the rotation curves of a sample of 46 low- and high-surface brightness galaxies are considered in the context of milgrom's modi_ed dynamics (mond) to test a new interpolating function proposed by zhao et al. (2010) [1] and compare with the results of simple interpolating function. the predicted rotation curves are calculated from the total baryonic matter based on the b-band surface photometry,...

it is inferred from the symmetrical and luminous x-ray emission of fossil groups that they are mature, relaxed galaxy systems. cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (bggs), the central early-t...

The rotation curves of a sample of 46 low- and high-surface brightness galaxies are considered in the context of Milgrom's modi_ed dynamics (MOND) to test a new interpolating function proposed by Zhao et al. (2010) [1] and compare with the results of simple interpolating function. The predicted rotation curves are calculated from the total baryonic matter based on the B-band surface photometry,...

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

We report on a survey of NH2D towards protostellar cores in low–mass star formation and quiescent regions in the Galaxy. Twenty–three out of thirty-two observed sources have significant (∼5σ) NH2D emission. Ion–molecule chemistry, which preferentially enhances deuterium in molecules above its cosmological value of 1.6× 10 sufficiently explains these abundances. NH2D/NH3 ratios towards Class 0 s...

Arcsecond-resolution spectral observations toward the protobinary system IRAS 16293-2422 at 344 and 354 GHz were conducted using the Submillimeter Array. Complex organic molecules such as CH3OH and HCOOCH3 were detected. Together with the rich organic inventory revealed, it clearly indicates the existence of two, rather than one, compact hot molecular cores (. 400 AU in radius) associated with ...

We investigate the propagation of a shock wave into a warm neutral medium and cold neutral medium by one-dimensional hydrodynamic calculations with detailed treatment of thermal and chemical processes. Our main result shows that thermal instability inside the shock-compressed layer produces a geometrically thin, dense layer in which a large amount of hydrogen molecules is formed. Linear stabili...

To study the evolution of high-mass cores, we have searched for evidence of collapse motions in a large sample of starless cores in the Orion molecular cloud. We used the Caltech Submillimeter Observatory telescope to obtain spectra of the optically thin (HCO ) and optically thick (HCO ) high-density tracer molecules in 27 cores with masses 11 M . The redand blue-asymmetries seen in the line pr...