Day 11

Woke up at 4am and started working, then went for a run at 7am around Ewha campus with Tobias this morning.  Excitement with Eric (Huff)'s paper being ready for submission--but he will need to redo the lensing analysis!  A little sleepy at 9:30am.  Must finish ApJ refereeing today, good thing it's a good paper and I won't have to comment much on it.


http://arxiv.org/abs/1106.0505
GHASP: an H-alpha kinematic survey of spiral and irregular galaxies -- IX. The NIR, stellar and baryonic Tully-Fisher relations
Torres-Flores, Epinat, Amram, Plana, Mendes de Oliveira


* Wow, a 9th paper on a survey, cool.
* A Tully-Fisher relation is: an empirical relationship in spiral galaxies between the intrinsic luminosity and rotation curve amplitude. (L-v relation)
* A Fabry-Perot interferometer consists of a transparent plate with two reflecting surfaces.  The reflection off of the two parallel surfaces causes interference patterns.  I don't know how this works with galaxy spectra, though.


Uses "homogenerous Fabry-Perot sample of galaxies to get 2D velocity fields, which finds the maximum rotational velocities better.
Compare with 2MASS (IR) photometry, optical colors, neutral Hydrogen masses and various M/L estimators, and find slope of 4.5 and 3.6 for the stellar (IR) and baryonic (HI gas) Tully-Fisher relation [why would it be different from optical?  I mean it probably should be different, but why?  This would depend on the stellar population.]
Rising or asymmetric rotation curves show a larger dispersion in the Tully-Fisher relation than flat or symmetric ones. [This makes sense, if you assume that symmetric/flat galaxies live in a stable gravitational potential than the others.]
Surface baryonic mass density (from baryonic mass and optical radius) is almost constant for all galaxies [for all luminosity range?  Shouldn't it differ for different gravitational potentials?].
There is a break in the NIR Tully-Fisher relation at M(H,K) ~ -20 [why?  due to SNe feedback?  do the H,K magnitudes differ for early and late-type spirals?  By how much?]; late-types have higher total mass relative to baryonic (HI) mass than early-type spirals.  This suggests SNe is an important issue in late-type spirals.


* I'm not sure if I really understood this abstract.  I guess they did Tully-Fisher measurements, and found some interesting things, like correlation between asymmetry and scatter in T-F relation, or SNe feedback on T-F relation.