Related papers: PAHs in Galaxies: their Properties and Evolution
This work presents theoretical calculations of infrared spectra of nitrogen (N)-containing polycyclic aromatic hydrocarbon (PAH) molecules with incorporation of N, NH and NH$_2$ using density functional theory (DFT). The properties of their…
We present here $Spitzer$ mid-infrared (IR) spectra and modeling of the spectral energy distribution (SED) of a selection of post-Asymptotic Giant Branch (PAGB) stars. The mid-IR spectra of majority of these sources showed spectral features…
We present mid-infrared (MIR) spectra of HII regions within star-forming galaxies M83 and M33. Their emission features are compared with Galactic and extragalactic HII regions, HII-type galaxies, starburst galaxies, and Seyfert/LINER type…
In this paper we analyze the evolution of actively star forming galaxies in the mid-infrared (MIR). This spectral region, characterized by continuum emission by hot dust and by the presence of strong emission features generally ascribed to…
Observationally, the interstellar gas-phase abundance of deuterium (D) is considerably depleted and the missing D atoms are often postulated to have been locked up into carbonaceous solids and polycyclic aromatic hydrocarbon (PAH)…
We present a {\em Spitzer}-based mid-infrared study of a large sample of Blue Compact Dwarf galaxies (BCD) using the Infrared Spectrograph (IRS), including the first mid-IR spectrum of IZw18, the archetype for the BCD class and among the…
We calibrate the integrated luminosity from the polycyclic aromatic hydrocarbon (PAH) features at 6.2\micron, 7.7\micron\ and 11.3\micron\ in galaxies as a measure of the star-formation rate (SFR). These features are strong (containing as…
The infrared signature of polycyclic aromatic hydrocarbons (PAHs) are present in many protostellar disks and these speciesare thought to play an important role in heating of the gas in the photosphere. We aim to consider PAH cluster…
JWST observations of polycyclic aromatic hydrocarbon (PAH) emission provide some of the deepest and highest resolution views of the cold interstellar medium (ISM) in nearby galaxies. If PAHs are well mixed with the atomic and molecular gas…
The unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 micrometer, commonly attributed to polycyclic aromatic hydrocarbon (PAH) molecules, have been recently ascribed to coal- or kerogen-like organic nanoparticles…
Small organic molecules are thought to provide building blocks for the formation of complex interstellar polycyclic aromatic hydrocarbons (PAHs). However, the underlying chemical mechanisms remain unclear, particularly concerning the role…
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…
Based on a one-zone evolution model of grain size distribution in a galaxy, we calculate the evolution of infrared spectral energy distribution (SED), considering silicate, carbonaceous dust, and polycyclic aromatic hydrocarbons (PAHs). The…
Infrared emission from polycyclic aromatic hydrocarbons (PAHs) play a major role in determining the charge balance of their host environments that include photo-dissociation regions (PDRs) in galaxies, planetary nebulae, and rims of…
Ram pressure stripping (RPS) plays a crucial role in shaping galaxy evolution in dense environments, yet its impact on the molecular and dusty phases of the interstellar medium remains poorly understood. We present JWST/NIRCam…
We present optical and mid-infrared photometry of a statistically complete sample of 29 very faint dwarf galaxies (M_r > -15 mag) selected from the SDSS spectroscopic sample and observed in the mid-infrared with Spitzer IRAC. This sample…
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…
A combined mid-IR spectrum of five colliding-wind, massive, dust-producing Population I Wolf-Rayet (WR) binaries shows a wealth of absorption and emission details coming from the circumstellar dust envelopes, as well as from the…
We examine polycyclic aromatic hydrocarbon (PAH), dust and atomic/molecular emission toward the Galactic bulge using Spitzer Space Telescope observations of four fields: C32, C35, OGLE and NGC 6522. These fields are approximately centered…
The behavior of the aromatic features as a function of metallicity/radiation field hardness in M101 HII regions and starburst galaxies is investigated using Spitzer/IRS spectra. These spectra reveal that the 6.2, 7.8+8.6, and 11.3 micron…