We present high resolution (R = 75,000–100,000) mid-infrared spectra of the high-mass embedded young star IRS 1 in the NGC 7538 star-forming region. Absorption lines from many rotational states of C2H2, CCH2, CH3, CH4, NH3, HCN, HNCO, and CS are seen. The gas temperature, column density, covering factor, line width, and Doppler shift for each molecule are derived. All molecules were fit with tw...

More than 140 different molecules have been identified in the interstellar medium (ISM) to date. Dust grain particles are also found in the ISM, and some of these molecules freeze out at the cold temperatures (10-20 K) to form molecular ices. Understanding the adsorption and desorption of these ices is crucially important in understanding the processes that lead to star and planet formation, an...

We present a 5–37 μm infrared spectrum obtained with the Spitzer Space Telescope toward the southeastern lobe of the young protostellar outflow HH211. The spectrum shows an extraordinary sequence of OH emission lines arising in highly excited rotational levels up to an energy E/ k ≈ 28200K above the ground level. This is, to our knowledge, by far the highest rotational excitation of OH observed...

“Who” and how? In this simple question the complexity of interstellar chemistry is encapsulated. refers to what molecules are present in medium (ISM) “how” mechanisms that led their formation. While large number discovered ISM (∼250) demonstrates rich occurring there, a significant unknown species waiting for an identification processes synthesis identified still hotly debated or even unknown. ...

Networks of reactions on dust grain surfaces play a crucial role in the chemistry of interstellar clouds, leading to the formation of molecular hydrogen in diffuse clouds as well as various organic molecules in dense molecular clouds. Due to the sub-micron size of the grains and the low flux, the population of reactive species per grain may be very small and strongly fluctuating. Under these co...

Aliphatic hydrocarbons exhibit an absorption feature at 3.4 m, observed toward sources that sample diffuse regions of the interstellar medium (ISM). The absorbers responsible for this feature are assumed to reside in some component of interstellar dust, but the physical nature of the particles (size, shape, structure, etc.) is uncertain. Observations of interstellar polarization provide discrim...

Abundances for 5 molecules (CO, CS, NH3, H2CO, and C3H2) and 1 molecular ion (N2H ) and upper limits for the abundances of 1 molecule (CO) and 1 molecular ion (HCO) are derived for gas within the Bok globule Barnard 68 (B68). The abundances were determined using our own BIMA millimeter interferometer data and single-dish data gathered from the literature, in conjunction with a Monte Carlo radia...

Abundances for 5 molecules (CO, CS, NH3, H2CO, and C3H2) and 1 molecular ion (N2H ) and upper limits for the abundances of 1 molecule (CO) and 1 molecular ion (HCO) are derived for gas within the Bok globule Barnard 68 (B68). The abundances were determined using our own BIMA millimeter interferometer data and single-dish data gathered from the literature, in conjunction with a Monte Carlo radia...

We mapped the inner 40 ′′ of the HH212 Class 0 outflow in SiO(2–1), SiO(5–4) and continuum using the Plateau de Bure interferometer in its extended configurations. The unprecedented angular resolution (down to 0. 34) allows accurate comparison with a new, deep H2 image obtained at the VLT. The SiO emission is confined to a highly-collimated bipolar jet (width ∼ 0. 35) along the outflow axis. Th...

Abstract Interstellar Grains (IGs) spread in the Medium (ISM) host a multitude of chemical reactions that could lead to production interstellar Complex Organic Molecules (iCOMs), relevant context prebiotic chemistry. These IGs are composed silicate-based core covered by several layers amorphous water ice, known as grain mantle. from ISM gas-phase can be adsorbed at surfaces, diffuse and react g...