1305.5389
The AGILE science alert system (ASAS)
Trifoglio et al
ASAS habe been developed to provide prompt processing of science data for detection and alerts on gamma-ray galactic and extra galactic transients, gamma-ray bursts, Xe-ray bursts and other transients in the hard X-rays. The system is distributed among the AGILE data center of Italian space agency, Frascati, and the AGILE team quick look sites (Bologna and Roma). Present ASAS architecture and performances in the first 2 years of AGILE payload.
1305.5393
Cosmic-ray propagation in molecular clouds
Padovani, Galli
CRs constitute the main ionizing and heating agent in dense, starless, molecular cloud cores. Re-examine the physical quantities necessary to determine the CR ionization rate (at E<1 GeV and the ionization cross sections), and calculate the ionization rate as a function of the column density of molecular hydrogen. Available data support the existence of a low-energy component (<100 MeV) of CR electrons or protons responsible for the ionization of diffuse and dense clouds. Compute the attenuation of the CR flux rate in a cloud core taking into account magnetic focusing and magnetic mirroring, following the propagation of CRs along flux tubes enclosing different amount of mass and mass-to-flux ratios. Find that mirroring always dominates over focusing, implying a reduction of the CR ionization rate by a factor of 3-4 depending on the position inside the core and the magnetization of the core.
1305.5425
WFIRST-2.4: what every astronomer should know
Spergel, .. Donahue, .. Hirata, .. Perlmutter, .. Rhodes, ..
WFIRST Science definition team (SDT) presents a design reference mission (DRM) for WFIRST that employs one of the 2.4m, Hubble-quality mirror assemblies recently made available to NASA. The 2.4m primary mirror enables a mission with greater sensitivity and higher angular resolution than the smaller aperture designs previously considered for WFIRST, increasing both the science return of the primary surveys and the capabilities of WFIRST as a Guest Observer Facility. The option of adding an on-axis, coronagraphic instrument would enable imaging and spectroscopic studies of planets around nearby stars. This short article, produced as a companion to the SDT report, summarizes the key points of the WFIRST-2.4 DRM. Highlights opportunities that WFIRST affords for advances in many fields of astrophysics and cosmology, including DE, the demographics and characterization of exoplanets, the evolution of galaxies and quasars, and teh stellar populations of the MW and its neighbors.
13035.5441
Why is the moon synchronously rotating?
Makarov
If the Moon's spin evolved from faster prograde rates, it could have been captured into a higher spin-orbit resonance than the current 1:1 resonance. At the current value of orbital eccentricity, the probability of capture into the 3:2 resonance is as high as 0.6, but it strongly depends on the temperature and average viscosity of the Moon's interior. A warmer, less viscous Moon on a higher-eccentricity orbit is even more easily captured into super-synchronous resonances. Discuss two likely scenarios for the present spin-orbit state: a cold Moon on a low-eccentricity orbit and a retrograde initial rotation [spin, not orbital I presume].
1305.5471
Super-isothermality within the effective radius and global S-shape pattern in the mass density profile of elliptical galaxies out to the halo virial radius
Chae, Bernardi, Kravtsov
As the title says. Results suggest that the isothermal profile is not a universal profile for elliptical galaxies, but the pseudo-phase-space density Q(r)=rho(r)/sigma_r(r)^3, where rho(r) is the total density profile and sigma_r(r) is the radial stellar velocity dispersion profile, may well have a universal profile. Find that the slope of the Q(r) profile is ~-1.8, remarkably similar to the corresponding slope of dark matter halo profile in dissipation-less N-body simulations.
1305.5519
Gas rotation in galaxy clusters: signatures and detectability in X-rays
Bianconi, Ettori, Nipoti
Study simple models of massive galaxy clusters in which the ICM rotates differentially in equilibrium in the cluster gravitational potential. Obtain the X-ray surface brightness maps, evaluating the isophote flattening due to the gas rotation. Using a set of different rotation laws, put constraint on the amplitude of the rotation velocity, finding that rotation curves with peak velocity up to ~600 km/s are consistent with the ellipticity profiles of observed clusters. Convolve each of the models with the instrument response of ASTRO-H X-ray calorimeter to calculate the simulated X-ray spectra at different distance from the X-ray center. Demonstrate that such an instrument will allow us to measure rotation of the ICM in massive clusters, even with rotation velocities as low as ~100 km/s.
1305.5527
Using CMB polarization to constrain the anomalous nature of the cold spot with an incomplete sky-coverage
Fernandez-Cobos, et al
Cold Spot anomaly in CMB: probe its anomalous nature using X-correlation of temperature and polarization of the CMB fluctuations. Extend such approach to deal with realistic data sets with a partial sky-coverage. In particular, exploit the radial and tangential polarization patterns around temperature spots. Explore the capacity of the method to distinguish between a standard Gaussian CMB scenario and an alternative one, in which the Cold Spot arises from a physical process that does not present correlated polarization features, as a function of the instrumental-noise level. Consider more in detail the case of an ideal noise-free experiment and those ones with the expected instrumental-noise levels in QUIJOTE and Planck experiments. Also present an application to WMAP9 data, without being able to obtain firm conclusions, with a significance level of 32%. In the ideal case, the alternative scenario could be rejected at a significance level of around 1%, whereas for expected noise levels of QUIJOTE and Planck experiments, the corresponding significance levels are 1.5%
7.4%, respectively.
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