Results 101 to 110 of about 2,145,468 (291)

Considerations Regarding Cometary and Interstellar Molecules. [PDF]

The Astrophysical Journal, 1942
The visual continua in the spectra of three nebulae photographed with a narrow slit are not produced by the blending of atomic emission lines but must have a physical origin. Several strong He I emission lines just beyond the Balmer limit may tend to vitiate measurements of the intensity distribution in the Balmer continuum on plates taken with a wide ...
openaire   +2 more sources

Molecules in galaxies

, 2007
The main achievements, current developments and prospects of molecular studies in external galaxies are reviewed. They are put in the context of the results of several decades of studies of molecules in local interstellar medium, their chemistry and ...
Omont, Alain
core   +2 more sources

Determining the Methanol Deuteration in the Disk Around V883 Orionis with Laboratory Measured Spectroscopy

The Astronomical Journal
Deuterium fractionation, as studied through mono-deuterated methanol, is frequently used as a diagnostic tool to trace the physical conditions and chemical evolution of interstellar sources. This study investigates methanol deuteration in the disk around
Shaoshan Zeng, Jae-Hong Jeong, Takahiro Oyama, Jeong-Eun Lee, Yao-Lun Yang, Nami Sakai   +5 more
doaj   +1 more source

Quantum mechanical modeling of interstellar molecules on cosmic dusts: H₂O, NH₃, and CO₂. [PDF]

Front Chem, 2022
Li F, Quan D, Zhang X, Li X, Esimbek J.
europepmc   +1 more source

Interstellar grain chemistry and organic molecules [PDF]

The detection of prominant infrared absorption bands at 3250, 2170, 2138, 1670 and 1470 cm(-1) (3.08, 4.61, 4.677, 5.99 and 6.80 micron m) associated with molecular clouds show that mixed molecular (icy) grain mantles are an important component of the ...
Allamandola, L. J., Sandford, S. A.
core   +1 more source

The formation of H_2 and HD with the master equation approach

, 2005
The formation of H2 and HD molecules on interstellar dust grains is studied using rate equation and master equation models. Rate equations are used in the analysis of laboratory experiments which examine the formation of molecular hydrogen on ...
Biham, Ofer, Lipshtat, Azi, Perets, Hagai B.   +2 more
core   +1 more source

ALMA Reveals Diverse Dust-to-gas Mass Ratios and Quenching Modes in Old Quiescent Galaxies

The Astrophysical Journal Letters
Recent discoveries of dust and molecular gas in quiescent galaxies (QGs) up to z ∼ 4 challenge the long-standing view that the interstellar medium depletes rapidly once star formation ceases, raising key questions of whether dust and gas coevolve in QGs,
G. Lorenzon, D. Donevski, A. W. S. Man, M. Romano, K. E. Whitaker, S. Belli, D. Liu, M. M. Lee, D. Narayanan, A. Long, I. Shivaei, A. Nanni, K. Lisiecki, P. Sawant, G. Rodighiero, I. Damjanov, Junais, R. Davé, C. Pappalardo, C. Lovell, M. Hamed   +20 more
doaj   +1 more source

Studies of interstellar vibrationally-excited molecules [PDF]

Several molecules thus far have been detected in the ISM in vibrationally-excited states, including H2, SiO, HC3N, and CH3CN. In order for vibrational-excitation to occur, these species must be present in unusually hot and dense gas and/or where strong ...
Erickson, N. R., Snell, R. L., Ziurys, L. M.   +2 more
core   +1 more source

Origin of Interstellar Molecules [PDF]

Progress of Theoretical Physics, 1973
It is concluded from a thermochemical calculation that the interstellar molecules in the compact H II regions may be formed in places of high temperature and high pressure. A possibility of the locations of molecular formation may be the prestellar atmospheres, but the atmospheres of late type stars are other possible candidates.
openaire   +1 more source

The electronic spectra of protonated PANH molecules

, 2015
Aims. This study was designed to examine the viability of protonated nitrogen-substituted polycyclic aromatic hydrocarbons (H+PANHs) as candidates for the carriers of the diffuse interstellar bands (DIBs). Methods.
Dedonder, C., Jouvet, C., Noble, J. A.
core   +1 more source