4.18. IXO 31 This IXO in the dwarf galaxy Holmberg II (Fig. 5) is
well studied in X-rays (e.g., Colbert & Mushotzky 1999, Zezas,
Georgantopoulos, & Ward 1999, and Miyaji, Lehmann, & Hasinger 2001).
It is located in the middle of an H II region complex and is also
coincident with a luminous radio source (cf. Miyaji et al. 2001).