Radio Galaxies
Science & Technology
- PYQs5
- Articles1
Background
Understanding the universe's large-scale structure, galaxy evolution, the role of black holes, and the frontiers of astronomical research. India's contribution to such discoveries highlights its scientific capabilities and advancements in space science.
Radio galaxies are a class of active galaxies that emit powerful radio waves, often far exceeding their optical luminosity. They are typically powered by supermassive black holes at their cores, which accrete matter and launch energetic jets of relativistic plasma into the surrounding intergalactic medium.
Facts & tables
- Power Source
- Supermassive black holes at their core
- Emission
- Very high amounts of energy in radio waves
- Key Feature
- Often launch enormous jets of relativistic magnetised plasma
- Interaction
- Morphology can reveal interaction with surrounding hot gas and bow shocks
| Type | Reference |
|---|---|
| Conceptual area | Astrophysics |
| Conceptual area | Cosmology |
| Body | Role |
|---|---|
| RAD@home Astronomy Collaboratory | Discovery and research platform |
| University of Mumbai | Lead institution for the study |
| LOFAR (Low Frequency Array) | Observational facility used for discovery |
Prelims angle
Prelims angle: Multi-statement analysis
Prelims angle: Conceptual understanding
- Definition: Active galaxies emitting strong radio waves.
- Power Source: Supermassive black holes at their core.
- Key Features: Relativistic plasma jets, interaction with intergalactic medium.
- Significance: Insights into galaxy evolution and cosmic structures.
- Discovery: RAD-BAARG, a rare 'bow and arrow' type, discovered by Indian team.
| Year | Framing tags |
|---|---|
| 2024 | Statement-based questions, Conceptual understanding |
| 2023 | Multi-statement analysis, Factual recall |
| 2022 | Multi-statement analysis, Conceptual understanding |
| 2019 | Conceptual understanding, Cause and effect relationships |
| 2018 | Multi-statement analysis, Factual recall |
Timeline
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Astrophysics
Conceptual area
-
Cosmology
Conceptual area
-
Prelims 2018
Multi-statement analysis, Factual recall
-
Prelims 2019
Conceptual understanding, Cause and effect relationships
-
Prelims 2022
Multi-statement analysis, Conceptual understanding
-
Prelims 2023
Multi-statement analysis, Factual recall
-
Prelims 2024
Statement-based questions, Conceptual understanding
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Indian team discovers rare ‘bow and arrow’ radio galaxy two billion light years from Earth
Radio galaxies are active galaxies driven by central supermassive black holes, characterized by strong radio emissions and often large-scale jets. Their study provides insights into cosmic evolution and intergalactic processes, with recent discoveries like RAD-BAARG by Indian researchers advancing our understanding.
See also
Past papers
2018–2024 · 5 questions
In the news
Indian team discovers rare ‘bow and arrow’ radio galaxy two billion light years from Earth
Radio galaxies are active galaxies driven by central supermassive black holes, characterized by strong radio emissions and often large-scale jets. Their study provides insights into cosmic evolution and intergalactic processes, with recent discoveries like RAD-BAARG by Indian researchers advancing our understanding.
Try these PYQs
If a major solar storm (solar-flare) reaches the Earth, which of the following are the possible effects on the Earth?
1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.
Select the correct answer using the code given below:
Out of the listed effects of a major solar storm, the most likely ones are Statement 1 is correct. A solar storm can disrupt the Earth's ionosphere, which can affect the signal transmission of GPS and other radio-based navigation systems. Statement 3 is correct. Strong currents induced by the solar storm in power grids can damage transformers and cause widespread blackouts. Statement 4 is correct. Solar storms can energize particles in the Earth's magnetosphere, leading to spectacular auroras at lower latitudes than usual. Statement 6 is correct. The drag from a solar storm can alter the orbits of satellites, especially those in lower Earth orbit. Statement 7 is correct. Similar to GPS, radio communication can be affected by disturbances in the ionosphere. Statement 2 is incorrect. Tsunamis are caused by underwater earthquakes or volcanic eruptions, not solar storms. Statement 5 is incorrect. While a solar storm could potentially ignite some fires through electrical sparks, this is not a widespread effect. Therefore, codes 2 and 5 should not form the part of answer.
Consider the following statements:
1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket- powered only in the initial phase of flight.
2. Agni-V is a medium- range supersonic cruise missile, while BrahMos is a solid- fuelled intercontinental ballistic missile.
Which of the statements given above is/are correct?
* Neither of the statements about ballistic missiles and cruise missiles is accurate. * Ballistic missiles: These are rocket-powered weapons that follow a high, arcing trajectory after a brief powered ascent. They travel at supersonic speeds throughout most of their flight due to inertia. * Cruise missiles: These are jet-propelled weapons that fly at relatively low altitudes and can manoeuvre throughout their flight path. They can be subsonic, supersonic, or hypersonic depending on the design. * Agni-V: This is a long-range intercontinental ballistic missile (ICBM) developed by India. It is not a medium-range cruise missile. * BrahMos: This is a supersonic cruise missile jointly developed by India and Russia. It is not a solid-fueled ICBM. BrahMos uses a ramjet engine for sustained supersonic flight after a booster rocket launch.
In which of the following areas can GPS technology be used?
1. Mobile phone operations
2. Banking operations
3. Controlling the power grids
Select the correct answer using the code given below:
GPS, or Global Positioning System, is a satellite-based navigation system that provides geolocation and time information to a GPS receiver anywhere on or near the Earth. It has a wide range of applications. Statement 1 is correct. GPS is used in mobile phones for various purposes such as location tracking, navigation, and location-based services. Statement 2 is correct. GPS is used in banking operations for ATM location services and for time-stamping transactions, which is crucial for maintaining accurate records. Statement 3 is correct. GPS is used for time-stamping power system measurements, which is vital for grid stability and synchronization. Therefore, GPS technology can be used in all the three areas mentioned.
Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation?
The merger of black holes is expected to generate powerful gravitational waves. Gravitational waves are ripples in spacetime caused by accelerating massive objects. Detecting these waves with instruments like LIGO (Laser Interferometer Gravitational-Wave Observatory) allows us to study these events even when they are too far away or obscured to observe directly. This opens a new window for astronomical observations.
With reference to radioisotope thermoelectric generators (RTGs), consider the following statements:
1. RTGs are miniature fission reactors.
2. RTGs are used for powering the onboard systems of spacecrafts.
3. RTGs can use Plutonium-238, which is a by-product of weapons development.
Which of the statements given above are correct?
* Statement 1: Incorrect. RTGs (Radioisotope Thermoelectric Generators) are not miniature fission reactors. Fission reactors use nuclear fission, a process of splitting atoms to release a tremendous amount of energy. RTGs, on the other hand, utilize the natural radioactive decay of isotopes to generate heat, which is then converted to electricity through a process called thermoelectricity. * Statement 2: Correct. RTGs are indeed a reliable power source for spacecraft, especially those venturing far from the sun where solar panels become ineffective. They provide consistent, low-level electric power for extended periods, making them ideal for probes, satellites, and rovers in deep space. * Statement 3: Correct. Plutonium-238 is a common isotope used in RTGs due to its long half-life (the time it takes for half of the material to decay) and its ability to generate a steady heat output from its decay process. While it can be a byproduct of weapons development, there are also alternative ways to produce Plutonium-238 specifically for peaceful applications like RTGs.