Related papers: Lack of PAH emission toward low-mass embedded youn…
Aims: We search for PAH features towards T Tauri stars and compare them with surveys of Herbig Ae/Be stars. The presence and strength of the PAH features are interpreted with disk radiative transfer models exploring the PAH feature…
Our aim is to determine the presence and location of the emission from polycyclic aromatic hydrocarbons (PAHs) towards low and intermediate mass young stars with disks using large aperture telescopes. VLT-VISIR N-band spectra and VLT-ISAAC…
A distinct set of broad emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 $\mu$m, is often detected in protoplanetary disks (PPDs). These features are commonly attributed to polycyclic aromatic hydrocarbons (PAHs). We model these…
Low-resolution, mid-infrared Spitzer/IRS spectral maps are presented for three nearby, low-metallicity dwarf galaxies (NGC 55, NGC 3109 and IC 5152) for the purpose of examining the spatial distribution and variation of polycyclic aromatic…
We investigate the presence and properties of PAHs on the surface of circumstellar disks around Herbig Ae/Be stars by comparing the predictions of disk models with observations. We present results of a radiation transfer code for disks…
Polycyclic Aromatic Hydrocarbons (PAHs) are commonly detected in protoplanetary disks, but it is unclear what causes the wide range of intensities across the samples. In this work, the measured PAH intensities of a range of disks are…
We present spectra of a sample of Herbig Ae and Be (HAeBe) stars obtained with the Infrared Spectrograph on the Spitzer Space Telescope. All but one of the Herbig stars show emission from polycyclic aromatic hydrocarbons (PAHs) and seven of…
Depending on whom you ask, PAHs are either the smallest dust particles or the largest gas-phase molecules in space. Whether referred to as gas or dust, these PAHs can contain up to 20% of the total cosmic carbon abundance and as such also…
We have used sensitive archival data from the Infrared Space Observatory (ISO) to make maps of the edge-on low SFR galaxy, NGC 5907, in 6 different MIR bands: LW2, LW5, LW6, LW7, LW8, and LW10, covering the spectrum from 6.5 to 15.0 microns…
We present the analysis of Spitzer-IRS spectra of four early-type galaxies, NGC 1297, NGC 5044, NGC 6868, and NGC 7079, all classified as LINERs in the optical bands. Their IRS spectra present the full series of H2 rotational emission lines…
Only 8% of the protoplanetary discs orbiting a T Tauri star show emission features of polycyclic aromatic hydrocarbons (PAHs). As PAHs are strong absorbers of UV radiation, they contribute to the heating of the discs photosphere, shielding…
The T Tauri star T Cha is known to have a protoplanetary disk with a dust gap separating the inner and outer disk regions. The mid-infrared JWST spectrum of T Cha shows multiple prominent aromatic infrared bands (AIBs) around 6.2, 8.1, and…
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…
In this Paper we analyze the mid-infrared (mid-IR) emission of very small dust particles in a sample of 12 protoplanetary disks to see how they are connected to interstellar dust particles and to investigate the possibility that their…
We present 5-20 micron spectral maps of the reflection nebula NGC2023 obtained with the Infrared Spectrograph SL and SH modes on board the Spitzer Space Telescope which reveal emission from polycyclic aromatic hydrocarbons (PAHs), C60, and…
For one decade, the spectral-type and age of the $\rho$ Oph object IRS-48 were subject to debates and mysteries. Modelling its disk with mid-infrared to millimeter observations led to various explanations to account for the complex…
Planet-forming disks of gas and dust around young stars contain polycyclic aromatic hydrocarbons (PAHs). We aim to characterize how the charge state of PAHs can be used as a probe of flows of gas through protoplanetary gaps. In this…
Aims. The chemistry of, and infrared (IR) emission from, polycyclic aromatic hydrocarbons (PAHs) in disks around Herbig Ae/Be and T Tauri stars are investigated. The equilibrium distribution of the PAHs over all accessible…
We study the PAH emission from protoplanetary disks. First, we discuss the dependence of the PAH band ratios on the hardness of the absorbed photons and the temperature of the stars. We show that the photon energy together with a varying…
Polycyclic Aromatic Hydrocarbons (PAHs) are believed to be the small-size tail of the interstellar carbonaceous dust grain population. Their vibrational emission is the most widely accepted source of the aromatic near-infrared features, and…