Related papers: Atomic Oxygen in the Comae of Comets
Recent astrochemical models and experiments have explained that complex organic molecules (COMs; molecules composed of six or more atoms) are produced on the dust grain mantles in cold and dense gas in prestellar cores. However, the…
Cometary comae are generally depleted in nitrogen. The main carriers for volatile nitrogen in comets are NH3 and HCN. It is known that ammonia readily combines with many acids like e.g. HCN, HNCO, HCOOH, etc. encountered in the interstellar…
(Abridged) Complex organic molecules (COMs) are commonly detected in and near star-forming regions. However, the dominant process in the release of these COMs from the icy grains - where they predominately form - to the gas phase is still…
A recent study announced the detection of three bands in the ultraviolet emission spectra of more than a dozen comets, assigning two of them to pentacene (C$_{22}$H$_{14}$) and the third one to toluene (C$_7$H$_8$). The comparison of the…
The close encounter of Comet C/2013 A1 (Siding Spring) with Mars on October 19, 2014 presented an extremely rare opportunity to obtain the first flyby quality data of the nucleus and inner coma of a dynamically new comet. However, the…
The 12C14N/12C15N and 12C14N/13C14N isotopic ratios have been determined in comets C/1995 O1 (Hale-Bopp), C/2001 Q4 (NEAT) and C/2003 K4 (LINEAR) at heliocentric distances of, respectively, 2.7, 3.7 and 2.6 AU. These ratios have also been…
Single-dish observations suggest that the abundances of organic species in star-forming regions of the outer Galaxy, characterised by sub-Solar metallicities, are comparable to those found in the local Galaxy. To understand this…
We report observations of molecular oxygen (O$_2$) rotational transitions at 487 GHz, 774 GHz, and 1121 GHz toward Orion Peak A. The O2 lines at 487 GHz and 774 GHz are detected at velocities of 10-12 km/s with line widths 3 km/s; however,…
Oxygen is the most abundant "metal" element in stars and in the cosmos. But determining oxygen abundances in stars has proven challenging, because of the shortage of detectable atomic oxygen lines in their optical spectra as well as…
We carried out photometric and spectroscopic observations of comet 29P/Schwassmann-Wachmann 1 at the 6-m BTA telescope (SAO RAS, Russia) and the 1.6-m telescope of the National Laboratory for Astro-physics (LNA, Brazil) on February 20,…
We quantified ten parent volatiles in comet C/2009 P1 (Garradd) before perihelion, through high-dispersion infrared spectra acquired with CRIRES at ESO's VLT on UT 2011 August 07 (Rh = 2.4 AU) and September 17-21 (Rh = 2.0 AU). On August…
We report the first detection of molecular gas beyond redshift 7. The molecular gas is associated with the host galaxy of the quasar candidate PSO J145.5964+19.3565 and its companion PSO J145.5964+19.3565N separated by 20.7 kpc. The…
Comets formed in the outer and cold parts of the disk which eventually evolved into our Solar System. Assuming that the comets have undergone no major processing, studying their composition provides insight in the pristine composition of…
Comet composition provides critical information on the chemical and physical processes that took place during the formation of the Solar system. We report here on millimetre spectroscopic observations of the long-period bright comet C/2014…
Comets spend most of their lives at large distances from any star, during which time their interior compositions remain relatively unaltered. Cometary observations can therefore provide direct insight into the chemistry that occurred during…
Cool gas (T$\sim$10$^{4}$~K) traced by hydrogen Ly$\alpha$ emission is now routinely detected around $z\sim3$ quasars, but little is known about their molecular gas reservoirs. Here, we present an APEX spectroscopic survey of the CO(6-5),…
The rich structure of the Fourth Positive System (A-X) of carbon monoxide accounts for many of the spectral features seen in long slit HST-STIS observations of comets 153P/Ikeya-Zhang, C/2001 Q4 (NEAT), and C/2000 WM1 (LINEAR), as well as…
Complex organic molecules (COMs) have been detected abundantly at various stages of star formation, particularly in the warm protostellar phase. The progress in gas-phase measurements has been accelerated by the advent of the Atacama Large…
The Alice far-ultraviolet imaging spectrograph onboard Rosetta observed emissions from atomic and molecular species from within the coma of comet 67P/Churyumov-Gerasimenko during the entire escort phase of the mission from 2014 August to…
We report the detection of several emission bands in the CO Fourth Positive Group from comet 103P/Hartley during ultraviolet spectroscopic observations from the Hubble Space Telescope (HST) on 2010 November 4 near the time of closest…