<p>Normally, the two main sources of cosmic rays are considered to be the Sun (<a href="https://en.wikipedia.org/wiki/Solar_energetic_particles" rel="nofollow noreferrer">solar energetic particles</a>) and galactic or extragalactic sources, although extragalactic sources are more common. Surprisingly, though, there <em>is</em> a third source, a family of particles known as <a href="http://solarphysics.livingreviews.org/Articles/lrsp-2013-3/articlese3.html" rel="nofollow noreferrer"><em>anomalous cosmic rays</em></a> (see <a href="http://adsabs.harvard.edu/abs/1973ICRC....2.1498H" rel="nofollow noreferrer">Hovestadt et al. (1973)</a> and <a href="http://adsabs.harvard.edu/abs/1973ApJ...182L..81G" rel="nofollow noreferrer">Garcia-Munoz et al. (1973)</a>). These are particles - generally ionized nuclei of lighter elements - primarily originating from interstellar space with energies on the order of $\sim10$ to $\sim10^2\text{ MeV}$.</p>

<p>Anomalous cosmic rays are generally accelerated at the <a href="https://en.wikipedia.org/wiki/Heliosphere#Termination_shock" rel="nofollow noreferrer">termination shock</a> of the heliosphere, moving into the heliosheath. Some may then escape into the inner Solar System. Here's an image from <a href="http://adsabs.harvard.edu/abs/2005Sci...309.2017S" rel="nofollow noreferrer">Stone et al. (2005)</a>, which shows them as a distinct population from galactic cosmic rays:</p>

<p><a href="https://i.sstatic.net/zqA6B.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zqA6B.png" alt="enter image description here"></a></p>

<p>Now, these particles are technically of interstellar origin, even though they are accelerated to great speeds only at the boundary of the Solar System. However, a related population may have been found in the Kuiper Belt (see <a href="http://onlinelibrary.wiley.com/doi/10.1029/2002GL015829/abstract;jsessionid=C5D5BFA51F6A411A0ED76B777325DE20.f02t04" rel="nofollow noreferrer">Schwadron et al. (2002)</a>), formed from grains there after collisions between objects. While these are not necessarily - or even likely - the dominant source of anomalous cosmic rays, they do exist, and thus constitute another source of cosmic rays inside the Solar System.</p>

CC BY-SA 3.0
2016-10-26T17:32:54.217Z
2016-11-01T23:51:00.540Z
2016-11-01T23:51:00.540Z
HDE 226868
<p>Earth receives shower of both solar and cosmic radiations every seconds. The Sun put up a heliosphere around the solar system and thus foreign high energy charged particles could not penetrate easily. Is there any other source most probably that lies within our solar system?</p>

<p>Note: </p>

<ol>
<li>Very high energy cosmic particle beyond 5.7 x 10^19 eV were observed
by Pierre Auger Observatory in Argentina. (rare but the GZK limit
seems to rule out distance sources)</li>
<li>GZK limit roughly capped the upper energy level of cosmic ray as
they are slowed due to CMB over vast distance</li>
</ol>

CC BY-SA 3.0
2015-04-10T01:45:19.383Z
You many need to be more specific.  The sun emits a large number of (high energy) particles, including neutrinos and alpha particles.  This is generally known as the solar wind.  Particles interacting with our atmosphere can also produce high-energy particles.  Are there particular kinds of particles, or particular energy scales, you wish to focus on?
zibadawa timmy
CC BY-SA 3.0
2015-04-10T03:14:50.143Z
@zibadawa Timmy see note
user6760
CC BY-SA 3.0
2015-04-10T11:48:54.947Z
[GZK limit](https://en.wikipedia.org/wiki/Greisen%E2%80%93Zatsepin%E2%80%93Kuzmin_limit) rules out sources further than ~160 million light years - there's no way particles of similar energy could be created in solar system.
Mithoron
CC BY-SA 3.0
2015-04-10T12:47:42.943Z
@Mithoron the radius of observable universe is ~46 billion light years so the limit already ruled out large number of space leaving the figure you 've pointed out for search including solar system.
user6760
CC BY-SA 3.0
2015-04-10T13:00:42.047Z
Our Galaxy has only 100 thousand light years; even our whole [Virgo Supercluster](https://en.wikipedia.org/wiki/Virgo_Supercluster) has only 110 million light-years diameter so it could come from outside of it.
Mithoron
CC BY-SA 3.0
2015-04-10T13:05:01.230Z
@yes definitely possible however since voyager 1 detected the heliosphere where there is a sudden drop off of charged particles remember how aurora occurs on Earth.
user6760
CC BY-SA 3.0
2015-04-10T13:18:58.217Z
Magnetic field of Sun can't stop high energy rays - they are ultrarelativistic - probably got out of one of most powerful magnetic fields in Universe... definitly not solar.
Mithoron
CC BY-SA 3.0
2015-04-10T13:23:32.380Z
http://astronomy.stackexchange.com/questions/1448/are-gamma-ray-bursts-of-galactic-or-extragalactic-origin
Mithoron
CC BY-SA 3.0
2015-04-10T13:23:40.693Z
@Mithoron the heliosphere isn't due to Sun magnetic field it is the clashes of the titans... solar winds against interstellar winds.
user6760
CC BY-SA 3.0
2015-04-10T13:24:26.730Z
Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/22735/discussion-between-mithoron-and-user6760).
Mithoron
CC BY-SA 3.0
2015-04-11T01:32:36.367Z
http://arxiv.org/abs/1411.0704
Count Iblis
<the-sun><solar-system><cosmic-ray>
Source of high energy cosmic particles
user6760
# Source of high energy cosmic particles

(Asked by: username_0 on 2015-04-10)

Earth receives shower of both solar and cosmic radiations every seconds. The Sun put up a heliosphere around the solar system and thus foreign high energy charged particles could not penetrate easily. Is there any other source most probably that lies within our solar system?

Note:

1. Very high energy cosmic particle beyond 5.7 x 10^19 eV were observed
   by Pierre Auger Observatory in Argentina. (rare but the GZK limit
   seems to rule out distance sources)
2. GZK limit roughly capped the upper energy level of cosmic ray as
   they are slowed due to CMB over vast distance

**Tags:** the-sun, solar-system, cosmic-ray

> **Comments:**
> **username_1**: You many need to be more specific.  The sun emits a large number of (high energy) particles, including neutrinos and alpha particles.  This is generally known as the solar wind.  Particles interacting with our atmosphere can also produce high-energy particles.  Are there particular kinds of particles, or particular energy scales, you wish to focus on?  
> **username_0**: @zibadawa Timmy see note  
> **username_2**: [GZK limit](https://en.wikipedia.org/wiki/Greisen%E2%80%93Zatsepin%E2%80%93Kuzmin_limit) rules out sources further than ~160 million light years - there's no way particles of similar energy could be created in solar system.  
> **username_0**: @username_2 the radius of observable universe is ~46 billion light years so the limit already ruled out large number of space leaving the figure you 've pointed out for search including solar system.  
> **username_2**: Our Galaxy has only 100 thousand light years; even our whole [Virgo Supercluster](https://en.wikipedia.org/wiki/Virgo_Supercluster) has only 110 million light-years diameter so it could come from outside of it.  
> **username_0**: @yes definitely possible however since voyager 1 detected the heliosphere where there is a sudden drop off of charged particles remember how aurora occurs on Earth.  
> **username_2**: Magnetic field of Sun can't stop high energy rays - they are ultrarelativistic - probably got out of one of most powerful magnetic fields in Universe... definitly not solar.  
> **username_2**: http://astronomy.stackexchange.com/questions/1448/are-gamma-ray-bursts-of-galactic-or-extragalactic-origin  
> **username_0**: @username_2 the heliosphere isn't due to Sun magnetic field it is the clashes of the titans... solar winds against interstellar winds.  
> **username_2**: Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/22735/discussion-between-mithoron-and-username_0).  
> **username_3**: http://arxiv.org/abs/1411.0704  

---

## 1 answers

### Answer by username_4 on 2016-10-26. Score: 4

Normally, the two main sources of cosmic rays are considered to be the Sun ([solar energetic particles](https://en.wikipedia.org/wiki/Solar_energetic_particles)) and galactic or extragalactic sources, although extragalactic sources are more common. Surprisingly, though, there *is* a third source, a family of particles known as [*anomalous cosmic rays*](http://solarphysics.livingreviews.org/Articles/lrsp-2013-3/articlese3.html) (see [Hovestadt et al. (1973)](http://adsabs.harvard.edu/abs/1973ICRC....2.1498H) and [Garcia-Munoz et al. (1973)](http://adsabs.harvard.edu/abs/1973ApJ...182L..81G)). These are particles - generally ionized nuclei of lighter elements - primarily originating from interstellar space with energies on the order of $\sim10$ to $\sim10^2\text{ MeV}$.

Anomalous cosmic rays are generally accelerated at the [termination shock](https://en.wikipedia.org/wiki/Heliosphere#Termination_shock) of the heliosphere, moving into the heliosheath. Some may then escape into the inner Solar System. Here's an image from [Stone et al. (2005)](http://adsabs.harvard.edu/abs/2005Sci...309.2017S), which shows them as a distinct population from galactic cosmic rays:

[![enter image description here](https://i.sstatic.net/zqA6B.png)](https://i.sstatic.net/zqA6B.png)

Now, these particles are technically of interstellar origin, even though they are accelerated to great speeds only at the boundary of the Solar System. However, a related population may have been found in the Kuiper Belt (see [Schwadron et al. (2002)](http://onlinelibrary.wiley.com/doi/10.1029/2002GL015829/abstract;jsessionid=C5D5BFA51F6A411A0ED76B777325DE20.f02t04)), formed from grains there after collisions between objects. While these are not necessarily - or even likely - the dominant source of anomalous cosmic rays, they do exist, and thus constitute another source of cosmic rays inside the Solar System.


---

