Early-type Dwarf Galaxies: Origin, Evolution, Characteristics

 
→ Statements on early-type dwarfs from the participants

→ Summaries of the discussions

dIrrs, take a good look at dEs - because that's how you're going to end up

dE: one or several galaxy populations?

In what way are the dEs important in understanding galaxy evolution?

What can dEs teach us about galaxy formation?

Dwarfs get crazy about their environment, but they keep some things internal

Location in the color-magnitude diagram should replace morphology as the primary means of selecting galaxy samples in the study of scaling relations.

dSphs and dEs are from the same family

Only blue/metal-poor UCDs are the remnant nuclei of dwarf ellipticals!

dSphs and dEs cannot have cuspy dark matter profiles

The theoretical baryonic mass limit below which dEs cannot form is about 10^3 M_sun.

Star formation and chemical evolution in dwarf ellipticals is mostly determined by internal processes.

Giant ellipticals are the high luminosity extension of dEs (and not vice versa) but they are different in their formation.

Nuclei of dwarf galaxies are the progenitors of all massive UCDs

dEs are not the low luminosity extension of massive ellipticals.

dEs fall on the Fundamental (Mass) Plane of elliptical galaxies.

Resonant stripping is an efficient mechanism to explain morphological evolution from disks into spheroids

The morphology of 25-100% of the dEs observed today can be explained by mergers, or by a different mode of galaxy formation at high redshift.

dEs result naturally from environmentally affected late-type disks without the need for harassment

A parcel of gas today having 10^6 M_sun is a thousand times more likely to turn into a globular cluster than a dE, but 10 billion years ago, it was only a hundred times more likely.

Maybe, the early type dwarf galaxies are heterogeneous objects. Therefore, morphological evolution of early type dwarf galaxies is not simple and dEs have various progenitor galaxies. Their physical characteristics should be classified in detail.

Dwarfs may well dethrone our favorite cosmological model.

Harassment, ram pressure stripping, tidal origin, cosmological formation - do we observe enough dEs or are we too effective in explaining them?

Detections of ultra-faint "dwarf galaxies", such as Segue 1, Willman 1, Uma II, Leo IV, etc., have solved the missing satellite/subhalo/dwarf galaxy problem!

Dwarf elliptical galaxies which form today are unlikely to be nucleated.

dEs - spectacular in the inner parts and the outskirts are still a mystery.

There may be a diversity of origin of dE nuclei, there is such a diversity for UCDs

Dwarf galaxies are irrelevant objects in the overall build up of the Hubble sequence

Dwarf ellipticals are not dark-matter dominated!

dE nuclei are NOT made from globular clusters.

UCDs are simply the extension of the cE sequence to lower luminosities and masses.

Ultra-faint "dwarf galaxies", such as Segue 1, Willman 1, Uma II, Leo IV, etc., are not galaxies (M_V < -4, fainter than a typical GC) at all albeit their luminosity-metallicity relation suggests that they formed as galaxies!

How can we distinguish two sides of dEs: nature and nurture?

NO! (globular clusters are not dE nuclei).

The different behavior of dE and E galaxies in the M – <μ>_e (and M – μ_e) diagram, and the <μ>_e – log(R_e) diagram, are expected from the continuous and linear relation between M and μ_0, and M and log(n)

Dwarf galaxies - their time has yet to come

Early-type dwarfs - formed or built?

Dwarf elliptical galaxies are not progenitors of giant ellipticals.

Whether you call a galaxy a dE or a dE,N depends mainly on the resolving power of your telescope.

The idea that supermassive black holes are the incarnation of nuclear star clusters in high mass galaxies is wrong.

There is no such thing as a primordial dE, all of them had late-type progenitors.

In Virgo, the destruction rate of dEs exceeds the accretion rate.

Who needs media sexy overly hyped high-redshift (z > 8) galaxies, we have extremely metal-poor local dwarfs, which by analogy will tell us about the epoch of galaxy formation.

The dEs we see today are not the oldest galaxies in the Universe.