Related papers: A Search for Carbon-Chain-Rich Cores in Dark Cloud…
We present deep NH$_3$ observations of the L1495-B218 filaments in the Taurus molecular cloud covering over a 3 degree angular range using the K-band focal plane array on the 100m Green Bank Telescope. The L1495-B218 filaments form an…
Using data from the SCUBA Legacy Catalogue (850 um) and Spitzer Space Telescope (3.6 - 70 um), we explore dense cores in the Ophiuchus, Taurus, Perseus, Serpens, and Orion molecular clouds. We develop a new method to discriminate…
As an ongoing study of Magellanic Cloud PNe we have obtained UV spectra of 9 PNe in the SMC to measure their carbon abundances. The spectra have been acquired with ACS HRC/PR200L and SBC/PR130L. The ACS prisms give a reasonable resolution…
We present an analysis of the QUARKS survey sample, focusing on protoclusters where Hot Molecular Cores (HMCs, traced by CH3CN(12--11)) and UC HII regions (traced by H30\alpha/H40\alpha) coexist. Using the high-resolution, high-sensitivity…
A variety of homologous carbon chains (HCnH, HCnN, CnS, CnO, and OCnO) are found to exhibit an appealing even-odd effect. Chains containing a number of carbon atoms of a certain parity possess singlet ground states, while members of…
We present the results of a spectral-line survey of the W51e1/e2 star-forming region at 68-88 GHz. 79 molecules and their isotopologues were detected, from simple diatomic or triatomic molecules, such as SO, SiO, and CCH, to complex organic…
Using the IRAM 30 m telescope, a mapping survey in optically thick and thin lines was performed towards 46 high mass star-forming regions. The sample includes UC H{\sc ii} precursors and UC H{\sc ii} regions. Seventeen sources are found to…
We present results obtained towards the HII regions N159, N166, and N132 from the emission of several molecular lines in the 345 GHz window. Using ASTE we mapped a 2.4' $\times$ 2.4' region towards the molecular cloud N159-W in the…
The Kleinmann-Low nebula in Orion (Orion-KL) is the nearest example of a high-mass star-forming environment. For the first time, we complemented 1.3 mm Submillimeter Array (SMA) interferometric line survey with IRAM 30 m single-dish…
We present results from a time dependent gas phase chemical model of a hot core based on the physical conditions of G305.2+0.2. While the cyanopolyyne HC_3N has been observed in hot cores, the longer chained species, HC_5N, HC_7N, and HC_9N…
We study molecular emission in a massive condensation at the border of the HII region RCW 120, paying particular attention to the Core 1 and Core 2 objects, the most massive fragments of the condensation found previously by ALMA. The latter…
It is well known that metal-poor red giant branch (RGB) stars show variations in some elemental abundances, including carbon, due to the internal mixing accompanied by their own in situ CN cycle in the hydrogen burning shell. With our new…
We present a survey of molecules in a sample of Galactic center molecular clouds using the Karl G. Jansky Very large Array, which includes M0.25+0.01, the clouds near Sgr A, and Sgr B2. The molecules detected are primarily NH3 and HC3N; in…
We present Orion A giant molecular cloud core catalogs, which are based on 1.1 mm map with an angular resolution of 36 arcsec (sim 0.07 pc) and C18O (1-0) data with an angular resolution of 26.4 arcsec (sim 0.05 pc). We have cataloged 619…
To study the impact of the initial effects of metallicity (i.e., the abundance of elements heavier than helium) on star formation and the formation of different molecular species, we searched for hot molecular cores in the sub-solar…
In the study of high-mass star formation, hot cores are empirically defined stages where chemically rich emission is detected toward a massive YSO. It is unknown whether the physical origin of this emission is a disk, inner envelope, or…
To constrain models of high-mass star formation, the Herschel/HOBYS KP aims at discovering massive dense cores (MDCs) able to host the high-mass analogs of low-mass prestellar cores, which have been searched for over the past decade. We…
The CHAOS project is building a large database of LBT H II region spectra in nearby spiral galaxies to use direct abundances to better determine the dispersion in metallicity as a function of galactic radius. Here, we present CHAOS LBT…
The chemical evolution of pre-stellar cores during their transition to a protostellar stage is not yet fully understood. Detailed chemical characterizations of these sources are needed to better define their chemistry during star formation.…
We present a survey of the ortho-H2D+(1_{1,0}-1_{1,1}) line toward a sample of 10 starless cores and 6 protostellar cores, carried out at the Caltech Submillimeter Observatory. The high diagnostic power of this line is revealed for the…