Radio continuum and far-infrared emission of spiral galaxies: Implications of correlations

Researchers present a study extending the correlation seen between radio continuum and far-infrared emissions from spiral galaxies to a lower frequency of 408 MHz and also as a function of radio spectral index. The tight correlation seen between the two luminosities is then used to constrain several parameters governing the emissions such as the changes in star formation rate and mass function, frequency of supernovae that are parents of the interstellar electrons and factors governing synchrotron radio emission

On a problem relating to a tetrahedron

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Run up flow of a couple stress fluid between parallel plates

Consider the flow of an incompressible fluid between two parallel plates, initially induced by a constant pressure gradient. After steady state is attained, the pressure gradient is suddenly with drawn while the plates are impulsively started simultaneously. The arising flow is referred to as run up flow and the present paper aims at studying this flow in the context of a couple stress fluid. Using Laplace transform technique, the expression for velocity is obtained in Laplace transform domain which is later inverted to the space time domain using a numerical approach. The variation of velocity with respect to various flow parameters is presented through graphs

Stokes' Problems for an Incompressible Couple Stress Fluid

Stokes’ first and second problems for an incompressible couple stress fluid are considered under isothermal conditions. The problems are solved through the use of Laplace transform technique. Inversion of the Laplace transform of the velocity component in each case is carried out using a standard numerical approach. Velocity profiles are plotted and studied for different times and different values of couple stress Reynolds number. The results are presented through graphs in each case

Far-infrared observations of Circinus and NGC 4945 galaxies

Circinus and NGC 4945 are two galaxies luminous in the infrared and are characterized by compact non thermal radio nuclei, deep silicate absorption features and unusually strong water vapor maser luminosities. Moorwood and Glass (1984) have observed these galaxies extensively in the 1 to 20 micron range. In the far-infrared, observations up to 100 microns are available from the Infrared Astronomy Satellite (IRAS). In order to study the cool dust component of these galaxies, researchers observed them at 150 microns using the Tata Institute of Fundamental Research (TIFR) 100 cm balloon-borne telescope. Here, they report observations along with deconvolved maps at 50 and 100 microns obtained from the Chopped Photometric Channel (CPC) on board IRAS

Dust in a few southern H II regions

The property of dust in four southern H II region/molecular cloud complexes (RCW 108, RCW 57, RCW 122, and G351.6-1.3) was discussed. These regions were observed at an effective wavelength of 150 micron using TIFR balloon borne 1 m telescope and deconvolved maps with a resolution of 1 min were obtained. The data were combined with other available data to derive the properties of the infrared emitting dust in these regions

Distribution of dust in W31 complex

W31 is a H II region/molecular cloud complex in the galactic plane at a distance of 6 Kpc. This complex consists of two prominent radio continuum sources (G10.2-0.3 and G10.3-0.1) representing H II regions. An extended region covering both these H II regions was mapped in the Far IR (FIR) using the TIFR 1 m balloon-borne telescope with an angular resolution of approx. 1 min and a dynamic range of 100. The resulting flux density distribution at an effective wavelength of 160 microns is presented. The coadded IRAS survey scan data at 60 and 100 microns were deconvolved using a maximum entropy method to generate the flux density maps of the same region. These 60 and 100 micron maps are given and are briefly discussed