A. Burkert et P. Ruizlapuente, DORMANT DWARF SPHEROIDAL GALAXIES, DEACTIVATED BY TYPE IA SUPERNOVAE, The Astrophysical journal, 480(1), 1997, pp. 297-302
Some dwarf spheroidal galaxies have experienced periods many Gyr long
without star formation. We show that Type Ia supernovae, formed from a
first generation of stars, can delay a second epoch of star formation
by several Gyr, if the total gas mass in the dwarf spheroidals is sma
ller than 10(8) M.. The details depend on the assumed Type Ia supernov
a model and the mass fraction of stars formed in the first population.
This scenario requires that dwarf spheroidals be confined by dark mat
ter halos, since otherwise the heated gas would be lost due to tidal e
ffects and galactic winds. If Type Ia supernovae play an important rol
e, heating the gas in dwarf spheroidals, they should also increase the
ir iron abundance during the epoch without star formation. The subsequ
ent stellar generation should then start with a higher [Fe/H] than tha
t of the most iron-rich stars found in the previous generation.