Average Alert Times Supported by ATAR Classes A1, A2, and A3
This presentation shows the average warning and corrective alert times supported by the ATAR classes A1, A2, and A3
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This presentation shows the average warning and corrective alert times supported by the ATAR classes A1, A2, and A3
Searches for electromagnetic counterparts of gravitational-wave signals have redoubled since the first detection in2017 of a binary neutron star merger with a gamma-ray burst, optical/infrared kilonova, and panchromatic after glow. Yet, one LIGO/Virgo observing run later, there has not yet been a second, secure identification of an electromagnetic counterpart. This is not surprising given that the localization uncertainties of events in LIGO and Virgo’s third observing run, O3, were much larger than predicted. We explain this by showing that improvements in data analysis that now allow LIGO/Virgo to detect weaker and hence more poorly localized events have increased the overall number of detections, of which well-localized, gold-plated events make up a smaller proportion overall. We present simulations of the next two LIGO/Virgo/KAGRA observing runs, O4 and O5, that are grounded in the statistics ofO3 public alerts. To illustrate the significant impact that the updated predictions can have, we study the follow-up strategy for the Zwicky Transient Facility. Realistic and timely forecasting of gravitational-wave localization accuracy is paramount given the large commitments of telescope time and the need to prioritize which events are followed up. We include a data release of our simulated localizations as a public proposal planning resource for astronomers
The Relativistic Electron Alert System for Exploration (“REleASE”) exploits the prompt arrival of near-relativistic electrons in the Earth/moon system to rapidly warn human explorers of the imminent arrival of hazardous energetic ions from solar energetic particle (SEP) events. Since 2008, the REleASE system has been implemented in near-real-time, initially with electron observations from SOHO, and since 2017 with additional observations from ACE as “HESPERIA REleASE”: upcoming opportunities will utilize IMAP and SWFO observations. REleASE is undergoing performance validation as part of the NASA/CCMC SEP scoreboarding process (https://ccmc.gsfc.nasa.gov/scoreboards/sep/). The ongoing return of STEREO-A to the vicinity of Earth provides observations of radio waves in near-real-time and allows REleASE to be combined with the identification of type-III radio bursts, which provide additional evidence of particle escape from the Sun (the use of type-III bursts for SEP forecasting was pioneered by “ESPERTA” developed by Laurenza et al., 2009). The aim of this planned “REleASE+” system is to further reduce the rate of false alarms. Another opportunity, facilitated by the CLEAR space weather center (PI L. Zhao, Univ. Michigan) will combine REleASE with “SEPSTER” (Richardson et al., 2018) to reduce the high rate of false alarms produced by SEPSTER, which is triggered by reports of CMEs, the vast majority of which do not result in detected SEP ion events. This presentation will give a status update on these objectives.
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The gamma-ray burst (GRB) rate is essential for revealing the connection between GRBs, supernovae, and stellar evolution. Additionally, the GRB rate at high redshift provides a strong probe of star formation history in the early universe. While hundreds of GRBs are observed by Swift, it remains difficult to determine the intrinsic GRB rate due to the complex trigger algorithm of Swift. Current studies of the GRB rate usually approximate the Swift trigger algorithm by a single detection threshold. However, unlike the previously flown GRB instruments, Swift has over 500 trigger criteria based on photon count rate and an additional image threshold for localization. To investigate possible systematic biases and explore the intrinsic GRB properties, we develop a program that is capable of simulating all the rate trigger criteria and mimicking the image threshold. Our simulations show that adopting the complex trigger algorithm of Swift increases the detection rate of dim bursts. As a result, our simulations suggest that bursts need to be dimmer than previously expected to avoid overproducing the number of detections and to match with Swift observations. Moreover, our results indicate that these dim bursts are more likely to be high redshift events than low-luminosity GRBs. This would imply an even higher cosmic GRB rate at large redshifts than previous expectations based on star formation rate measurements, unless other factors, such as the luminosity evolution, are taken into account. The GRB rate from our best result gives a total number of 4568{sub −1429}{sup +825} GRBs per year that are beamed toward us in the whole universe.
Physical parameters of both the mass donor and compact object can be constrained in X-ray binaries with well-defined eclipses, as our survey of wind-fed supergiant X-ray binaries IGR J16393-4643, IGR J16418-4532, IGR J16479-4514, IGR J18027-2016, and XTE J1855-026 reveals. Using the orbital period and Kepler’s third law, we express the eclipse half-angle in terms of radius, inclination angle, and the sum of the masses. Pulse-timing and radial velocity curves can give masses of both the donor and compact object as in the case of the “double-lined” binaries IGR J18027-2016 and XTE J1855-026. The eclipse half angles are 15{sub −2}{sup +3}, 31.7{sub −0.8}{sup +0.7}, 32 ± 2,34 ± 2, and 33.6±0.7 degrees for IGR J16393-4643, IGR J16418-4532, IGR J16479-4514, IGR J18027-2016, and XTE 1855-026, respectively. In wind-fed systems, the primary not exceeding the Roche-lobe size provides an upper limit on system parameters. In IGR J16393-4643, spectral types of B0 V or B0-5 III are found to be consistent with the eclipse duration and Roche-lobe, but the previously proposed donor stars in IGR J16418-4532 and IGR J16479-4514 were found to be inconsistent with the Roche-lobe size. Stars with spectral types O7.5 I and earlier are possible. For IGR J18027-2016, the mass and radius of the donor star lie between 18.6–19.4 M{sub ⊙} and 17.4–19.5 R{sub ⊙}. We constrain the neutron star mass between 1.37 and 1.43 M{sub ⊙}.We find the mass and radius of the donor star in XTE J1855-026 to lie between 19.6–20.2 M{sub ⊙} and 21.5–23.0 R{sub ⊙}. The neutron star mass was constrained to 1.77–1.82 M{sub ⊙}. Eclipse profiles are asymmetric in IGR J18027-2016 and XTE J1855-026, which we attribute to accretion wakes.
Abstract Background On 20 September 2022, the Ugandan Ministry of Health declared an outbreak of Ebola disease caused by Sudan ebolavirus. Methods From 6 October 2022 to 10 January 2023, Centers for Disease Control and Prevention (CDC) staff conducted public health assessments at five US ports of entry for travellers identified as having been in Uganda in the past 21 days. CDC also recommended that state, local and territorial health departments (‘health departments’) conduct post-arrival monitoring of these travellers. CDC provided traveller contact information, daily to 58 health departments, and collected health department data regarding monitoring outcomes. Results Among 11 583 travellers screened, 132 (1%) required additional assessment due to potential exposures or symptoms of concern. Fifty-three (91%) health departments reported receiving traveller data from CDC for 10 114 (87%) travellers, of whom 8499 (84%) were contacted for monitoring, 1547 (15%) could not be contacted and 68 (1%) had no reported outcomes. No travellers with high-risk exposures or Ebola disease were identified. Conclusion Entry risk assessment and post-arrival monitoring of travellers are resource-intensive activities that had low demonstrated yield during this and previous outbreaks. The efficiency of future responses could be improved by incorporating an assessment of risk of importation of disease, accounting for individual travellers’ potential for exposure, and expanded use of methods that reduce burden to federal agencies, health departments, and travellers.
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Cyber network analysts follow complex processes in their investigations of potential threats to their network. Much research is dedicated to providing automated tool support in the effort to make their tasks more efficient, accurate, and timely. This tool support comes in a variety of implementations from machine learning algorithms that monitor streams of data to visual analytic environments for exploring rich and noisy data sets. Cyber analysts, however, often speak of a need for tools which help them merge the data they already have and help them establish appropriate baselines against which to compare potential anomalies. Furthermore, existing threat models that cyber analysts regularly use to structure their investigation are not often leveraged in support tools. We report on our work with cyber analysts to understand they analytic process and how one such model, the MITRE ATT&CK Matrix [32], is used to structure their analytic thinking. We present our efforts to map specific data needed by analysts into the threat model to inform our eventual visualization designs. We examine data mapping for gaps where the threat model is under-supported by either data or tools. We discuss these gaps as potential design spaces for future research efforts. We also discuss the design of a prototype tool that combines machine-learning and visualization components to support cyber analysts working with this threat model.
A high-energy neutrino event detected by IceCube on 22 September 2017 was coincident in direction and time with a gamma-ray flare from the blazar TXS 0506+056. Prompted by this association, we investigated 9.5 years of IceCube neutrino observations to search for excess emission at the position of the blazar. We found an excess of high-energy neutrino events, with respect to atmospheric backgrounds, at that position between September 2014 and March 2015. Allowing for time-variable flux, this constitutes 3.5σ evidence for neutrino emission from the direction of TXS 0506+056, independent of and prior to the 2017 flaring episode. This suggests that blazars are identifiable sources of the high-energy astrophysical neutrino flux.
As part of technology foraging for the Responder Technology Alliance, established by the Department of Homeland Science and Technologies First Responders Group, this report summarizes technologies that are relevant in the area of “wearables,” with the potential for use by first responders. The content was collected over the previous month(s) and reproduced from a general Internet search using the term wearables. Additional information is available at the websites provided. This report is not meant to be an exhaustive list nor an endorsement of any technology described herein. Rather, it is meant to provide useful information about current developments in the areas wearable technology.
As part of technology foraging for the Responder Technology Alliance, established by the Department of Homeland Science and Technologies First Responders Group, this report summarizes technologies that are relevant in the area of “wearables,” with the potential for use by first responders. The content was collected over the previous month(s) and reproduced from a general Internet search using the term wearables. Additional information is available at the websites provided. This report is not meant to be an exhaustive list nor an endorsement of any technology described herein. Rather, it is meant to provide useful information about current developments in the areas wearable technology.
As part of technology foraging for the Responder Technology Alliance, established by the Department of Homeland Science and Technologies First Responders Group, this report summarizes technologies that are relevant in the area of “wearables,” with the potential for use by first responders. The content was collected over the previous month(s) and reproduced from a general Internet search using the term wearables. Additional information is available at the websites provided. This report is not meant to be an exhaustive list nor an endorsement of any technology described herein. Rather, it is meant to provide useful information about current developments in the areas wearable technology. The content is organized by technology function including: Sensors – Devices that detect physiological, particle, and chemical activity; Displays – Heads-up and body-worn visual displays; Power – Wearable power systems including chargers, batteries, self-powering or harvesting technologies, and power supplies; Integrated Communications – Voice and data communications systems utilizing Bluetooth, wireless, hands-free, ergonomically optimized systems, noise-filtering digital speakers or microphones, etc.; Exoskeletons – Whole or partial body suit that enhances mobility and physical performance; Wearable Computers – Body-worn data processing devices; General – Miscellaneous technologies as well as emerging trends or recent advances in the field of wearables.
As part of technology foraging for the Responder Technology Alliance, established by the Department of Homeland Science and Technologies First Responders Group, this report summarizes technologies that are relevant in the area of “wearables,” with the potential for use by first responders. The content was collected over the previous month(s) and reproduced from a general Internet search using the term wearables. Additional information is available at the websites provided. This report is not meant to be an exhaustive list nor an endorsement of any technology described herein. Rather, it is meant to provide useful information about current developments in the areas wearable technology.