A pulsating auroral X-ray hot spot on Jupiter

Area of Science:

• Planetary Science
• Space Physics
• Astrophysics

Background:

• Jupiter's X-ray aurora was previously attributed to energetic sulfur and oxygen ions from the inner magnetosphere.
• This precipitation was believed to be the primary driver of X-ray emissions in the planet's polar regions.

Purpose of the Study:

• To investigate the source and characteristics of Jupiter's X-ray auroral emissions using high-spatial-resolution observations.
• To challenge and refine existing models of Jovian auroral excitation mechanisms.

Main Methods:

• High-spatial-resolution X-ray observations of Jupiter's northern auroral regions.
• Analysis of emission locations, temporal variations, and correlation with other electromagnetic phenomena.

Main Results:

• Most northern auroral X-rays originate from a distinct 'hot spot' poleward of inner magnetosphere connection latitudes.
• This hot spot exhibits fixed magnetic latitude and longitude, co-located with anomalous infrared and ultraviolet emissions.
• X-ray pulsations occur with a ~45-minute period, matching high-latitude radio and electron bursts.

Conclusions:

• The primary source of particles exciting Jupiter's X-ray aurora is the outer magnetosphere, not the inner magnetosphere.
• The findings invalidate previous theories of steady precipitation of heavy ions.
• Unexplained outer magnetosphere processes likely generate these localized, variable, and broadband X-ray emissions.