Two planetary nebulae in the Sagittarius Dwarf Galaxy

TL;DR

This paper reports the discovery of two planetary nebulae in the Sagittarius Dwarf Galaxy, confirming its mass and structure, and providing insights into its composition and tidal features.

Contribution

It is the first to confirm planetary nebulae in Sagittarius Dwarf Galaxy and discusses implications for its mass and tidal tail structure.

Findings

Sagittarius Dwarf Galaxy contains at least two planetary nebulae.

The galaxy's mass is estimated to be a few times 10^7 solar masses.

Planetary nebulae are located along the galaxy's major axis near the tidal tail.

Abstract

Two planetary nebulae are shown to belong to the Sagittarius Dwarf Galaxy, on the basis of their radial velocities. This is only the second dwarf spheroidal galaxy, after Fornax, found to contain planetary nebulae. Their existence confirms that this galaxy is at least as massive as the Fornax dwarf spheroidal which has a single planetary nebula, and suggests a mass of a few times 10**7 solar masses. The two planetary nebulae are located along the major axis of the galaxy, near the base of the tidal tail. There is a further candidate, situated at a very large distance along the direction of the tidal tail, for which no velocity measurement is available. The location of the planetary nebulae and globular clusters of the Sagittarius Dwarf Galaxy suggests that a significant fraction of its mass is contained within the tidal tail.