A halo may be produced by gas.Logical formLearned from3 sentences. (Halo stars) can be in a galaxy.Logical formLearned from3 sentences. A halo can be constituted-of-or-filled-with flames.Logical formLearned from3 sentences. A (halo system) may pertain-to a company.Logical formLearned from3 sentences. A density may pertain-to a halo.Logical formLearned from3 sentences. A dark-matter halo can be extended.Logical formLearned from3 sentences. A halo can be isothermal.Logical formLearned from3 sentences. A halo may remain stationary.Logical formLearned from3 sentences. Haloes may appear.Logical formLearned from3 sentences. A halo can be around clusters.Logical formLearned from3 sentences. (Gamma rays) may form a halo.Logical formLearned from3 sentences. A halo may undergo a development.Logical formLearned from3 sentences. A halo may pertain-to a cluster.Logical formLearned from3 sentences. Observations may constrain a state of a halo.Logical formLearned from3 sentences. Haloes may pertain-to spirals.Logical formLearned from3 sentences.