Author

Culliton, Phil, Levinson, Michael, Ehresman, Alice, Wherry, Joshua, Steingrub, Jay S., and Gallant, Stephen I.

Subjects
Computer Science - Computers and Society, Computer Science - Learning
Abstract

Employing a machine learning approach we predict, up to 24 hours prior, a diagnosis of severe sepsis. Strongly predictive models are possible that use only text reports from the Electronic Health Record (EHR), and omit structured numerical data. Unstructured text alone gives slightly better performance than structured data alone, and the combination further improves performance. We also discuss advantages of using unstructured EHR text for modeling, as compared to structured EHR data., Comment: Accepted at workshop on Machine Learning For Health at the conference on Neural Information Processing Systems, 2017. Near-final draft version

Published
2017

248. HESS J1741-302: a hidden accelerator in the Galactic plane

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Armand, C., Arrieta, M., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Donath, A., Drury, L. O'C., Dyks, J., Edwards, T., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., Żywucka, N., Collaboration, NANTEN, Enokiya, R., Fukui, Y., Hayakawa, T., Okuda, T., Torii, K., and Yamamoto, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The H.E.S.S. collaboration has discovered a new very high energy (VHE, E $>$ 0.1 TeV) $\gamma$-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV $\gamma$-ray energies, and the source remains unidentified. An analysis of 145-hour of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source ($\sim$1$\%$ of the Crab Nebula flux), with a spectral index of $\Gamma$ = 2.3 $\pm$ 0.2$_{\text{stat}}$ $\pm$ 0.2$_{\text{sys}}$, extending to energies up to 10 TeV without any clear signature of a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068$^{\circ}$ at a 99$\%$ confidence level. The $\gamma$-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged., Comment: 9 pages, 4 figures

Published
2017
Full Text
View/download PDF

249. TeV gamma-ray observations of the binary neutron star merger GW170817 with H.E.S.S

Author

Collaboration, H. E. S. S., Abdalla, H., Abramowski, A., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, S., Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Donath, A., Drury, L. O'C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Garrigoux, T., Gaté, F., Giavitto, G., Giebels, B., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Klochkov, D., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. -P., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Malyshev, D., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morå, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Poon, H., Prokhorov, D., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, H., Spanier, F., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We search for high-energy gamma-ray emission from the binary neutron star merger GW170817 with the H.E.S.S. Imaging Air Cherenkov Telescopes. The observations presented here have been obtained starting only 5.3h after GW170817. The H.E.S.S. target selection identified regions of high probability to find a counterpart of the gravitational wave event. The first of these regions contained the counterpart SSS17a that has been identified in the optical range several hours after our observations. We can therefore present the first data obtained by a ground-based pointing instrument on this object. A subsequent monitoring campaign with the H.E.S.S. telescopes extended over several days, covering timescales from 0.22 to 5.2 days and energy ranges between $270\,\mathrm{GeV}$ to $8.55\,\mathrm{TeV}$. No significant gamma-ray emission has been found. The derived upper limits on the very-high-energy gamma-ray flux for the first time constrain non-thermal, high-energy emission following the merger of a confirmed binary neutron star system., Comment: published in ApJL

Published
2017
Full Text
View/download PDF

250. Science with the Cherenkov Telescope Array

Author

Consortium, The Cherenkov Telescope Array, Acharya, B. S., Agudo, I., Samarai, I. Al, Alfaro, R., Alfaro, J., Alispach, C., Batista, R. Alves, Amans, J. -P., Amato, E., Ambrosi, G., Antolini, E., Antonelli, L. A., Aramo, C., Araya, M., Armstrong, T., Arqueros, F., Arrabito, L., Asano, K., Ashley, M., Backes, M., Balazs, C., Balbo, M., Ballester, O., Ballet, J., Bamba, A., Barkov, M., de Almeida, U. Barres, Barrio, J. A., Bastieri, D., Becherini, Y., Belfiore, A., Benbow, W., Berge, D., Bernardini, E., Bernardini, M. G., Bernardos, M., Bernlöhr, K., Bertucci, B., Biasuzzi, B., Bigongiari, C., Biland, A., Bissaldi, E., Biteau, J., Blanch, O., Blazek, J., Boisson, C., Bolmont, J., Bonanno, G., Bonardi, A., Bonavolontà, C., Bonnoli, G., Bosnjak, Z., Böttcher, M., Braiding, C., Bregeon, J., Brill, A., Brown, A. M., Brun, P., Brunetti, G., Buanes, T., Buckley, J., Bugaev, V., Bühler, R., Bulgarelli, A., Bulik, T., Burton, M., Burtovoi, A., Busetto, G., Canestrari, R., Capalbi, M., Capitanio, F., Caproni, A., Caraveo, P., Cárdenas, V., Carlile, C., Carosi, R., Carquín, E., Carr, J., Casanova, S., Cascone, E., Catalani, F., Catalano, O., Cauz, D., Cerruti, M., Chadwick, P., Chaty, S., Chaves, R. C. G., Chen, A., Chen, X., Chernyakova, M., Chikawa, M., Christov, A., Chudoba, J., Cieślar, M., Coco, V., Colafrancesco, S., Colin, P., Conforti, V., Connaughton, V., Conrad, J., Contreras, J. L., Cortina, J., Costa, A., Costantini, H., Cotter, G., Covino, S., Crocker, R., Cuadra, J., Cuevas, O., Cumani, P., D'Aì, A., D'Ammando, F., D'Avanzo, P., D'Urso, D., Daniel, M., Davids, I., Dawson, B., Dazzi, F., De Angelis, A., Anjos, R. de Cássia dos, De Cesare, G., De Franco, A., Pino, E. M. de Gouveia Dal, de la Calle, I., Lopez, R. de los Reyes, De Lotto, B., De Luca, A., De Lucia, M., de Naurois, M., Wilhelmi, E. de Oña, De Palma, F., De Persio, F., de Souza, V., Deil, C., Del Santo, M., Delgado, C., della Volpe, D., Di Girolamo, T., Di Pierro, F., Di Venere, L., Díaz, C., Dib, C., Diebold, S., Djannati-Ataï, A., Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Drass, H., Dravins, D., Dubus, G., Dwarkadas, V. V., Ebr, J., Eckner, C., Egberts, K., Einecke, S., Ekoume, T. R. N., Elsässer, D., Ernenwein, J. -P., Espinoza, C., Evoli, C., Fairbairn, M., Falceta-Goncalves, D., Falcone, A., Farnier, C., Fasola, G., Fedorova, E., Fegan, S., Fernandez-Alonso, M., Fernández-Barral, A., Ferrand, G., Fesquet, M., Filipovic, M., Fioretti, V., Fontaine, G., Fornasa, M., Fortson, L., Coromina, L. Freixas, Fruck, C., Fujita, Y., Fukazawa, Y., Funk, S., Füßling, M., Gabici, S., Gadola, A., Gallant, Y., Garcia, B., López, R. Garcia, Garczarczyk, M., Gaskins, J., Gasparetto, T., Gaug, M., Gerard, L., Giavitto, G., Giglietto, N., Giommi, P., Giordano, F., Giro, E., Giroletti, M., Giuliani, A., Glicenstein, J. -F., Gnatyk, R., Godinovic, N., Goldoni, P., Gómez-Vargas, G., González, M. M., González, J. M., Götz, D., Graham, J., Grandi, P., Granot, J., Green, A. J., Greenshaw, T., Griffiths, S., Gunji, S., Hadasch, D., Hara, S., Hardcastle, M. J., Hassan, T., Hayashi, K., Hayashida, M., Heller, M., Helo, J. C., Hermann, G., Hinton, J., Hnatyk, B., Hofmann, W., Holder, J., Horan, D., Hörandel, J., Horns, D., Horvath, P., Hovatta, T., Hrabovsky, M., Hrupec, D., Humensky, T. B., Hütten, M., Iarlori, M., Inada, T., Inome, Y., Inoue, S., Inoue, T., Inoue, Y., Iocco, F., Ioka, K., Iori, M., Ishio, K., Iwamura, Y., Jamrozy, M., Janecek, P., Jankowsky, D., Jean, P., Jung-Richardt, I., Jurysek, J., Kaaret, P., Karkar, S., Katagiri, H., Katz, U., Kawanaka, N., Kazanas, D., Khélifi, B., Kieda, D. B., Kimeswenger, S., Kimura, S., Kisaka, S., Knapp, J., Knödlseder, J., Koch, B., Kohri, K., Komin, N., Kosack, K., Kraus, M., Krause, M., Krauß, F., Kubo, H., Mezek, G. Kukec, Kuroda, H., Kushida, J., La Palombara, N., Lamanna, G., Lang, R. G., Lapington, J., Blanc, O. Le, Leach, S., Lees, J. -P., Lefaucheur, J., de Oliveira, M. A. Leigui, Lenain, J. -P., Lico, R., Limon, M., Lindfors, E., Lohse, T., Lombardi, S., Longo, F., López, M., López-Coto, R., Lu, C. -C., Lucarelli, F., Luque-Escamilla, P. L., Lyard, E., Maccarone, M. C., Maier, G., Majumdar, P., Malaguti, G., Mandat, D., Maneva, G., Manganaro, M., Mangano, S., Marcowith, A., Marín, J., Markoff, S., Martí, J., Martin, P., Martínez, M., Martínez, G., Masetti, N., Masuda, S., Maurin, G., Maxted, N., Mazin, D., Medina, C., Melandri, A., Mereghetti, S., Meyer, M., Minaya, I. A., Mirabal, N., Mirzoyan, R., Mitchell, A., Mizuno, T., Moderski, R., Mohammed, M., Mohrmann, L., Montaruli, T., Moralejo, A., Morcuende-Parrilla, D., Mori, K., Morlino, G., Morris, P., Morselli, A., Moulin, E., Mukherjee, R., Mundell, C., Murach, T., Muraishi, H., Murase, K., Nagai, A., Nagataki, S., Nagayoshi, T., Naito, T., Nakamori, T., Nakamura, Y., Niemiec, J., Nieto, D., Nikołajuk, M., Nishijima, K., Noda, K., Nosek, D., Novosyadlyj, B., Nozaki, S., O'Brien, P., Oakes, L., Ohira, Y., Ohishi, M., Ohm, S., Okazaki, N., Okumura, A., Ong, R. A., Orienti, M., Orito, R., Osborne, J. P., Ostrowski, M., Otte, N., Oya, I., Padovani, M., Paizis, A., Palatiello, M., Palatka, M., Paoletti, R., Paredes, J. M., Pareschi, G., Parsons, R. D., Pe'er, A., Pech, M., Pedaletti, G., Perri, M., Persic, M., Petrashyk, A., Petrucci, P., Petruk, O., Peyaud, B., Pfeifer, M., Piano, G., Pisarski, A., Pita, S., Pohl, M., Polo, M., Pozo, D., Prandini, E., Prast, J., Principe, G., Prokhorov, D., Prokoph, H., Prouza, M., Pühlhofer, G., Punch, M., Pürckhauer, S., Queiroz, F., Quirrenbach, A., Rainò, S., Razzaque, S., Reimer, O., Reimer, A., Reisenegger, A., Renaud, M., Rezaeian, A. H., Rhode, W., Ribeiro, D., Ribó, M., Richtler, T., Rico, J., Rieger, F., Riquelme, M., Rivoire, S., Rizi, V., Rodriguez, J., Fernandez, G. Rodriguez, Vázquez, J. J. Rodríguez, Rojas, G., Romano, P., Romeo, G., Rosado, J., Rovero, A. C., Rowell, G., Rudak, B., Rugliancich, A., Rulten, C., Sadeh, I., Safi-Harb, S., Saito, T., Sakaki, N., Sakurai, S., Salina, G., Sánchez-Conde, M., Sandaker, H., Sandoval, A., Sangiorgi, P., Sanguillon, M., Sano, H., Santander, M., Sarkar, S., Satalecka, K., Saturni, F. G., Schioppa, E. J., Schlenstedt, S., Schneider, M., Schoorlemmer, H., Schovanek, P., Schulz, A., Schussler, F., Schwanke, U., Sciacca, E., Scuderi, S., Seitenzahl, I., Semikoz, D., Sergijenko, O., Servillat, M., Shalchi, A., Shellard, R. C., Sidoli, L., Siejkowski, H., Sillanpää, A., Sironi, G., Sitarek, J., Sliusar, V., Slowikowska, A., Sol, H., Stamerra, A., Stanič, S., Starling, R., Stawarz, Ł., Stefanik, S., Stephan, M., Stolarczyk, T., Stratta, G., Straumann, U., Suomijarvi, T., Supanitsky, A. D., Tagliaferri, G., Tajima, H., Tavani, M., Tavecchio, F., Tavernet, J. -P., Tayabaly, K., Tejedor, L. A., Temnikov, P., Terada, Y., Terrier, R., Terzic, T., Teshima, M., Testa, V., Thoudam, S., Tian, W., Tibaldo, L., Tluczykont, M., Peixoto, C. J. Todero, Tokanai, F., Tomastik, J., Tonev, D., Tornikoski, M., Torres, D. F., Torresi, E., Tosti, G., Tothill, N., Tovmassian, G., Travnicek, P., Trichard, C., Trifoglio, M., Pujadas, I. Troyano, Tsujimoto, S., Umana, G., Vagelli, V., Vagnetti, F., Valentino, M., Vallania, P., Valore, L., van Eldik, C., Vandenbroucke, J., Varner, G. S., Vasileiadis, G., Vassiliev, V., Acosta, M. Vázquez, Vecchi, M., Vega, A., Vercellone, S., Veres, P., Vergani, S., Verzi, V., Vettolani, G. P., Viana, A., Vigorito, C., Villanueva, J., Voelk, H., Vollhardt, A., Vorobiov, S., Vrastil, M., Vuillaume, T., Wagner, S. J., Wagner, R., Walter, R., Ward, J. E., Warren, D., Watson, J. J., Werner, F., White, M., White, R., Wierzcholska, A., Wilcox, P., Will, M., Williams, D. A., Wischnewski, R., Wood, M., Yamamoto, T., Yamazaki, R., Yanagita, S., Yang, L., Yoshida, T., Yoshiike, S., Yoshikoshi, T., Zacharias, M., Zaharijas, G., Zampieri, L., Zandanel, F., Zanin, R., Zavrtanik, M., Zavrtanik, D., Zdziarski, A. A., Zech, A., Zechlin, H., Zhdanov, V. I., Ziegler, A., and Zorn, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

The Cherenkov Telescope Array, CTA, will be the major global observatory for very high energy gamma-ray astronomy over the next decade and beyond. The scientific potential of CTA is extremely broad: from understanding the role of relativistic cosmic particles to the search for dark matter. CTA is an explorer of the extreme universe, probing environments from the immediate neighbourhood of black holes to cosmic voids on the largest scales. Covering a huge range in photon energy from 20 GeV to 300 TeV, CTA will improve on all aspects of performance with respect to current instruments. The observatory will operate arrays on sites in both hemispheres to provide full sky coverage and will hence maximize the potential for the rarest phenomena such as very nearby supernovae, gamma-ray bursts or gravitational wave transients. With 99 telescopes on the southern site and 19 telescopes on the northern site, flexible operation will be possible, with sub-arrays available for specific tasks. CTA will have important synergies with many of the new generation of major astronomical and astroparticle observatories. Multi-wavelength and multi-messenger approaches combining CTA data with those from other instruments will lead to a deeper understanding of the broad-band non-thermal properties of target sources. The CTA Observatory will be operated as an open, proposal-driven observatory, with all data available on a public archive after a pre-defined proprietary period. Scientists from institutions worldwide have combined together to form the CTA Consortium. This Consortium has prepared a proposal for a Core Programme of highly motivated observations. The programme, encompassing approximately 40% of the available observing time over the first ten years of CTA operation, is made up of individual Key Science Projects (KSPs), which are presented in this document., Comment: 213 pages, including references and glossary. Version 2: credits and references updated, some figures updated, and author list updated

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results