1111.3328 (Special Topic)
The quantum state cannot be interpreted statistically
shulevski
1111.4477
An improved fitting formula for the dark matter bispectrum
Gil-Marin, Wagner, Fragkoudi, Jiminez, Verde
Fitting formula for the DM bispectrum, using a set of LCDM simulations to calibrate the fitting parameters for 0.03 h/Mpc < k < 0.4 h/Mpc and 0<z<1.5. The BAO features well described. Deviation of fitting formula typically <5%, and never above 10%.
1111.4478
Jet-induced star formation in gas-rich galaxies
Gaibler, Kochfar, Krause, Silk
Feedback from AGN in massive galaxies: AGN jet provide large energy and quench cooling flows. Impact on host galaxy not understood, primarily focused on quenching of star formation. Simulate interaction of a powerful AGN jet with the massive gaseous disk (1e11 Msun) of a high redshift galaxy. Spatially resolve both jet and the clumpy, multi-phase interstellar medium (ISM) and include an explicit star formation model in the simulation. Over 1e7 years, jet activity excavates the central region, but overall causes change in shape of density probability distribution function and hence SFR due to the formation of a blast wave with strong compression and cooling in the ISM. This results in a ring- or disc-shaped population of young stars. At later times, the increase in SFR also occurs in the disk regions further out since the jet cocoon pressurizes the ISM. The total mass of the additionally formed stars may be up to 1e10 Msun for one duty cycle. Discuss details of the jet-induced star formation and potential consequences for galaxy evolution and observable signatures.
1111.4483
Probing the neutrino mass hierarchy with the rise time of a supernova burst
Chakraborty, Fischer, Hudepohl, Janka, Mirizzi, Serpico
Diagnositc tool for the neutrino mass hierarch at large 1-3 leptonic mixing angle theta_13 possible with the rise time of a Galactic SN \bar{nu}_e lightcurve (observable at Icecube Cherenkov detector). Matter suppression--a sufficiently rast rise time and the lack of long accretion-enhancement of the early Fe-core SN signal are indicative of an inverted mass hierarchy. Test robustness of this feature (concerning differences of the progenitor structure, high-density equation of state, detailed treatment of neutrino-matter interactions and dimensionality of the simulation) with two different codes. Find: faster rise time for an inverted hierarchy as compared to normal hierarchy is predicted by all models.
1111.4485
Ctability, chaos and entrapment of stars in very wide pairs
Makarov
* Jacobi radius: ??
Widely separated celestial objects affected by gravitational potential of the Galaxy, but they can exists over times comparable to Hubble type, under appropriate initial conditions. For arbitrarily chosen initial coordinates of a pair of stars, there exists a volume of the space of initial velocity components where the orbits remain bound in the planar tidal field for longer than 10 Gyr, even though the initial separaton is well outside the Jacobi radius. Boundary of this phase space of stable orbits is fractal, and the motion at the boundary conditions is chaotic. Pairs may remain confined for several Gyr, and then suddenly disintegrate due to a close rendezvous. Entrapment of unrelated stars into wide pairs is possible, but quite rare. Astrometry survey revealed that extremely wide pairs of stars are present in significant numbers in the Galaxy; results are expected to help discriminating the cases of genuine binarity and chance entrapment; can test limits of Newtonian gravitation [not very specific here].
1111.4492
Type Ia SN rates and the progenitor problem, a review
Maoz, Mannuci
Some problem with SN Ia rate measurements, which can provide clues to projenitors. The delay time distribution (DTD--SN Ia rate versus time that would follow a hypothetical brief burst of star formation) show t^-1 power law--at face value, this results supports the idea of a double-degenerate progenitor origin for SN Ia. Single-degenerate, probably immediately after SB, or if the red-giant donor channel is more efficient than theory. DTD normalization good agreement among various measurements. WD binary population measurement suggests that WD merger rate can explain the galactic SN Ia rage, if sub-Chandra mergers lead to SN Ia events.
* they haven't read the singular-progenitor scenario paper!! I think that one has the most promise.
1111.4588
Low-resolution spectroscopy of the SZ effect and estimates of cluster parameters
de Bernardis, et al
Estimates of the physical parameters of clusters (optical depth, plasma temperature, peculiar velocity, non-thermal components, etc.) obtained from ground-based multi-band SZ photometry can be significantly biased, owing to the reduced frequency coverage, to the degeneracy between the parameters and to the presence of a number of independent components larger than the number of frequencies measured. Low resolution spectroscopic measurements of SZ effect that cover >270 Ghz are effective in removing the degeneracy. Use simulation with different experimental configurations (4-band, 6-band,multi-range differential spectrometer, full coverage spectrometer) and intracluster plasma stratifications. Find: measurements with ground-based few-band photometers are biased towards high electron temperatures and low optical depths, and require coverage of high frequency and/or independent complementary observation to produce unbiased information, and requires coverage of high frequency and/or independent complementary observations to produce unbased information. A differnetial spectrometer that covers 4 bands with a resolution of ~6GHz eliminates most if not all bias. Full-range differential spectrometers are the ultimate resource that allows a full recovery of all parameters.
1111.4659
One gravitational potential or two? Forecasts and tests
Bertschinger
Metric of perturbed RW spacetime charcterized by three functions: a(t), Phi(r,t), Psi(r,t). Newtonian potential Phi moves matter, causes LSS. Massless particles respond equally to Phi and Psi. The difference of the two potentials, called the gravitational slpi, is predicted to be very small in GR by can be substantial in modified gravity theories. The two potentials can be measured, and gravity tested on cosmological scales, by combining weak gravitational lensing or the ISW effect with galaxy peculiar velocities of clustering.
1111.4770
Dynamical processes in galaxy centers
Combes
Different processes to cause rapid gas inflow/outflow in galaxy centers reviewed. Non-axisymmetries can be created or maintained by internal disk instabilities, or galaxy interactions. Simulations and observations tell us that the fueling is a chaotic and intermittent processes, with different scenarios and time-scales, according to the various radial scales across a galaxy.
1111.4843
Iron and alpha-element production in the first one billion years after the big bang
Becker, Sargent, Rauch, Carswell
Measure column densities in 9 low-ionization systems (quasar spectra) at 4.7<z<6.3 using Keck, Magellan, and VLT. The column density ratios among C II, O I, Si II, and Fe II are nearly identical to sub-DLAs and metal-poor ([M/H] < -1) DLAs at lower redshifts, with no significant evolution over 2<z<6. The abundances in the z>4.7 systems are likely to represent the typical integrated yields from stellar populations within the first gigayear of cosmic history. Because it happened so early in the universe, this observation places direct constraints on the metal production of massive stars, including iron yields of prompt supernovae. Lack of redshift evolution further suggests that the metal inventories of most metal-poor absorptions systems at z>2 are also dominated by massive stars, with minimal contributions from delayed Type Ia SNe or AGB winds. The relative abundances in our systems broadly agree with those in very metal-poor, non-carbon-enhanced Galactic halo stars. This is consistent with the picture in which present-day metal-poor stars were potentiall formed as early as one billion years after the big bang.
Iron and alpha-element production in the first one billion years after the big bang
Becker, Sargent, Rauch, Carswell
Measure column densities in 9 low-ionization systems (quasar spectra) at 4.7<z<6.3 using Keck, Magellan, and VLT. The column density ratios among C II, O I, Si II, and Fe II are nearly identical to sub-DLAs and metal-poor ([M/H] < -1) DLAs at lower redshifts, with no significant evolution over 2<z<6. The abundances in the z>4.7 systems are likely to represent the typical integrated yields from stellar populations within the first gigayear of cosmic history. Because it happened so early in the universe, this observation places direct constraints on the metal production of massive stars, including iron yields of prompt supernovae. Lack of redshift evolution further suggests that the metal inventories of most metal-poor absorptions systems at z>2 are also dominated by massive stars, with minimal contributions from delayed Type Ia SNe or AGB winds. The relative abundances in our systems broadly agree with those in very metal-poor, non-carbon-enhanced Galactic halo stars. This is consistent with the picture in which present-day metal-poor stars were potentiall formed as early as one billion years after the big bang.
1111.4878
The non-thermal emission of extended radio galaxy lobes with curved electron spectra
Duffy, Blundell
Explain the spectral curvature and turnover at radio frequencies for synchrotron-emitting lobes of radio galaxies and quasars. Lorentz factor at the turnover in the energy distribution gives the equipartition magnetic field strength and the total energy of the radiating plasma, obviating the need for any assumed values of the cutoff frequencies. This framework readily yields the form of X-ray emission due to inverse-Compton (IC) scattering of CMB photons by the electrons in the plasma having Lorentz factors of ~1000. Also present contribution to CMB anisotropies due to relativistic plasmas such as giant radio galaxy lobes, expressed in terms of the extent to which the lobes have their magnetic field and particle energies are in equipartition with one another.
1111.4919
Overview of Saturn lightning observations
Fischer et al
1111.4983
Weak lensing results of the merging cluster A1758
Ragozzine, Clowe, Markevitch, Gonzalez, Bradac
Weak lensing results of A1758 (two separate mergers, N and S). N agrees with previous WL results of clusters, whose X-ray gas components were found to be largely separated from their clusters' gravitational potentials. The WL mass peaks of the two northern clusters are separated at the 2.5 sigma level. Estimate the combined mass of the two N clustersis 2.2e15 M_sun and r_200=2.3 Mpc. Detect 7 strong lensing candidates, two of which may provide information that would improve the mass measurements of A1758N.
1111.4985
Milky Way tomography IV: Dissecting Dust
Berry, Ivezic, et al
Use SDSS photometry of 73M stars to simultaneouly obtain best-fit main-sequence stellar energy distribution and amount of dust extinction along the line of sight towards each star. SDSS photometry sufficient to break degeneracies between intrinsic stellar color and dust amount, if the shape of extinction curve is fixed. Absorption R_V can be determined to 0.1 mag uncertainty, if SDSS+2MASS photometry used. Allow detailed studies of dust properties and its spatial distribution, and of the stellar spatial distribution at low Galactic latitudes. Results in good agreement with the SFD dust maps at high northern Galactic latitudes, but indicate that the SFD extinction map consistently overestimated by about 20% in the sourthern sky, in agreement with Schlafly+ (2010). Dust extinction curve supports Fitzpatrick (1999) and Cardelli+ (1989). Find R_V=3.0 over most of the high-latitude sky. At low galactic latitudes (|b|<5), demonstrate that the SFD map cannot be reliably used to correct for extinction as most stars are embedded in dust, rather than behind it. Introduce a method for efficient selection of candidate red giant stars in the disk, dubbed "dusty parallax relation", which utilizes a correlation between distance and the extinction along the LoS. Best-fit parameters made public.
1111.5006
CLASH: discovery of a bright z~6.2 dwarf galaxy quadruply lensed by MACS J0329.6-0211
Zitrin et al
18-band photometry shows photoz of this dwarf galaxy to be ~6.2, lensed by a cluster at z=0.45. Cluster has additional 15 multiply-imaged candidates of sources spanning the range z~2-4. Mass model independently supports the high photoz (magnification = 12, 17, 4, and 4). Construct source image with physical resolution of ~200 pc when the universe was ~0.9 Gyr old, where the z~6.2 galaxy occupies a source-pane area of approximately 2.2 kpc^2. [is this big or small?] Estimate stellar mass of ~1e9 Msun, subsolar metallicity (Z/Z_sun~0.5), low dust content (A_V~0.1 mag), a demagnified SFR of ~3.2 M_sun/yr, and a specific SFR of ~3.4 /Gyr, all consistent with the properties of local dwarf galaxies.
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