Polarization in the Lagoon nebula

A V-band polarimetric survey of stars associated with the Lagoon nebula was conducted. The data were combined with existing photometric and spectroscopic observations in order to investigate the alignment of magnetic field lines with identifiable symmetry axes and to evaluate the nature of dust in the immediate vicinity. Although stars are not in general highly polarized, electric vectors align with the minor axis of the Lagoon nebula, perpendicular to the major axis of the spatial distribution of massive stars. The observations indicate that the collapse of the molecular cloud progenitor was inhibited along directions perpendicular to magnetic field lines. Considering the low polarization efficiency and the high ratio of total to selective extinction, smaller grains of intranebular dust appear to have been destroyed

A Study on Emotional Maturity of College Students

The Emotional maturity becomes important in the behaviour of individuals. As the students are the pillars of the future generations their Emotional maturity is vital one. So the present study intends to measure the Emotional Maturity of college students. Normative survey method and random sampling technique has been used in the present study. The “Emotional Maturity Scale†standardized by K.M.Roma Pal [5] was used for this study. The result of the study shows that the emotional maturity of college students is extremely unstable

Effect of Several Auxiliary Ligands on the Extraction of Manganese(II) With 4-Benzoyl-3-methyl-1-phenyl-5-pyrazolone

The effect of 2-methyl pyridine N-oxide, 4-methyl pyridine N-oxide, pyridine N-oxide, 8-aminoquinoline, dibenzyl sulfoxide on the extraction of manganese(II) by 4-benzoyl-3-methyl-1-phe-\u27 nyl-5-pyrazolone (BMPP) in benzene from an aqueous buffered solution was studied. Synergistic enhancement was observed in all systems. Equilibrtum extraction constants and adduct formation constants were calculated. The results showed that synergistic extraction is due to the formation of adducts such as Mn(BMPP)2B where B represents the auxiliary ligand

Low-Alloy High-Strength Steels

IT is significant that this symposium on alloy steels is being held in the year 1956 which marks the centenary of the birth of tonnage steel. It was exactly a hundred years ago that Henry Bessemer heralded it new era by making it possible to produce steel for the first time in commercial tonnages. The largest proportion of steel made and rolled today finds its way into, structural appli-cations such as the building of bridges, transport cars, etc. Therefore structural steel occupies a promin-ent place in the eyes of the metallurgist and the engineer. Although the manufacture of Bessemer steel was well established within a few years of its discovery, the general use of steel in building bridges and other struc-tural uses had to wait for several years. As late as 1877, a Board of Trade Regulation in England prohibited the use of mild steel in bridges. The Firth of Forth Bridge built during 1 2380-1 8 90 used for the first time steel in large quantities. The earliest use of mild steel for bridges in U.S.A. was in the Eads Bridge over the 'Mississippi river. Since then the use of mild steel for bridges has become almost universal

Dolomite as a flux for High-Alumina Blast Furnace Slags

BLAST FURNACE operators at Jamshedpur have to face a peculiar problem arising out of the high concentration of it alumina in the slag. The normal analyses are 37.3-37.8% CaO, 3.4-3.9% MgO,30.4-31.5% SiO2, 26.2-27.0% Al2O3, 0.69-0.78% FeO and 0.69-0.82% S. The actual level, i.e. 26 to 28% is much higher than that common elsewhere and brings into force a series of adverse effects. Briefly, these consist of the greater viscosity of the alumina slags, greater tendency towards silicon reduction, and less efficient desulphurisation. As a result, it becomes rather difficult consistently to produce low-sulphur hot metal without exceeding the silicon level normally specified for basic iron

The star formation properties of disk galaxies: Halpha imaging of galaxies in the Coma supercluster

We present integrated H alpha measurements obtained from imaging observations of 98 late-type galaxies, primarily selected in the Coma supercluster. These data, combined with H alpha photometry from the literature, include a magnitude selected sample of spiral (Sa to Irr) galaxies belonging to the "Great Wall" complete up to mp=15.4, thus composed of galaxies brighter than Mp=-18.8 (H0=100 km Mpc^-1 s^-1). The frequency distribution of the H alpha E.W., determined for the first time from an optically complete sample, is approximately gaussian peaking at E.W. ~25 A. We find that, at the present limiting luminosity, the star formation properties of spiral+Irr galaxies members of the Coma and A1367 clusters do not differ significantly from those of the isolated ones belonging to the Great Wall. The present analysis confirms the well known increase of the current massive star formation rate (SFR) with Hubble type. Moreover perhaps a more fundamental anticorrelation exists between the SFR and the mass of disk galaxies: low-mass spirals and dwarf systems have present SFRs ~50 times higher than giant spirals. This result is consistent with the idea that disk galaxies are coeval, evolve as "closed systems" with exponentially declining SFR and that the mass of their progenitor protogalaxies is the principal parameter governing their evolution. Massive systems having high initial efficiency of collapse, or a short collapse time-scale, have retained little gas to feed the present epoch of star formation. These findings support the conclusions of Gavazzi & Scodeggio (1996) who studyed the color-mass relation of a local galaxy sample and agree with the analysis by Cowie et al. (1996) who traced the star formation history of galaxies up to z>1.Comment: 13 pages (LateX) + 24 figures + 4 tables. To appear in Astronomical Journal, April 1998 issu

Optical Polarization of 52 Radio-Loud QSOs and BL Lac Objects

Polarization measurements are presented for 52 radio-loud QSOs and BL Lac objects. For 9 highly polarized (p >3%) AGN, these are the first published polarization measurements. Of these 9, 7 are highly-polarized QSOs (HPQs), one is a BL Lac object and another is a likely BL Lac object. Polarization variability is confirmed for some of these new and previously known highly-polarized AGN. While 6 of the HPQs have flat radio spectra are almost certainly blazars, PKS 1452-217 is probably a new member of the rare class of radio-loud QSOs that show high polarization by scattering, and is therefore important for testing orientation Unified Schemes. In competition for the highest redshift HPQ are the well-observed QSO PKS 0438-43 at z = 2.85, with maximum p = 4.7%, and PKS 0046-315 at z = 2.72, for which we find p = 13%.Comment: 6 pages. Astronomical Journal, in pres

An Old Cluster in NGC 6822

We present spectroscopy of two clusters in the dwarf irregular galaxy NGC 6822. From these we deduce an age for Cluster VII of 11 Gyr and [Fe/H] = -1.95 +/- 0.15 dex. Cluster VII appears to be an analog of the metal-poor galactic globular clusters. Cluster VI is found to be much younger and more metal rich, with an age of approximately 2 Gyr. Its derived metallicity, [Fe/H], of approximately -1.0 dex is comparable to that of the gas seen today in NGC 6822. The existence of a metal-poor old cluster in NGC 6822 rules out models for the chemical evolution of this galaxy with significant prompt initial enhancement. We find that a star formation rate which is constant with time and is within a factor of two of the present star formation rate can reproduce the two points on the age-metallicity relationship for NGC 6822 over the past 10 Gyr defined by these two clusters.Comment: 8 pages; accepted for publication in A

The Red-Sequence Luminosity Function in Galaxy Clusters since z~1

We use a statistical sample of ~500 rich clusters taken from 72 square degrees of the Red-Sequence Cluster Survey (RCS-1) to study the evolution of ~30,000 red-sequence galaxies in clusters over the redshift range 0.35<z<0.95. We construct red-sequence luminosity functions (RSLFs) for a well-defined, homogeneously selected, richness limited sample. The RSLF at higher redshifts shows a deficit of faint red galaxies (to M_V=> -19.7) with their numbers increasing towards the present epoch. This is consistent with the `down-sizing` picture in which star-formation ended at earlier times for the most massive (luminous) galaxies and more recently for less massive (fainter) galaxies. We observe a richness dependence to the down-sizing effect in the sense that, at a given redshift, the drop-off of faint red galaxies is greater for poorer (less massive) clusters, suggesting that star-formation ended earlier for galaxies in more massive clusters. The decrease in faint red-sequence galaxies is accompanied by an increase in faint blue galaxies, implying that the process responsible for this evolution of faint galaxies is the termination of star-formation, possibly with little or no need for merging. At the bright end, we also see an increase in the number of blue galaxies with increasing redshift, suggesting that termination of star-formation in higher mass galaxies may also be an important formation mechanism for higher mass ellipticals. By comparing with a low-redshift Abell Cluster sample, we find that the down-sizing trend seen within RCS-1 has continued to the local universe.Comment: ApJ accepted. 11 pages, 5 figure

Observations of NGC 4151 During 1970 in the Optical and Infra-red

Observations of NGC 4151 at seven wavelengths from 0.3 to 3.4 microns made during the 1970 season are presented. Variations are found at all observed wavelengths but the optical and infra-red light curves are different: an optical maximum was reached in April but the galaxy continued brightening at 2.2 μ . until the end of June. The energy distributions of the point source and the background galaxy have been separated and that of the point source Closely resembles that of the quasar 3C273. The general form of the light curves can possibly be attributed to a dust model for the infra-red emission but this would be ruled out if suspected rapid infra-red variations are confirmed