Polycyclic Aromatic Hydrocarbons Archives

Graphic Abstract - ACS Earth and Space Chemistry

Theoretical and Experimental IR Spectra of Astronomical PAHs and PANHs in the 2000–1650 cm–1 Range (∼5–6 μm)

by Keith CowingJune 30, 2026June 30, 2026

[ACS Earth and Space Chemistry] Recent James Webb Space Telescope observations reveal unprecedented details in the 2000–1650 cm–1 (∼5–6 μm) region, including the well-known 5.25 and 5.75 μm bands.

Left: GO 2433’s F770W map of NGC 891, with the H2 S (1) maps for the four MRS pointings in our study, in colour. The contours in the background and inset images are F770W surface brightnesses. The white cross marks the centre of the galaxy. Right: Total intensity maps for a few key dust features in all observations. The maps are obtained by fitting a 1D model to each pixel independently, and summing the intensities of all sub-features belonging to the same complex. Because the 11.2 µm feature dominates the emission, each map is shown with its own scaling; we focus on the variations within each maps rather than the absolute intensity values. Non-fit pixels, skipped by PAHFIT, are shown in white. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Imaging & Spectroscopy, Interstellar, Status Report

Survival Of Very Small Carbonaceous Dust Grains In The Inner-CGM Of NGC 891 From JWST/MIRI MRS

by Keith CowingMay 28, 2026May 28, 2026

We present new spectroscopic observations of the inner circumgalactic medium (CGM) of NGC 891 taken with the Mid-Infrared Imager/Medium Resolution Spectroscopy instrument onboard JWST, in four positions: two near the […]

Two images of protoplanetary discs Tau 042021 (left) and Oph 163131 (right). -- ESA Larger imagery

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Pair Of Planet-forming Disks

by Keith CowingApril 3, 2026April 3, 2026

This month’s ESA/Webb Picture of the Month offers us a two-for-one on brand new stars — with some potential planets thrown in as well! This visual highlights views from the […]

A region in Ursa Major with maps of individual simulation components and their sum; these have been evaluated for a spectral channel centered on 0.803 µm. The color schemes vary in order to best illustrate the features of the individual signals. Notice how the scan pattern manifests in several of the components. The contributing images were generated with the Sky Simulator described in B. P. Crill et al. (2025). Real flag masks (Sec. 3.2) have been applied and are most noticeable at the centers of bright stars. -- astro-ph.IM

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Missions & Hardware, Status Report

Spectral Map Making With SPHEREx

by Keith CowingMarch 30, 2026March 30, 2026

We present map-making methodologies and preliminary spectral data cubes for SPHEREx, a NASA Explorer mission that launched in March 2025 and has been performing an all-sky near-infrared spectral survey.

Comparison of various tracers of dust, gas, and extinction toward the CygX region. Cyan contours in all images indicate H2O ice peak optical depths of 0.25, derived from the H2O ice map smoothed with a Gaussian kernel of σ ∼ 31′′ (5 pixels). (a) 2MASS NICEST AJ extinction, with a resolution of 3′ . (b) FCRAO 13CO (1–0) Moment 0 map (beamsize 45′′ FWHM) integrated over −10 to +20 km s−1 , corresponding to the ensemble of star-forming molecular clouds directly associated with the Cyg OB2 cluster (N. Schneider et al. 2006). (c) Herschel-derived NH2 column density. (d) Herschel-derived dust temperature, Td. Both Herschel images are at a resolution of 36.4′′ -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Intelligence & Language, Press Release

SPHEREx Wide-Field Infrared Spectral Mapping of Interstellar Ices and Polycyclic Aromatic Hydrocarbons

by Keith CowingMarch 16, 2026March 16, 2026

We present some of the first infrared spectral maps acquired by SPHEREx. These maps, which to our knowledge are the largest of their type ever compiled in the near-infrared, reveal […]

James Webb Space Telescope Near-infrared Camera (JWST NIRCam) false colour image of IRAS07251-0248, made by combining exposures with the 2 mm (Blue), 2.77 mm (Green) and 3.56 mm (Red) wide filters on NIRCam. Data are part of the observations carried out under JWST GO Programme ID 3368 (P.I. L. Armus). Calibrated data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. Credit - Data came from Mikulski Archive for Space Telescopes, Space Telescope Science Institute, Association of Universities for Research in Astronomy, Inc., NASA.

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

James Webb Space Telescope Reveals An Exceptional Richness Of Organic Molecules In One Of The Most Infrared Luminous Galaxies In The Local Universe

by Keith CowingFebruary 9, 2026February 9, 2026

The study focuses on IRAS 07251–0248, an ultra-luminous infrared galaxy whose nucleus is hidden behind vast amounts of gas and dust. This material absorbs most of the radiation emitted by […]

A color–magnitude Hess diagram of Sextans A with JWST/ NIRCam photometry at 2.7 and 4.4 μm with the positions of the JWST/LRS targets overplotted. COLIBRI isochrones with [M/H] = −1.7 are plotted for log(age) = 8.3 in orange and log(age) = 9 in blue (P. Marigo et al. 2013), both showing prominent branches of thermally pulsing AGB stars at red colors (F277W − F444W > 0 mag). The population of faint red objects is dominated by unresolved background galaxies and young stellar objects (J. T. Warfield et al. 2023; L. Lenkić et al. 2024). -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

JWST Captures Growth of Aromatic Hydrocarbon Dust Particles in the Extremely Metal-poor Galaxy Sextans A

by Keith CowingJanuary 13, 2026January 13, 2026

The mid-infrared spectrum of star-forming, high metallicity galaxies is dominated by emission features from aromatic and aliphatic bonds in small carbonaceous dust grains, often referred to as polycyclic aromatic hydrocarbons […]

Graphic of the proposed scenario of sublimation in a disk with a warm dust trap, viewed from the side, based on van der Marel et al. (2021b). If the bulk of the dust content is located in a dust trap inside the CO snowline at 30 K, this implies that fragments of its icy pebbles can be transported vertically to the higher disk layers above the H2O snow surface at 150 K, and sublimate their icy content into the gasphase, where it becomes observable. If the bulk of the pebbles is located outside the CO snowline, its icy layers may remain frozen out and its contents are not revealed in the gas phase. Such a scenario may also apply to PAHs, which is the hypothesis of this work. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

Observational Evidence For A Possible Link Between PAH Emission And Dust Trap Locations In Protoplanetary Disks

by Keith CowingDecember 30, 2025December 30, 2025

Polycyclic Aromatic Hydrocarbons (PAHs) are commonly detected in protoplanetary disks, but it is unclear what causes the wide range of intensities across the samples.

The different views of B3LYP-D3(BJ)/6- 311++G(d,p) level optimized geometric structures for 9- iminofluorene (left) and benzophenone imine (right). The arrow shows C9 position of iminofluorene. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

Rotational Spectra And Search For Aromatic Imines: 9-Iminofluorene And Benzophenone Imine

by Keith CowingDecember 26, 2025December 26, 2025

Interstellar detections of several cyano derivatives of large polycyclic aromatic hydrocarbons (PAHs) have now been achieved, enabled by accurate laboratory measurements of their microwave rotational spectra.

Free organic volatiles and IOM thermal degradation products liberated by flash heating to ~610 °C of Bennu samples.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Meteorites & Asteroids, Missions & Hardware, Robotics/Rovers/UAVs, Sample Return, Status Report, Tricorders & Sensors

Prebiotic Organic Compounds In Samples Of Asteroid Bennu Indicate Heterogeneous Aqueous Alteration

by Keith CowingNovember 25, 2025November 25, 2025

NASA’s OSIRIS-REx mission characterized the asteroid Bennu and delivered pristine samples of its regolith to Earth.

Polycyclic Aromatic Hydrocarbons

Theoretical and Experimental IR Spectra of Astronomical PAHs and PANHs in the 2000–1650 cm–1 Range (∼5–6 μm)

Survival Of Very Small Carbonaceous Dust Grains In The Inner-CGM Of NGC 891 From JWST/MIRI MRS

A Pair Of Planet-forming Disks

Spectral Map Making With SPHEREx

SPHEREx Wide-Field Infrared Spectral Mapping of Interstellar Ices and Polycyclic Aromatic Hydrocarbons

James Webb Space Telescope Reveals An Exceptional Richness Of Organic Molecules In One Of The Most Infrared Luminous Galaxies In The Local Universe

JWST Captures Growth of Aromatic Hydrocarbon Dust Particles in the Extremely Metal-poor Galaxy Sextans A

Observational Evidence For A Possible Link Between PAH Emission And Dust Trap Locations In Protoplanetary Disks

Rotational Spectra And Search For Aromatic Imines: 9-Iminofluorene And Benzophenone Imine

Prebiotic Organic Compounds In Samples Of Asteroid Bennu Indicate Heterogeneous Aqueous Alteration

Indigenizing The Drake Equation: How Indigenous Methods Can Help Us Understand Life In The Milky Way Galaxy

NASA Spaceline Current Awareness List #1,205 26 June 2026 (Space Life Science Research Results)

Theoretical and Experimental IR Spectra of Astronomical PAHs and PANHs in the 2000–1650 cm–1 Range (∼5–6 μm)

Ecological Constraints To Mirror Life

Theoretical Determination Of The Binding Energies Of Methanol And Related Species Onto Amorphous Solid Water Ice