{"product_id":"toward-an-understanding-of-the-joshua-s-bloom-9781581121698","title":"Toward an Understanding of the Progenitors of Gamma-Ray Bursts","description":"The various possibilities for the origin (\"progenitors\") of gamma-ray bursts (GRBs) manifest in differing observable properties. Through deep spectroscopic and high-resolution imaging observations of some GRB hosts, I demonstrate that well-localized long-duration GRBs are connected with otherwise normal star-forming galaxies at moderate redshifts of order unity. Using high-mass binary stellar population synthesis models, I quantify the expected spatial extent around galaxies of coalescing neutron stars, one of the leading contenders for GRB progenitors. I then test this scenario by examining the offset distribution of GRBs about their apparent hosts making extensive use of ground-based optical data from Keck and Palomar and space-based imaging from the Hubble Space Telescope. The offset distribution appears to be inconsistent with the coalescing neutron star binary hypothesis (and, similarly, black-hole--neutron star coalescences); instead, the distribution is statistically consistent with a population of progenitors that closely traces the ultra-violet light of galaxies. This is naturally explained by bursts which originate from the collapse of massive stars   collapsars''). This claim is further supported by the unambiguous detections of intermediate-time (approximately three weeks after the bursts) emission   bumps'' which appear substantially more red than the afterglows themselves. I claim that these bumps could originate from supernovae that occur at approximately the same time as the associated GRB; if true, GRB 980326 and GRB 011121 provide strong observational evidence connecting cosmological GRBs to high-redshift supernovae and implicate massive stars as the progenitors of at least some long-duration GRBs.\u003cbr\u003e\u003cbr\u003e\u003cb\u003eAuthor:\u003c\/b\u003e Joshua S. Bloom\u003cbr\u003e\u003cb\u003eISBN-10:\u003c\/b\u003e 1581121695\u003cbr\u003e\u003cb\u003eISBN-13:\u003c\/b\u003e 9781581121698\u003cbr\u003e\u003cb\u003ePublisher:\u003c\/b\u003e Dissertation.com\u003cbr\u003e\u003cb\u003eLanguage:\u003c\/b\u003e English\u003cbr\u003e\u003cb\u003ePublished:\u003c\/b\u003e 11\/12\/2002\u003cbr\u003e\u003cb\u003ePages:\u003c\/b\u003e 200\u003cbr\u003e\u003cb\u003eFormat:\u003c\/b\u003e Paperback\u003cbr\u003e\u003cb\u003eWeight:\u003c\/b\u003e 0.57lbs\u003cbr\u003e\u003cb\u003eSize:\u003c\/b\u003e 8.50h x 5.50w x 0.46d","brand":"Joshua S. Bloom","offers":[{"title":"Paperback","offer_id":46739046662399,"sku":"9781581121698","price":19.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0662\/2982\/9887\/files\/img_0c5f489d-bfd9-4357-be31-6a235973a156.jpg?v=1743277045","url":"https:\/\/www.whiterainbookhouse.com\/products\/toward-an-understanding-of-the-joshua-s-bloom-9781581121698","provider":"WR Book House","version":"1.0","type":"link"}