相关论文: The detectability of mm-wave molecular rotational …
[This is truncated to suit the whims of the archivers ...] Parameter studies in LVG models are used to show how the low-lying rotational transitions of common polar molecules HCO+, HCN and CS vary with number density, column density and…
The {\it Far Ultraviolet Spectroscopic Explorer} ({\it FUSE}) has allowed precise determinations of the column densities of molecular hydrogen ($\Hmol$) in Galactic lines of sight with a wide range of pathlengths and extinction properties.…
The optically thin critical densities and the effective excitation densities to produce a 1 K km/s (or 0.818 Jy km/s $(\frac{\nu_{jk}}{100 \rm{GHz}})^2 \, (\frac{\theta_{beam}}{10^{\prime\prime}})^2$) spectral line are tabulated for 12…
Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS1830-211. Obtaining average radial velocities and performing Large Velocity Gradient…
The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we…
The current generation of (sub)mm-telescopes has allowed molecular line emission to become a major tool for studying the physical, kinematic, and chemical properties of extragalactic systems, yet exploiting these observations requires a…
The redshifted spectral line radiation emitted from both atomic fine-structure and molecular rotational transitions in the interstellar medium (ISM) of high-redshift galaxies can be detected in the centimetre, millimetre and submillimetre…
Molecular line emission from high-redshift galaxies holds great promise for the study of galaxy formation and evolution. The weak signals can only be detected with the largest mm-wave telescopes, such as the IRAM interferometer. We report…
It becomes possible now to detect cold molecules at high redshift in the millimeter domain. Since the first discovery in 1992 by Brown and van den Bout of CO lines at z=2.28 in a gravitationally lensed starburst galaxy, nearly ten objects…
Models are presented for CO rotational line emission by high redshift starburst galaxies. The influence of the cosmic microwave background on the thermal balance and the level populations of atomic and molecular species is explicitly…
Trends observed in galaxies, such as the Gao \& Solomon relation, suggest a linear relation between the star formation rate and the mass of dense gas available for star formation. Validation of such relations requires the establishment of…
We propose observations of the molecular gas distribution during the era of reionization. At $z \sim $ 6 to 8, $^{12}$CO$(J=1-0)$ line intensity results in a mean brightness temperature of about 0.5 $\mu$K with rms fluctuations of 0.1…
Understanding the heating and cooling mechanisms in nearby (Ultra) luminous infrared galaxies can give us insight into the driving mechanisms in their more distant counterparts. Molecular emission lines play a crucial role in cooling…
The abundance of cold molecular gas plays a crucial role in models of galaxy evolution. While deep spectroscopic surveys of CO emission lines have been a primary tool for measuring this abundance, the difficulty of these observations has…
Some recent results are presented about high redshift molecular absorption lines, namely about chemical abundances of elements, and in particular of water and molecular oxygen. Excitation temperatures of several molecules are found lower…
The rotationally resolved spectrum of the A ^1Pi_u <- X ^1Sigma^+_g 000-000 transition of C3, centered at 4051.6A, has been observed along 10 translucent lines of sight. To interpret these spectra, a new method for the determination of…
Aims: Our aims are threefold: a) To compare the $uv$ and mm-wave results; b) to interpret 13CO and 12CO abundances in terms of the physical processes which separately and jointly determine them; c) to interpret observed J=1-0 rotational…
The rotational transitions of carbon monoxide (CO) are the primary means of investigating the density and velocity structure of the molecular interstellar medium. Here we study the lowest four rotational transitions of CO towards…
New millimeter-wavelength emission lines are reported for the Cloverleaf (H1413+117), a gravitationally lensed quasar at redshift 2.56. High signal-to-noise ratio spectra of four lines in CO (J=3-2, J=4-3, J=5-4, and J=7-6) have been…
We used the ARO 12m antenna to observe emission from the J=1-0 lines of carbon monoxide, \hcop\ and HNC and the J=2-1 line of CS toward and around the continuum peak used for absorption studies and we compare them with CH, HNC, C\p\ and…