Day 281

Thursday.  


1207.2466
Multiwavelength observations of V2775 Ori, an outbursting protostar in L 1641: exploring the edge of the FU Orionis Regime
Fischer et al


* FU Orinois stars: pre-main sequence stars that display an extreme change in magnitude and spectral type.  Current model: abrupt mass transfer from accretion disk onto a young, T Tauri star.  Average young star undergoes ~10-20 Fuor eruptions over its lifetime.


A protostar undergone an order-of-magnitude increase in luminosity: physics of episodic accretion and how that affects luminosity distribution of protostars.  Blueshifted HeI absorption, no HI emission, H2O and CO absorption (all typical of FU Orionis).  The least luminous documented FU Orionis outburster with a protostellar envelope.  A range of episodic accretion phenomena can occur, explaining the observed spread in protostellar luminosities.


1207.2468
Why baryons matter: the kinematics of dwarf spheroidal satellites
Brooks, Zolotov


SNe feedback and tidal stripping (baryonic physics) significantly reduces the DM mass in the central regions of luminous satellite galaxies.  Reduced central mass reproduce the observed internal dynamics of MW and M31 satellites as a function of luminosity.  Including baryonic physics and CDM models naturally explains the observed low DM densities in MW's dSph population.  This simulation resolves the tension between kinematics predicted in CDM and observations of satellites, without invoking alternative forms of dark matter.


1207.2470
MgII Absorption at 2 < z < 6 with Magellan / FIRE. II: A longitudinal study of HI, metals, and ionization in galactic haloes
Matejek, Simcoe


Study of HI and metals for 110 MgII absorption systems at 2<z<5.3 in the IR spectra of high-z QSOs.  Strengthening of HI as z goes higher: all MgII systems at z~3 are either damped Ly-alpha absorbers or sub DLAs with 40% of systems exceeding DLA threshold (compared to 16% at z~0.9).  The classical MgII system (typically associated with sub-DLAs) are quite metal-rich at 0.1 solar.  Strong systems have very large MgII and FeII velocity spreads (non-virialized dynamics) or are more quiescent DLAs.  Weaker MgII systems represent accreting gas?  Reaccretion of enriched gas?


1207.2471
Joint analysis of gravitational lensing, clustering and abundance: toward the unification of large-scale structure analysis
Yoo, Seljak


* Jaiyul!  How's married life?


WL cosmological constraints from LSS, 3 methods.  (i) galaxy lensing constrain halo bias; combine with LS galaxy clustering to measure DM clustering.  (ii) large-scale galaxy clustering and large-scale gg lensing can be combined into a direct measurement of the DM clustering.  Combine i and ii to make use of lensing measurements on all scales.  (iii) add abundance information on method i.  [abundance of what?]  Explore the statistical power of  approaches as a function of galaxy luminosity to investigate optimal mass range for each method and constraining power.  For SDSS, Find 3 methods give comparable constraints, but not in the same mass range: ii works for M~1e13Msun, and i and iii work for 1e14Msun.  Discuss robustness of each method against various systematics.  Cluster abundance falls short of i+ii combination, in both statistical power and robustness against systematic errors.  Cosmic shear is just as good as the combined method, but suffer from additional systematic effects.  i+ii method recommended!  For DES, Euclid, and LSST.


1207.2472
Characterizing the red optical sky background fluctuations from narrow-band imaging
Puech et al


As the title says.  OH airglow lines (temporal and spatial fluctuations) must be removed to 1% accuracy.  For study of faint objects, relevant for 39m E-ELT.


1207.2492
The VMC survey - VI. Quasars behind the Magellanic system
Cioni, et al


Expect to find 1500 QSOs behind LMC, 600 behind SMC, 300 behind the bridge and 50 behind the Stream, using VISTA survey (YJKs bands and 12 epochs in the Ks bands).  Useful for astrometric reference (proper motion of LMC/SMC/bridge/stream).


1207.2524
A public void catalog from the SDSS DR7 galaxy redshift surveys based on the watershed transform
Sutter, Lavaux, Wandelt, Weinberg


SDSS DR7 Main sample out to z=0.2 and LRG out to z=0.44: void catalogs.  (i) voids that are near masks included (for void galaxy studies), and (ii) bias-free catalog of voids away from any masks (for void statistics).  Voids have effective radii of 5 to 135 Mpc/h.  Radial profiles of stacked voids show a qualitatively similar behavior across two decades of void radii and throughout the full z range.