TY - JOUR
T1 - The lowest-mass stellar black holes
T2 - catastrophic death of neutron stars in gamma-ray bursts
AU - Belczynski, K.
AU - O'Shaughnessy, R.
AU - Kalogera, V.
AU - Rasio, F.
AU - Taam, R. E.
AU - Bulik, T.
PY - 2008
Y1 - 2008
N2 - Mergers of double neutron stars are considered the most likely progenitors for short gamma-ray bursts. Indeed, such a merger can produce a black hole with a transient accreting torus of nuclear matter, and the conversion of a fraction of the torus mass-energy to radiation can power a gamma-ray burst. Using available binary pulsar observations supported by our extensive evolutionary calculations of double neutron star formation, we demonstrate that the fraction of mergers that can form a black hole-torus system depends very sensitively on the (largely unknown) maximum neutron star mass. We show that the available observations and models put a very stringent constraint on this maximum mass under the assumption that black hole formation is required to produce a short gamma-ray burst in a double neutron star merger. Specifically, we find that the maximum neutron star mass must be within 2-2.5 MȮ. Moreover, a single unambiguous measurement of a neutron star mass above 2.5 MȮ would exclude a black hole-torus central engine model of short gamma-ray bursts in double neutron star mergers. Such an observation would also indicate that if in fact short gamma-ray bursts are connected to neutron star mergers, the gamma-ray burst engine is best explained by the lesser known model invoking a highly magnetized massive neutron star.
AB - Mergers of double neutron stars are considered the most likely progenitors for short gamma-ray bursts. Indeed, such a merger can produce a black hole with a transient accreting torus of nuclear matter, and the conversion of a fraction of the torus mass-energy to radiation can power a gamma-ray burst. Using available binary pulsar observations supported by our extensive evolutionary calculations of double neutron star formation, we demonstrate that the fraction of mergers that can form a black hole-torus system depends very sensitively on the (largely unknown) maximum neutron star mass. We show that the available observations and models put a very stringent constraint on this maximum mass under the assumption that black hole formation is required to produce a short gamma-ray burst in a double neutron star merger. Specifically, we find that the maximum neutron star mass must be within 2-2.5 MȮ. Moreover, a single unambiguous measurement of a neutron star mass above 2.5 MȮ would exclude a black hole-torus central engine model of short gamma-ray bursts in double neutron star mergers. Such an observation would also indicate that if in fact short gamma-ray bursts are connected to neutron star mergers, the gamma-ray burst engine is best explained by the lesser known model invoking a highly magnetized massive neutron star.
KW - Binaries: Close
KW - Black hole physics
KW - Gravitational waves
KW - Stars: Evolution stars: Neutron
UR - http://www.scopus.com/inward/record.url?scp=48749083943&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=48749083943&partnerID=8YFLogxK
U2 - 10.1086/589970
DO - 10.1086/589970
M3 - Article
AN - SCOPUS:48749083943
VL - 680
SP - L129-L132
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2 PART 2
ER -