Cosmology Views

Milky Way had Too Few Satellite Galaxies But Now Too Many

Apparently we are not finding the correct number of satellites for our Milky Way. There are now too many!
Earlier there were too few, known as the 'missing galaxy problem.' Do we really have a basis for such a prediction?

Since we are not hitting the target so far, our basis appears to be inadequate.
Maybe we can lose some to fix the count.

From the attached publication:
We report on the discovery of a new Milky Way (MW) satellite in Boötes

we estimate that there should be about two MW satellites at MV ≤ 0 in the 676 deg^2 covered by HSC-SSP, whereas that area includes six satellites (Sextans, Leo IV, Pegasus III, Cetus III, Virgo I, and Boötes IV). Thus, the observed number of satellites is larger than the theoretical prediction. On the face of it, we have a problem of too many satellites, instead of the well-known missing satellites problem whereby the Lamda-CDM theory overpredicts the number of satellites in a MW-sized halo. This may imply that the models need more refinement for the assignment of subhalos to satellites, such as considering those found by the current deeper survey.