1204.2543
Spatially resolving substructures within the massive envelope around an intermediate-mass protostar: MMS 6/OMC 3
Takahashi, Saigo, Ho, Tomida
Brightest (sub-)millimeter continuum source in the OMC-2/3 region (MMS 6) observed in the 850 um continuum emission with 0.3" (120 AU at orion) angular resolution. Size: 132 x 120 AU), 0.29 Mo [?], and 2.1e25 cm^-2. The estimated extremely high mean number density (1.5e10 cm^-3) suggests that MMS 6 is likely optically thick at 850 um. Compare with 3 theoretical core models: prestellar core, protostellar core+disk-like structure, and first adiabatic core. These comparisons clearly show that the observational data cannot be modeled as a simple prestellar core with a gas temperature of 20K. A self-luminous source is necessary to explain the observed flux density in the sub-millimeter wavelengths. Very compact and energetic outflow in the CO (3-2) and HCN (4-3) lines support the presence of a protostar. An intermediate mass protostellar core at an extremely young stage. In addition to the MMS 6-main peak, have also spatially resolved a number of spiky structures and sub-clumps, distributed over the central 1000 AU. Masses of the sub-clumps are 0.07 Mo (order brown dwarf masses). Higher angular resolution and higher sensitivity observations will reveal the origin and nature of these structures : fragmentation, spiral arms, inhomogeneity within the disk-like structures/envelope.
1204.2546
The dark matter crisis: falsification of the current standard model of cosmology
Kroupa
Standard model of cosmology require the dual dwarf galaxy theorem---two types of dwarf galaxies must exist: primordial DM dominated (type A), and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM. In the model, type A dwarfs are distributed approximately spherically following the shape of the host DM, and type B dwarfs are correlated in phase-space. Type B must exist in any theories in which galaxies interact. Only one type of dwarf galaxy is observed to exist on the baryonic Tully-Fisher plot and in the radius-mass plane. ... Dual Galaxy Theorem falsified by observation of phase-space-correlated structure in MW and Andromeda, and dynamically relevant cold or warm DM on galactic scales cannot exist. Also show that the standard model of cosmology incompatible with a large set of other extragalactic observations. In particular, alone the empiricaal mass-discrepancy-acceleration correlation constitutes convincing evidence that galactic-scale dynamics cannot be Einsteinian/Newtonian. Major problems with inflationary BB cosmologies remain unresolved.
1204.2547
The physics of galactic winds driven by AGN
Faucher-Gguere, Quataert
AGN drive fast winds in the ISM of their host galaxies. Commonly assumed that the high ambient density and intense radiation fields in galactic nuclei imply short cooling times, thus making the outflows momentum-conserving. Show that cooling of high-velocity, shocked winds in AGN is in fact inefficient in many circumstances, including ULIRGs, resulting in energy-conserving outflows. Further show that fast energy-conserving outflows can tolerate a large amount of mixing with cooler gas before radiative losses become important. [what is the mechanism for "momentum-conserving" vs "energy-conserving"?] Shocked wind develops a two-temperature structure. While most of the thermal pressure support is provided by the protons, the cooling processes operate directly only on the electrons. This significantly slows down inverse Compton cooling, while free free cooling is negligible. Slower winds 1000 km/s (radiation pressure on dust) can also experience energy-conserving phases but under more restrictive conditions. Energy-conserving outflows driven by fast AGN winds (0.1c) may therefore explain the momentum fluxes Pdot >> L_AGN/c of galaxy-scale outflows recently measured in luminous quasars and ULIRGs. Shocked wind bubbles expanding normal to galactic disks may also explain the large-scale bipolar structures observed in some systems, including around the Galactic Center, and can produce significant radio, X-ray and gamma-ray emission.
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