Affiliations

Research School of Astronomy and Astrophysics, Australian National University, Canberra 2611, Australia. Roland M. Crocker

, Ashley J. Ruiter

, Ivo R. Seitenzahl

, Fiona H. Panther

, Anais Möller

, David M. Nataf

& Brad E. Tucker ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), Canberra 2611, Australia. Ashley J. Ruiter

, Ivo R. Seitenzahl

, Fiona H. Panther

, Anais Möller

& Brad E. Tucker School of Physical, Environmental and Mathematical Sciences, UNSW Canberra, Australian Defence Force Academy, Canberra 2612, Australia. Ivo R. Seitenzahl School of Mathematics and Physics, Queen’s University, University Road, Belfast BT7 1NN, UK. Stuart Sim School of Mathematics and Physics, University of Queensland, Brisbane 4072, Australia. Holger Baumgardt Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA. David M. Nataf Center for Astrophysical Sciences, The Johns Hopkins University, Baltimore, Maryland 21218, USA. David M. Nataf Mathematical Sciences Institute, Australian National University, Canberra 2601, Australia. Lilia Ferrario Department of Physics, University of Auckland, Auckland 1010, New Zealand. J. J. Eldridge Department of Physics, University of Adelaide, Adelaide 5005, Australia. Martin White Dublin Institute for Advanced Studies, 10 Burlington Road, Dublin 4, D04 C932, Ireland. Felix Aharonian Max-Planck-Institut für Kernphsik, Saupfercheckweg 1, 69117 Heidelberg, Germany. Felix Aharonian

Contributions

All the authors discussed the results and commented on the manuscript. R.M.C. wrote the paper. A.J.R. performed the BPS modelling and provided theoretical input. I.R.S. provided theoretical input, helped with calculating the yields of the helium detonations and contributed to the writing of the paper. F.H.P., A.M. and B.E.T. provided advice about the rates, prevalence and distribution of 91bg in supernova searches. H.B., L.F. and J.J.E. provided advice on the BPS modelling. A.M. and M.W. provided statistical analysis. D.M.N. provided advice about the star formation history of the Galactic bulge and other theoretical input. S.S. provided input on the phenomenology of SN explosions. F.A. provided input on the phenomenology of positron transport and annihilation radiation. All the authors commented on the draft text.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Roland M. Crocker.