From 1439f9e886a3e29eb0869e62c6076c35add341fc Mon Sep 17 00:00:00 2001 From: Aditya Prakhar Date: Sun, 15 Sep 2024 02:14:51 +0530 Subject: [PATCH 1/4] Update FRBs --- theory/energetic sources/FRBs.md | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/theory/energetic sources/FRBs.md b/theory/energetic sources/FRBs.md index a0e3cda..c9e6592 100644 --- a/theory/energetic sources/FRBs.md +++ b/theory/energetic sources/FRBs.md @@ -7,3 +7,28 @@ nav_order: 6 --- ## Fast Radio Bursts (FRBs) + +Fast Radio Bursts are enigmatic flashes of radio waves coming from deep space and last just milliseconds. + +### Some Key Characteristics + +1. Duration: Generally, FRBs tend to last just a few milliseconds. +2. Energy: Although less energetic than in the case of [GRBs](./GRBs.html), FRBs still release a huge amount of energy in the form of radio waves. +3. Wavelength: FRBs radiate mainly in the radio part of the electromagnetic spectrum. +4. Dispersion: The radio signal from FRBs gets dispersed due to free electrons present in space. Higher frequencies reach earth before lower ones. + +### Origins + +The exact cause of FRBs remains one of the biggest mysteries in modern astronomy. Some possible explanations that have been suggested include: + +1. Magnetars: Highly magnetized [neutron stars](../special%20stars/neutron%20stars.html) undergoing "starquakes" or magnetic reconnection events. The detection, in 2020, of an FRB-like signal from a Galactic magnetar supports this hypothesis to some extent. +2. Neutron star mergers: Similar to that for short GRBs, but possibly viewed from a different angle. +3. [Pulsar](../special%20stars/pulsars.html) phenomena: Some models interpret FRBs as giant pulses from young, highly magnetized pulsars. +4. Alien signals: Some suspect artificial origins, however, this is now considered extremely improbable. + +Primarily, FRBs are detected via radio telescopes like CHIME and ASKAP. The issue with exploring FRBs is that they are very quick, and identifying where they originate from is challenging. + +FRBs are valuable tools for the study of the intergalactic medium because radio waves are dispersed by free electrons when they propagate in space. This can be measured, so it helps astronomers to have an estimate of the matter located between Earth and the origin of the FRB. + +{: .fun} +> The FRBs are far more frequent than [GRBs](./GRBs.html). It is possible that thousands of FRBs may be observed all over the sky every day, whereas only a few GRBs can be usually detected daily. From 7dc3c351d4697cdbe905e93e18032d5b2aa8f3b9 Mon Sep 17 00:00:00 2001 From: Aditya Prakhar Date: Sun, 15 Sep 2024 02:21:58 +0530 Subject: [PATCH 2/4] Update GRBs --- theory/energetic sources/GRBs.md | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/theory/energetic sources/GRBs.md b/theory/energetic sources/GRBs.md index d48c471..80fcc93 100644 --- a/theory/energetic sources/GRBs.md +++ b/theory/energetic sources/GRBs.md @@ -8,26 +8,27 @@ nav_order: 5 ## Gamma Ray Bursts (GRBs) -Gamma-ray bursts are incredibly powerful explosions that burst forth from distant galaxies. They represent the most luminous electromagnetic events in the universe in terms of release of pure energy. +Gamma-Ray Bursts are incredibly powerful explosions that burst forth from distant galaxies. They represent the most luminous electromagnetic events in the universe in terms of release of pure energy. ### Key Characteristics + 1. Duration - Bursts generally last between a few milliseconds and several minutes. -2. Energy - In a few seconds, they emit an amount of energy equal to what our Sun will emit in its whole lifetime which has been predicted to exceed 10 billion years. +2. Energy - In a few seconds, they emit an amount of energy equal to what our Sun will emit in its whole lifetime that has been predicted to exceed 10 billion years. 3. Wavelength: As the name itself indicates, they emit mainly gamma rays, which are of the highest energy among the electromagnetic radiation. 4. Afterglow: In events that follow the burst, GRBs are usually followed by an afterglow in X-ray, ultraviolet, optical, infrared, and radio wavelengths. {: .fun } ->If a [Gamma Ray Burst](#gamma-ray-bursts-grbs) directed towards us happens in the Milky Way, it will lead to the extinction of life on Earth. +>If a [Gamma Ray Burst](#gamma-ray-bursts-grbs) directed towards us happens in the Milky Way, it will lead to the extintion of life on Earth. ### Origins + The generally assumed origins of GRBs are from two major sources : 1. Core-collapse of massive stars: long-duration GRBs- greater than 2 seconds in length-arise from the collapse of very massive stars into black holes: A hypernova or collapsar is a [supernova](./supernovae.html) resulting in a [black hole](../special%20stars/black%20holes.html) when the core of a massive star directly collapses into one. 2. Mergers of compact objects: short bursts (< 2 s) likely arise from mergers of [neutron stars](../special%20stars/neutron%20stars.html) or black holes and neutron stars. Now, these sources have also been detected to emit [gravitational waves](../cosmology/gravitational%20waves.html) by the observation of GW170817 in 2017. - GRBs are usually detected by space-based observatories, such as the NASA Swift and Fermi satellites. When a GRB is detected, its position is quickly broadcast to ground-based telescopes, which make follow-up observations of the afterglow. GRBs allow insight into high-energy astrophysics, the formation of black holes, and the early universe. They can be detected from incredibly far distances, making them excellent probes of the cosmos across vast stretches of space and time. From 3a2cdd85267927e3986be6c2e8442b85f6f3bf22 Mon Sep 17 00:00:00 2001 From: Aditya Prakhar Date: Wed, 25 Sep 2024 23:50:24 +0530 Subject: [PATCH 3/4] Update GRBs.md --- theory/energetic sources/GRBs.md | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/theory/energetic sources/GRBs.md b/theory/energetic sources/GRBs.md index 80fcc93..8530f4a 100644 --- a/theory/energetic sources/GRBs.md +++ b/theory/energetic sources/GRBs.md @@ -13,13 +13,16 @@ Gamma-Ray Bursts are incredibly powerful explosions that burst forth from distan ### Key Characteristics 1. Duration - Bursts generally last between a few milliseconds and several minutes. + 2. Energy - In a few seconds, they emit an amount of energy equal to what our Sun will emit in its whole lifetime that has been predicted to exceed 10 billion years. + 3. Wavelength: As the name itself indicates, they emit mainly gamma rays, which are of the highest energy among the electromagnetic radiation. + 4. Afterglow: In events that follow the burst, GRBs are usually followed by an afterglow in X-ray, ultraviolet, optical, infrared, and radio wavelengths. {: .fun } ->If a [Gamma Ray Burst](#gamma-ray-bursts-grbs) directed towards us happens in the Milky Way, it will lead to the extintion of life on Earth. +>If a [Gamma Ray Burst](#gamma-ray-bursts-grbs) directed towards us happens in the Milky Way, it will lead to the extinction of life on Earth. ### Origins From f6f688ce3965602810b382e68c29e0f312b87342 Mon Sep 17 00:00:00 2001 From: Aditya Prakhar Date: Wed, 25 Sep 2024 23:52:03 +0530 Subject: [PATCH 4/4] Update FRBs.md --- theory/energetic sources/FRBs.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/theory/energetic sources/FRBs.md b/theory/energetic sources/FRBs.md index c9e6592..2f3a7c4 100644 --- a/theory/energetic sources/FRBs.md +++ b/theory/energetic sources/FRBs.md @@ -13,8 +13,11 @@ Fast Radio Bursts are enigmatic flashes of radio waves coming from deep space an ### Some Key Characteristics 1. Duration: Generally, FRBs tend to last just a few milliseconds. + 2. Energy: Although less energetic than in the case of [GRBs](./GRBs.html), FRBs still release a huge amount of energy in the form of radio waves. + 3. Wavelength: FRBs radiate mainly in the radio part of the electromagnetic spectrum. + 4. Dispersion: The radio signal from FRBs gets dispersed due to free electrons present in space. Higher frequencies reach earth before lower ones. ### Origins @@ -22,8 +25,11 @@ Fast Radio Bursts are enigmatic flashes of radio waves coming from deep space an The exact cause of FRBs remains one of the biggest mysteries in modern astronomy. Some possible explanations that have been suggested include: 1. Magnetars: Highly magnetized [neutron stars](../special%20stars/neutron%20stars.html) undergoing "starquakes" or magnetic reconnection events. The detection, in 2020, of an FRB-like signal from a Galactic magnetar supports this hypothesis to some extent. + 2. Neutron star mergers: Similar to that for short GRBs, but possibly viewed from a different angle. + 3. [Pulsar](../special%20stars/pulsars.html) phenomena: Some models interpret FRBs as giant pulses from young, highly magnetized pulsars. + 4. Alien signals: Some suspect artificial origins, however, this is now considered extremely improbable. Primarily, FRBs are detected via radio telescopes like CHIME and ASKAP. The issue with exploring FRBs is that they are very quick, and identifying where they originate from is challenging.