Results 41 to 50 of about 36,750 (220)

Ne and Fe Abundances in the Interstellar Medium: Archival Study of Fe-L and Ne-K Edges in Chandra and XMM-Newton

The Astrophysical Journal
The abundance of elements in the interstellar medium is a key facet for many fields of astrophysical study. In the soft X-ray spectra, absorption by interstellar gas can result in deep absorption features that affect continuum measurements. In this paper,
D. L. Moutard, L. R. Corrales, I. Psaradaki, E. Temple, M. Shi   +4 more
doaj   +1 more source

Shaken or Stirred: The Diffuse Interstellar Medium with Exceptionally High SiO Abundance

The Astrophysical Journal, 2023
Interstellar shocks, a key element of stellar feedback processes, shape the structure of the interstellar medium (ISM) and are essential for the chemistry, thermodynamics, and kinematics of interstellar gas.
Daniel R. Rybarczyk, Snežana Stanimirović, Antoine Gusdorf   +2 more
doaj   +1 more source

Enlightening the Chemistry of Infalling Envelopes and Accretion Disks Around Sun-Like Protostars: The ALMA FAUST Project

Frontiers in Astronomy and Space Sciences, 2021
The huge variety of planetary systems discovered in recent decades likely depends on the early history of their formation. In this contribution, we introduce the FAUST Large Program which focuses specifically on the early history of solar-like protostars
C. Codella, C. Codella, C. Ceccarelli, C. Chandler, N. Sakai, S. Yamamoto, The FAUST Team   +6 more
doaj   +1 more source

INTERSTELLAR ABUNDANCES TOWARD X Per, REVISITED [PDF]

The Astrophysical Journal, 2013
The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of O, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ACIS-S and XMM-Newton's RGS instruments.
Lynne A. Valencic, Randall K. Smith
openaire   +1 more source

New Interstellar Dust Models Consistent with Extinction, Emission, and Abundance Constraints

, 2003
We present new interstellar dust models which have been derived by simultaneously fitting the far-ultraviolet to near-infrared extinction, the diffuse infrared (IR) emission and, unlike previous models, the elemental abundance constraints on the dust for
Backus G. E., Colangeli L., Desert F. X., Eli Dwek, Leger A., Lehtinen K., Li A., Lutz D., Mathis J. S., Morgan D. H., Narayan R., Ossenkopf V., Richard G. Arendt, Schutte W. A., Stognienko R., Viktor Zubko, Warren S. G., Zubko V. G., Zubko V. G., Zubko V. G.   +19 more
core   +2 more sources

Physical Structure of Small Wolf-Rayet Ring Nebulae [PDF]

, 1998
We have selected the seven most well-defined WR ring nebulae in the LMC (Br 2, Br 10, Br 13, Br 40a, Br 48, Br 52, and Br 100) to study their physical nature and evolutionary stages. New CCD imaging and echelle observations have been obtained for five of
Breysacher J., Chu Y.-H., Chu Y.-H., Conti P. S., Davies R. D., Donald R. Garnett, Esteban C., Garcia-Segura G., Garcia-Segura G., Haynes R. F., Henize K. G., Hutsemekers D., Kerstin Weis, Langer N., Rosado M., Shaver P. A., Smith L. J., Smith L. J., Solf J., van der Hucht K. A., Weis K., Weis K., You-Hua Chu   +22 more
core   +2 more sources

Charge State Influence on Stability and Isomerism in Dehydrogenated PAHs: Insights from Anthracene, Acridine, and Phenazine

ChemPhysChem, Volume 26, Issue 6, March 15, 2025.
The ionization of anthracene, acridine, and phenazine has been explored, along with the removal of one and two hydrogen atoms, to provide valuable information for astrochemists and to understand the behavior of the resulting structures and their electronic reorganization. Abstract In this study, we systematically explored the stability and isomerism of
Khaldia Zghida, Farouk Hamza Reguig, Manuel Alcamí, Al Mokhtar Lamsabhi   +3 more
wiley   +1 more source

Generalized Te([O iii])–Te(He i) Discrepancies in Ionized Nebulae: Possible Evidence of Case B Deviations and Temperature Inhomogeneities

The Astrophysical Journal
The physics of recombination lines in the He i singlet system is expected to be relatively simple, supported by accurate atomic models. We examine the intensities of He i singlets λ 3614,  λ 3965,  λ 5016,  λ 6678, and  λ 7281 and the triplet He i λ 5876
J. E. Méndez-Delgado, E. D. Skillman, E. Aver, C. Morisset, C. Esteban, J. García-Rojas, K. Kreckel, N. S. J. Rogers, F. F. Rosales-Ortega, K. Z. Arellano-Córdova, S. R. Flury, E. Reyes-Rodríguez, M. Orte-García, S. Tan   +13 more
doaj   +1 more source

Out There No One Has a Right to Die

Bioethics, EarlyView.
ABSTRACT The eventual goal of space exploration is to colonize exoplanets and their moons outside our solar system. This is a dangerous and immoral endeavour. The extraterrestrial life forms encountered would be hostile, vulnerable or both, and the descendants of the original pioneers would be involuntarily exposed to hazardous conditions and ...
Matti Häyry
wiley   +1 more source

Abundances in Diffuse Interstellar Clouds [PDF]

Highlights of Astronomy, 1980
Interstellar clouds are concentrations of cold (T ≲ 100 K) neutral gas (cf. Spitzer 1978) which are immersed within an intercloud medium. It is worthwhile to distinguish between diffuse clouds (roughly those with E[B-V] ≳ 0.5) and dark clouds (those with E[B-V] ≳ 0.5). This distinction is useful in the sense that diffuse clouds are relatively warm (T ∼
openaire   +1 more source