after_glow

af·ter·glow

 noun \ˈaf-tər-ˌglō\

Definition of AFTERGLOW

1

: a glow remaining where a light has disappeared

2

: a pleasant effect or feeling that lingers after something is done, experienced, or achieved <basking in the afterglow of success>

Source: http://www.merriam-webster.com/dictionary/afterglow