Chemical galaxy

As mentioned, a number of different forms of tables, charts, and diagrams for the arrangements of the chemical elements have been proposed and designed. One of the newest and unique designs is the Chemical Galaxy version of the periodic table devised by Philip Stewart. Copies of this unique periodic table are available at the Chemical Galaxy Web site (http // www.chemicalgalaxy.co.uk/). 

Figure 3.6 Though he arranged the elements in a chart, Mendeleyev believed that a three-dimensional helix would be the most effective way to display them. This image of a chemical galaxy attempts to simulate Mendeleyev s idea in two dimensions.

Aris Chemicals, Galaxy Corp., Matherson, Urbane Industries and Wolkem India. 

The composition of the Earth was determined both by the chemical composition of the solar nebula, from which the sun and planets formed, and by the nature of the physical processes that concentrated materials to form planets. The bulk elemental and isotopic composition of the nebula is believed, or usually assumed to be identical to that of the sun. The few exceptions to this include elements and isotopes such as lithium and deuterium that are destroyed in the bulk of the sun s interior by nuclear reactions. The composition of the sun as determined by optical spectroscopy is similar to the majority of stars in our galaxy, and accordingly the relative abundances of the elements in the sun are referred to as "cosmic abundances." Although the cosmic abundance pattern is commonly seen in other stars there are dramatic exceptions, such as stars composed of iron or solid nuclear matter, as in the case with neutron stars. The... 

A drop of water contains an unimaginable number of molecules, as our molecular inset shows. Water is essential to life as we know it. The simple yet unusual fact that solid water (ice) floats atop liquid water allows life to exist on our planet. Just as important is the fact that water dissolves an immense range of chemical compounds Water is the solvent of life. In fact, water is so important to our perspective of life that the search for water is a key feature of our quest to discover life in other quarters of the galaxy. The inset photo of the surface of Mars, for example, shows no sign of water at present, but some erosional features appear to have been caused by flowing water in the past. 

Chemical Abundances and Mixing in Red Clump Stars of the Galaxy... 

The studies of other elements in metal-rich planet-host stars is also giving important information about the chemical evolution of the Galaxy. 

Planetary nebulae (PNe) offer the opportunities 1) to study stellar nucleosynthesis in the advanced phases of stellar evolution of stars in the wide mass range - -O. S to Mq and 2) to probe radial and as well horizontal/vertical chemical gradients in spiral galaxies by the time of formation of their progenitors. 

As a consequence chemical abundances in PNe are of primary importance for the chemical evolution of spiral galaxies, including our own and related topics. 

Recent observations of the HF (1-0) R9 line at 2.3 /tm with the Phoenix spectrograph on the Gemini-South telescope has opened a new window that sheds light on understanding the chemical evolution of fluorine and the nuclear processes that produce this element. Until recently, only a small number of observations of fluorine were available and the trend of fluorine abundances with metallicity had yet to be probed in the Galaxy. 

Abstract. We have investigated the abundance of several chemical elements in two large stellar samples kinematically representative of the thin and the thick disks of the Galaxy. Chemical, kinematical and age data have been collected from high quality sources in the literature. Velocities (U,V,W) have been computed and used to select stars with the highest probability to belong to the thin disk and the thick disk respectively. Our results show that the two disks are chemically well separated. Both exhibit a decline of [a/Fe] with increasing [Fe/H]. A transition between the thin/thick disks stars is observed at 10 Gyr... 

Abstract. In an effort to determine accurate stellar parameters and abundances for a large sample of nearby stars, we have performed the detailed analysis of 350 high-resolution spectra of FGK dwarfs and giants. This sample will be used to investigate behavior of chemical elements and kinematics in the thick and thin disks, in order to better constrain models of chemical and dynamical evolution of the Galaxy. 

The abundance patterns of individual stars of different ages and environments enable us to unlock the evolutionary history of galaxies. Many physical characteristics of a galaxy may change over time, such as shape and colour, however the metal content and abundance ratios of stellar atmospheres are not so easy to tamper with. Stars retain the chemical imprint of the interstellar gas out of which they formed, and metals can only increase with time. This method to study galaxy evolution has been elegantly named Chemical Tagging [2],... 

The analysis of bright nebular emission lines of Hu regions has been the most frequent approach to modeling chemical evolution of more distant galaxies to... 

The most metal-rich stars in dwarf spheroidals (dSph) have been shown to have significantly lower even-Z abundance ratios than stars of similar metallicity in the Milky Way (MW). In addition, the most metal-rich dSph stars are dominated by an s-process abundance pattern in comparison to stars of similar metallicity in the MW. This has been interpreted as excessive contamination by Type la super-novae (SN) and asymptotic giant branch (AGB) stars ( Bonifacio et al. 2000, Shetrone et al. 2001, Smecker-Hane McWilliam 2002). By comparing these results to MW chemical evolution, Lanfranchi Matteucci (2003) conclude that the dSph galaxies have had a slower star formation rate than the MW (Lanfranchi Matteucci 2003). This slow star formation, when combined with an efficient galactic wind, allows the contribution of Type la SN and AGB stars to be incorporated into the ISM before the Type II SN can bring the metallicity up to MW thick disk metallicities. 

Recent abundance ratio work in this field falls into two categories. The first category has been investigations into aspects of metal-poor AGB and Type la SN yields and their relationship to the chemical evolution in the dSph galaxies, e.g. McWilliam et al. (2003), Venn et al. (2004), McWilliam Smecker-Hane (2005). In these works the abundances of specific elements are compared to... 

Monaco L., 2004 in Chemical Abundances and Mixing in Stars in the Milky Way Galaxy and its Satellites, L. Pasquini S. Randich eds., Springer-Verlag, Berlin, P-... 

The Composition of the Sagittarius Dwarf Spheroidal Galaxy and Implications for Nucleosynthesis and Chemical Evolution... 

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