Thin Layer Approximation in 3-D

Equations are derived which describe a propagation of strong shocks in the interstellar matter, without any demands for a symmetry, in a thin layer approximation (2.5 dimensions). Using these equations permits to calculate a propagation of shock waves from nonsymmetric supernovae explosions in the medium with arbitrary density distribuion, formation of superbubbles in galaxies.Comment: 4 pages, 2 figure

Super stellar clusters with a bimodal hydrodynamic solution: an Approximate Analytic Approach

We look for a simple analytic model to distinguish between stellar clusters undergoing a bimodal hydrodynamic solution from those able to drive only a stationary wind. Clusters in the bimodal regime undergo strong radiative cooling within their densest inner regions, which results in the accumulation of the matter injected by supernovae and stellar winds and eventually in the formation of further stellar generations, while their outer regions sustain a stationary wind. The analytic formulae are derived from the basic hydrodynamic equations. Our main assumption, that the density at the star cluster surface scales almost linearly with that at the stagnation radius, is based on results from semi-analytic and full numerical calculations. The analytic formulation allows for the determination of the threshold mechanical luminosity that separates clusters evolving in either of the two solutions. It is possible to fix the stagnation radius by simple analytic expressions and thus to determine the fractions of the deposited matter that clusters evolving in the bimodal regime blow out as a wind or recycle into further stellar generations.Comment: 5 pages, 4 figures, accepted by A&

ALMA CO(3-2) Observations of Star-Forming Filaments in a Gas-Poor Dwarf Spheroidal Galaxy

We report ALMA observations of $^{12}$CO(3-2) and $^{13}$CO(3-2) in the gas-poor dwarf galaxy NGC 5253. These 0.3"(5.5 pc) resolution images reveal small, dense molecular gas clouds that are located in kinematically distinct, extended filaments. Some of the filaments appear to be falling into the galaxy and may be fueling its current star formation. The most intense CO(3-2) emission comes from the central $\sim$100 pc region centered on the luminous radio-infrared HII region known as the supernebula. The CO(3-2) clumps within the starburst region are anti-correlated with H$\alpha$ on $\sim$5 pc scales, but are well-correlated with radio free-free emission. Cloud D1, which enshrouds the supernebula, has a high $^{12}$CO/$^{13}$CO ratio, as does another cloud within the central 100 pc starburst region, possibly because the clouds are hot. CO(3-2) emission alone does not allow determination of cloud masses as molecular gas temperature and column density are degenerate at the observed brightness, unless combined with other lines such as $^{13}$CO.Comment: 7 pages, 5 figures, Accepted to Ap

On the Energy Required to Eject Processed Matter from Galaxies

We evaluate the minimum energy input rate that starbursts require for expelling their newly processed matter from their host galaxies. Special attention is given to the pressure caused by the environment in which a galaxy is situated, as well as to the intrinsic rotation of the gaseous component. We account for these factors and for a massive dark matter distribution, and develop a self-consistent solution for the interstellar matter gas distribution. Our results are in excellent agreement with the results of Mac Low & Ferrara (1999) for galaxies with a flattened disk-like ISM density distribution and a low intergalactic gas pressure ($P_{IGM}/k$ $\leq$ 1 cm$^{-3}$ K). However, our solution also requires a much larger energy input rate threshold when one takes into consideration both a larger intergalactic pressure and the possible existence of a low-density, non-rotating, extended gaseous halo component.Comment: 7 pages, 4 figures, 1 table, Accepted for publication in Ap

Dense CO in Mrk 71-A: Superwind Suppressed in a Young Super Star Cluster

We report the detection of CO(J=2-1) coincident with the super star cluster (SSC) Mrk 71-A in the nearby Green Pea analog galaxy, NGC 2366. Our NOEMA observations reveal a compact, ~7 pc, molecular cloud whose mass (10^5 M_sun) is similar to that of the SSC, consistent with a high star-formation efficiency, on the order of 0.5. There are two, spatially distinct components separated by 11 km/s. If expanding, these could be due to momentum-driven, stellar wind feedback. Alternatively, we may be seeing the remnant infalling, colliding clouds responsible for triggering the SSC formation. The kinematics are also consistent with a virialized system. These extreme, high-density, star-forming conditions inhibit energy-driven feedback; the co-spatial existence of a massive, molecular cloud with the SSC supports this scenario, and we quantitatively confirm that any wind-driven feedback in Mrk 71-A is momentum-driven, rather than energy-driven. Since Mrk 71-A is a candidate Lyman continuum emitter, this implies that energy-driven superwinds may not be a necessary condition for the escape of ionizing radiation. In addition, the detection of the nebular continuum emission yields an accurate astrometric position for the Mrk 71-A. We also detect four other massive, molecular clouds in this giant star-forming complex.Comment: 8 pages, 4 figures, accepted by ApJ Letter

The algorithm of forecasting of the oil well intervention effect

The paper reviews stages of oil well intervention effect forecasting. The proposed algorithm based on regression equation solution automates the process of oil well intervention effect forecasting. An assessment of the hydraulic fracturing effect was provided as a validation of the algorithm. According to assessments results, the suggested regression algorithm allows a 1.87-time decrease of an estimation error according to the error of central tendency