Open AccessIRAM observations of JVAS/CLASS gravitational lenses
Author(s) -
Xanthopoulos E.,
Combes F.,
Wiklind T.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04414.x
Subject(s) - physics , molecular absorption , astrophysics , excitation temperature , spectral line , absorption spectroscopy , wavelength , gravitational lens , millimeter , gravitation , hydrogen molecule , absorption (acoustics) , emission spectrum , hydrogen , atomic physics , optics , astronomy , quantum mechanics , galaxy , redshift
We have searched for molecular absorption lines at millimetre wavelengths in 11 gravitational lens systems discovered in the JVAS/CLASS surveys of flat spectrum radio sources. Spectra of only one source 1030+074 were obtained in the 3‐, 2‐ and 1.3‐mm bands at the frequencies corresponding to common molecular transitions of CO and HCO + as continuum emission was not found in any of the other sources. We calculated upper limits to the column density in molecular absorption for 1030+074, using an excitation temperature of 15 K, to be N CO <6.3×10 13 cm −2 and N HCO+ <1.3×10 11 cm −2 , equivalent to hydrogen column density of the order N H <10 18 cm −2 , assuming standard molecular abundances. We also present the best upper limits of the continuum at the lower frequency for the other 10 gravitational lenses.