Related papers: The formation of polycyclic aromatic hydrocarbons …
The recent detection of the hydrocarbon anion C6H- in the interstellar medium has led us to investigate the synthesis of hydrocarbon anions in a variety of interstellar and circumstellar environments. We find that the anion/neutral…
In the interstellar medium (ISM), polycylic aromatic hydrocarbons (PAHs) are believed to be an important carbon reservoir, accounting for up to a quarter of all interstellar carbon in our galaxy. This makes the investigation of their…
Polycyclic aromatic hydrocarbons (PAHs) are responsible for a variety of near- and mid-infrared spectral features in Galactic and extragalactic sources. A feature at 1.05 $\mu$m arising from electronic transitions in PAH cations is…
Interstellar space hosts nanometre- to micron-sized dust grains. The carbonaceous-rich component of these grain populations emits in infrared bands, observed remotely for decades with telescopes and satellites. They are a key ingredient of…
It is generally considered, as a rule of thumb, that carbon monoxide forms very early in envelopes of AGB stars, and that it consumes most of the carbon, or most of the oxygen, depending on whether the photosphere is oxygen-rich or…
Carbonaceous grains represent a major component of cosmic dust. In order to understand their formation pathways, they have been prepared in the laboratory by gas-phase condensation reactions such as laser pyrolysis and laser ablation. Our…
The mid-infrared spectrum contains rich diagnostics to probe the physical properties of galaxies, among which the pervasive emission features from polycyclic aromatic hydrocarbons (PAHs) offer a promising means of estimating the star…
We examine the relation between polycyclic aromatic hydrocarbon (PAH) emission at 8 microns and far-infrared emission from hot dust grains at 24 microns and from large dust grains at 160 and 250 microns in the nearby spiral galaxies NGC…
Astrochemistry lies at the nexus of astronomy, chemistry, and molecular physics. On the basis of precise laboratory data, a rich collection of more than 200 familiar and exotic molecules have been identified in the interstellar medium, the…
We present Spitzer measurements of the aromatic (also known as PAH) features for 35 Seyfert galaxies from the revised Shapley-Ames sample and find that the relative strengths of the features differ significantly from those observed in…
It has been an unanswered question how many dusty galaxies have been undetected from the state-of-the-art observational surveys. JWST enables us to detect faint IR galaxies that have prominent polycyclic aromatic hydrocarbon (PAH) features…
We study the behaviour of polycyclic aromatic hydrocarbon emission in galaxies at z=0.3-1.4 using 1868 samples from the revised catalogue of AKARI North Ecliptic Pole Deep survey. The continuous filter coverage at 2-24um makes it possible…
Various studies have emphasized variations of the charge state and composition of the interstellar polycyclic aromatic hydrocarbon (PAH) population in photodissociation regions (PDRs). We aim to model the spatial evolution of the charge and…
The chemistry of astronomical hydrocarbons, responsible for the well-known infrared emission features detected in a wide variety of targets, remains enigmatic. Here we focus on the group of young intermediate-mass Herbig Ae stars. We have…
A mechanism based on the penetration of interstellar ultraviolet photons into the inner layers of clumpy circumstellar envelopes around AGB stars is proposed to explain the non-equilibrium chemistry observed in such objects. We show through…
Polycyclic aromatic hydrocarbon (PAH) dust emission has been proposed as an effective extinction-independent star formation rate (SFR) indicator in the mid-infrared (MIR), but this may depend on conditions in the interstellar medium. The…
Polycyclic aromatic hydrocarbon (PAH) molecules are widely considered as the preferred candidate for the carrier of the unidentified infrared emission bands observed in the interstellar medium and circumstellar envelopes. In this paper we…
The commonly accepted mechanism governing the formation of the nascent wind in oxygen-rich AGB stars combines an initial boost above the photosphere, given by shock waves resulting from stellar pulsations and convective cell granulation,…
For star-forming galaxies, we investigate a global relation between polycyclic aromatic hydrocarbon (PAH) emission luminosity at 3.3 um, L_PAH3.3, and infrared (8-1000 um) luminosity, L_IR, to understand how the PAH 3.3 um feature relates…
We present 10-15 micron spectra of a sample of H II regions, YSOs and evolved stars that show strong unidentified infrared emission features, obtained with the ISO/SWS spectrograph on-board ISO. These spectra reveal a plethora of emission…