Missing mass in collisional debris from galaxies.
Recycled dwarf galaxies can form in the collisional debris of massive galaxies. Theoretical models predict that, contrary to classical galaxies, these recycled galaxies should be free of nonbaryonic dark matter. By analyzing the observed gas kinematics of such recycled galaxies with the help of a numerical model, we demonstrate that they do contain a massive dark component amounting to about twice the visible matter. Staying within the standard cosmological framework, this result most likely indicates the presence of large amounts of unseen, presumably cold, molecular gas. This additional mass should be present in the disks of their progenitor spiral galaxies, accounting for a substantial part of the so-called missing baryons.
Bournaud
Frédéric
F
Laboratoire Astrophysique des Interactions Multi-Echelles, Commissariat à l'Energie Atomique (CEA) Direction des Sciences de la Matière-CNRS-Université Paris Diderot, France. frederic.bournaud@cea.fr
Duc
Pierre-Alain
PA
Brinks
Elias
E
Boquien
Médéric
M
Amram
Philippe
P
Lisenfeld
Ute
U
Koribalski
Bärbel S
BS
Walter
Fabian
F
Charmandaris
Vassilis
V