The galaxy-halo mass connection at dwarf scales

[ahgpeter]

Includes a discussion of the dwarf luminosity function

[bechtol]

I'd like to see a calculation for the expected signal strength for stacked weak lensing around a sample of "Magellanic Cloud"-scale dwarfs at redshift ~0.1 . Could we learn about the typical halo mass and profile? How many such dwarfs would we need for the expected LSST source galaxy density? I think the DESC DC2 sims might be appropriate to answer this question, but an analytic estimate would also be good. I've been thinking a bit about how to select the sample of dwarf lenses.

[rmandelb]

@bechtol - I have the tools for this and also some thoughts on how to weed out the contamination from higher-z things that you think are lower-z dwarfs. @ahgpeter and I are talking.

[ahgpeter]

@bechtol Rachel made a new dwarf galaxy repository off the main lsst dark matter meeting page. https://github.com/lsstdarkmatter/dwarf-halo-mass

[ahgpeter]

A plot from my paper with Matt Buckley. Focus on the bottom panel for now. The vmax function is a CDM prediction. The vrot curve shows the abundance of galaxies from ALFALFA. Do we have a missing dwarf problem, or a cusp core problem? We'll only know when we have an accurate map from vrot to vmax.

[ahgpeter]

Mstar-Mhalo relation with two different methods, at z=0.5. Moster et al. 2013 uses galaxy stellar mass functions and star formation histories, layered on top of CDM merger trees. Miller et al. 2014 measures rotation curves, and translates them to halo mass using the optical-to-virial velocity conversion (determined at higher mass) from @rmandelb 's paper with Reina Reyes. I made this plot for my paper with Matt Buckley, https://arxiv.org/abs/1712.06615.

[yymao]

Plots made with @rmandelb.

Shear signal-to-noise, for LMC-like galaxies, 0.2 < z < 0.4, LSST sky area and source density:

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Same but for galaxies -14 < Mr < -13:

[ahgpeter]

Halo mass ideas and considerations:
https://github.com/lsstdarkmatter/dwarf-halo-mass/blob/master/Ideas