Results 21 to 30 of about 49,075 (253)

The C60:C60+ ratio in diffuse and translucent interstellar clouds [PDF]

Astronomy & Astrophysics, 2021
Context. Insight into the conditions that drive the physics and chemistry in interstellar clouds is gained from determining the abundance and charge state of their components. Aims.
G. Rouill'e, S. Krasnokutski, Yvain Carpentier Max Planck Institute for Astronomy, Friedrich-Schillor-Universitat Jena, University of Lille   +4 more
semanticscholar   +1 more source

Interstellar hydrocarbons: degradation chemistry in diffuse clouds [PDF]

Monthly Notices of the Royal Astronomical Society, 2022
ABSTRACT Observations of diffuse clouds showed that they contain a number of simple hydrocarbons [e.g. CH, C2H, (l- and c-)C3H2, and C4H] in abundances that may be difficult to understand on the basis of conventional gas-phase chemical models.
Zainab Awad, Serena Viti
openaire   +4 more sources

Mid-infrared Spectroscopy of Protonated Benzonitrile, 2-Cyanonaphthalene, and 9-Cyanoanthracene for Astrochemical Consideration. [PDF]

Chemphyschem
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,
Rasmussen AP, Rossi C, Gans B, Finazzi L, Oomens J, Berden G, Jacovella U.   +6 more
europepmc   +2 more sources

Dissociative Recombination of Rotationally Cold OH+ and Its Implications for the Cosmic Ray Ionization Rate in Diffuse Clouds

The Astrophysical Journal Letters, 2023
Observations of OH ^+ are used to infer the interstellar cosmic ray ionization rate in diffuse atomic clouds, thereby constraining the propagation of cosmic rays through and the shielding by interstellar clouds, as well as the low energy cosmic ray ...
Ábel Kálosi, Lisa Gamer, Manfred Grieser, Robert von Hahn, Leonard W. Isberner, Julia I. Jäger, Holger Kreckel, David A. Neufeld, Daniel Paul, Daniel W. Savin, Stefan Schippers, Viviane C. Schmidt, Andreas Wolf, Mark G. Wolfire, Oldřich Novotný   +14 more
doaj   +1 more source

Diffuse Interstellar Clouds [PDF]

Highlights of Astronomy, 1992
AbstractDiffuse clouds are interstellar objects through which starlight is not greatly extinguished. As a result, many studies rely on ultraviolet and visible measurements. The focus of this review is on spectroscopic work involving atomic and molecular lines. From these measurements, the physical and chemical makeup of the clouds is derived.
David L. Lambert, S. R. Federman
openaire   +1 more source

The contribution of unresolved sources on the gamma-ray spectrum of molecular clouds [PDF]

EPJ Web of Conferences, 2023
Fermi-LAT observations of the large-scale diffuse gamma-ray emission unveiled that in some locations, towards the inner Galaxy, the spectrum of this component is harder than the local one, measured at the Earth position. If this signal is associated with
Vecchiotti Vittoria, Peron Giada, Pagliaroli Giulia, Villante Francesco Lorenzo   +3 more
doaj   +1 more source

Atomistic Modeling of Methyl Formate and Glycolaldehyde Formation on Interstellar Dirty Ice Mantles via a "Radical + Ice" Mechanism. [PDF]

Chempluschem
The presence of interstellar complex organic molecules (COMs) has been baffling astrochemists for a long time. Methyl formate and glycolaldehyde are widely detected but their abundances mismatch kinetic astrochemical model predictions. Here, the formation of these two COMs is characterized onto a mixed ice surface, highlighting the importance of ...
Perrero J, Pantaleone S, Ugliengo P, Rimola A.   +3 more
europepmc   +2 more sources

Compact Dusty Clouds and Efficient H2 Formation in Diffuse Interstellar Medium [PDF]

Astrophysical Journal, 2018
The formation of compact dusty clouds in diffuse interstellar medium (ISM) has been recently proposed and studied by Tsytovich et al. In the present paper, the effect of the clouds on the rate of H → H2 transition in the ISM is examined.
A. Ivlev, A. Burkert, A. Vasyunin, Paola Caselli   +3 more
semanticscholar   +1 more source

Diffuse interstellar band formation in dense clouds [PDF]

Astrophysics and Space Science, 1974
Measurements of the strengths of the diffuse interstellar bands at 4430, 5780 and 5797 A show that the bands tend to be weak with respect to extinction in dense interstellar clouds. Data on 10 stars in the Q Ophiuchi cloud complex show further that the diffuse band-producing efficiency of the grains decreases systematically with increasing grain size ...
Snow, Theodore P., Jr., Cohen, Judith G.
openaire   +5 more sources

Cyanogen excitation in diffuse interstellar clouds

The Astrophysical Journal, 1995
Katherine C. Roth, David M. Meyer
openaire   +2 more sources