Results 31 to 40 of about 476,181 (204)
Detection of diffuse interstellar bands in the Magellanic Clouds
The Astrophysical Journal, 2002 With the Ultraviolet Visual Echelle Spectrograph mounted at the Very Large Telescope, we have observed at unprecedented spectral resolution the absorption spectrum toward reddened stars in the Magellanic Clouds over the wavelength range of 3500-10500 Angstrom.
Ehrenfreund, P +5 more
core +3 more sources
Interstellar processes: Ortho/para conversion, radiative association, and dissociative recombination
EPJ Web of Conferences, 2015 The study of the ortho-to-para ratio of assorted gas-phase interstellar molecules such as H2, H2O, NH3, and H2O+ has gained interest in recent years, based partially on new spectral observations of light hydrides by the Herschel Space Observatory ...
Herbst Eric
doaj +1 more source
Far-ultraviolet Dust Extinction and Molecular Hydrogen in the Diffuse Milky Way Interstellar Medium
The Astrophysical Journal, 2023 We aim to compare variations in the full-UV dust extinction curve (912–3000 Å), with the H i /H _2 /total H content along diffuse Milky Way sightlines, to investigate possible connections between ISM conditions and dust properties. We combine an existing
Dries Van De Putte +4 more
doaj +1 more source
C2absorption-line diagnostics of diffuse interstellar clouds [PDF]
, 2017 The excitation of the diatomic carbon molecule in diffuse interstellar clouds is discussed for a cloud with large density fluctuations of small linear filling factor along the line of sight. Possible implications for the chemistry of the diffuse cloud in
Dalgarno, Alexander +1 more
core +1 more source
EXCITATION OF C2IN DIFFUSE INTERSTELLAR CLOUDS
The Astrophysical Journal, 2012 We investigate the effects and the implications of incorporating new collision and radiative rates in modeling the excitation of diatomic carbon molecule. The present results suggest that diffuse and translucent interstellar clouds may present a structure in which regions with different densities and kinetic temperatures overlap along the line of sight,
S. Casu, Cesare Cecchi-Pestellini
openaire +2 more sources
The formation of molecules in diffuse interstellar clouds
The Astrophysical Journal, 1977 A chemical system involving carbon and hydrogen is used to obtain steady-state abundances of a number of molecules over a wide range of densities. The calculated CH abundance agrees well with the astronomical observations. For reasonable values of the rate coefficients, the present system of reactions cannot explain, simultaneously, the measured ...
G. F. Mitchell +2 more
openaire +1 more source
Electronic spectroscopy of cold ions in a radio-frequency trap [PDF]
, 2010 The low density of ions in mass spectrometers generally precludes direct absorption measurements. The spectrum of ions can nonetheless be obtained by using resonance two-color photofragmentation or multiphoton photofragmentation techniques.
Rudnev, Vitaly S.
core +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 +2 more
doaj +1 more source
On the detection of rubidium in diffuse interstellar clouds
The Astrophysical Journal, 1985 A search for absorption from neutral rubidium at 7800 A was conducted. No evidence for absorption to a 3 sigma limit of less than 1.5 mA was seen in the diffuse interstellar gas toward the stars omicron Persei, zeta Persei, and zeta Ophiuchi. Present results do not confirm the detection by Jura and Smith (1981) toward zeta Oph.
S. R. Federman +3 more
openaire +1 more source
A search for interstellar H2O(+) in diffuse clouds
The Astrophysical Journal, 1984 Searches for H2O(+) toward HD 187982, Zeta Oph, O micron Per, and Zeta Per have yielded significant upper limits for H2O(+) when compared with existing models for similar lines of sight. Using available oscillator strength data, the column density for HD 187982, for example, cannot exceed 3 x 10 to the 12th per sq cm H2O(+) molecules.
Wm. H. Smith +2 more
openaire +1 more source