Could the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>2.6</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:msub><mml:mrow><mml:mi>M</mml:mi></mml:mrow><mml:mrow><mml:mo stretchy="false">⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math> object in GW190814 be a primordial black hole?
Kyriakos Vattis, Isabelle S. Goldstein, Savvas M. Koushiappas
Abstract
On June 20, 2020, the LIGO-Virgo collaboration announced the discovery of GW190814, a gravitational wave event originating from a binary system merger between a black hole of mass ${M}_{1}={23.2}_{\ensuremath{-}1.0}^{+1.1}\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ and an unidentified object with a mass of ${M}_{2}=2.5{9}_{\ensuremath{-}0.09}^{+0.08}\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$. This second object would be either the heaviest neutron star or lightest black hole observed to date. Here we investigate the possibility of the $\ensuremath{\sim}2.6\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ object being a primordial black hole (PBH). We find that a primordial black hole explanation to GW190814 is unlikely as it is limited by the formation rate of the primary stellar progenitor and the time available for a pair of primordial- and stellar-origin black hole binaries to form and merge within a hubble time.