112 research outputs found
Solar Jet Hunter: Jet Catalog from HEK Events 2011-2016
No full textData are in the form of CSV and JSON files that include information about each jet found by the project. For each jet, the primary information included is the date, time, and duration of the event, the basepoint X and Y coordinates in arcsec and latitude/longitude, the maximum height to which the jet was observed, the width, and velocity. Auxiliary information is also included.This database constitutes the first release of data from the Solar Jet Hunter project. Solar Jet Hunter is a Zooniverse-based citizen science project that has, since 2021, enlisted volunteers from the general public to help identify extreme ultraviolet jets of plasma in the Sun’s corona. These jets release magnetic energy at the Sun and enable streams of plasma and energetic particles to escape to the solar system, but the origins of and mechanisms underlying these jets are still not understood. In Solar Jet Hunter, videos of possible jets are presented to volunteers, who are asked to identify whether a jet is present, and if so, its start time, end time, and base location. Volunteers also box the jet, providing information on its shape and height over time. The results from many volunteers are then aggregated into consensus results for each potential jet in the study. Those results are listed in this data set. The data presented to volunteers is from the Solar Dynamic Observatory / Atmospheric Imaging Assembly instrument, specifically the 304 angstrom filter, and all of the candidate jets were identified as possible jets in the Heliophysics Event Knowledgebase (HEK). The data set included here lists Solar Jet Hunter results from the years 2011 through 2016.NASA HGI grant 80NSSC20K0718NSF CAREER grant AGS1752268Musset, Sophie; Sankar, Ramanakumar; Lasko, Kekoa; Jol, Paloma; Glesener, Lindsay; Fleishman, Gregory; Panesar, Navdeep; Zhang, Yixian; Hurlburt, Neal; Fortson, Lucy; Ostlund, Erik; Alnahari, Suhail; Jeunon, Mariana; Kapsiak, Charles. (2023). Solar Jet Hunter: Jet Catalog from HEK Events 2011-2016. Retrieved from the Data Repository for the University of Minnesota (DRUM), https://doi.org/10.13020/83de-jf51
Model file for Ishikawa et al. "Automatic Detection of Occulted Hard X-ray Flares Using Deep-Learning Methods" in Sol. Phys. (2021)
No full textThe file named "model_occulted_flare_classifier.h5" is a Keras model file to detect occulated hard X-ray flares by RHESSI spectrogram data described in Ishikawa et al. 2021. The model file was created with Python 3.6.8, Tensorflow 1.14.0 and Keras 2.2.4.Deep-learning model for occulted hard X-ray flare detection was published in association with the publication Ishikawa et al. "Automatic Detection of Occulted Hard X-ray Flares Using Deep-Learning Methods" in Sol. Phys. (2021). We checked the model file with the Google Colaboratory environment (Python 3.6.9 and Tensorflow 2.4.0).Ishikawa, Shin-nosuke; Matsumura, Hideaki; Uchiyama, Yasunobu; Glesener, Lindsay. (2021). Model file for Ishikawa et al. "Automatic Detection of Occulted Hard X-ray Flares Using Deep-Learning Methods" in Sol. Phys. (2021). Retrieved from the University Digital Conservancy, https://doi.org/10.13020/wtbm-2258
Signal of Opportunity Time Difference of Arrival Estimation Using Adaptive Filtering Techniques
No full textEXACT and SOCRATES are a pair of CubeSats being developed to advance the TRL of a dual-use sensor. It can function either as x-ray detector used for characterization of high energy photons or as a sensor for measuring relative ranges between users in deep space operations. The ranging function of the sensor is described in this paper. After describing the measurements generated by the sensor, the algorithms that make use of this information to generate a position solution are presented. As a validation case study, data from the Japanese spacecraft Suzaku’s observation of the Crab Nebula Pulsar is used to estimate the spacecraft’s change in position along the line-of-sight to the pulsar, using this estimation scheme. Suzaku’s observations are suitable for this application because the spacecraft's Hard X-Ray Detector (HXD) is similar in effective surface area to the prototype X-Ray/gamma-ray detector currently under development for use onboard EXACTand SOCRATES. Thus, validation of this technique using data from Suzaku serves to verify the feasibility of this navigation technique onboard other spacecraft with detectors of similar size.Runnels, Joel T.; Gebre-Egziabher, Demoz; Glesener, Lindsay. (2017). Signal of Opportunity Time Difference of Arrival Estimation Using Adaptive Filtering Techniques. Retrieved from the University Digital Conservancy, 10.1109/AERO.2017.7943932
Monolithic pixel sensors in deep-submicron SOI technology with analog and digital pixels
No full textDevelopment of CMOS Monolithic Pixel Sensors With In-Pixel Correlated Double Sampling and Fast Readout
No full textFOXSI Detector Data from 2018-2019 Advanced Light Source Experiments
No full textThere were three experimental runs (March, May 2018, April 2019). Each is documented individually in the readme, in chronological order. Data files are provided in three compressed folders (one for each experimental run). A .CSV file is also included for each experimental run, which gives file-specific parameters (e.g. beam position, energy, etc).This dataset consists of several hundreds of data files taken by the Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket x-ray detectors during tests at the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. These tests involve illumination of the FOXSI semiconductor double-sided strip detectors with a fine, collimated beam at known X-ray energies produced by the ALS synchrotron. Some of the tests involve fine scans across the surface of the detectors, characterizing spatial dependence of detector performance, including at multiple locations within specific strips. The purpose of these experiments was to improve characterization of the detectors both before and after the flight of FOXSI-3. This characterization includes determining detector quantum efficiency, as well as measuring charge sharing between detector strips.Glesener, Lindsay E.; Duncan, Jessie M.. (2022). FOXSI Detector Data from 2018-2019 Advanced Light Source Experiments. Retrieved from the University Digital Conservancy, https://doi.org/10.13020/KKFH-5M05
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Faint Coronal Hard X-rays From Accelerated Electrons in Solar Flares
No full textSolar flares are huge explosions on the Sun that release a tremendous amount of energy from the coronal magnetic field, up to 1033 ergs, in a short time (100--1000 seconds), with much of the energy going into accelerated electrons and ions. An efficient acceleration mechanism is needed, but the details of this mechanism remain relatively unknown. A fraction of this explosive energy reaches the Earth in the form of energetic particles, producing geomagnetic storms and posing dangers to spaceborne instruments, astronauts, and Earthbound power grids. There are thus practical reasons, as well as intellectual ones, for wishing to understand this extraordinary form of energy release.Through imaging spectroscopy of the hard X-ray (HXR) emission from solar flares, the behavior of flare-accelerated electrons can be studied. The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft launched in 2002 with the goal of better understanding flare particle acceleration. Using rotation modulation collimators, RHESSI is able to cover a wide energy range (3 keV--17 MeV) with fine angular and energy resolutions. RHESSI's success in the last 10 years in investigating the relationship between energetic electrons and ions, the nature of faint sources in the corona, the energy distribution of flares, and several other topics have significantly advanced the understanding of flares.But along with the wealth of information revealed by RHESSI come some clear observational challenges. Very few, if any, RHESSI observations have come close to imaging the electron acceleration region itself. This is undoubtedly due to a lack of both sensitivity (HXRs from electron beams in the tenuous corona are faint) and dynamic range (HXR sources at chromospheric flare footpoints are much brighter and tend to obscure faint coronal sources). Greater sensitivity is also required to investigate the role that small flares in the quiet Sun could play in heating the corona.The Focusing Optics X-ray Solar Imager (FOXSI) is a developing project to address these observational difficulties. FOXSI is a sounding rocket payload developed under NASA's Low Cost Access to Space program. The project spearheads a shift to using direct imaging via focusing grazing-incidence HXR optics rather than the indirect Fourier techniques used by RHESSI and its predecessors. Such optics can attain higher sensitivity since photons are focused onto a small detector volume and have significantly better dynamic range than Fourier methods do. On November 2, 2012 the FOXSI rocket payload was flown for a 6-minute observation and successfully imaged a solar flare, providing the first focused HXR spectroscopic images of the Sun above 5 keV.The motivation, construction, testing, and flight of FOXSI will be described in this text, along with case studies on the use of FOXSI to analyze unique coronal HXR sources from two solar flares
Electron Acceleration and Jet-facilitated Escape in an M-class Solar Flare on 2002 August 19
No full textSudden jets of collimated plasma arise from many locations on the Sun, including active regions. The magnetic field along which a jet emerges is often open to interplanetary space, offering a clear escape route for any flare-accelerated electrons, making jets lucrative targets for studying particle acceleration and the solar sources of transient heliospheric events. Bremsstrahlung hard X-rays (HXRs) could, in principle, trace the accelerated electrons that escape along the paths of the jets, but measurements of the escaping electron beams are customarily difficult due to the low densities of the corona. In this work, we augment HXR observations with gyrosynchrotron emission observed in microwaves, as well as extreme ultraviolet (EUV) emission and modeling to investigate flare-accelerated electrons in a coronal jet. HXR and microwave data from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Owens Valley Solar Array (OVSA), respectively, give complementary insight into electron spectra and locations, including the presence of accelerated electrons in the jet itself. High-time-resolution HXR data from the Konus-Wind instrument suggest electron acceleration timescales on the order of 1 s or shorter. We model the energetic electron distributions in the GX Simulator framework using the Solar and Heliospheric Observatory (SOHO)/Michelson Doppler Imager (MDI), the Transition Region and Coronal Explorer (TRACE), RHESSI, and OVSA data as constraints. The result is a modeled distribution, informed and constrained by measurements, of accelerated electrons as they escape the Sun. Combining the detection of microwave gyrosynchrotron emission from an open, rather than closed, magnetic configuration, with realistic 3D modeling constrained by magnetograms, EUV, and X-ray emission, we obtain the most stringent constraints to date on the accelerated electrons within a solar jet
Monolithic pixel sensors in deep-submicron SOI technology with analog and digital pixels
No full textThis paper presents the design and test results of a prototype monolithic pixel sensor manufactured in deep-submicron fully depleted Silicon-On-Insulator (SOI) CMOS technology. In the SOI technology, a thin layer of integrated electronics is insulated from a (high-resistivity) silicon substrate by a buried oxide. Vias etched through the oxide allow to contact the substrate from the electronics layer, so that pixel implants can be created and a reverse bias can be applied. The prototype chip, manufactured in OKI 0.15muM SOI process, features both analog and digital pixels on a 10muM pitch. Results of tests performed with an infrared laser and 1.35 GeV electrons and a first assessment of the effect of ionising and non-ionising doses are discussed
European Literatures of Military Occupation
No full textOccupation literature: a new perspective on European identities
What does it mean to live under occupation? How does it shape the culture and identities of European nations? How does it affect the way we write and read literature? These are fundamental questions that set the stage for an in-depth exploration. Focusing on the literary works of writers from various European countries that were occupied by Nazi Germany, the Soviet Union or the Allies during and after World War II, the contributions in this edited volume seek to unravel the complex interplay between historical circumstances and literary expression. Centered on the concept of occupation literature as a genre in its own right, differentiating it from 'war literature', the book navigates this subtle distinction, drawing connections with the Holocaust novel and extending the timeframe beyond Nazi occupation.
European Literatures of Military Occupation argues that the multifaceted experiences of occupation have played a pivotal role in shaping European identities. Moreover, the volume links European identities to the experience of occupation by unveiling the complex and diverse ways in which writers respond to historical and political circumstances. Introducing the concept of 'affective realism' and exploring its intersection with the occupation novel, the book provides nuanced insights into the intricate relationship between history, identity, and literature. It combines theoretical perspectives relevant to researchers in the humanities with detailed case studies, generating a truly interdisciplinary perspective, enriched by a strong transnational dimension, creating a cohesive narrative that intervenes innovatively in the fields of literary, cultural, and historical criticism.
Ebook available in Open Access.
This publication is GPRC-labeled (Guaranteed Peer-Reviewed Content).Contributors: Klaus-Michael Bogdal (Bielefeld University), Jan Andres (Bielefeld University), Benedikts Kalnačs (University of Latvia), Stefan Laffin (Leibnitz University of Hannover), Daniela Lieb (Centre national de littérature, Luxembourg), Atinati Mamatsashvil (Ilia State University), Christopher Meid (University of Freiburg), Aleksandar Momčilović (independent scholar), Jeroen Olyslaegers (independent literary author), Joanna Rzepa (University of Essex), Sandra Schell (Heidelberg University), Meinolf Schumacher (Bielefeld University), Stefanie Siess (Heidelberg University
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