Related papers: The relation between column densities of interstel…
Based on the analysis of available published data and archival data along 24 sightlines (5 of which are new) we derive more accurate estimates of the column densities of OH and CH towards diffuse/translucent clouds and revisit the typically…
We demonstrate relations between column densities of simple molecules: CH, CH$^{+}$, H$_{2}$ and OH. The H$_{2}$, CH and OH molecules seem to occupy the same environments because of tight relations between their column densities. In…
We investigate the correlation between OH and H2 column densities in diffuse Galactic clouds, in order to identify potential molecular tracers of interstellar H2. For this, we analyse near-UV spectra extracted from the ESO/VLT archives…
We analyze mutual relations between interstellar extinction E(B-V) and column densities of diatomic molecules such as CN, CH and CH cation observed along translucent sightlines. Observational material acquired using five echelle…
We have conducted OH 18 cm survey toward 141 molecular clouds in various environments, including 33 optical dark clouds, 98 Planck Galactic cold clumps (PGCCs) and 10 Spitzer dark clouds with the Arecibo telescope. The deviations from local…
Using archival, high-resolution far-ultraviolet HST/STIS spectra of 34 Galactic O and B stars, we measure CI column densities and compare them with measurements from the literature of CO and H_2 with regard to understanding the presence of…
We present high-sensitivity CH 9 cm ON/OFF observations toward 18 extra-galactic continuum sources that have been detected with OH 18 cm absorption in the Millennium survey with the Arecibo telescope. CH emission was detected toward six of…
We have used archival far-ultraviolet spectra from observations made by HST/STIS and FUSE to determine the column densities and rotational excitation temperatures for CO and H2, respectively, along the lines of sight to 23 Galactic O and B…
OH(1720 MHz) masers are created by the interaction of supernova remnants with molecular clouds. These masers are pumped by collisions in warm, shocked molecular gas with OH column densities in the range 10^{16}--10^{17} cm^{-2}. Excitation…
We used archival data acquired with the Copernicus satellite to reexamine CO column densities because self-consistent oscillator strengths are now available. Our focus is on lines of sight containing modest amounts of molecular species. Our…
Three interstellar absorption lines near 1370 A seen toward zeta Oph have been assigned by Watson to Rydberg transitions in the G-X (or 3d-X) band of CH. Our survey of a dozen diffuse interstellar lines of sight shows that the three…
While recent studies of the solar-mass protostar IRAS16293-2422 have focused on its inner arcsecond, the wealth of Herschel/HIFI data has shown that the structure of the outer envelope and of the transition region to the more diffuse ISM is…
We observed the 9-cm Lambda-doubling lines of CH along the dense filament of TMC-1. The CH column densities were compared with the total H2 column densities derived using the 2MASS NIR data and previously published SCUBA maps and with OH…
Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the…
We present interstellar C II (1334.5323 \AA) and C II* (1335.7077 \AA) column density measurements along 14 Galactic sight-lines. These sight-lines sample a variety of Galactic disk environments and include paths that range nearly two…
We use the EAGLE cosmological, hydrodynamical simulations to predict the column density and equivalent width distributions of intergalactic O VII ($E=574$ eV) and O VIII ($E=654$ eV) absorbers at low redshift. These two ions are predicted…
We report on the abundance of interstellar neutral oxygen (OI) for 26 sightlines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE), the International Spectroscopic Explorer (IUE), and the Hubble Space Telescope (HST). OI…
Observations of interstellar dust are often used as a proxy for total gas column density $N_\mathrm{H}$. By comparing $\textit{Planck}$ thermal dust data (Release 1.2) and new dust reddening maps from Pan-STARRS 1 and 2MASS (Green et al.…
Detailed analysis of intensity ratios of unsaturated methylidyne (CH) A--X and B--X bands suggests consistency of the recently published oscillator strengths of A$^{2}\Delta$ -- X$^{2}\Pi$ (0, 0) -- 4300 \AA\ and B$^{2}\Sigma^{-}$ --…
A linear relation between the hydrogen column density (N_H) and optical extinction (A_V) in the Galaxy has long been observed. A number of studies found differing results in the slope of this relation. Here, we utilize the data on 22…