While we don't know much about the content of the jets. We know that there are ordinary matter in there. Specifically we observed nickel and iron [1]. The posi

While we don't know much about the content of the jets. We know that there are ordinary matter in there. Specifically we observed nickel and iron [1]. The positive charge in these jets was initially unclear, with possibilities being either positrons (the antimatter 'opposite' of electrons) or positively charged atoms. However, the discovery of nickel and iron indicates that the positive charge is provided by positively charged atoms, not positrons [1] https://phys.org/news/2013-11-astronomers-reveal-contents-mysterious-black.html https://phys.org/news/2013-11-astronomers-reveal-contents-my...