The remarkable 1994 discovery of the Sagittarius dwarf galaxy ( Sgr ) revealed that , together with the Magellanic Clouds , there are at least three major dwarf galaxies , each with a total mass of order 10 ^ { 10 } -10 ^ { 11 } M _ { \odot } , falling onto the Galaxy in the present epoch .
Beyond a Galactic radius of 300 kpc , dwarfs tend to retain their gas .
At roughly 50 kpc , the Magellanic Clouds have experienced substantial gas stripping as evidenced by the Magellanic Stream which extends from them .
Since Sgr experienced star formation long after it fell into the Galaxy , it is interesting to explore just how and when this dwarf lost its gas .
To date , there has been no definitive detection of an associated gas component .
We revisit recent simulations of the stellar and dark matter components of Sgr but , for the first time , include gas that is initially bound to the infalling galaxy .
We find that the gas stripping was 30 - 50 % complete at its first disc crossing \sim 2.7 Gyr ago , then entirely stripped at its last disc crossing \sim 1 Gyr ago .
Our timeline is consistent with the last substantial burst of star formation in Sgr which occurred about the time of the last disc crossing .
We discuss the consequences of gas stripping and conclude that the vast majority of the stripped gas was fully settled onto the Galaxy by \sim 300 Myr ago .
It is highly unlikely that any of the high- or intermediate-velocity clouds have a direct association with the Sgr dwarf .