Tuesday. Already. I did get the histogram ready for meeting with Rachel today, though. I need to code astrometry this week. Then I need to think about how to test different variants of shape measurement methods, both for KiDS and for GREAT3. I'm going to have a telecon everyday, starting this week (good thing I got a nice headset).
1111.2862
Kiloparsec-scale spatial offsets in double-peaked narrow-line AGNs. I. Markers for selection of compelling dual AGN candidates
Comerford, Gerke, Stern, COoper, Weiner, Newman, Harrison, Madsen, Barrows
Take 81 double-peaked, narrow-line AGNs in SDSS at 0.03<z<0.36 and run a follow-up longslit spectroscopy (longslit for spatial resolution). Find all 81 systems exhibit double AGN emission components with ~kpc projected spatial separations on the sky--could be kpc-scale dual AGN, or kpc-scale outflows, jets, or rotating gaseous disks. Find 58% of objects with spatially-compact emission components may be preferentially produced by dual AGNs, while the other with spatially-extended emission components may be preferentially produced by AGN outflows. Also find 32% of the two-AGN emission components preferentially aligned with the host galaxy major axis, as expected for dual AGNs orbiting in the host galaxy potential. Results both narrow the list of possible physical mechanisms producing the double AGN components, and suggest observational criteria for selecting the most promising dual AGN candidates from the full sample of double-peaked narrow-line AGNs. Determine the 17 most compelling dual AGN candidates in sample.
1111.2863
An excursion-set model for the structure of GMCs and the ISM
Hopkins
Develop excursion-set model for the formation and time evolution of dense gas structures (GMCs, massive clumps, and cores), based on the supersonic turbulence of ISM on a range of scales. Construct statistical properties of the density field smoothed on a scale R (just like excursion set). Compare conditions for self-gravitating collapse including thermal, turbulent, and rotational support: a well-defined barrier crossing problem. Derive 'bound object mass function' can be derived, from sonic length to above the disk Jeans mass. Agreems remarkably well with observed GMC mass functions. Only inputs are the mass and size of the galaxies (to normalize the model). Explains the mass function cutoff and its power-law slope (close to, but shallower than, -2). The model also predicts the linewidth-size and the size-mass relations of clouds and the dependence of their residuals on surface density/pressure. Use this to predict the spatial correlation function/clustering of clouds and star clusters; these also agree well with observations. Predict the size/mass function of ISM 'bubbles' or 'holes', and show this can account for observed HI hold distributions, without any local feedback. Generalize the model to construct time-dependent 'merger/fragmentation trees' which can be used to follow cloud evolution and construct semi-analytic models for the ISM. Provide explicit recipes to construct the trees. Use a simple example to show that, if clouds are not destroyed in ~1-5 crossing times, then all ISM mass would be trapped in collapsing objects even if the large-scale turbulence were maintained.
1111.2864
The formation of shell galaxies similar to NGC 7600 in the CDM cosmogony
Cooper, Martinez-Delgado, Helly, Frenk, Cole, Crawford, Zibetti, Carballo-Bello, Gabany
Present deep observations of 'shell' structures in the nearby galaxy NGC 7600, along a movie of galaxy formation in a CDM universe based on ab initio comological simulation. Shows continuous accretion of clumps of DM and stars creates a swarth of diffuse circumgalactic structures. The disruption of a massive clump on a near-radial orbit creates a complex system of transient concentric shells, very similar to NGC 7600. Interpret with aid of simulation.
1111.2869
The star-formation histories of z~2 DOGs and SMGs
Bussmann, Dey, Armus, Brown, Desai, Gonzalez, Jannuzi, Melbourne, Soifer
Spitzer identified ULIRGs at z~2 (important role in massive galaxy formation?). Measure stellar mass of DOGs (dust-obscured galaxies, extremely red R-[24] colors), and compare results with SMGs (submillimeter selected galaxies). Two populations: "bump DOGs" (mid-IR SED at rest-frame 1.6um stellar emission) and "power-law DOGs" (spectral features typical of AGN). Test a variety of stellar population synthesis codes, SFHs, and initial mass functions (which are self-consistent to broad-band photometry in rest-frame UV, optical and near-IR of each of these populations). Simple SFH and Chabrier IMF, find median and inner quartile stellar masses of SMGs, bump DOGs and power-law DOGs are very similar (1e10.4 to 1e10.7, in order). Implement more complex SFH increases these mass estimates by up to 0.5 dex. Stellar mass estimates consistent with physical mechanisms for the origin of z~2 ULIRGs that result in high SF rates for a given stellar mass. Such mechanisms are driven by a major merger of two gas-rich systems, ,rather than smooth accretion of gas and small satellites.
1111.2887
Dark atoms of DM and their stable charged constituents
Khlopov
DM particle candidate possibility: new stable quarks and charged leptons exist and are hidden from detection, being bound in neutral dark atoms of composite dark matter. Stable -2 charged particles O- are bound with primordial helium in O-Helium (OHe) atoms, being specificnuclear interacting form of composite dark matter. ...
1111.2889
Measuring equality horizon with the zero-crossing of the galaxy correlation function
Prada, Klypin, Yepes, Nuza, Gottloeber
Zero-crossing (r_c) of the 2pt galaxy correlation function closely related to the horizon size at matter-radiation equality for a large variety of flat LCDM models. Zero-crossing unaltered by non-linear evolution of density fluctuations, z-distortions, and galaxy biases. A new standard ruler!
1111.2905
Evidence for a non-universal stellar IMF in low-z high-density early-type galaxies
determine an absolute calibration of stellar M/L ratios for the densest 3% of early-type galaxies in the local universe from SDSS DR7, ~4000 objects with Sigma_e>2500 Msun/pc^2, M_sps< 1e10.8 Msun, and sigma_ap=168 km/s. These dense early-type galaxies follow the virial fundamental plane (mass follows light). Assuming that any DM does not follow the light, the dynamical masses of dense galaxies provide a direct measurement of stellar masses. Dynamical stellar mass consistent with Salpeter IMF; bottom heavy IMFs and standard MW IMF strongly disfavored. Results consistent with, but do not require, a dependence on IMF on dynamical mass or velocity dispersion. Find evidence for a color dependence to the IMF: redder galaxies have heavier IMFs. May reflect a more fundamental dependence of the IMF on the age or metallicity of a stellar population, or the density at which the stars formed.
1111.3066
The effects of baryons on the halo mass function
Cui, Borgani, Dolag, Murante, Tornatore
Fractional difference between halo masses in the hydro and DM-only simulations almost constant for halos more massive than 1e13.5 Msun/h. Mass increase in the hydro simulations is about 4-5% at M500 and 1-2% at M200. Differences are mearly the same for both radiative and non-radiative simulations. Halo mass function similar for M200 (3%) and M500 (7%), but 10-20 % for M1500. Increase in the radiative case larger by x2 than non-radiative case.
1111.3090
Dusty gas with SPH - I. Algorithm and test suite
Laibe, Price
Simulate two-fluid gas and dust mixtures in SPH; systematically address a number of key issues including the generalised SPH density estimate in multi-fluid systems. Consistent treatment of variable smoothing length, finite particle size, time step stability, tehrmal coupling terms, and choice of kernel and smoothing length used in the drag operator. Find: using double-hump shaped kernels improves the accuracy of the drag interpolation by a factor of several hundred compared to the use of standard SPH bell-shaped kernels. Simple standardised simple test problems for gas and dust mixtures, for comparison with analytic solutions. Spatial resolution criterion Delta < cs ts is a necessary condition in all gas+dust codes that become critical at high drag (small stopping time ts) in order to correctly predict the dynamics. Implicit timestepping and implementation of realistic astrophysical drag regimes are addressed in a companion paper.
1111.3149
CMB map restoration
Bobin, Starck, Sureau, Fadili
Foreground contamination removal of CMB with Linear Iterative Wavelet Filtering.
1111.3202
Averaging the AGN X-ray spectra from Chandra fields
Faloco, et al
The X-ray spectra of AGN carry signatures of the emission from the central region close to SMBH. Fe K line most often observed, which can be broadened and deformed by relativistic effects if emitted close enough to the central SMBH. Statistical studies of X-ray spectra of AG samples show a narrow Fe line is ubiquitous, while whether the broad feature is common may not be. Make an average AGN spectrum, spans a broader range of X-ray luminosities. Subsamples defined in terms of column density of the local absorber, luminosity and z investigated. Find very significant Fe line with a narrow profile in all samples and in almost all the subsamples constructed. EW of the narrow line in the avg sample is 74 eV. The broad line component is significantly detected in the subsample AGNs with L<1.43e44 cgs and z<0.76, with EW=108eV. Conclude that the narrow Fe line is ubiquitous feature of the X-ray spectra of the AGN up to z=3.5. The broad line component is significant in the X-ray spectra of AGN with low luminosity and low z.
1111.3205
Enhancement of dark matter capture by neutron stars in binary systems
Brayeur, Tinyakov
Capture of DM particles by neutron stars in close binary systems. Amplification of DM capture is x3.5 for a specific binary pulsar with orbital period of 4hrs.
1111.3216
Electron-positron Annihilation lines and decaying sterile neutrinos
Chan, Chu
The diffuse positron annihilation line at the MW center *may* be due to massive sterile neutrinos decaying into photons and/or electron-positron pairs. Calculate decay rate.
1111.3245
A search for water maser emission in nearby low-luminosity QSO host galaxies
König, Eckart, Henkel, Garcia-Marin
None found for the 17 sources of Seyfert 1 QSO's observed. It's hard.
1111.3269
Shape, structure, and morphology in planetary nebulae
Shaw
Planetary nebulae (PN)'s precursors are AGB stars (helium shell burning). PN formation from AGB stars not fully understood. Use PN morphology for interpretation.
1111.3285
The radio-x-ray relation as a SF indicator: results from the VLA--E-CDFS survey
Vattakunnel et al
268 source detected in both X-ray and radio; redshifts available for ~95 of the sources. Identify 43 objects consistent with SF. Find clear linear relation between radio and x-ray luminosity in SF galaxies over 3 orders of magnitude, up to z~1.5, with significant scatter of 0.4 dex, higher at low z. Correlation does not evolve with redshift, and is consistent with what is observed locally. ...
1111.3314
Selection constraints on high redshift quasar searches in the VISTA kilo-degree infrared galaxy survey
Findlay, Sutherland, Venemans, Reyle, Robin, Bonfield, Bruce, Jarvis
VISTA Kilo-degree Infrared Galaxy Survey (VIKING) forms a natural intermediate between current wide shallow, and deeper more concentrated surveys, by targeting two patches totallin 1500 sq.deg with ZYJHKs. Hard to get high-z quasars, and...
1111.3338
Power spectrum estimation from Peculiar velocity catalogues
Macaulay, Feldman, Ferreira, Jaffe, Agarwal, Hudson, Watkins
Catalogue of 4537 peculiar velocity measurements with a characteriestic depth of 33 Mpc/h to estimate the matter power spectrum. Compare constraints with this method. Good agreement with LCDM model, minor deviation (1 sigma level excess power) for large scales.
1111.3357
WMAP anomaly: weak lensing in disguise
Rotti, Aich, Souradeep
Gravitational lensing will induce signals which mimic isotropy violation even in an isotropic universe. Constraining SI (statistical isotropy) violation will only be possible by complementing CMB data with measurements of LSS DM distribution.
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