Molecular Line Observations in the Magellanic Clouds

2005 ◽  
Vol 13 ◽  
pp. 854-859
Author(s):  
Mónica Rubio
Keyword(s):  
Interstellar Medium ◽  
Molecular Species ◽  
Chemical Properties ◽  
Present Knowledge ◽  
Magellanic Clouds ◽  
Molecular Gas ◽  
Physical And Chemical Properties ◽  
Molecular Line ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractWe review the present knowledge of molecular line studies and its relation to interstellar medium properties in the Large and Small Magellanic Clouds. The physical and chemical properties of the molecular gas together with the abundance of different molecular species will be discussed.

scholarly journals Molecular Line Observations in the Magellanic Clouds

1999 ◽  
Vol 190 ◽  
pp. 116-117
Author(s):  
Lars E.B. Johansson ◽  
Arto Heikkilä ◽  
Hans Olofsson
Keyword(s):  
Spectral Line ◽  
Interstellar Medium ◽  
Line Emission ◽  
Chemical Properties ◽  
Magellanic Clouds ◽  
Physical And Chemical Properties ◽  
Molecular Line ◽  
Wide Range ◽  
Physical And Chemical ◽  
And Chemical Properties

We have observed spectral line emission from a sample of clouds in the Magellanic Clouds to investigate the effects of metallicity and FUV radiation on the physical and chemical properties of the interstellar medium. The clouds were identified by CO surveys and selected to cover a wide range of environments. We present molecular line data for five clouds in the LMC and one cloud in the SMC.

scholarly journals The Interstellar Medium of Dwarf Galaxies

Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Christian Henkel ◽  
Leslie K. Hunt ◽  
Yuri I. Izotov
Keyword(s):  
Interstellar Medium ◽  
Dwarf Galaxies ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Ionized Gas ◽  
Green Pea ◽  
Physical And Chemical ◽  
The Impact ◽  
The Universe ◽  
And Chemical Properties

Dwarf galaxies are by far the most numerous galaxies in the Universe, showing properties that are quite different from those of their larger and more luminous cousins. This review focuses on the physical and chemical properties of the interstellar medium of those dwarfs that are known to host significant amounts of gas and dust. The neutral and ionized gas components and the impact of the dust will be discussed, as well as first indications for the existence of active nuclei in these sources. Cosmological implications are also addressed, considering the primordial helium abundance and the similarity of local Green Pea galaxies with young, sometimes protogalactic sources in the early Universe.

scholarly journals VERA Observations of the H2O Maser Burst in Orion KL

2012 ◽  
Vol 8 (S287) ◽  
pp. 103-107
Author(s):  
Tomoya Hirota ◽  
Masato Tsuboi ◽  
Kenta Fujisawa ◽  
Mareki Honma ◽  
Noriyuki Kawaguchi ◽  
...  
Keyword(s):  
Radio Source ◽  
Chemical Properties ◽  
Stellar Object ◽  
Molecular Gas ◽  
Physical And Chemical Properties ◽  
Proper Motions ◽  
Young Stellar Object ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractIn 2011 February, a burst of the 22 GHz H2O maser in Orion KL was reported. In order to identify the bursting maser features, we have been carrying out observations of the 22 GHz H2O maser in Orion KL with VERA, a Japanese VLBI network dedicated for astrometry. The bursting maser turns out to consist of two spatially different features at 7.58 and 6.95 km s−1. We determine their absolute positions and find that they are coincident with the shocked molecular gas called the Orion Compact Ridge. We tentatively detect the absolute proper motions of the bursting features toward the southwest direction, perpendicular to the elongation of the maser features. It is most likely that the outflow from the radio source I or another young stellar object interacting with Compact Ridge is a possible origin of the H2O maser burst. We will also carry out observations with ALMA in the cycle 0 period to monitor the submillimeter H2O maser lines in the Orion Compact Ridge region. These follow-up observations will provide novel information on the physical and chemical properties of the mastering region.

scholarly journals Physical and Chemical Properties of Polycyclic Aromatic Hydrocarbons

1989 ◽  
Vol 135 ◽  
pp. 155-171
Author(s):  
S. Leach
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Interstellar Medium ◽  
Aromatic Hydrocarbons ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Polycyclic Aromatic ◽  
The Stability ◽  
Physical And Chemical ◽  
And Chemical Properties

A review is presented of some physical and chemical properties of polycyclic aromatic hydrocarbons (PAHs) that are relevant for interpreting various aspects of observations and speculations on PAHs in the interstellar medium. The subjects discussed are: the stability and reactivity of neutral and ionic PAHs; the spectroscopy and photophysics of neutral and monocationic PAHs; the photostabilities of PAH monocations and dications and their astrophysical implications.

Nanoparticles: Aspects of Safety and Risk Management

2010 ◽  
Vol 113-116 ◽  
pp. 222-225
Author(s):  
Jun Chen ◽  
Cheng Sun
Keyword(s):  
Risk Management ◽  
Human Health ◽  
Chemical Properties ◽  
Present Knowledge ◽  
Physical And Chemical Properties ◽  
Safety Standards ◽  
Fast Growing ◽  
Technical Basis ◽  
Physical And Chemical ◽  
And Chemical Properties

Nanotechnologies and nanoparticles represent a promising and fast-growing field. This is principally because a nanodimensional substance can have physical and chemical properties that are different from those of the same substance with larger dimensions. However, the present knowledge is not yet sufficient for the elaboration of nanospecific regulations. Many projects with the aim of completing the necessary scientific and technical basis for the assessment of nanotechnology related risks are under way. Under these circumstances closely relationship between the industries and government bodies is necessary to build up safety standards or regulations by all stakeholders constitute an appropriate tool for the protection of human health and the environment.

scholarly journals Chemical Properties of Interstellar Polycyclic Aromatic Molecules

1987 ◽  
Vol 120 ◽  
pp. 545-546 ◽  
Author(s):  
Alain Omont
Keyword(s):  
Interstellar Medium ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Substantial Evidence ◽  
Interstellar Molecules ◽  
Aromatic Molecules ◽  
Polycyclic Aromatic ◽  
Physical And Chemical ◽  
And Chemical Properties

There is substantial evidence of the presence of polycyclic aromatic molecules, mainly hydrocarbons (PAH's) in the interstellar medium (Léger and Puget, 1984, Allamandola et al. 1985, Léger and d'Hendecourt in these proceedings). They should contain typically NC = 20–100 carbon atoms, and they can contain perhaps 1–10% of the total interstellar carbon. I have recently discussed in detail their physical and chemical properties (Omont, 1986), which should be intermediate between that of conventional interstellar molecules and grains.

Studies on the Nature of the Action of Organic Accelerators for Rubber Vulcanization. VII. The Effect of Heat on the Surface Tension of Rubber Solutions

1935 ◽  
Vol 8 (1) ◽  
pp. 69-72
Author(s):  
Keiichi Shimada
Keyword(s):  
Surface Tension ◽  
Molecular Species ◽  
Present Author ◽  
Dynamic Equilibrium ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Dilute Solutions ◽  
Actual Concentration ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract In the previous paper on the effect of heat on the viscosity of rubber solutions (J. Rubber Soc., Japan,3, 413 (1931)), the present author suggested that the reduction in viscosity of dilute solutions of rubber on heating is probably a sign of depolymerization and not of physical disaggregation. In this report, the surface tension of rubber solutions has been investigated in an attempt to elucidate the effect of heat on rubber solutions and to draw some more definite conclusions. It should be possible, in the author's opinion, to detect depolymerization of rubber molecules by observing the surface tension variations of rubber solutions on heating, since the depolymerization of rubber would produce molecules differing widely in physical and chemical properties from the polymerized substance, and having most probably a different effect on the surface tension of the solution, whereas disaggregation of the dissolved substance in a solution is likely to produce no change in the surface tension, as aggregation implies merely coalescing particles to form larger groups, with no change in molecular species. it is possible that in solution a dynamic equilibrium exists between the particles and the aggregates, though the actual concentration of disaggregated material may be small. The results of the present work offer support to the theory that the effect of heat on dilute rubber solutions involves chemical depolymerization, that is, a breaking up of the long rubber molecules into shorter ones.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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