Description

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Context

The recent discovery at the High Energy Stereoscopic System (HESS) observatory in Namibia has brought attention to the highest-energy cosmic rays ever recorded reaching up to 40 teraelectronvolts (TeV).

Highlights of the Discovery

Detected cosmic rays exhibited energies as high as 40 TeV: 40,000 times the energy of visible light. These represent the highest-energy electrons and positrons ever recorded.

The source of these rays is likely within a few thousand light years of Earth relatively close on a galactic scale. This proximity is crucial because cosmic rays lose energy as they interact with light and magnetic fields during their journey.

Alongside electrons, their antimatter counterparts, positrons were also detected. Positrons share the same mass as electrons but carry a positive charge emphasizing the energy intensity and unique nature of these cosmic rays.

The findings hint at powerful processes such as exploding stars (supernovas), rapidly rotating pulsars and black hole activity.

What Are Cosmic Rays?

High-energy particles including protons, electrons and atomic nuclei originating from cosmic sources.

First detected in 1912 by Austrian physicist Victor Hess using high-altitude balloon experiments.

Sources

Known Sources:

The Sun: Produces lower-energy cosmic rays.

Supernovas: Explosions of dying stars.

Pulsars: Rapidly spinning neutron stars.

Unknown Sources:

The origin of high-energy cosmic rays like those discovered recently remains largely unexplained.

Effects

Cosmic rays create showers of secondary particles upon entering Earth's atmosphere.

They can interfere with electronics, satellites and other technologies.

Read about cosmic rays: https://www.iasgyan.in/daily-current-affairs/amaterasu#:~:text=Cosmic%20rays%20are%20high%2Denergy,Hess%20during%20a%20balloon%20flight.

High Energy Stereoscopic System (HESS) Observatory

Aspect	Details
Definition	The High Energy Stereoscopic System (HESS) is an array of telescopes in Namibia designed to study gamma rays and cosmic phenomena.
Location	Khomas Highlands Namibia.
Purpose	To observe gamma rays and cosmic rays with very high energy (VHE) and explore extreme astrophysical environments.
Significant Features	Telescopes: Five imaging atmospheric Cherenkov telescopes including a large central one. Gamma-Ray Detection: Detects Cherenkov radiation produced when gamma rays interact with Earth's atmosphere. Cherenkov radiation happens when electrically charged particles such as protons or electrons, travel faster than lightin a clear medium like water. When this happens the water molecules and particles interact to give off light.
How It Works	Gamma rays entering Earth's atmosphere create particle cascades. Cherenkov radiation, a bluish light is emitted during these cascades. Telescopes capture and analyze this radiation to trace the origin and energy of gamma rays.
Collaborations	Part of international efforts in gamma-ray astronomy working with observatories like MAGIC and VERITAS.

Sources:

TIMESOFINDIA

PRACTICE QUESTION

Q.Consider the following statements regarding the High Energy Stereoscopic System (HESS):

HESS is a ground-based observatory designed to study high-energy gamma rays.
It is located in Namibia and consists of multiple imaging atmospheric Cherenkov telescopes.
HESS detects gamma rays originating from sources beyond the Milky Way galaxy.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 1 and 3 only

(d) 1, 2 and 3

Answer: (a)

Explanation:

Statement 1 is correct. The High Energy Stereoscopic System (HESS) is a ground-based observatory designed to detect and study high-energy gamma rays. These rays provide insights into extreme cosmic phenomena.

Statement 2 is correct. HESS is situated in Namibia and consists of an array of imaging atmospheric Cherenkov telescopes. These telescopes observe the Cherenkov radiation produced when gamma rays interact with Earth’s atmosphere.

Statement 3 is incorrect. HESS mainly detects gamma rays from sources within the Milky Way galaxy such as pulsars, supernova remnants and black holes although it occasionally observes extragalactic sources.