1110.1375
Astroseismic diagrams from a survey of solar-like oscillations with Kepler
White et al
Kepler can detect solar-like oscillations in other stars. Measured 3 astroseismic parameters that characterize the oscillations: the large frequency separation (\Delta\nu), the small frequency separation between modes of l=0 and l=2 (\delta\nu_02), and the dimensionless offset (\epsilon). These measurements allow construction of astroseismic diagrams (C-D diagram of delta nu_02 vs Delta nu) and the epsilon diagram. Compare Kepler results with previously observed solar-type stars and theoretical models. Positions of stars in these diagrams places constraints on their masses and ages. Confirm observational relationship between epsilon and T_eff that allows for the unambiguous determination of radial order; should help resolve problem of mode identification in F stars.
* not sure how they detect these oscillation modes: by photometry alone, I suppose. What is the amplitude of these oscillation in magnitudes?
1110.1376
The formation of large galactic disks: revival or survival?
Hammer, Puech, Flores, Athanassoula, Yang, Wang, Rodrigues, Fouquet
From observation of distant galaxies, investigate how extended disks could have formed: spatially-resolved kinematics, detailed morphologies and photometry from UV to mid-IR). 6e9 years ago, half of the present-day spiral progenitors had anomalous kinematics and morphologies, as well as relatively high gas fractions. Argue: gas-rich major mergers can be the likeliest driver for such strong peculiarities. Suggests new channel of disk formation: many disks reformed after gas-rich mergers. Agrees with LCDM prediction semi-empirical models: Sensitivity in detecting mergers at all phases, from pairs to relaxed post-mergers, find more accurate merger rate. Confront scenario to properties of nearby galaxies, including M31 and galaxies showing ultra-fait, gigantic structures in their haloes.
* cool photos of galaxy morphologies. at z=0.65 (6 Byr ago), 52% of galaxies are "peculiar", where today only 10%. The difference is mostly accounted for in the spiral galaxies fraction. The elliptical fraction remains the same (17-18%).
1110.1377
Core-collapse SNe and host galaxy stellar populations
Kelly, Kirshner
Examine host galaixes of 519 nearby SNe (SDSS); colors at the sites of explotions as well as chemical abundances and specific SFR of the host galaxies provide circumstantial evidence on the origin of each SNe type. SN Ic: small host offsets, exceptionally strongly SF, metal-rich, dusty stellar populations near their centers. SN Ic-BL and IIb: exceptionally blue locations, host galaixes have lower oxygen abundance than Ic and Ib (close spectroscopic cousins). Ic-BL: exhibit strong central sSFR. Find no strong evidence for different environments for SN IIn compared to SN II.
1110.1379
ECOSMOG: an efficient code for simulating modified gravity
Li, Zhao, Teyssier, Koyama
N-body simulations for a wide class of modified gravity and dynamical DE theories. Based on RAMSES code: solves Poisson equation on adaptively refined meshes.
1110.1380
Mapping the universe: the 2010 Russel lecture
Geller, Diaferio, Kurtz
Redshift surveys map the distribution of mass and light in the universe: (1) measuring mass distribution extending into the infall regions of rich clusters, (2) applying deep redshift surveys to the selection of clusters of galaxies and very large structures. Preview HectoMAP project.
1110.1420
Evolution of the galaxy-DM connection and the assembly of galaixes in DM halos
Yang, Mo, van den Bosch, Zhang, Han
New model to describe the galaxy-DM connection, unlike subhalo abundance matching. Takes into account (i) subhaloes are accreted at different times, and (ii) properties of satellite galaxies may evolve after accretion. Use galaxy stellar mass function out to z~4, conditional stellar mass function at z~0.1 obtained from SDSS, and the 2pt correlation function of galaixes at z~0.1 as function of stellar mass, constrain the relation between galaxies and DM haloes over the entire cosmic history from z~4 to present. Use this relation to predict the median assembly histories of idfferent stllar mass components within DM haloes (central, satellite, and halo stars). Predict high-z galaxies as function of stellar mass. Find: (i) model reasonably fits all data within observational uncertainties, consistency with LCDM. (ii) ...
1110.1594
Testing inflation with DM halos
LoVerde, Ferraro, Smith
Cosmic inflation: early density perturbations that seeded the LSS today. Primordial non-Guassianity is the most promising of few observational tests of physics at this epoch. At present, non-G is best constrained by CMB, but in the near temr LSS may be competitive so long as the effects of primordial non-G can be modeled through the non-linear process of structure formation. Discuss recent work modeling effects of a few types of primordial non-G on the large-scale halo clustering and the halo mass function. Specifically: compare analytic and N-body results for two variants of the curvaton model of inflation.
* missing results, but I guess this is a conference talk.
MPIfR Bonn, lunch colloquium
Searching for radio pulsars, just about everywhere!
Ralph Eatough
Summarize the work at MPIfR on searching for radio pulsars (neutron star astrophysics). All-sky pulsar surveys at Effelsberg and Parkes. Order 20 pulsars been discovered. Einstein@home reduction. Highly-relativistic binary pulsars (NS-NS or NS-BH), but to date, no target systems have been found. Future searches discussed.
* missing results, but I guess this is a conference talk.
MPIfR Bonn, lunch colloquium
Searching for radio pulsars, just about everywhere!
Ralph Eatough
Summarize the work at MPIfR on searching for radio pulsars (neutron star astrophysics). All-sky pulsar surveys at Effelsberg and Parkes. Order 20 pulsars been discovered. Einstein@home reduction. Highly-relativistic binary pulsars (NS-NS or NS-BH), but to date, no target systems have been found. Future searches discussed.
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