Results 91 to 100 of about 63,242 (201)

Observation of interstellar lithium in the low-metallicity Small Magellanic Cloud

, 2012
The primordial abundances of light elements produced in the standard theory of Big Bang nucleosynthesis (BBN) depend only on the cosmic ratio of baryons to photons, a quantity inferred from observations of the microwave background.
AJ Korn, BD Fields, Brian D. Fields, D Romano, DC Knauth, DE Welty, DE Welty, DE Welty, DL Lambert, F Iocco, G Steigman, G Steigman, Grant J. Mathews, H Dekker, J Dunkley, J Meléndez, J. Christopher Howk, JC Weingartner, K Jedamzik, L Sbordone, M Asplund, M Pospelov, M Spite, N Prantzos, Nicolas Lehner, NLJ Cox, RH Cyburt, S Kawanomoto, SIB Cartledge, T Prodanović, TK Suzuki   +30 more
core   +1 more source

Sloan Digital Sky Survey IV MaStar: Quantification and Abatement of Interstellar Absorption in the Largest Empirical Stellar Spectral Library

The Astrophysical Journal
We assess the impact of Ca ii λ λ 3934, 3969 and Na i λ λ 5891, 5897 absorption arising in the interstellar medium (ISM) on the Sloan Digital Sky Survey-IV MaNGA Stellar Library (MaStar) and produce corrected spectroscopy for 80% of the 24,162-star ...
Kate H. R. Rubin, Kyle B. Westfall, Claudia Maraston, Daniel Thomas, Renbin Yan, J. Christopher Howk, Erick Aguirre, Kaelee S. Parker, David R. Law   +8 more
doaj   +1 more source

Interstellar 12C/13C from CH+ absorption lines: Results from an extended survey

, 2007
The 12C/13C isotope ratio in the interstellar medium (ISM), and its evolution with time, is an important tracer of stellar yields. Spatial variations of this ratio can be used to study mixing in the ISM.
Casassus, S., Stahl, O., Wilson, T. L.
core   +2 more sources

Analysis of the 3.2–3.3 μm Interstellar Absorption Feature on Three Milky Way Sightlines

The Astrophysical Journal
We report new analyses of spectra of the 3.2–3.3 μ m absorption feature observed in the diffuse interstellar medium toward three Milky Way sources: 2MASS J 17470898 − 2829561 (2M1747) and the Quintuplet Cluster, both located in the Galactic center, and ...
L. S. Bernstein, T. R. Geballe
doaj   +1 more source

The first results from the Herschel-HIFI mission

, 2012
This paper contains a summary of the results from the first years of observations with the HIFI instrument onboard ESA's Herschel space observatory. The paper starts by outlining the goals and possibilities of far-infrared and submillimeter astronomy ...
van der Tak, Floris
core   +2 more sources

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

A compressed cloud in the Vela supernova remnant [PDF]

To elucidate the nature of the interstellar medium in the vicinity of the Vela supernova remnants (SNR) an extensive study with the International Ultraviolet Explorer of interstellar absorption lines toward 35 stars in the vicinity of the Vela SNR was ...
Jenkins, E. B., Leep, E. M., Silk, J., Wallerstein, G.   +3 more
core   +1 more source

Analytic formulas for frequency and size dependence of absorption and scattering efficiencies of astronomical polycyclic aromatic hydrocarbons

, 2012
In a series of two recent papers, the frequency and size distribution dependence of extinction spectra for astronomical silicate and graphite grains was analyzed by us in the context of MRN type interstellar dust models.
Ashim K. Roy, Cardelli, Cecchi-Pestellini, Donn, Draine, Draine, Draine, Fitzpatrick, Klacka, Li, Li, Li, Mathis, Pendorf, Platt, Pritesh Ranadive, Ranjan Gupta, Roy, Roy, Subodh K. Sharma, Weingartner   +20 more
core   +1 more source

Interstellar grain mantles [PDF]

Interstellar molecular grain mantles are an important component of the interstellar dust inside dense molecular clouds as evidenced by the detection of absorption bands at 2.97, 3.08, 4.61, 6.0 and 6.8 microns.
Allamandola, Louis J., Bregman, J., Tielens, Alexander G. G. M., Witteborn, F. C.   +3 more
core   +1 more source

IUE absorption studies of broad- and narrow-line gas in Seyfert galaxies [PDF]

The interstellar medium of a galaxy containing an active nucleus may be profoundly affected by the high energy (X-ray, EUV) continuum flux emanating from the central source.
Begelman, M. C., Shull, J. M., Voit, G. M.   +2 more
core   +1 more source