Related papers: Redshifted formaldehyde from the gravitational len…

We present deep GMRT OH and WSRT HI absorption spectra of the $z = 0.6846$ gravitational lens toward B0218+357. Both the 1665 MHz and 1667 MHz OH lines are clearly detected for the first time while a new wide absorption component was…

We present the methodology for ``blind'' millimetre-wave surveys for redshifted molecular absorption in the CO/HCO$^+$ rotational lines. The frequency range $30-50$ GHz appears optimal for such surveys, providing sensitivity to absorbers at…

The molecular gas content of high-redshift galaxies is a highly sought-after property. However, H$_2$ is not directly observable in most environments, so its mass is probed through other emission lines (e.g., CO, [CI], [CII]), or through a…

We present high resolution spectroscopy of a QSO whose sight-line passes through the halo of a pair of elliptical galaxies at redshift 2.38. This pair of galaxies probably lies at the center of a galaxy proto-cluster, and is embedded in a…

ALMA data toward QSO J1851+0035 ($l$=$33.498^{\circ}$, $b$=$+0.194^{\circ}$) were used to study absorption lines by Galactic molecular gas. We detected 17 species (CO, $^{13}$CO, C$^{18}$O, HCO$^+$, H$^{13}$CO$^+$, HCO, H$_2$CO, C$_2$H,…

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…

Using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) the COS Science Team has conducted a high signal-to-noise survey of 14 bright QSOs. In a previous paper (Savage et al. 2014) these far-UV spectra were used to…

We report the discovery of a new double-image quasar that was found during a search for gravitational lenses in the southern sky. Radio source PMN J1838-3427 is composed of two flat-spectrum components with separation 1", flux density ratio…

We used the Atacama Pathfinder Experiment (APEX) 12 m telescope to observe the J_KaKc=3_03-2_02, 3_22-2_21, and 3_21-2_20 transitions of para-H_2CO at 218 GHz simultaneously to determine kinetic temperatures of the dense gas in the central…

Aims: A large scale survey of the Galactic center region in he 3 mm rotational transitions of SiO, HCO+ and H13CO+ (beamsize ~ 3. 6 arcmin) was conducted to provide an estimate of cloud conditions, heating mechanisms, chemistry and other…

We report the detection of absorption lines by the reactive ions OH+, H2O+ and H3O+ along the line of sight to the submillimeter continuum source G10.6$-$0.4 (W31C). We used the Herschel HIFI instrument in dual beam switch mode to observe…

Sagittarius B2 (Sgr B2) is one of the most massive and luminous star-forming regions in the Galaxy and shows chemical and physical conditions similar to those in distant extragalactic starbursts. We present large-scale far-IR/submm…

We have observed CH absorption lines ($J=3/2, N=1 \leftarrow J=1/2, N=1$) against the continuum source Sgr~B2(M) using the \textit{Herschel}/HIFI instrument. With the high spectral resolution and wide velocity coverage provided by HIFI, 31…

We analyze the CO-to-H$_2$ conversion factor ($\alpha_{\rm{CO}}$) in the nearby barred spiral galaxy M83. We present new HI observations from the JVLA and single-dish GBT in the disk of the galaxy, and combine them with maps of CO(1-0)…

Infrared-dark high-mass clumps are among the most promising objects to study the initial conditions of the formation process of high-mass stars and rich stellar clusters. In this work, we have observed the (3-2) rotational transition of…

The CO-to-H$_2$ conversion factor ($\alpha_\rm{CO}$) is central to measuring the amount and properties of molecular gas. It is known to vary with environmental conditions, and previous studies have revealed lower $\alpha_\rm{CO}$ in the…

We report single-dish multi-transition measurements of the 12^CO, HCN, and HCO^+ molecular line emission as well as HNC J=1-0 and HNCO in the two ultraluminous infra-red galaxies Arp220 and NGC6240. Using this new molecular line inventory,…

An independent analysis of the molecular hydrogen absorption system at z = 2.059 in the spectrum of the quasar J2123-0050 is presented. The H_2 system consists of two components (A and B) with column densities log N^A(H_2) = 17.94+/-0.01…

We present results of a multi-line study of the filamentary infrared dark cloud G351.78-0.54 in the 1.3 and 0.8 mm wavelength bands. The lines of the three isotopologues of carbon monoxide CO, N$_2$H$^+$, CH$_3$CCH and HNCO were observed.…

We present ISO observations of several H2 pure-rotational lines (from S(0) to S(5)) towards a sample of 16 molecular clouds distributed along the central ~ 500 pc of the Galaxy. We also present C18O and 13CO J=1->0 and J=2->1 observations…