相关论文: New PAH mode at 16.4 microns
We have carried out a detailed analysis of the 3.4 micron spectral feature arising from Polycyclic Aromatic Hydrocarbons (PAH), using JWST archival data. For the first time in an external galaxy (NGC 6240), we have identified two distinct…
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…
Polycyclic Aromatic Hydrocarbons (PAHs) constitute a significant fraction of the Universe's carbon budget, playing a key role in the cosmic carbon cycle and dominating the mid-infrared spectra of astrophysical environments in which they…
Infrared emission features at 3.3, 6.2, 7.7, 8.6, and 11.2 $\mu$m, attributed to polycyclic aromatic hydrocarbons, show variations in relative intensity, shape, and peak position. These variations depend on the physical conditions of the…
Long-slit 8-13 um spectroscopy of the nebula around NGC 1333 SVS reveals spatial variations in the strength and shape of emission features which are probably produced by polycyclic aromatic hydrocarbons (PAHs). Close to SVS 3, the 11.2 um…
Astronomical mid-IR spectra show two minor PAH features at 5.25 and 5.7 $\mu$m (1905 and 1754 cm$^{\rm - 1}$) that hitherto have been little studied, but contain information about the astronomical PAH population that complements that of the…
We present a systematic study of mid-infrared spectra of galaxies including star-forming galaxies and Active Galactic Nuclei observed with JWST MIRI-MRS and NIRSpec-IFU. We focus on the relative variations of the 3.3, 6.2, 7.7, 11.3, 12.7…
In this Letter we report the results of density functional theory calculations on medium-sized neutral Polycyclic Aromatic Hydrocarbon (PAH) molecules with armchair edges. These PAH molecules possess strong C-H stretching and bending modes…
NGC 7023 is a well-studied reflection nebula, which shows strong emission from polycyclic aromatic hydrocarbon (PAH) molecules in the form of aromatic infrared bands (AIBs). The spectral variations of the AIBs in this region are connected…
We present 15 - 20 micron long-slit spectra, from the Infrared Spectrograph (IRS) on Spitzer, of NGC 7023. We observe recently-discovered interstellar emission features, at 15.9, 16.4, 17.0, 17.4, 17.8, and 18.9 microns, throughout the…
Polycyclic aromatic hydrocarbons (PAHs) appear to be ubiquitous in terrestrial atmosphere as well as in the interstellar medium (ISM). In the astrophysical context presence of PAHs is interpreted by the observations of mid-IR emission bands…
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 report new correlations between ratios of band intensities of the 15-20 {\mu}m emission bands of polycyclic aromatic hydrocarbons (PAHs) in a sample of fifty-seven sources observed with Spitzer/IRS. This sample includes Large Magellanic…
We study the Polycyclic Aromatic Hydrocarbons (PAH) bands, ionic emission lines, and Mid-infrared continuum properties, in a sample of 171 emission line galaxies taken from literature plus 15 new active galactic nuclei (AGN) Spitzer…
We investigate the mid-infrared (IR) emission in the Orion Bar photodissociation region, using archival photometric and spectroscopic observations from UKIRT, Spitzer, ISO, and SOFIA telescopes. Specifically, we consider flux densities of…
We present observations from the First Light Infrared TEst CAMera (FLITECAM) on board the Stratospheric Observatory for Infrared Astronomy (SOFIA), the Spitzer Infrared Array Camera (IRAC) and the Spitzer Infrared Spectrograph (IRS) SH mode…
We report the results of a search for emission features from interstellar deuterated polycyclic aromatic hydrocarbons (PAHs) in the 4um region with the Infrared Camera (IRC) onboard AKARI. No significant excess emission is seen in 4.3-4.7um…
The mid-IR spectra of six large, irregular PAHs with formulae (C84H24 - C120H36) have been computed using Density Functional Theory (DFT). Trends in the dominant band positions and intensities are compared to those of large, compact PAHs as…
Interstellar Polycyclic Aromatic Hydrocarbon (PAH) molecules exist in diverse forms depending on the local physical environment. Formation of ionized PAHs (anions and cations) is favourable in the extreme conditions of the ISM. Besides in…
Based on theoretical spectra computed using Density Functional Theory we study the properties of Polycyclic Aromatic Hydrocarbons (PAH). In particular using bin-average spectra of PAH molecules with varying number of carbons we investigate…