New highlights of gamma-ray observations by ASIM

ASIM has now observed several hundreds of TGFs since the launch in 2018. Highlights and new science from the first ten months of observations were presented in &#216;stgaard et al. (2019) paper. In this presentation we will present observational highlights from the last 1.5 year, when the relative timing accuracy between the TGF observations and the optical measurements is +/- 5 us (compared to +/- 80 us before march 2019). This includes many more simultaneous TGF and Elve observations, high flux TGFs, double TGFs simultaneous with double optical pulses and many TGFs with good radio measurements.&#160; ASIM has also observed several Gamma Ray Bursts.&#160;

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GLAST and Gamma-Ray Bursts

Symposium - International Astronomical Union ◽

10.1017/s0074180900194793 ◽

2003 ◽

Vol 214 ◽

pp. 391-398

Author(s):

Robert D. Preece

Keyword(s):

Gamma Ray ◽

Gamma Ray Bursts ◽

Large Area ◽

Space Telescope ◽

New Science

The two instruments aboard the Gamma-Ray Large Area Space Telescope (GLAST) mission will make unprecedented spectral observations of gamma-ray bursts. I will discuss what new science we can expect from GLAST.

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Investigating the relationship between TGF durations and the onset times of the optical pulses and the TGFs

10.5194/egusphere-egu21-14757 ◽

2021 ◽

Author(s):

Chris Alexander Skeie ◽

Nikolai Østgaard ◽

Andrey Mezentsev ◽

Ingrid Bjørge-Engeland ◽

David Sarria ◽

...

Keyword(s):

Gamma Ray ◽

Space Station ◽

High Energy ◽

Optical Measurements ◽

Temporal Uncertainty ◽

Optical Pulses ◽

International Space ◽

Imaging Array ◽

Lightning Detection ◽

The Relationship

We investigate and determine the sequence of the Terrestrial Gamma-ray Flashes (TGFs) and the observed optical emissions associated with lightning flashes, as well as the connection between the duration of TGFs and the time between the onset of the TGFs and the observed main optical pulses. Over 200 observations from the instruments of the Atmosphere-Space Interactions Monitor (ASIM) on board the International Space Station (ISS) are used, together with data from the lightning detection networks GLD360 and WWLLN. The ASIM data consist of two separate recordings: High energy measurements from the Modular X- and Gamma-ray Sensor (MXGS), and optical measurements from the Modular Multi-Spectral Imaging Array (MMIA). The optical measurements are from photometers operating in the 337 and 777.4 nm bands, and the temporal uncertainty between the two instruments of ASIM is +- 5 &#181;s.

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Lightning optical context associated with ASIM TGFs

10.5194/egusphere-egu2020-8157 ◽

2020 ◽

Author(s):

Andrey Mezentsev ◽

Nikolai Østgaard ◽

Martino Marisaldi ◽

Pavlo Kochkin ◽

Torsten Neubert ◽

...

Keyword(s):

Gamma Ray ◽

Space Station ◽

High Energy ◽

Relative Timing ◽

Science Data ◽

Timing Accuracy ◽

Transient Luminous Events ◽

Imaging Array ◽

Lightning Discharges ◽

Energy Detectors

Launched and installed at the International Space Station in April 2018, the Atmosphere-Space Interactions Monitor (ASIM) provides science data since June 2018. Suite of onboard instruments contains optical and high energy detectors payloads. Modular Multi-spectral Imaging Array (MMIA) includes three photometers (180-240 nm, 337 nm and 777.4 nm) sampling at 100 kHz, and two cameras (337 nm and 777.4 nm) sampling at 12&#160;Hz. It allows for lightning and transient luminous events (TLEs) observations during the orbital eclipses. The Modular X- and Gamma-ray Sensor (MXGS) detects X- and Gamma-ray photons, and is dedicated to detection of Terrestrial Gamma-ray Flashes (TGFs). The mutual relative timing accuracy between MXGS and MMIA is as good as +/- 5 &#181;s.&#160;TGFs are known to be associated with the +IC lightning discharges. ASIM provides a unique possibility for simultaneous observations of TGFs together with the underlying optical activity inside the thundercloud. In this contribution we summarize the almost two years of ASIM observations to make an overview of the various optical contexts accompanying the TGF production.

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Time sequence of TGFs and optical pulses detected by ASIM

10.5194/egusphere-egu2020-7113 ◽

2020 ◽

Author(s):

Ingrid Bjørge-Engeland ◽

Nikolai Østgaard ◽

Chris Alexander Skeie ◽

Andrey Mezentsev ◽

Torsten Neubert ◽

...

Keyword(s):

Multispectral Imaging ◽

Gamma Ray ◽

Space Station ◽

High Energy ◽

Time Sequence ◽

Relative Timing ◽

Optical Pulses ◽

Optical Signals ◽

Timing Uncertainty ◽

Using Data

In 2018, the Atmospheric Space Interactions Monitor (ASIM) was launched and mounted onboard the Columbus module of the International Space Station (ISS). Using data from the Modular X- and Gamma-Ray Sensor (MXGS) and the Modular Multispectral Imaging Array (MMIA), we investigate the time sequence of the TGFs detected by MXGS and the optical pulses detected by the MMIA. The optical pulses are observed in the 337 nm and 777.4 nm, and the X- and gamma-rays are detected by the High Energy Detector of MXGS, which is sensitive to energies from 300 keV to more than 30 MeV. We will also look into the TGF duration and any correlation with the time between the TGFs and the main optical signals. The data used is from June 2018 (shortly after mounting on the Columbus module) until the end of March 2019, when the relative timing uncertainty between the two instruments was +/- 80 us. The data after this is presented in Skeie et al.

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