Aims. Magnetic fields play a primordial role in the star formation process. The Zeeman effect on the CN radical lines is one of the few methods of measuring magnetic fields in the dense gas of star formation regions. Methods. We report new observations of the Zeeman effect on seven hyperfine CN N = 1−0 lines in the direction of 14 regions of star formation. Results. We have improved the sensitivity of previous detections, and obtained five new detections. Good upper limits are also achieved. The probability distribution of the line-of-sight field intensity, including non-detections, provides a median value of the total field B tot = 0.56 mG while the average density of the medium sampled is n(H 2 ) = 4.5 × 10 5 cm −3 . We show that the CN line probably samples regions similar to those traced by CS and that the magnetic field observed mostly pervades the dense cores. The dense cores are found to be critical to slightly supercritical with a mean mass-to-flux ratio M/Φ ∼ 1 to 4 with respect to critical. Their turbulent and magnetic energies are in approximate equipartition.

No abstract

No abstract

Abstract. Heterodyne observations of Neptune have provided a measurement of the CO(2-1) line profile with a total bandpass of almost 8 GHz and a resolution of 4 MHz. The lineshape indicates that the CO mole fraction in Neptune's atmosphere is not uniform, but increases by a factor of ∼2 from the troposphere/lower stratosphere (0.5 ppm at p > 20 mbar) to the upper stratosphere (1 ppm at p < 20 mbar). This indicates the existence of both external and internal sources of CO. The equivalent flux associated with the external source is ∼1 × 10 8 cm −2 s −1 . We propose that the stratospheric CO results from a large (2 km) cometary impact that occurred ∼200 years ago, although there remains problems with this hypothesis.

A spectral survey in the 1 mm wavelength range was undertaken in the long-period comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy) using the 30 m telescope of the Ins titut de radioastronomie millimétrique (IRAM) in April and November−December 2013. We report the detection of ethylene glycol (CH 2 OH) 2 (aGg' conformer) and formamide (NH 2 CHO) in the two comets. The abundances relative to water of ethylene glycol and formamide are 0.2-0.3% and 0.02% in the two comets, similar to the values measured in comet C/1995 O1 (Hale-Bopp). We also report the detection of HCOOH and CH 3 CHO in comet C/2013 R1 (Lovejoy), and a search for other complex species (methyl formate, glycolaldehyde).