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Caltech Chemical Engineer Explains Oxygen Mystery on Comets
Caltech Chemical Engineer Oxygen Mystery Comets
2017/7/20
A Caltech chemical engineer who normally develops new ways to fabricate microprocessors in computers has figured out how to explain a nagging mystery in space—why comets expel oxygen gas, the same gas...
Chemical trail on Titan may be key to prebiotic conditions
Chemical trail Titan prebiotic conditions
2016/7/15
NASA’s Cassini and Huygens missions have provided a wealth of data about chemical elements found on Saturn’s moon Titan, and Cornell scientists have uncovered a chemical trail that suggests prebiotic ...
Probing chemical evolution in molecular clouds with millimeter -wave observations
Cereal chemistry The interstellar medium Millimeter wavelength Molecular emission Dynamics Temperature observation The density of hydrogen molecules
2014/12/9
We present results for a study of gas-phase and grain chemical processes in the dense interstellar medium (ISM) using millimeter-wavelength observations of the pure rotational transitions of molecules...
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. IV. Two bulge populations
Gravitational lensing: micro—Galaxy: bulge —Galaxy: formation —Galaxy: evolution —Stars: abundances
2011/10/20
Based on high-resolution (R~42000 to 48000) and high signal-to-noise (S/N~50 to 150) spectra obtained with UVES/VLT, we present detailed elemental abundances (O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn...
The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes
galaxy: activity galaxy: formation galaxy: chemical evolution
2011/10/20
Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances,...
Detailed Chemical Abundances of Four Stars in the Unusual Globular Cluster, Palomar 1
Detailed Chemical Abundance Unusual Globular Cluster Palomar
2011/10/17
Detailed chemical abundances for twenty one elements are presented for four red giants in the anomalous outer halo globular cluster Palomar 1 ($R_{\rm{GC}} = 17.2$ kpc, $Z=3.6$ kpc) using high-resolut...
Chemical properties in the most distant radio galaxy
galaxies: active – galaxies: nuclei – quasars: emission lines – quasars: general
2011/10/21
We present a deep optical spectrum of TN J0924-2201, the most distant radio galaxy at z = 5.19, obtained with FOCAS on the Subaru Telescope. We successfully detect, for the first time, the CIV1549 emi...
Chemical evolution of a protoplanetary disk
accretion disks astrochemistry diff usion line:formation molecular processes
2011/10/13
In this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition o...
A Chemical Abundance Study of 10 Open Clusters Based on WIYN-Hydra Spectroscopy
Chemical Abundance Study Clusters Based WIYN-Hydra Spectroscopy
2011/10/12
We present a detailed chemical abundance study of evolved stars in 10 open clusters based on Hydra multi-object echelle spectra obtained with the WIYN 3.5m telescope. From an analysis of both equivale...
Excitation of the aromatic infrared emission bands: Chemical energy in hydrogenated amorphous carbon particles?
Excitation aromatic infrared emission bands: Chemical energy
2011/10/11
We outline a model for the heating of hydrogenated amorphous (HAC) dust via the release of stored chemical energy and show that this energy (~12 kJ/mole) is sufficient to heat dust grains of classical...
The Peculiar Chemical Inventory of NGC 2419 -- An Extreme Outer Halo "Globular Cluster"
Peculiar Chemical Inventory Extreme Outer
2011/10/8
NGC 2419 is a massive outer halo Galactic globular cluster whose stars have previously been shown to have somewhat peculiar abundance patterns. We have observed seven luminous giants that are members ...
Chemical abundance analysis of the Open Clusters Berkeley 32, NGC 752, Hyades and Praesepe
Stars: abundances – Galaxy: disc – Galaxy: open clusters and associations: individual: NGC 752 Hyades Berkeley 32 Preasepe (M 44)
2011/10/8
Context. Open clusters are ideal test particles to study the chemical evolution of the Galactic disc. However the existing high-resolution abundance determinations, not only of [Fe/H], but also of oth...
Chemical history of molecules in circumstellar disks
astrochemistry – stars: formation – circumstellar matter – planetary systems: pro- toplanetary disks – molecular processes
2011/10/8
The chemical composition of a protoplanetary disk is determined not only by in situ chemical processes during the disk phase, but also by the history of the gas and dust before it accreted from the na...
Chemical abundances in the protoplanetary disk LV2 (Orion) - II: High dispersion VLT observations and microjet properties
ISM – abundances HII regions ISM:stars: pre-main-sequence protostars protoplan- etary disks
2011/9/29
Integral field spectroscopy of the LV2 proplyd is presented taken with the VLT/FLAMES Argus array at an angular resolution of 0.31x0.31 arcsec^2 and velocity resolutions down to 2 km/s per pixel. Foll...
The impact of chemical differentiation of white dwarfs on thermonuclear supernovae
chemical differentiation thermonuclear supernovae
2011/1/10
Gravitational settling of 22Ne in cooling white dwarfs can affect the outcome of thermonuclear supernovae. We investigate how the supernova energetics and nucleosynthesis are in turn influenced by thi...