@article{7252ff27cc2145a4a9a4c298e18d37fc,
title = "Circumstellar material in type Ia supernovae via sodium absorption features",
abstract = "Type Ia supernovae are key tools for measuring distances on a cosmic scale. They are generally thought to be the thermonuclear explosion of an accreting white dwarf in a close binary system. The nature of the mass donor is still uncertain. In the single-degenerate model it is a main-sequence star or an evolved star, whereas in the double-degenerate model it is another white dwarf. We show that the velocity structure of absorbing material along the line of sight to 35 type Ia supernovae tends to be blueshifted. These structures are likely signatures of gas outflows from the supernova progenitor systems. Thus, many type Ia supernovae in nearby spiral galaxies may originate in single-degenerate systems.",
author = "Assaf Sternberg and Avishay Gal-Yam and Simon, {J. D.} and Leonard, {D. C.} and Quimby, {R. M.} and Phillips, {M. M.} and N. Morrell and Thompson, {I. B.} and I. Ivans and Marshall, {J. L.} and Filippenko, {A. V.} and Marcy, {G. W.} and Bloom, {J. S.} and F. Patat and Foley, {R. J.} and D. Yong and Penprase, {B. E.} and Beeler, {D. J.} and {Allende Prieto}, {Prieto, C.}",
note = "W. M. Keck Foundation; French-Israeli Astrophysics Network; Israeli Science Foundation; European Union; Weizmann-UK program; Peter Gruber Award; Patricia Gruber Award; NSF [AST-0908886]; TABASGO Foundation; Clay FellowshipWe thank the anonymous reviewers for their comments. Some of the data presented here were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA; the observatory was made possible by the generous financial support of the W. M. Keck Foundation. We thank the staffs of the various observatories at which we obtained data, as well as J. G. Cohen, G. D. Becker, A. L. Kraus, W. L. W. Sargent, E. Norris, G. J. Herczeg, G. Preston, and I. Toro-Martinez for their data contributions. We thank T. Barlow for work on developing the MAKEE reduction pipeline, and J. X. Prochaska and B. Weiner for advice. A. G. acknowledges support by The French-Israeli Astrophysics Network program, The Israeli Science Foundation, a European Union FP7 Marie Curie IRG Fellowship, The Weizmann-UK program, and a research grant from the Peter and Patricia Gruber Awards. A.V.F.'s group at the University of California Berkeley has been supported by NSF grant AST-0908886 and the TABASGO Foundation. R. J. F. is supported by a Clay Fellowship. G. S. S. thanks S. Hawley for allocating Director's Discretionary Time at Apache Point Observatory (APO), and the APO observing staff. The data described in the paper are presented in the Supporting Online Material.",
year = "2011",
month = aug,
day = "12",
doi = "https://doi.org/10.1126/science.1203836",
language = "الإنجليزيّة",
volume = "333",
pages = "856--859",
journal = "Science",
issn = "0036-8075",
publisher = "American Association for the Advancement of Science",
number = "6044",
}