<p>Virial shocks appear when gas falls in toward a galaxy, and the shocked gas stays hot so the pressure in the post-shock gas can support the shock and keep it away from the galactic disk. 
 The alternative is if the post-shock gas cools and loses pressure support, and the (non-virial) shock collapses right down to the galactic disk.  The significance is that if gas falls directly onto the high-density disk, it has different effects than if it meets a low-density shock well away from the galaxy.  There's a lot of information at <a href="https://academic.oup.com/mnras/article/345/1/349/984798" rel="nofollow noreferrer">https://academic.oup.com/mnras/article/345/1/349/984798</a></p>

CC BY-SA 4.0
2019-04-09T22:51:00.527Z
2019-04-09T22:51:00.527Z
Ken G
<p>In the review paper on protoclusters, <a href="https://link.springer.com/article/10.1007/s00159-016-0100-3" rel="nofollow noreferrer">Roderik Overzier (pg 25)</a> mentions the concept of <em>virial shock heating</em> which seems to be a process involved with galaxy cluster formation.</p>

<p>I'm not fully certain what a virialized galaxy cluster is apart from the fact that it's in hydrostatic equilibrium, and is one of the key distinguishing features between a protocluster and a fully formed galaxy cluster.</p>

<p>I vaguely understand that shock heating relates to the heating that occurs when something is travelling at supersonic speed within a medium and produces a shock.</p>

<cosmology><galaxy-cluster><hydrostatic-equilibrium>
Virial Shock Heating
chou
# Virial Shock Heating

(Asked by: username_0 on 2019-04-09)

In the review paper on protoclusters, [Roderik Overzier (pg 25)](https://link.springer.com/article/10.1007/s00159-016-0100-3) mentions the concept of *virial shock heating* which seems to be a process involved with galaxy cluster formation.

I'm not fully certain what a virialized galaxy cluster is apart from the fact that it's in hydrostatic equilibrium, and is one of the key distinguishing features between a protocluster and a fully formed galaxy cluster.

I vaguely understand that shock heating relates to the heating that occurs when something is travelling at supersonic speed within a medium and produces a shock.

**Tags:** cosmology, galaxy-cluster, hydrostatic-equilibrium


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## 1 answers

### Answer by username_1 on 2019-04-09. Score: 2

Virial shocks appear when gas falls in toward a galaxy, and the shocked gas stays hot so the pressure in the post-shock gas can support the shock and keep it away from the galactic disk.
The alternative is if the post-shock gas cools and loses pressure support, and the (non-virial) shock collapses right down to the galactic disk. The significance is that if gas falls directly onto the high-density disk, it has different effects than if it meets a low-density shock well away from the galaxy. There's a lot of information at <https://academic.oup.com/mnras/article/345/1/349/984798>


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