How to disable a particle system playing when instatiating it?

I’m trying to instantiate an explosion particle system without playing it immediately (and I will call the
play() function to play it later), here is my code:

// my GameManager Awake function
private void Awake()
    GameObject explosion = Instantiate(explosionPrefab);
    ParticleSystem[] pss = explosion.GetComponentsInChildren<ParticleSystem>();
    foreach (ParticleSystem ps in pss)

Note that the explosionPrefab is the very prefab “explosion” in the standard assets → ParticleSystems → Prefabs. I’ve toggled off all of the “play on awake” in its paricle system children, but it still plays when instantiating it. How to disable the playing when instantiating it? Thanks.

There’s a checkbox in the particle system editor labeled “Play on Awake” that prevents the particle system from playing automatically when unchecked.