Related papers: Redshifted formaldehyde from the gravitational len…
Determining temperatures in molecular clouds from ratios of CO rotational lines or from ratios of continuum emission in different wavelength bands suffers from reduced temperature sensitivity in the high-temperature limit. In theory, the…
We present measurements of interstellar H_2 absorption lines in the continuum spectra of seven early-type stars in the Galactic disk at distances between 1 and 4 kpc. Five of these stars provide lines of sight through the Sagittarius spiral…
The Central Molecular Zone (CMZ) at the center of our Galaxy is the best template to study star formation processes under extreme conditions, similar to those in high-redshift galaxies. We observed on-the-fly maps of para-H$_{2}$CO…
Using the Green Bank Telescope (GBT), we have detected the (J,K) = (1,1) to (10,10) ammonia inversion lines, up to 1030 K above the ground state, in a face-on spiral galaxy viewed against the radio continuum of the lensed background source…
We have used the Arecibo telescope to carry out an survey of 31 dark clouds in the Taurus/Perseus region for narrow absorption features in HI ($\lambda$ 21cm) and OH (1667 and 1665 MHz) emission. We detected HI narrow self--absorption…
The formation mechanisms of intensely starbursting galaxies at high redshift remain unknown. One possible mechanism for triggering these starbursts is mergers and interactions, but detecting these at high redshift remains a challenge.…
ABRIDGED: Context: HI and CO large scale surveys of the Milky Way trace the diffuse atomic clouds and the dense shielded regions of molecular hydrogen clouds. However, until recently, we have not had spectrally resolved C+ surveys to…
We present Atacama Large Millimeter/submillimeter Array observations of the brightest cluster galaxy Hydra-A, a nearby ($z=0.054$) giant elliptical galaxy with powerful and extended radio jets. The observations reveal CO(1-0), CO(2-1),…
We aim to explore the capabilities of dust emission and rays for probing the properties of the interstellar medium in the nearby anti-centre region, using gamma-ray observations with the Fermi Large Area Telescope (LAT), and the thermal…
Using the Plateau de Bure interferometer, we observed the 3mm absorption lines of CN, HCN and HNC from some of the diffuse clouds which lie toward our well-studied sample of compact extragalactic mm-wave continuum sources. The column…
We present new 2 cm and 6 cm maps of H2CO, radio recombination lines, and the radio continuum in the W51 star forming complex acquired with Arecibo and the Green Bank Telescope at ~50" resolution. We use H2CO absorption to determine the…
We present Westerbork Synthesis Radio Telescope HI images, Lovell Telescope multibeam HI wide-field mapping, Wisconsin H-alpha Mapper facility images, William Herschel Telescope longslit echelle CaII observations, and IRAS ISSA 60 and 100…
We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between \sim100 MeV and \sim100 GeV…
Using data from the Southern Galactic Plane Survey (SGPS) we analyze an HI self-absorption cloud centered on l = 318.0 deg, b = -0.5 deg, and velocity, v = -1.1 km/s. The cloud was observed with the Australia Telescope Compact Array (ATCA)…
[Abridged] Do some environments favor efficient conversion of molecular gas into stars? To answer this, we need to be able to estimate the H2 mass. Traditionally, this is done using CO and a few assumptions but the Herschel observations in…
Far-infrared continuum data from the {\it COBE}/{\it DIRBE} instrument were combined with Nagoya 4-m $\cOone$ spectral line data to infer the multiparsec-scale physical conditions in the Orion$ $A and B molecular clouds, using…
Absorption lines from molecular hydrogen ($\rm H_2$) in the spectra of background sources are a powerful probe of the physical conditions in intervening cold neutral medium. At high redshift, $z>2$, $\rm H_2$ lines are conveniently shifted…
We report the first high angular resolution imaging (3.4\arcsec $\times$ 3.0\arcsec) of deuterated formaldehyde (HDCO) toward Orion--KL, carried out with the Submillimeter Array (SMA). We find that the spatial distribution of the…
We measure the CO-to-H$_2$ conversion factor ($\alpha_\mathrm{CO}$) in 37 galaxies at 2~kpc resolution, using dust surface density inferred from far-infrared emission as a tracer of the gas surface density and assuming a constant…
We report on strong H2 and CO absorption from gas within the host galaxy of gamma-ray burst (GRB) 080607. Analysis of our Keck/LRIS afterglow spectrum reveals a very large HI column density (NHI = 10^22.70 cm^-2) and strong metal-line…