Results 21 to 30 of about 1,843 (251)

Cosmological Implications of the First Measurement of the Local ISM Abundance of $^3$He [PDF]

The Astrophysical Journal, 1996
Deuterium plays a crucial role in testing big-bang nucleosynthesis. Its chemical evolution, while simple (it is burned to $^3$He), is intertwined with the more complicated evolution of $^3$He. Gloeckler \& Geiss' new measurement of the $^3$He abundance and the HST measurement of D, both in the local ISM today, can be compared to the pre-solar ...
Turner, Michael S., Truran, James W., Schramm, David N., Copi, Craig J.   +3 more
openaire   +3 more sources

Precursors of fatty alcohols in the ISM: Discovery of [PDF]

, 2022
Context. Theories of the origins of life propose that early cell membranes were synthesised from amphiphilic molecules simpler than phospholipids, such as fatty alcohols.
Shaoshan Zeng, Lucas F. Rodríguez-Almeida, Eizi Hirota, Sergio Martín, Fernando Rico-Villas, Mattia Melosso, Yoshiyuki Kawashima, Cristina Puzzarini, Jesús Martín-Pintado, Belén Tercero, Víctor M. Rivilla, Pablo de Vicente, Miguel A. Requena-Torres, Izaskun Jiménez-Serra, Laura Colzi   +14 more
core   +1 more source

Studying the ISM at ∼10 pc scale in NGC 7793 with MUSE [PDF]

Astronomy & Astrophysics, 2021
Context. Feedback from massive stars affects the interstellar medium (ISM) from the immediate surroundings of the stars (parsec scales) to galactic (kiloparsec) scales. High-spatial resolution studies of H II regions are critical to investigate how this mechanism operates. Aims.
Lorenza Della Bruna, Angela Adamo, Janice C. Lee, Linda J. Smith, Mark Krumholz, Arjan Bik, Daniela Calzetti, Anne Fox, Michele Fumagalli, Kathryn Grasha, Matteo Messa, Göran Östlin, Rene Walterbos, Aida Wofford   +13 more
openaire   +5 more sources

Relative thermodynamic stability of the [C,N,O] linkages as an indication of the most abundant structures in the ISM [PDF]

Astronomy & Astrophysics, 2020
Context. Most of the compounds detected in the interstellar medium (ISM) that possess isomers correspond to the thermodynamically most stable isomer of a given chemical formula. Using the minimun energy principle (MEP) as a pragmatic tool is particularly efficient for less than six atoms, but for larger systems combinatorial analysis gives an ...
Fourré, I., Matz, O., Ellinger, Y., Guillemin, J.-C.   +3 more
openaire   +2 more sources

A Cosmic Abundance Standard: Chemical Homogeneity of the Solar Neighborhood and the ISM Dust-Phase Composition [PDF]

The Astrophysical Journal, 2008
A representative sample of unevolved early B-type stars in nearby OB associations and the field is analysed to unprecedented precision using NLTE techniques. The resulting chemical composition is found to be more metal-rich and much more homogeneous than indicated by previous work.
Przybilla, N., Nieva, M., Butler, K.
openaire   +3 more sources

Warm ISM in the Sgr A complex [PDF]

Astronomy & Astrophysics, 2021
Context. The Arches Cluster – Arched Filaments (AF) system is our Galaxy’s prime example of the complexity involved in the interaction between the strong radiation field of numerous OB stars and their surrounding ISM in extremely harsh environments such as the Galactic center (GC) of the Milky Way.
P. García, N. Abel, M. Röllig, R. Simon, J. Stutzki   +4 more
openaire   +2 more sources

Absorption-line Abundances in the SMC-like Galaxy UGC 5282: Evidence of ISM Dilution from Inflows on Kiloparsec Scales* [PDF]

The Astrophysical Journal, 2020
Abstract We present a Hubble Space Telescope Cosmic Origins Spectrograph spectrum of the QSO SDSS J095109.12+330745.8 ( ) whose sightline passes through the SMC-like dwarf galaxy UGC 5282 ( , cz = 1577 km s−1 ...
David V. Bowen, Todd M. Tripp, Edward B. Jenkins, Max Pettini, Doron Chelouche, Renyue Cen, Donald G. York   +6 more
openaire   +2 more sources

Galactic abundances: Report of working group 3 [PDF]

, 2001
We summarize the various methods and their limitations and strengths to derive galactic abundances from in-situ and remote-sensing measurements, both from ground-based observations and from instruments in space. Because galactic abundances evolve in time
Laming, M., Thielemann, F.-K., Bothmer, V., Klecker, B., Buclin, F., Kunow, H., Sofia, U. J., Wiedenbeck, M. E., Jones, F. C., Salerno, E., Keller, J. W., Stone, E. C., Wenzel, K.-P., B. Klecker, Flückiger, E. O., Kirilova, D., Tranquille, C., George, J. S., Christian, E. R., Hofer, M. Y., Cummings, A. C.   +20 more
core   +1 more source

Influence of galactic arm scale dynamics on the molecular composition of the cold and dense ISM – II. Molecular oxygen abundance [PDF]

Monthly Notices of the Royal Astronomical Society, 2019
ABSTRACT Molecular oxygen has been the subject of many observational searches as chemical models predicted it to be a reservoir of oxygen. Although it has been detected in two regions of the interstellar medium, its rarity is a challenge for astrochemical models.
I A Bonnell, P Gratier, M Ruaud, V Wakelam   +3 more
openaire   +3 more sources

Deuterium Abundance in the Local ISM and Possible Spatial Variations [PDF]

Space Science Reviews, 1998
Excellent HST/GHRS spectra of interstellar hydrogen and deuterium Lyman-α absorption toward nearby stars allow us to identify systematic errors that have plagued earlier work and to measure accurate values of the D/H ratio in local interstellar gas. Analysis of 12 sightlines through the Local Interstellar Cloud leads to a mean value of D/H = (1.50 ± 0 ...
openaire   +1 more source