Results 121 to 130 of about 793,175 (240)

Are Stars Really Ingesting Their Planets? Examining an Alternative Explanation

The Astrophysical Journal
Numerous stars exhibit surprisingly large variations in their refractory element abundances, often interpreted as signatures of planetary ingestion events.
Nadine H. Soliman, Philip F. Hopkins
doaj   +1 more source

Isotope abundances in interstellar molecular clouds

The Astrophysical Journal, 1976
The J=1..-->..J=0 transition of carbon monoxide is used to study the abundance ratios of carbon and oxygen isotopes in dense molecular clouds. Very high-quality spectra were obtained of /sup 12/C/sup 16/O (CO), /sup 13/C/sup 16/C(/sup 13/CO), and /sup 12/C/sup 18/O(C/sup 18/O) in 14 regions distributed throughout the galactic plane.
P. G. Wannier, A. A. Penzias, R. A. Linke, R. W. Wilson   +3 more
openaire   +1 more source

Rocky Planetesimals as the Origin of Metals in DZ Stars

, 2010
{Abridged}. An analysis of the calcium and hydrogen abundances, Galactic positions and kinematics of 146 DZ stars from the Sloan Digital Sky Survey demonstrates that interaction with the interstellar medium cannot account for their externally polluted ...
Aannestad, Abazajian, Adelman-McCarthy, Alcock, Allègre, Bahcall, Bahcall, Baschek, Beers, Bergeron, Bondi, Charbonneau, Chen, Dame, Dehnen, Dufour, Dufour, Dupuis, Dupuis, Dupuis, Eddington, Edgar, Eisenstein, Farihi, Fontaine, Friedrich, Friedrich, Gianninas, Greenstein, Gänsicke, Hambly, J. Farihi, Jahreiß, Jura, Jura, Kamp, Kepler, Kilic, Koester, Koester, Koester, Koester, Koester, Kuijken, Lepine, Lockman, M. A. Barstow, Matese, McCook, Mihalas, Munn, Munn, N. C. Hambly, P. Dufour, Paquette, Pauli, Redfield, Redfield, S. Redfield, Schatzman, Silvestri, Sion, Sion, Sion, van Maanen, Venn, Voss, Welsh, Welsh, Wesemael, Wesemael, Wolff, Zuckerman, Zuckerman   +73 more
core   +1 more source

Laboratory Rotational Spectroscopy Leads to the First Interstellar Detection of Singly Deuterated Methyl Mercaptan (CH2DSH)

The Astrophysical Journal Letters
We report an extensive rotational spectroscopic analysis of singly deuterated methyl mercaptan (CH _2 DSH) using both millimeter and far-infrared synchrotron spectra to achieve a global torsional analysis of the three lowest torsional substates ( e _0 ...
Hayley A. Bunn, Silvia Spezzano, Laurent H. Coudert, Jean-Claude Guillemin, Yuxin Lin, Christian P. Endres, Brant Billinghurst, Olivier Pirali, Jes Jørgensen, Valerio Lattanzi, Paola Caselli   +10 more
doaj   +1 more source

New Observations of the Interstellar Medium in the Lyman Break Galaxy MS 1512-cB58

, 2001
We present the results of a detailed study of the interstellar medium of MS 1512-cB58, an L* Lyman break galaxy at z = 2.7276, based on new spectral observations obtained with the Echelle Spectrograph and Imager on the Keck II telescope at 58 km/s ...
Alice E. Shapley, Charles C. Steidel, Dufton P. L., Edmunds M. G., Kurt L. Adelberger, Mar D. P., Matthew P. Hunt, Max Pettini, Nakanishi K., Pagel B. E. J., Samantha A. Rix   +10 more
core   +1 more source

Dust extinction and absorption: the challenge of porous grains

, 2005
In many models of dusty objects in space the grains are assumed to be composite or fluffy. However, the computation of the optical properties of such particles is still a very difficult problem.
Dubkova, D. N., Henning, Th., Il'in, V. B., Voshchinnikov, N. V.   +3 more
core   +1 more source

Experimental Limit to Interstellar 244Pu Abundance

, 2001
10 p, 1 fig, LateX(AASTeX) Accepted for publication in ApJL, aug 2 ...
Paul, M., Valenta, A., Ahmad, I., Berkovits, D., Bordeanu, C., Ghelberg, S., Hashimoto, Y., Hershkowitz, A., Jiang, S., Nakanishi, T., Sakamoto, K.   +10 more
openaire   +2 more sources

Cosmic rays from supernova remnants and superbubbles

, 2018
Recent high energy gamma-ray observations of both single supernova remnants and superbubbles, together with observations of supernovae, star formation regions, and local cosmic ray composition, now provide an integrated framework tying together the ...
Lingenfelter, Richard E.
core   +1 more source

Element Nucleosynthetic Origins from Abundance Spatial Distributions beyond the Milky Way

The Astrophysical Journal Letters
An element’s astrophysical origin should be reflected in the spatial distribution of its abundance, yielding measurably different spatial distributions for elements with different nucleosynthetic sites.
Zefeng Li, Mark R. Krumholz, Anna F. McLeod, A. Mark Swinbank, Emily Wisnioski, J. Trevor Mendel, Francesco Belfiore, Giovanni Cresci, Giacomo Venturi, Jia-Lai Kang   +9 more
doaj   +1 more source

Potential Nitrogen Enrichment via Direct-collapse Wolf–Rayet Stars in a z = 4.7 Star-forming Galaxy

The Astrophysical Journal
We present analyses of a nitrogen-enriched star-forming galaxy, ID60001, at z = 4.6928 based on James Webb Space Telescope/NIRSpec Multi-Object Spectroscopy and NIRCam photometry. From rest-frame optical emission lines we derive the nitrogen-to-oxygen (N/
Yechi Zhang, Takahiro Morishita, Massimo Stiavelli   +2 more
doaj   +1 more source