Results 91 to 100 of about 547 (181)

Investigations of MWISP Filaments. I. Filament Identification and Analysis Algorithms, and Source Catalog

The Astrophysical Journal Supplement Series
Filaments play a crucial role in providing the necessary environmental conditions for star formation, actively participating in the process. To facilitate the identification and analysis of filaments, we introduce Directional and Positional Consistency ...
Yu Jiang, Xuepeng Chen, Sheng Zheng, Zhibo Jiang, Zhiwei Chen, Yao Huang, Yang Su, Li Sun, Jian-Cheng Feng, Haoran Feng, Ji Yang   +10 more
doaj   +1 more source

The Relation between Variances of 3D Density and Its 2D Column Density Revisited

The Astrophysical Journal
We revisit the relation between the variance of three-dimensional (3D) density ( ${\sigma }_{\rho }^{2}$ ) and that of the projected two-dimensional (2D) column density ( ${\sigma }_{{\rm{\Sigma }}}^{2}$ ) in turbulent media, which is of great importance
Heesun Yoon, Jungyeon Cho
doaj   +1 more source

Formaldehyde production in diffuse interstellar clouds [PDF]

Monthly Notices of the Royal Astronomical Society, 1979
Millar, TJ, Duley, W.W., Williams, D.A.
openaire   +1 more source

CO-dark Molecular Gas Traced by HCO+ in the Diffuse Interstellar Medium

The Astrophysical Journal
A classic problem in the study of the interstellar medium (ISM) is the near-invisibility of molecular hydrogen (H _2 ) in cold environments. Observations of CO emission are typically used to indirectly trace H _2 , but a significant fraction of H _2 in ...
Daniel R. Rybarczyk, Michael P. Busch, J. R. Dawson, Min-Young Lee, Gan Luo   +4 more
doaj   +1 more source

The abundance of interstellar C60 molecules toward BD+31°643 and other stars

Astronomy & Astrophysics
Context. The diffuse interstellar bands (DIBs) at 9577 and 9632 Å are attributed to electronic transitions of the C60+ fullerene ion; thus, its column density in molecular clouds may be inferred.
Rouillé Gaël, Gredel Roland
doaj   +1 more source

Morphological Evidence for the eROSITA Bubbles Being Giant and Distant Structures

The Astrophysical Journal Letters
There are two contradictory views of the eROSITA bubbles: either a 10 ^4 pc scale pair of giant bubbles blown by the Galactic center (GC), or a 10 ^2 pc scale local structure coincidentally located in the direction of GC.
Teng Liu, Andrea Merloni, Jeremy Sanders, Gabriele Ponti, Andrew Strong, Michael C. H. Yeung, Nicola Locatelli, Peter Predehl, Xueying Zheng, Manami Sasaki, Michael Freyberg, Konrad Dennerl, Werner Becker, Kirpal Nandra, Martin Mayer, Johannes Buchner   +15 more
doaj   +1 more source

The Densities in Diffuse and Translucent Molecular Clouds: Estimates from Observations of C2 and from Three-dimensional Extinction Maps

The Astrophysical Journal
Newly computed collisional rate coefficients for the excitation of C _2 in collisions with H _2 , presented recently by Najar & Kalugina, are significantly larger than the values adopted previously in models for the excitation of the C _2 molecule, a ...
David A. Neufeld, Daniel E. Welty, Alexei V. Ivlev, Paola Caselli, Gordian Edenhofer, Nick Indriolo, Marta Obolentseva, Kedron Silsbee, Paule Sonnentrucker, Mark G. Wolfire   +9 more
doaj   +1 more source

Rotational equilibrium of C₂ in diffuse interstellar clouds

Astronomy & Astrophysics
Context. Recent spectroscopic measurements have revealed absorption from higher rotational levels in C2 than previous observations. These improvements are accompanied by the availability of updated radiative and collisional data. Aims. We revisit the density and radiation field intensity diagnostics provided by the observations of many rotational ...
J. Le Bourlot, E. Roueff, S. R. Federman, A. M. Ritchey, D. L. Lambert   +4 more
openaire   +2 more sources

Inverse Raman Scattering and the Diffuse Interstellar Bands: An Exploration of the Systemic Interconnections between Spontaneous and Inverse Raman Scattering and Extended Red Emission, Red Rectangle Bands, and Diffuse Interstellar Bands

The Astrophysical Journal
First identified in 1964, inverse Raman scattering (IRS) is a nonlinear stimulated phenomenon that induces Raman-scattered absorptions where Raman emissions would be expected.
Frédéric Zagury
doaj   +1 more source

A Tale of Two Sightlines: Comparison of Hydrocarbon Dust Absorption Bands toward Cygnus OB2-12 and the Galactic Center

The Astrophysical Journal
Infrared spectra of hydrocarbon dust absorption bands toward the bright hypergiant Cygnus OB2-12 are compared to published spectra of the Quintuplet Cluster, a sightline to the Galactic center. The Cyg OB2-12 data include a new ground-based 2.86−3.70 μ m
Yvonne J. Pendleton, T. R. Geballe, Laurie E. U. Chu, Marjorie Decleir, Karl D. Gordon, A. G. G. M. Tielens, Louis J. Allamandola, Jeroen Bouwman, J. E. Chiar, Curtis Dewitt, Burcu Gunay, Thomas Henning, Vito Mennella, M. E. Palumbo, Alexey Potapov, Maisie Rashman, Sascha Zeegers   +16 more
doaj   +1 more source