https://astrostephen.com/about/https://astrostephen.com/wp-content/uploads/2018/04/per_a_chandra_filtered_walker_nolabels_2160.jpgPer_A_Chandra_filtered_Walker_nolabels_2160https://astrostephen.com/wp-content/uploads/2018/04/per_a_chandra_filtered_walker_labeled_2160.jpgPer_A_Chandra_filtered_Walker_labeled_2160https://astrostephen.com/wp-content/uploads/2017/08/ngc4696_hubble_1500.jpgngc4696_Hubble_1500https://astrostephen.com/wp-content/uploads/2017/08/stairs-lights-abstract-bubbles1.jpgPlaceholder Image2025-12-02T20:46:40+00:00weekly0.6https://astrostephen.com/welcome/child-page/https://astrostephen.com/wp-content/uploads/2018/07/news25_cover.jpgnews25_coverhttps://astrostephen.com/wp-content/uploads/2018/07/natas_coverapril2018.jpegNatAs_coverApril2018https://astrostephen.com/wp-content/uploads/2017/08/walker_stephen_medium.jpgWalker,_Stephen_medium2025-09-17T20:01:49+00:00weekly0.6https://astrostephen.com/welcome/press-releases-2/2025-03-24T06:16:42+00:00weekly0.6https://astrostephen.com/talks/https://astrostephen.com/wp-content/uploads/2023/07/ngc4839_unlabeled.jpgThe NGC 4839 group of galaxies is plunging into the Coma galaxy cluster and leaving behind a tail of superheated gas.2024-07-31T03:47:56+00:00weekly0.6https://astrostephen.com/my-research-group/https://astrostephen.com/wp-content/uploads/2020/07/36188814_10215863982648690_8504969169538646016_o-e1594693878687.jpg36188814_10215863982648690_8504969169538646016_o2024-05-12T04:58:46+00:00weekly0.6https://astrostephen.com/resources/2023-08-07T19:56:42+00:00weekly0.6https://astrostephen.com/teaching/2023-07-22T00:04:59+00:00weekly0.6https://astrostephen.comdaily1.02025-12-02T20:46:40+00:00