Related papers: A search for CO+ in planetary nebulae
Early results from the Herschel Space Observatory revealed the water cation H2O+ to be an abundant ingredient of the interstellar medium. Here we present new observations of the H2O and H2O+ lines at 1113.3 and 1115.2 GHz using the Herschel…
For decades, the detection of phosphorus-bearing molecules in the interstellar medium was restricted to high-mass star-forming regions (as e.g. SgrB2 and Orion KL) and the circumstellar envelopes of evolved stars. However, recent…
We present maps and spectra of the HCN(1-0) and HCO$^+$(1-0) lines in the extreme outer Galaxy, at galactocentric radii between 14 and 22 kpc, with the 13.7 meter Delingha telescope. The 9 molecular clouds were selected from a CO/$^{13}$CO…
New Planetary Nebulae (PNe) were discovered through an [O III] 5007 A emission line survey in the Galactic bulge region with l>0 deg. We detected 240 objects, including 44 new PNe. Deep Halpha+[N II] CCD images as well as low resolution…
Magnetic fields are an important but largely unknown ingredient of planetary nebulae. They have been detected in oxygen-rich AGB and post-AGB stars, and may play a role in the shaping of their nebulae. Here we present SCUBA sub-millimeter…
Molecular hydrogen (H$_2$) is by far the most abundant molecule in the Universe. However, due to the low emissivity of H$_2$, carbon monoxide (CO) is widely used instead to trace molecular gas in galaxies. The relative abundances of these…
The spectra of the planetary nebulae NGC3242 and NGC6369 are reanalysed using spectral measurements made in the mid-infrared with the Spitzer Space Telescope and the Infrared Space Observatory (ISO). The aim is to determine the chemical…
The molecular gas composition in the inner 1 kpc disk of the starburst galaxy M82 resembles that of Galactic Photon Dominated Regions (PDRs). In particular, large abundances of the reactive ions HOC+ and CO+ have been measured in the…
The deuterium enrichment of molecules is sensitive to their formation environment. Constraining patterns of deuterium chemistry in protoplanetary disks is therefore useful for probing how material is inherited or reprocessed throughout the…
Premise: This report is intended to provide useful background and information on how we find detect and compile Planetary Nebulae PNe candidates and then verify them. It is for postgraduate students entering the field and for more general…
The presence of H2D+ in dense cloud cores underlies ion-molecule reactions that strongly enhance the deuterium fractionation of many molecular species. We determine the H2D+ abundance in one starless core, Barnard 68, that has a…
We present first results from the analysis of a sample of 14 planetary nebulae with [WC] nucleus with detected faint carbon and oxygen recombination lines (RLs). The results are based on deep echelle spectra obtained with MIKE on the 6.5 m…
We present the results of a large-scale survey of the very dense gas in the Perseus molecular cloud using HCO+ and HCN (J = 4 - 3) transitions. We have used this emission to trace the structure and kinematics of gas found in pre- and…
Rocky planets may acquire a primordial atmosphere by outgassing of volatiles from their magma ocean. The distribution of O between H$_2$O, CO and CO$_2$ in chemical equilibrium subsequently changes significantly with decreasing temperature.…
The atmospheric chemical composition of a hot Jupiter can lead to insights into where in its natal protoplanetary disk it formed and its subsequent migration pathway. We use a 1-D chemical kinetics code to compute a suite of models across a…
We confirm the first detection of the molecular ion H3+ in an extragalactic object, the highly obscured ultraluminous galaxy IRAS 08572+3915 NW. We also have detected absorption lines of the fundamental band of CO in this galaxy. The CO…
Tracing dense molecular gas, the fuel for star formation, is essential for the understanding of the evolution of molecular clouds and star formation processes. We compare the emission of HCN(1-0), HNC(1-0) and HCO+(1-0) with the emission of…
We have compiled a large sample of O, Ne, S, Cl, and Ar abundances which have been determined for 85 galactic planetary nebulae in a consistent and homogeneous manner using spectra extending from 3600-9600 Angstroms. Sulfur abundances have…
Knowledge of the molecular component of the ISM is fundamental to understand star formation. The H2 component appears to dominate the gas mass in the inner parts of galaxies, while the HI component dominates in the outer parts. Observation…
Observations of molecular clouds, prestellar cores, and protoplanetary disks have established that the HNC/HCN ratio may be a potent diagnostic of molecular gas physical conditions. The processes that govern the relative abundances of these…