We present observations of circumstellar millimetrewave 13CO line emission towards a sample of 20 cool carbon stars. Using a detailed radiative transfer model we estimate the circumstellar 12CO/13CO-ratios, which we believe accurately measure the important stellar 12C/13C-ratios. For those optically bright carbon stars where it is possible, our derived 12C/13Cratios are compared with the photos...

Aims. Photodissociation by UV light is an important destruction mechanism for carbon monoxide (CO) in many astrophysical environments, ranging from interstellar clouds to protoplanetary disks. The aim of this work is to gain a better understanding of the depth dependence and isotope-selective nature of this process. Methods. We present a photodissociation model based on recent spectroscopic dat...

We explore the infrared M-band (4.7 lm) spectrum of the Class I protostar L1489 IRS in the Taurus molecular cloud. This is the highest-resolution wide-coverage spectrum at this wavelength of a low-mass protostar observed to date (R = 25,000; Dv = 12 km s 1). A large number of narrow absorption lines of gasphase 12CO, 13CO, and C18O are detected, as well as a prominent band of solid 12CO. The ga...

We conducted observations and analyses of the molecular cloud, N4, which is located at ~40 pc from SS433 same line sight as that radio shell, in 12CO(J=1-0), 12CO(J=3-2), 13CO(J=3-2), grand-state OH emissions.N4 has a strong gradient integrated intensity 12CO(J=1-0, 3-2) emission northern, eastern western edges. The main body N4 also velocity ~0.16 km s^-1 20"^-1. A shift by up to 3 systemic ~4...

Aims. We investigate the structure of a field around the position of V838 Mon as seen in the lowest CO rotational transitions. We also measure and analyse emission in the same lines at the position of V838 Mon. Methods. Observations have primarily been done in the 12CO J = 2→1 and J = 3→2 lines using the KOSMA telescope. A field of 3.4 squared degrees has been mapped in the on-the-fly mode in t...

We present the properties of the 12CO(1-0) and (3-2) line emission from the nuclei of 60 IR luminous SLUGS galaxies. This subsample is flux limited at S60μm ≥ 5.24 Jy with FIR luminosities mostly at LFIR > 10 10 L⊙. The emission line strengths of 12CO(1-0) and (3-2) transitions were compared at a common resolution of ∼ 15, and the line ratios r31 vary from 0.22 to 1.72 with a mean value of 0.66...

Context. BP Psc is a puzzling late-type, emission-line field star with large infrared excess. The star is encircled and enshrouded by a nearly edge-on, dusty circumstellar disk, and displays an extensive jet system similar to those associated with pre-main sequence (pre-MS) stars. However, the photospheric absorption features of the star itself appear more consistent with post-main sequence sta...

We present 12CO,13CO and C18O J=1→0, and 12CO and 13CO 2→1 and 3→2 observations of the Rosette Molecular Complex (RMC), obtained with the KOSMA 3m and IRAM 30m telescopes. We introduce a method for correcting error beam pick-up of single-dish telescopes in spectral line radio maps by using observations of a smaller telescope and apply it to correct the IRAM 30m data presented in this paper by t...