Search arXivSearch

arXiv · 2107.01359

Kinematics reconstruction of the EAS-like events registered by the TUS detector

Abstract

The Tracking Ultraviolet Set-up (TUS) is the world's first orbital imaging detector of Ultra High Energy Cosmic Rays (UHECR) and it operated in 2016-2017 as part of the scientific equipment of the Lomonosov satellite. The TUS was developed and manufactured as a prototype of the larger project K-EUSO with the main purpose of testing the efficiency of the method for measuring the ultraviolet signal of extensive air shower (EAS) in the Earth's night atmosphere. Despite the low spatial resolution ($\sim5\times5$ km$^2$ at sea level), several events were recorded which are very similar to EAS as for the signal profile and kinematics. Reconstruction of the parameters of such events is complicated by a short track length, an asymmetry of the image, and an uncertainty in the sensitivity distribution of the TUS channels. An advanced method was developed for the determination of event kinematic parameters including its arrival direction. In the present article, this method is applied for the analysis of 6 EAS-like events recorded by the TUS detector. All events have an out of space arrival direction with zenith angles less than 40°. Remarkably they were found to be over the land rather close to United States airports, which indicates a possible anthropogenic nature of the phenomenon. Detailed analysis revealed a correlation of the reconstructed tracks with direction to airport runways and Very High Frequency (VHF) omnidirectional range stations. The method developed here for reliable reconstruction of kinematic parameters of the track-like events, registered in low spatial resolution, will be useful in future space missions, such as K-EUSO.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S. Sharakin, O. I. Ruiz Hernandez. 2021-07-03. Kinematics reconstruction of the EAS-like events registered by the TUS detector. https://doi.org/10.1088/1748-0221%2F16%2F07%2Ft07013

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Performance characterization of a new Structural and Thermal Architecture for a future spaceborne Closed-Cycle Dilution Refrigerator

A Structural and Thermal Model (STM) has been developed to support the new spaceborne Closed-Cycle Dilution Refrigerator (CCDR), which aims to provide continuous cooling at 100~mK for long-duration astrophysical missions. The STM is based on a hexapod architecture that ensures both thermal decoupling and mechanical robustness during launch. In this paper, we present the characterization of its thermal and mechanical performances. A dedicated experimental setup was used to investigate the thermal behavior of the STM across a broad temperature range. The study reveals limitations of the collar design, with incomplete power interception from thermal boundary resistances and vibration test failure traced to defective strut gluing. These results guide the next STM iteration with optimized collar and strut assembly for reliable CCDR operation in space.

astro-ph.IM

The Simons Observatory: Development of a Pipeline to Detect Rapid Transients in Time-Ordered Data

We introduce a method for detecting astrophysical transients evolving on timescales of milliseconds to minutes using cosmic microwave background (CMB) survey telescopes. While previous transient searches in CMB data operate in map space, our pipeline directly processes the raw time-ordered data, enabling sensitivity to fast, dynamic signals. We integrate our detection approach into the Simons Observatory time-domain pipeline and assess the performance by injecting symmetric, stellar flare-like light curves into simulated observations. For events flaring with a timescale of 0.5 s, the pipeline detects $\gtrsim90$ % of events at flux densities of 800, 1150, 1650, and 4250\,mJy when measured in the 93, 145, 225, and 280 GHz bands respectively. At a fixed peak flux density, the pipeline more readily detects longer flares. The limiting flux density for 90 % completeness is four times lower for a $\ge5$ s flare than for a 0.5 s flare, while the flux density limits for $\gtrsim50$ % detection efficiency are comparable to the rms noise of the time-ordered data. We are able to determine the position of detected events in each observing band, with a positional uncertainty at the detection threshold comparable to the telescope resolution at that band. These results demonstrate the readiness of this pipeline for incorporation into upcoming Simons Observatory data analyses.

astro-ph.IM

Thermal conductivity of various CFRPs from 100 mK to 20 K

Carbon-fiber-reinforced polymers (CFRPs) are some of the most useful materials for building spacecraft and aerospace tools. They are especially valuable for systems that work at extremely cold (cryogenic) temperatures because they are strong, lightweight, and don't transfer heat easily. In this study, researchers measured how well heat moves through several different types of carbon fiber samples, specifically T300, T700, HS40, M55J, and IMA, at different fiber layouts and densities. These measurements were taken at ultra-cold temperatures ranging from 100 mK to 20 K. The team used a newly developed analysis method to calculate the thermal conductivity for each sample. Finally, they shared how each material behaved at different temperatures and compared their findings to previous research.

astro-ph.IM