相关论文: Cyanoacetylene in IC 342: An Evolving Dense Gas Co…

We carried out line survey observations at the 26-30 GHz band toward the four high-mass star-forming regions containing hot cores, G10.30-0.15, G12.89+0.49, G16.86-2.16, and G28.28-0.36, with the Robert C. Byrd Green Bank Telescope. We have…

We present the first interferometric detection of extragalactic NH_3(6,6) emission in the nearby galaxy IC 342 made using the VLA. The data have a resolution of 7.8''x 5.0'' and trace hot (T ~ 412 K) and dense (> 10^{4} cm^{-3}) molecular…

We have imaged emission from the millimeter lines of eight molecules--C2H, C34S, N2H+, CH3OH, HNCO, HNC, HC3N, and SO--in the central half kpc of the nearby spiral galaxy IC 342. The 5" (~50 pc) resolution images were made with OVRO. Using…

IRAM 30m observations reveal that the deeply obscured IR-luminous galaxy NGC4418 has a rich molecular chemistry - including unusually luminous HC3N line emission. We furthermore detect: ortho-H2CO 2-1, 3-2; CN 1-0, 2-1; HCO+, 1-0. 3-2, HCN…

We present the study of deuteration of cyanoacetylene (HC$_3$N) towards a sample of 28 high-mass star-forming cores divided into different evolutionary stages, from starless to evolved protostellar cores. We report for the first time the…

High-density molecular gas plays a vital role in supporting star formation within galaxies. However, traditional tracers of dense gas, such as the low-$J$ transitions of HCN and HCO$^+$, are predominantly optically thick. This…

$^{12}$C$/^{13}$C line intensity ratios have been derived from several carbon-bearing molecules to confine the range of carbon and oxygen isotope abundance ratios toward the nuclear regions of two infrared bright galaxies. The most…

Aims. We aim to systematically study the properties of the different transitions of the dense molecular gas tracer HC3N in galaxies. Methods. We have conducted single-dish observations of HC3N emission lines towards a sample of nearby…

Dense gas is important for galaxy evolution and star formation. Optically-thin dense-gas tracers, such as isotopologues of HCN, HCO+, etc., are very helpful to diagnose excitation conditions of dense molecular gas. However, previous studies…

We present new ALMA Band 7 ($\sim340$ GHz) observations of the dense gas tracers HCN, HCO$^+$, and CS in the local, single-nucleus, ultraluminous infrared galaxy IRAS 13120-5453. We find centrally enhanced HCN (4-3) emission, relative to…

We have observed HNC 1-0, CN 1-0 and 2-1 line emission in a sample of 13 IR luminous (LIRGs, L_IR > 10E11 Lo) starburst and Seyfert galaxies. HNC 1-0 is detected in 9, CN 1-0 is detected in 10 and CN 2-1 in 7 of the galaxies. We also report…

We report observations of dense molecular gas in the star-forming galaxy EGS 13004291 (z=1.197) using the Plateau de Bure Interferometer. We tentatively detect HCN and HNC (J=2-1) emission when stacked together at ~4sigma significance,…

We aim to study the properties of the dense molecular gas towards the inner few 100 pc of four nearby starburst galaxies dominated both by photo dissociation regions (M82) and large-scale shocks (NGC253, IC342 and Maffei2), and to relate…

Multilevel observations of formaldehyde (H_2CO) and methanol (CH_3OH) toward the nearby spiral galaxies NGC 253, Maffei 2, IC 342, M 82 and NGC 6946 are presented. H_2CO was detected in all galaxies (tentatively in NGC 6946). CH_3OH was…

Cyanopolyynes are chains of carbon atoms with an atom of hydrogen and a CN group on either side. They are detected almost everywhere in the ISM, as well as in comets. In the past, they have been used to constrain the age of some molecular…

We present deep WIYN H_alpha SparsePak and DensePak spatially-resolved optical spectroscopy of the dwarf irregular starburst galaxy NGC 1140. The different spatial resolutions and coverage of the two sets of observations have allowed us to…

We present high resolution maps ($\sim 2^{''}$) maps of the J=1-0 and J=2-1 transitions of C$^{18}$O in the central $\sim 150$ pc of the gas-rich nucleus of IC 342, made with the Owens Valley Millimeter Array. From the C$^{18}$O maps we are…

We present high spatial resolution (1.2") mm-interferometric observations of the CO(2-1) line emission in the central 300pc of the late-type spiral galaxy IC342. The data, obtained with the Owens Valley Radio Observatory, allow first-time…

We presented the result of a high resolution (FWHM~0.5'') 12 ks Chandra HRC-I observation of the starburst galaxy IC342 taken on 2 April 2006. We identified 23 X-ray sources within the central 30' x 30' region of IC342. Our HRC-I…

We use the H3O+ molecule to investigate the impact of starburst and AGN activity on the chemistry of the molecular interstellar medium. Using the JCMT, we have observed the 3+_2 - 2-_2 364 GHz line of p-H3O+ towards the centers of seven…