Related papers: CH$_3$OH as a User-Friendly Density Probe: Calibra…
Aims. We observe the dense gas tracer CS in two nearby starburst galaxies to determine how the conditions of the dense gas varies across the circumnuclear regions in starburst galaxies. Methods. Using the IRAM-30m telescope, we mapped the…
Single flux density measurements at observed-frame sub-millimeter and millimeter wavelengths are commonly used to probe dust and gas masses in galaxies. In this Letter, we explore the robustness of this method to infer dust mass, focusing…
Aims. Our goals are to compare the CS, N2H+ and dust distributions in a representative sample of high-mass star forming dense cores and to determine the physical and chemical properties of these cores. Methods. We compare the results of…
The H3+ ion plays a key role in the chemistry of dense interstellar gas clouds where stars and planets are forming. The low temperatures and high extinctions of such clouds make direct observations of H3+ impossible, but lead to large…
We report the results of ALMA 1-2 kpc-resolution, three rotational transition line (J=2-1, J=3-2, and J=4-3) observations of multiple dense molecular gas tracers (HCN, HCO$^{+}$, and HNC) for ten nearby (ultra)luminous infrared galaxies…
For the first time, we establish a gas phase abundance pattern calibration for quiescent galaxies using optical emission lines. Quiescent galaxies have warm ionized gas showing line ratios similar to low-ionization nuclear emission line…
We present the results of a spectral line survey from 138.3 to 150.7 GHz toward Orion-KL. The observations were made using the 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were between 500 and 700…
Aims. We want to understand the chemistry and physics of disks on the basis of a large unbiased and statistically relevant grid of disk models. One of the main goals is to explore the diagnostic power of various gas emission lines and line…
We present observations of HCO+ and H^13CO+, N2H+, HCS+, HCN and HN^13C, SO and ^34SO, CCH, SO_2, and CH_3OH-E towards a sample of 27 high-mass clumps coincident with water maser emission. All transitions are observed with or convolved to…
We derive new empirical calibrations for strong-line diagnostics of gas phase metallicity in local star forming galaxies by uniformly applying the Te method over the full metallicity range probed by the Sloan Digital Sky Survey (SDSS). To…
In the last years, ultra-low temperature chemical kinetic experiments have demonstrated that some gas-phase reactions are much faster than previously thought. One example is the reaction between OH and CH3OH, which has been recently found…
The measurement of oxygen lines in metal-poor unevolved stars, in particular near-UV OH lines, can provide invaluable information on the properties of the Early Galaxy. Near-UV OH lines constitute an important tool to derive oxygen…
We present a pilot survey of 21 lines of sight towards UCHII regions in the H2CO 1-1 (6cm) and 2-2 (2cm) transitions, using the H2CO centimeter lines as a molecular gas densitometer. Using Arecibo and Green Bank beam-matched observations,…
We present synthetic line observations of a simulated molecular cloud, utilising a self-consistent treatment of the dynamics and time-dependent chemical evolution. We investigate line emission from the three most common CO isotopologues…
We present synthetic continuum and $^{13}$CO and C$^{18}$O line emission observations of dense and cold filaments. The filaments are dynamically evolved using 3D-MHD simulations that include one of the largest on-the-fly chemical networks…
We present P-GADGET3-K, an updated version of GADGET3, that incorporates the chemistry package KROME. P-GADGET3-K follows the hydrodynamical and chemical evolution of cosmic structures, incorporating the chemistry and cooling of H$_2$ and…
(Abridged) We present a survey of the water emission in a sample of more than 20 outflows from low mass young stellar objects with the goal of characterizing the physical and chemical conditions of the emitting gas. We have used the HIFI…
Observations of low-mass protostellar systems show evidence of rich complex organic chemistry. Their low luminosity, however, makes determining abundance distributions of complex organic molecules (COMs) within the water snowline…
The disks that surround young stars are mostly composed of molecular gas, which is harder to detect and interpret than the accompanying dust. Disk mass measurements have therefore relied on large and uncertain extrapolations from the dust…
Context: It has been proposed that H$_2$ near-infrared lines may be excited by cosmic rays and allow for a determination of the cosmic-ray ionization rate in dense gas. One-dimensional models show that measuring both the H$_2$ gas column…