Friday. Was good in reading astro-ph recently, but intentionally took yesterday off. The Journal Club presentation was well received. (Although I do know that I'm not the best presenter in the world.)
1111.3947
Phi Zeta Delta: Growth of perturbations in parameterized gravity for an Einstein-de Sitter Universe
Baker
Parmeterized frameworks for modified gravity useful for model-independent test of GR. Test their behaviour on EdS. Implement mathematically consistent parameterization at the level of field equations; calculate evolution of perturbations in an EdS scenario. Parameterization allows for new scalar degrees of freedom; compare this with theories where the only degrees of freedom come from the metric and ordinary matter. Impact on ISW and canonically-conserved superhorizon perturations studied.
1111.3948
Non-equilibrium chemistry of dynamically evolving prestellar cores: I. Basic magnetic and non-magnetic models and parameter studies
Tassis, Willacy, Yorke, Turner
Combine dynamical and non-equilibrium chemical modeling of evolving prestellar molecular cloud cores, and explore the evolution of molecular abundances in the contracting core. ... Identify abundance ratios between particular molecules, the measurement of which would have maximal potential for discrimination among the different models examined here. The ratios between NH3 and CO; NH2 and CO; NH3 and HCO+ are sensitive to the evolutionary timescale. The ratio between HCN and OH is sensitive to the C/O ratio. Demonstrate that measurements of the central deviation (central depletion or enhancement) of abundances of certain molecules are good indicators of the dynamics of the core.
1111.3953
Constraints on interacting dark energy models from galaxy rotation curves
Baldi, Salucci
DE and DM interaction can significantly modify NL structures, e.g., their average concentration at a given mass. Constant interaction results in less concentrated density profiles; growth of coupling function as a function of time leads to large increase of halo concentrations, including halos hosting luminous spiral galaxies, worsens the "cusp-core" tension in LCDM. A pilot investigation of the effects of a DE interaction at small scales.
1111.3954
WIMP abundance and lepton (Flavour) asymmetry
Stuke, Schwarz, Starkman
Investigate how large lepton symmetries [what is this?] affect the evolution of the early universe before BBN and influence the relic density of WIMP dark matter.
1111.3956
Two new accreting, pulsating WDs: SDSS J1457+51 and BW Sculptoris
Uthas et al
Two cataclismic variables with prominent WD components in their spectra. GW Lib class of variable stars, with the fast periodic signals believed to arise from non-raidal pulsations in the underlying WD. Primary periods near 10 and 20 minutes. Also detect double-humped waves signifying the underlying orbital periods, hear 78 minutes for both stars.
1111.3960
Cosmological tests of GR: a principal component analysis
Hojjati, Zhao, Pogosian, Silvestri, Crittenden, Koyama
WL surveys: probe DE dynamics, matter overdensities, local curvature, Newtonian potential. PCA to find the eigenmodes and eigenvalues of time and scale-dependent functions. Consider impact of some systematic effects expected in WL surveys. Discuss merits of other functions. Analyze degeneracy between growth functions and cosmo params, with attention to w(z). Demonstrate the utility of PCA as an efficient data compression state.
* I should probably read this.
1111.3961
MAGPHYS: a publicly available tool to interpret observed galaxy SEDs
da Cunha, Charlot, Dunne, Smith, Rowlands
Consistently interpret emission from galaxies at UV, optical and IR wavelengths, in a simple, physically motivated model. Obtain robust statistical constraints on stellar content, star formation activity and dust content of galaxies. Apply to H-ATLAS survey; find diffuse ISM powered by old stars (>10Myr) accounts for half the total IR luminosity.
* for nearby stars; only for SEDs (not for broadband photometry)
1111.3964
Constraining sources of Ultra high energy cosmic rays using high energy observations with the Fermi satellite
Pe'er, Loeb
Conditions that enable acceleration of particles to UHE, ~1e20 eV (UHECRs). SHow broad band photon data from Fermi yield constraints on the ability of AGN to produce UHECRs. High-energy (MeV-GeV) photons are produced by Compton scattering of the emitted low energy photons and the CMB or extra-galactic BG light. Ratio of luminosities at high and low photon energies can be used as a probe of the physical conditions in the acceleration site. Find existing data excludes core regions of nearby radio-loud AGN as possible acceleration sites of UHECR protons. However, show giant radio lobes are not excluded. Apply to Cen A, show that acceleration of protons to 1e20 eV can only occur at distances >~100 kpc from the core.
1111.3978
Millihertz quasi-periodic oscillations and thermonuclear bursts from Terzan 5: a showcase of burning regimes
Linares, Altamirano, Chakrabarty, Cumming, Keek
mHz QPOs of NS transients/pulsars.
1111.3980
The large, oxygen-rich halos of star-forming galaxies are a major reservoir of galactic metals
Tumlinson, et al
Circumgalactic medium (CGM) is fed by galaxy outflows and accretion of intergalactic gas; mass, heavy element enrichment and relation to galaxy properties poorly constrained by observations. 42 galaxies with HST spectrograph detect ubiquitous, large (150 kpc) halos of ionized oxygen surround ing SF galaxies; find much less ionized oxygen around galaxies with little or no star formation. Ionized CGM contains substantial mass of heavy elements and gas, far exceeding the reservours of gas in the galaxies themselves. It's a basic component of nearly all SF galaxies that is removed or transformed during the quenching of SF and the transition to passive evolution.
1111.3981
A reservoir of ionized gas in the galactic halo to sustain star formation in the MW
Lehner, Howk
Find ionized high-velocity clouds (iHVC) in the foreground of galactic stars, with HST. Show iHVCs with 90<v<170 km/s at larger distances, which may be the next wave of infalling material.
1111.3982
The hidden mass and large spatial extent of a post starburst galaxy outflow
Tripp et al
Show warm-hot plasma at 1e5.5K contains 10-150 times more mass than the cold gas in a poststarburst galaxy wind. Wind extends to >68 kpc, and at least some portion will escape. The kinematical correlation of the cold and warm-hot phases indicates that the warm-hot plasma is related to the interaction of the cold matter with a hotter (unseen) phase at >>1e6K. Such multiphase winds can remove substantial masses and alter the evolution of poststarburst galaxies.
* that set of 3 was a Science paper.
1111.3983
The ADS All-Sky Survey
Pepe, Goodman, Meunch
ADSASS: ongoing effort aimed at turning the NASA ADS into a data source.
1111.4005
Amplitudes of low frequency modes in rotating B type stars
Lee
Estimate amplitudes of low frequence modes in a slowly pulsating B star (SPB), using weakly non-linear theory of oscillation, taking into account the effects of rotation on the modes. Find r-modes in a rapidly rotating star play a significant role in the amplitude determination through non-linear coupling. Find low M modes, the fractional amplitudes of the radiative luminosity caused by the low frequence modes are of order 1e-4 to 1e-3 at the surface.
1111.4084
The activity of the neighbours of AGN and starburst galaxies
Koulouridis, et al
* This paper says there is a evolution from starburst, Sy2, then to Sy1 after close interactions. This isn't mainstream thought on AGN, is it (I thought the difference between Sy2 and Sy1 was the viewing angle)? I do agree that interactions can trigger an AGN, but...
Results strenghen the link between close galaxy interactions and activity; provide more clues regarding evolutionary sequence inferred by (their) previous studies.
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