The Laser Interferometer Прастора Antenna (LISA) mission has received the go ahead of European Прастора Agency (ESA). This paves the way for developing the instruments and spacecrafts commencing January 2025. The mission is led by ESA and is a result of collaboration between ESA, its Member State прастору агенцтва, НАСА, and an international consortium of scientists.
Scheduled to be launched in 2035, LISA will be the first прасторуНа аснове гравітацыйная хваля observatory dedicated to detection and study of millihertz ripples caused by distortions in the fabric of прастору-час (гравітацыйныя хвалі) across the сусвет.
Unlike the ground based гравітацыйная хваля detectors (LIGO, VIRGO, KAGRA, and LIGO India) which detect гравітацыйныя хвалі in frequency range of 10 Hz to 1000 Hz, LISA will be designed to detect гравітацыйныя хвалі of much longer wavelengths in the low frequency range between 0.1 mHz and 1 Hz.
Ультранізкія частоты (10-9-10-8 Гц) гравітацыйныя хвалі (GWs) with wavelengths from weeks to years from supermassive binary чорныя дзіркі can be detected using ground-based Часавыя масівы пульсараў (PTA).). However, low frequency гравітацыйныя хвалі (GWs) with frequency between 0.1 mHz and 1 Hz can neither be detected by LIGO nor by Pulsar Timing Arrays (PTAs) – the wavelength of these GWs is too long for LIGO and too short for PTAs to detect. Hence, the need for прастору-based GW detector.
LISA will be a constellation of three spacecrafts in accurate equilateral triangle formation in space. Each side of the triangle will be 2.5 million km long. This formation (of the three spacecrafts) will арбіта Sun in an Earth-trailing heliocentric арбіта between 50 and 65 million km from Earth while maintaining a mean inter-spacecraft separation distance of 2.5 million km. This space-based configuration makes LISA an extremely large detector to study low frequency гравітацыйныя хвалі that ground-based detectors can not.
For detection of GWs, LISA will use pairs of test masses (solid gold-platinum cubes) free-floating in special chambers at the heart of each spacecraft. Гравітацыйнае ripples will make extremely small changes in the distances between test masses in the spacecrafts which will be measured through laser interferometry. As demonstrated by LISA Pathfinder mission, this technology is capable of measuring changes in distances to a few billionths of a millimetre.
LISA will detect GWs caused by merger of supermassive чорныя дзіркі at the centre of galaxies thus will shed light on evolution of galaxies. The mission should also detect the predicted gravitational "звон" склалася ў пачатковыя моманты ст сусвет у першыя секунды пасля вялікага выбуху.
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Спасылкі:
- ЕКА. Навіны - Захоп рабізны прасторы-часу: LISA атрымлівае адмашку. Апублікавана 25 студзеня 2024 г. Даступна па адрасе https://www.esa.int/Science_Exploration/Space_Science/Capturing_the_ripples_of_spacetime_LISA_gets_go-ahead
- НАСА. ЛІЗА. Даступны па адрасе https://lisa.nasa.gov/
- Pau Amaro-Seoane et al. 2017. Laser Interferometer Прастора Antenna. Preprint arXiv. DOI: https://doi.org/10.48550/arXiv.1702.00786
- Baker et al. 2019. The Laser Interferometer Прастора Antenna: Unveiling the Millihertz Gravitational Wave Sky. Preprint arXiv. DOI: https://doi.org/10.48550/arXiv.1907.06482
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