Related papers: Exploring morphological correlations among H2CO, 1…

Aims. We seek to understand how the 4.8 GHz formaldehyde absorption line is distributed in the MON R2, S156, DR17/L906, and M17/M18 regions. More specifically, we look for the relationship among the H2CO, 12CO, and 13CO spectral lines.…

We present large scale observations of C18O(1-0) towards four massive star forming regions for MON R2, S156, DR17/L906 and M17/M18. The transitions of H2CO(110-111), C18O(1-0) and 6 cm continuum were compared towards the four regions.…

We have carried out a blind search in the general direction of the Galactic Anticenter for absorption of the Cosmic Microwave Background (CMB) radiation near 4.83 GHz by molecular clouds containing gaseous ortho-formaldehyde (H_2CO). The…

We observed the H2CO(110-111) absorption lines and H110{\alpha} radio recombination lines (RRL) toward 180 NH3 sources using the Nanshan 25-m radio telescope. In our observation, 138 sources were found to have H2CO lines and 36 have…

We aim to develop the Orion B Giant Molecular Cloud (GMC) as a local template for interpreting extra-galactic molecular line observations. We use the wide-band receiver at the IRAM-30m to spatially and spectrally resolve the Orion B GMC.…

We examine the absorption of cosmic microwave background (CMB) photons by formaldehyde (H2CO) over cosmic time. The K-doublet rotational transitions of H2CO become "refrigerated" - their excitation temperatures are driven below the CMB…

We investigated the correlation between intensities of the $^{12}$CO and $^{13}$CO ($J=1$-0) lines toward the Galactic giant molecular clouds (GMCs) W51A, W33, N35-N36 complex, W49A, M17SW, G12.02-00.03, W43, and M16 using the FUGIN (FOREST…

Context. Radio frequency molecular absorption lines appear along sight lines with AV well below 1 mag, revealing the presence of H2 in diffuse gas even when 2.6mm CO emission is absent. Aims. We discuss absorption lines of HCO+, C2H, HCN,…

We present 45"-47" angular resolution maps at 50" sampling of the 12CO and 13CO J=1-0 emission toward a 1.39 deg x 1.33 deg region in the W51 HII region complex. These data permit the spatial and kinematic separation of several spectral…

Observations of various molecular lines toward a disk region of a nearby galaxy are now feasible, and they are being employed as diagnostic tools to study star-formation activities there. However, the spatial resolution attainable for a…

Two selected regions in the molecular gas spiral arms in M51 were mapped with the Owens Valley Radio Observatory (OVRO) mm-interferometer in the 12CO(2-1), 13CO(1-0), C18O(1-0), HCN(1-0) and HCO+(1-0) emission lines. The CO data have been…

We examine 20 diffuse and translucent Galactic sight lines and extract the column densities of the ^12CO and ^13CO isotopologues from their ultraviolet A--X absorption bands detected in archival Space Telescope Imaging Spectrograph data…

Estimating molecular abundances ratios from the direct measurement of the emission of the molecules towards a variety of interstellar environments is indeed very useful to advance in our understanding of the chemical evolution of the…

Formaldehyde (H2CO) is often observed at centimeter wavelengths as an absorption line against the cosmic microwave background (CMB). This is possible when energy level populations are cooled to the point where line excitation temperatures…

We aim to better understand the emission of molecular tracers of the diffuse and dense gas in giant molecular clouds and the influence that metallicity, optical extinction, density, far-UV field, and star formation rate have on these…

We present first results of neutral carbon ([CI], 3P1 - 3P0 at 492 GHz) and carbon monoxide (13CO, J = 1 - 0) mapping in the Vela Molecular Ridge cloud C (VMR-C) and G333 giant molecular cloud complexes with the NANTEN2 and Mopra…

We present a comprehensive study of formaldehyde (H2CO) absorption and radio recombination line (H110a) emission in 215 molecular clouds from the Bolocam Galactic Plane Survey (BGPS), observed using the Nanshan 25-m radio telescope. H2CO…

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…

We present a study of molecular outflows using six molecular lines (including 12CO/13CO/C18O/HCO+(J = 1-0) and SiO/CS(J = 2-1)) toward nine nearby high-mass star-forming regions with accurate known distances. This work is based on the…

We present Green Bank Telescope (GBT) observations of the 3(12)-3(13) (29 GHz) and 4(13)-4(14) (48 GHz) transitions of the H2CO molecule toward a sample of 23 well-studied star-forming regions. Analysis of the relative intensities of these…