Results 121 to 130 of about 25,001 (219)

The Molecular Cloud Life Cycle. II. Formation and Destruction of Molecular Clouds Diagnosed via H2 Fluorescent Emission

The Astrophysical Journal
Molecular hydrogen (H _2 ) formation and dissociation are key processes that drive the gas life cycle in galaxies. Using the SImulating the LifeCycle of Molecular Clouds zoom-in simulation suite, we explore the utility of future observations of H _2 ...
Blakesley Burkhart, Shmuel Bialy, Daniel Seifried, Stefanie Walch, Erika Hamden, Thomas J. Haworth, Keri Hoadley, Shuo Kong, Madisen Johnson, Sarah Jeffreson, Mark R. Krumholz, Min-Young Lee, Amiel Sternberg, Neal J. Turner   +13 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

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

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

Interstellar organics and possible connections with the carbonaceous components of meteorites and IDPs [PDF]

Studying the chemical and isotopic composition of interstellar ice and dust provides insight into the composition and chemical history of the solid bodies in the solar nebula and the nature of the materials subsequently brought into the inner part of the
Allamandola, L. J.
core   +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

Grain mantles: The impact on grain evolution and selective extinction [PDF]

Depletion studies are used to infer the presence of mantles and to constrain grain evolutionary models in the diffuse interstellar medium. The presence of these mantles appears to be important in the evolution of the grains inside diffuse as well as ...
Joseph, Charles L.
core   +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

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