Results 91 to 100 of about 793,175 (240)
Detection of Deuterated Hydrocarbon Nanoparticles in the Whirlpool Galaxy, M51
Deuteration of hydrocarbon material, including polycyclic aromatic hydrocarbons (PAHs), has been proposed to account for the low gas-phase abundances of D in the interstellar medium (ISM). JWST spectra of four star-forming regions in M51 show an emission
B. T. Draine +31 more
doaj +1 more source
Chemistry in Dense Molecular Clouds: Theory and Observational Constraints [PDF]
For the most part, gas phase models of the chemistry of dense molecular clouds predict the abundances of simple species rather well. However, for larger molecules and even for small systems rich in carbon these models often fail spectacularly.
Blake, Geoffrey A.
core
Detections of interstellar aromatic nitriles 2-cyanopyrene and 4-cyanopyrene in TMC-1
Polycyclic aromatic hydrocarbons (PAHs) are among the most widespread compounds in the universe, accounting for up to ~25% of all interstellar carbon. Since most unsubstituted PAHs do not possess permanent electric dipole moments, they are invisible to ...
Gabi Wenzel +21 more
semanticscholar +1 more source
Photoelectron Spectroscopy of the Phosphorus Monosulfide (PS) and Phosphorus Monoxide (PO) Radicals
Sketch of the experiment to measure the photo electron spectrum of the PS radical produced in situ with a mixture of PH3, H2S and F atoms. PO and PS radicals are the smallest units of phosphorus oxides and phosphorus sulfides, respectively, two rich families of refractory compounds widely employed in industrial and technological applications. These two
Pedro Recio +10 more
wiley +1 more source
The Definitive Abundance of Interstellar Oxygen
Using the Goddard High Resolution Spectrograph (GHRS) onboard HST, we have obtained high S/N echelle observations of the weak interstellar O I 1356 A absorption toward the stars Gamma Cas, Epsilon Per, Delta Ori, Epsilon Ori, 15 Mon, Tau CMa, and Gamma Ara. In combination with previous GHRS measurements in six other sightlines (Zeta Per, Xi Per, Lambda
Meyer, David M. +2 more
openaire +2 more sources
On the chemistry of hydrides of N atoms and O$^+$ ions [PDF]
Previous work by various authors has suggested that the detection by Herschel/HIFI of nitrogen hydrides along the low density lines of sight towards G10.6-0.4 (W31C) cannot be accounted for by gas-phase chemical models.
Awad, Zainab +2 more
core +2 more sources
Experimental infrared absorption spectra of three protonated cyano‐substituted PAHs measured by infrared multiple photon dissociation using the free‐electron laser Free‐Electron Laser for Infrared eXperiments are studied. These spectra are compared to an emission spectrum measured by JWST, and the largest measured protonated cyano‐PAH, cyanoanthracene,
Anne P. Rasmussen +6 more
wiley +1 more source
The Barium Star HD204075: Iron Abundance and the Absence of Evidence for Accretion
Spectroscopic observations of barium star ζ Capricornus (HD204075) obtained at the 8.2 m telescope of the European Southern Observatory, with a spectral resolving power R = 80,000 and signal to noise ratio greater than 300, were used to refine the ...
Yeuncheol Jeong +2 more
doaj +1 more source
Isotopic abundances in interstellar carbon monosulfide
A survey of the relative abundances of the isotopic species, /sup 12/C/sup 32/S, /sup 12/C/sup 34/S, and /sup 13/C/sup 32/S has been made in 14 dense molecular clouds through observations of the J=3-1 rotational transitions at 3 mm. The abundance ratio, (/sup 13/C/sup 32/S)/(/sup 12/C/sup 34/S), is found to be 1.9 times greater in the galactic center ...
R. W. Wilson +3 more
openaire +1 more source
Satellites and Small Bodies With ALMA: Insights Into Solar System Formation and Evolution
Abstract Our understanding of the formation and evolution of planetary systems has made major advances in the past decade. This progress has been driven in large part by the Atacama Large Millimeter/submillimeter Array (ALMA), which has given us an unprecedented view of solar system bodies themselves, and of the structure and chemistry of forming ...
Katherine de Kleer +3 more
wiley +1 more source

