Using the new 23 GHz receivers at the Very Large Array (VLA), we have detected NH3(6,6) emission (ν = 25.056025 GHz) from hot (> 150 K) molecular clouds in the central 10 pc of the Galaxy. This is the first successful detection of NH3(6,6) with the VLA. The brightest emission comes from a region interior to the “circumnuclear disk” (CND), less than 1.5 pc in projected distance from Sgr A*. This...

The calculation and use of molecular hydrogen optical depth templates to quickly identify and model molecular hydrogen absorption features longward of the Lyman edge at 912 Å are described. Such features are commonly encountered in spectra obtained by the Far Ultraviolet Spectroscopic Explorer and also in spectra obtained by the Space Telescope Imaging Spectrograph, albeit less commonly. Indivi...

We present NH3 observations of the B5 region in Perseus obtained with the Green Bank Telescope (GBT). The map covers a region large enough (∼11′×14′) that it contains the entire dense core observed in previous dust continuum surveys. The dense gas traced by NH3(1,1) covers a much larger area than the dust continuum features found in bolometer observations. The velocity dispersion in the central...

The complex carbon chemistry necessary for astrobiology in the ISM depends partially on the C + H3 + reaction. Gas-phase astrochemical models use a classically calculated thermal rate coefficient for the reaction C+H3 + forming CH; additionally, those models consider the CH2 + and CH3 + channels to be closed. However, new laboratory data have shown the CH2 + channel to be open; additionally, th...

Standard stellar evolution theory is inconsistent with the observed isotopic carbon ratio, C/C, in evolved stars. This theory is also inconsistent with the He/H abundance ratios observed in Galactic H II regions, when combined with chemical evolution theory. These discrepancies have been attributed to an extra, non-standard mixing which further processes material during the RGB and should lower...

We present new observations of the CepA-East region of massive star formation and describe an extended and dynamically distinct feature not previously recognised. This feature is present in emission from H2CS, OCS, CH3OH, and HDO at –5.5 km s , but is not traced by conventional tracers of star forming regions H2S, SO2, SO, CS. The feature is extended up to at least 0.1 pc. We show that the feat...

Observations from the Spitzer Space Telescope have drawn attention to spectroscopic structure longward of 15 mm that is associated with objects showing prominent unidentified infrared (UIR) bands in the mid-IR. If polycyclic aromatic hydrocarbons (PAHs) are indeed responsible for the UIR features, longer wavelength emission arising from out-of-plane PAH skeletal vibrations is required. Here we ...

Absorption and emission lines originating from the 3 C H stretching manifold of gas-phase CH4 were discovered in the high-resolution (R 1⁄4 25;000) infrared L-band spectrum along the line of sight toward NGC 7538 IRS 9. These observations provide a diagnostic of the complex dynamics and chemistry in a massive star-forming region. The line shapes resemble P Cygni profiles with the absorption and...

This article presents a multi-wavelength study towards the massive starforming region S87, based on a dataset of submillimeter/far-/mid-infrared (submm/FIR/MIR) images and molecular line maps. The sub-mm continuum emission measured with JCMT/SCUBA reveals three individual clumps, namely, SMM1, SMM2, and SMM3. The MIR/FIR images obtained by the Spitzer Space Telescope indicate that both SMM1 and...

Using the Very Large Array, we have detected weak OH maser emission near the Turner–Welch protostellar source in the W3 OH region. Unlike typical interstellar OH masers, which are associated with ultra-compact HII regions, our measured positions and proper motions (from Very Long Baseline Interferometry) indicate that these OH masers are associated with a bipolar outflow traced by strong H2O ma...