Results 51 to 60 of about 25,001 (219)

Unresolved velocity structure in diffuse interstellar clouds

The Astrophysical Journal, 1988
Recent high-resolution observations of interstellar absorption lines of CH and CN toward Zeta Oph obtained by Crane et al. (1986), and Palazzi et al. (1988), exhibit line widths that suggest thermal line broadening at high temperature, T about 1200 K.
Black, J.H., Dishoeck, E.F. van
openaire   +3 more sources

Enhanced cosmic-ray flux toward zeta Persei inferred from laboratory study of H3+ - e- recombination rate

, 2003
The H3+ molecular ion plays a fundamental role in interstellar chemistry, as it initiates a network of chemical reactions that produce many interstellar molecules. In dense clouds, the H3+ abundance is understood using a simple chemical model, from which
A. Al-Khalili, A. Ehlerding, A. J. Huneycutt, A. Neau, AE Orel, B. J. McCall, BD Savage, BJ McCall, BJ McCall, BJ McCall, CM Lindsay, D Strasser, E Herbst, EF van Dishoeck, F. Hellberg, F. Österdahl, G Sundström, G. H. Dunn, H Kreckel, IF Schneider, J. Semaniak, JA Cardelli, JB Paul, M Larsson, M. Larsson, MJ Jensen, N. Djuric, O. Novotny, R Plasil, R. J. Saykally, R. Thomas, RC Bohlin, S Lepp, S. Kalhori, SL Guberman, T Tanabe, T. R. Geballe, TR Geballe, TR Geballe, V Kokoouline, WD Watson   +40 more
core   +1 more source

Cosmic ray penetration in diffuse clouds [PDF]

, 2015
Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution.
Gabici, S., Morlino, G.
core   +4 more sources

NaH and LiH in diffuse interstellar clouds

The Astrophysical Journal, 1978
It has been suggested that NaH may be detectable in diffuse interstellar clouds. We discuss the photodissociation process of NaH and calculate the rate of destruction by the interstellar radiation field. In the unshielded field, the mean lifetime is about 10 years. There appears to be no efficient gas-phase mechanism for the production of NaH. If it is
K. Kirby, A. Dalgarno
openaire   +1 more source

Detection of C₃in Diffuse Interstellar Clouds [PDF]

The Astrophysical Journal, 2001
The smallest polyatomic carbon chain, C$_{3}$, has been identified in interstellar clouds (A$_{v}\sim$1 mag) towards $ $ Ophiuchi, 20 Aquilae, and $ $ Persei by detection of the origin band in its $A^{1} _{u}-X^{1} ^{+}_{g}$ electronic transition, near 4052 .
Maier, J. P., Lakin, N. M., Walker, G. A. H., Bohlender, D. A.   +3 more
openaire   +2 more sources

Deciphering the “Missing Xenon Paradox” in Celestial Bodies: A Multifaceted Perspective Toward Demystifying This Enigma

Journal of Geophysical Research: Planets, Volume 131, Issue 4, April 2026.
Abstract Xenon (Xe) is a heavy noble gas with intriguing chemical properties, such as having several stable isotopes and the ability to form compounds under extreme conditions. Despite the predictions based on cosmochemical models that suggest xenon should be relatively abundant in planetary reservoirs, empirical data indicate a significant depletion ...
Avinash Kumar Both, Avradip Ghosh, Chin Li Cheung   +2 more
wiley   +1 more source

The H2 Glow of a Quiescent Molecular Cloud Observed with JWST

The Astrophysical Journal Letters
We report JWST MIRI/MRS observations of the H _2 S (1) 17.04 μ m transition in two regions in the boundary of the Taurus molecular cloud. The two regions, denoted “Edge” (near the relatively sharp boundary of the ^13 CO J  = 1 → 0 emission) and “Peak ...
Paul F. Goldsmith, Shengzhe Wang, Xin Wang, Raphael Skalidis, Gary A. Fuller, Di Li, Chao-Wei Tsai, Lile Wang, Donghui Quan   +8 more
doaj   +1 more source

The CS molecule in diffuse interstellar clouds

The Astrophysical Journal, 1989
The CS J = 2-1 emission line at 98 GHz has been searched for in 10 diffuse molecular clouds. CS column densities are derived by performing statistical equilibrium calculations for the rotational population distribution which includes collisional excitation by electrons as well as by neutral species.
Drdla, K., Knapp, G.R., Dishoeck, E.F. van   +2 more
openaire   +3 more sources

Evidence for Spatially Distinct Galactic Dust Populations

The Astrophysical Journal
We present an implementation of a Bayesian mixture model using Hamiltonian Monte Carlo techniques to search for the spatial separation of Galactic dust populations. Utilizing intensity measurements from the Planck High Frequency Instrument, we apply this
Corwin Shiu, Steven J. Benton, Jeffrey P. Filippini, Aurélien A. Fraisse, William C. Jones, Johanna M. Nagy, Ivan L. Padilla, Juan D. Soler   +7 more
doaj   +1 more source

Absorption-line Observations of and CO in Sight Lines Toward the Vela and W28 Supernova Remnants

The Astrophysical Journal, 2023
Supernova remnants act as particle accelerators, providing the cosmic-ray protons that permeate the interstellar medium and initiate the ion–molecule reactions that drive interstellar chemistry. Enhanced fluxes of cosmic-ray protons in close proximity to
Nick Indriolo
doaj   +1 more source