Related papers: Star Formation Occurs in Dense Gas, but What Does …

An imaging survey of CO(1-0), HCN(1-0), and HCO$^+$(1-0) lines in the centers of nearby Seyfert galaxies has been conducted using the Nobeyama Millimeter Array and the RAINBOW interferometer. Preliminary results reveal that 3 Seyferts out…

We have mapped the large-scale structure of the Serpens cloud core using moderately optically thick (13CO(1--0) and CS(2--1)) and optically thin tracers (C18O(1--0), C34S(2--1), and N2H+(1--0)), using the 16-element focal plane array…

We present the detection of molecular gas using CO(1-0) line emission and follow up Halpha imaging observations of galaxies located in nearby voids. The CO(1-0) observations were done using the 45m telescope of the Nobeyama Radio…

Carbon monoxide (CO) is the primary tracer for interstellar clouds where stars form, yet CO has never been detected in galaxies with an Oxygen abundance relative to Hydrogen less than 20% of solar, even though such low metallicity galaxies…

We used the ARO 12m antenna to observe emission from the J=1-0 lines of carbon monoxide, \hcop\ and HNC and the J=2-1 line of CS toward and around the continuum peak used for absorption studies and we compare them with CH, HNC, C\p\ and…

Massive stars play an important role in the Universe. Unlike low-mass stars, the formation of these objects located at great distances is still unclear. It is expected to be governed by some combination of self-gravity, turbulence, and…

Using studies of nearby star formation with Spitzer, I will argue that star formation is restricted to dense cores within molecular clouds. The nature of these dense cores and their connection to star formation will be discussed. Their…

There is now convincing evidence that the intensity of HCN molecular line emission is enhanced around active galactic nuclei. In this paper we examine the specific case of the Seyfert galaxy NGC3227, for which there are subarcsecond…

We present Jansky Very Large Array observations of 20 - 37 GHz absorption lines from nearby Galactic diffuse molecular gas seen against four cosmologically-distant compact radio continuum sources. The main new observational results are that…

We present observations of 1.5 square degree maps of the 12CO, 13CO, and C18O (J=1-0) emission toward the complex region of the supernova remnant (SNR) W41 and SNR G22.7-0.2. A massive (~5E5Msun), large (~84x15 pc), and dense (~10E3 cm^-3)…

We use ALMA and IRAM 30-m telescope data to investigate the relationship between the spectroscopically-traced dense gas fraction and the cloud-scale (120 pc) molecular gas surface density in five nearby, star-forming galaxies. We estimate…

Using the Large Millimeter Telescope and the SEQUOIA 3~mm focal plane array, we have searched for molecular line emission from two atomic clouds associated with the Fermi Bubble of the Milky Way. Neither 12CO nor 13CO J=1-0 emission is…

We present Submillimeter Array (SMA) observations of seven massive molecular clumps which are dark in the far-infrared for wavelengths up to 70 $\mu$m. Our 1.3 mm continuum images reveal 44 dense cores, with gas masses ranging from 1.4 to…

(Abridged) We have observed CS and C17O lines, and 1.2 mm cont. emission towards a sample of 130 high-mass protostellar candidates with DEC<-30 deg. This is the first step of the southern extension of a project started more than a decade…

We present the results of a large-scale survey of the very dense gas in the Perseus molecular cloud using HCO+ and HCN (J = 4 - 3) transitions. We have used this emission to trace the structure and kinematics of gas found in pre- and…

High mass stars form in groups or clusters within massive cores in dense molecular clumps with sizes of 1pc and masses of 200Msun which are important laboratories for high-mass star formation in order to study the initial conditions. We…

Studying molecular gas in nearby galaxies using hydrogen cyanide (HCN) as a tracer for higher densities than CO emission still poses a significant challenge. Even though several galaxies have HCN maps on a few kpc scales, higher-resolution…

We report the second complete molecular line data release from the {\em Census of High- and Medium-mass Protostars} (CHaMP), a large-scale, unbiased, uniform mapping survey at sub-parsec resolution, of mm-wave line emission from 303…

We present high-resolution observations (0".2-1".5) of multiple dense gas tracers, HCN and HCO$^+$ ($J$ = 1-0, 3-2, and 4-3), HNC ($J$ = 1-0), and CS ($J$ = 7-6) lines, toward the nearby luminous infrared galaxy VV 114 with the Atacama…

Aims. The comparative study of several molecular species at the origin of the gas phase chemistry in the diffuse interstellar medium (ISM) is a key input in unraveling the coupled chemical and dynamical evolution of the ISM. Methods. The…