Day 101

Friday.  The first post today looks interesting.  Housing search is going nowhere.  I found a good flat in Poppelsdorf, but it was a single room...


1110.1086
Measuring sizes of ultra-faint dwarf galaxies
Munoz, Padmanabhan, Geha


Ultra-faint dwarf (UFD) galaxies extend the galaxy luminosity function down to few 1e2 M_sun luminosities; photometric characterization hard.  Structural parameters (half-light radius, cenral surface brightness) determination hard, can have up to 100% uncertainties with shallow photometric surveys (e.g., SDSS) are used.  To get 10% or better, (a) ration of the FoV to the high-light radius of the satellite must be >3, (b) total number of stars should be >1000, (c) the central BG stellar density ratio must be >20.  If one of these criteria are not met, the accuracy of the resulting structural parameters can be significantly compromised.  In the context of LSST, latter condition closely tied to our ability to remove unresolved BG galaxies.  Asses reliability of measured structural parameters will become increasingly critical for next generation of deep wide-field surveys beyond the reach of current spectro-surveys.


1110.1090
iGalFit: and interactive tool for GalFit
Ryan


* what the title says.  It's on IDL.


1110.1092
Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation
Bate


...Implying that gravity, hydrodynamics, and radiative feedback are the primary ingredients for determining the origin of the statistical properties of low-mass stars.


1110.1096
Confining the high-energy cosmic rays
Schure, Bell


Galactic cosmic rays are believed to originate predominantly from diffusive shock acceleration in SNe remnant shock waves.  Confinement of CR in the shock region is key in making this mechanism effective.  Study instability at scales longer than CR gyroradius, to study the efficiency of scattering of the highest energy CR.  Discuss driving mechanism and typical growth times.


1110.1098
The metallicity properties of long-GRB hosts
Mannucci


Fundamental Metallicity relation (FMR): dependence of metallicity on both mass and SFR.  Use FMR to study galaxies hosting long-GRBs.  GRB hosts have lower metallicities than typical galaxies, but are consistent with FMR.  Difference due to higher than average SFRs; GRBs with optical afterglows do not preferentially select low-metallicity hosts among the star-forming galaxies.


MPIfR Bonn, Special Colloquium
Molecular tracers of turbulent shocks and large scale collapse modes in star forming regions
Andy Pon, Victoria, Canada


Molecular clouds exhibit large linewidths, usually interpreted as being due to supersonic turbulence.  Turbulence plays a key role in SF, since it is believed to help support and fragment molecular clouds.  Simulation show this turbulence should decay rapidly through shocks; little work is done in determining how this dissipated energy leaves a molecular cloud and whether there would be any observable signature of this turbulent dissipation.  Describe recent work in determining the dominant cooling mechanisms of slow, C-type chocks.  Run models of C-type shocks.  Combine shock models with estimates for the rate of turbulent energy dissipation in nearby molecular clouds, produce synthetic CO spectra and predict those line emissions that will be observable with current and upcoming observational facilities (Herschel, ALMA, APEX, CCAT).  Find CO J=6-5 and 7-6 lines are powerful shock tracers.  Second project: determining how the ratio of local to global collapse times varies between molecular clouds with different geometries.