相关论文: Deuterium fractionation as a multi-phase component…
In this work, we constrain the star-forming properties of all possible sites of incipient high-mass star formation in the Milky Way's Galactic Center. We identify dense structures using the CMZoom 1.3mm dust continuum catalog of objects…
We present the results of on-the-fly mapping observations of 44 fields containing 107 SCUBA-2 cores in the emission lines of molecules, N$_2$H$^+$, HC$_3$N, and CCS at 82$-$94 GHz using the Nobeyama 45-m telescope. This study aimed at…
Supernova remnants (SNRs) may regulate star formation in galaxies. For example, SNR-driven shocks may form new molecular gas or compress pre-existing clouds and trigger the formation of new stars. To test this scenario, we measure the…
We present Green Bank Telescope (GBT) observations of the 3(12)-3(13) (29 GHz) and 4(13)-4(14) (48 GHz) transitions of the H2CO molecule toward a sample of 23 well-studied star-forming regions. Analysis of the relative intensities of these…
Molecular clouds in the central molecular zone (CMZ) have been observed to feature turbulent line widths that are significantly higher, and scale with cloud size more steeply, than in the rest of the Milky Way. In the same Galactic region,…
We are carrying out a physical and chemical study of the protostellar envelopes in a representative sample of IM Class 0 protostars. In our first paper (Crimier et al. 2010), we determined the physical structure (density-temperature radial…
The central molecular zone (CMZ) hosts some of the most massive and dense molecular clouds and star clusters in the Galaxy, offering an important window into star formation under extreme conditions. Star formation in this extreme…
Much of the dense gas in molecular clouds has a filamentary structure but the detailed structure and evolution of this gas is poorly known. We have observed 54 cores in infrared dark clouds (IRDCs) using N$_2$H$^+$ (1-0) and (3-2) to…
The conversion of gas into stars is a fundamental process in astrophysics and cosmology. Stars are known to form from the gravitational collapse of dense clumps in interstellar molecular clouds, and it has been proposed that the resulting…
In order to study the distribution of dense molecular gas and its relation to the central activities (starburst and AGN) in galaxies, we have conducted an imaging survey of HCN(1-0) and HCO+(1-0) emissions from nearby spiral galaxies with…
Measurements of deuterium in the local interstellar medium have revealed large variations in D/H along different lines of sight. Moreover, recent {\it Far Ultraviolet Spectroscopic Explorer} (FUSE) measurements find D/H to be anticorrelated…
We present the first systematic study of the density structure of clouds found in a complete sample covering all major molecular clouds in the Central Molecular Zone (CMZ; inner $\sim{}200~\rm{}pc$) of the Milky Way. This is made possible…
[abridged] The enhanced degrees of deuterium fractionation observed in envelopes around protostars demonstrate the importance of chemistry at low temperatures, relevant in pre- and protostellar cores. formaldehyde is an important species in…
Deuterium fractionation can constrain the physical and chemical conditions at the early stage of brown dwarf formation. We present IRAM 30m observations over a wide frequency range of 213-279 GHz of singly and doubly deuterated species of…
Recent observations indicate that organic molecules are prevalent towards starless and prestellar cores. Deuteration of these molecules has not been well-studied during the starless phase. Published observations of singly-deuterated…
Stars form out of the densest parts of molecular clouds. Far-IR emission can be used to estimate the Star Formation Rate (SFR) and high dipole moment molecules, typically HCN, trace the dense gas. A strong correlation exists between HCN and…
Infrared Dark Clouds (IRDCs) are cold, dense regions that are usually found within Giant Molecular Clouds (GMCs). Ongoing star formation within IRDCs is typically still deeply embedded within the surrounding molecular gas. Characterising…
Deuterated molecules are valuable probes for investigating the evolution and the kinematics in the earliest stages of star formation. In this study, we conduct a comprehensive investigation by performing a single point survey of 101…
Context. Deuterium in H-bearing species is enhanced during the early stages of star formation, however, only a small number of high spatial resolution deuteration studies exist towards protostellar objects, leaving the small-scale…
The HNC/HCN ratio is observationally known as a thermometer in Galactic interstellar molecular clouds. A recent study has alternatively suggested that the HNC/HCN ratio is affected by the ultraviolet (UV) field, not by the temperature. We…