Polycyclic Aromatic Hydrocarbons Archives

JWST/NIRCam F335M image of 30 Dor. The blue box represents the field of view of the MIRI/MRS Channel 1. The inset shows the spectroscopic FOVs: NIRSpec (green), MIRI/MRS Channel 1 (blue), MIRI/MRS Channel 2 (pink), and MIRI/MRS Channel 3 (yellow). -- astro-ph.GA

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

A Study of Polycyclic Aromatic Hydrocarbon Emission in 30 Dor as seen by JWST

by Keith CowingOctober 29, 2024October 29, 2024

Polycyclic aromatic hydrocarbons (PAHs) are responsible for strong mid-IR emission features near star-forming regions. It is well known that low-metallicity environments exhibit weaker PAH emission, but it is not clear […]

Two-dimensional fits of U, qPAH, and Σd as a function of a combination of the resolved stellar mass and star formation rate. Top row: 2D histograms of the Σ⋆–ΣSFR plane, where the bin values show the average U (left column), qPAH (center column), and Σd (right column). The light bins are calculated for all pixels passing the 3σ S/N cut, and the bright bins are calculated for pixels passing that same cut and that that have Σ⋆ and ΣSFR above the completeness thresholds. The 2D fit uses the standard deviations within each bin as errors in the linear regression. Bottom row: The x-axis shows the best-fit using both Σ⋆ and ΣSFR. The y-axis shows the observed data. The best-fit coefficients are reported in Table 5. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Interstellar, Status Report

The Resolved Behavior of Dust Mass, Polycyclic Aromatic Hydrocarbon Fraction, and Radiation Field in ~ 800 Nearby Galaxies

by Keith CowingOctober 8, 2024October 8, 2024

We present resolved 3.6−250 μm dust spectral energy distribution (SED) fitting for ∼800 nearby galaxies. We measure the distribution of radiation field intensities heating the dust, the dust mass surface […]

GOTHAM spectra showcasing several 1-cyanopyrene lines detected in TMC-1 observations. The original GOTHAM observational data for which one channel corresponds to 1.4 kHz were smoothed with a Hanning window to a resolution of 14 kHz, depicted in black. The spectrum of 1-cyanopyrene is overplotted in violet using source-dependent molecular parameters as reported in Table S4. The quantum numbers of each transition, ignoring 14N nuclear electric quadrupole splitting, are reported. Each line contains multiple closely spaced K-components of each transition which are denoted α, β, γ, δ = {0,1}, {1,2}, {2,3}, {3,4}. -- astro-ph.GA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Interstellar, Sample Return, Status Report

Discovery Of Interstellar 1-cyanopyrene: A Four-ring Polycyclic Aromatic Hydrocarbon In TMC-1

by Keith CowingOctober 5, 2024October 7, 2024

Polycyclic aromatic hydrocarbons (PAHs) are thought to be the most abundant class of molecules in space, yet their interstellar lifecycle is poorly understood due to difficulties detecting individual PAHs.

Velocity-stacked spectra and matched filter responses of 2- and 4-cyanopyrene. The stacked GOTHAM observations (black) are overlaid with the simulated stacked spectrum of 2- and 4-cyanopyrene (blue and pink, respectively), each consisting of the 150 brightest SNR lines (left panels). Marginalized posterior parameters were used in both simulations, as reported in Supplementary Table A3. The corresponding impulse response for the matched filtering analysis is shown, yielding a significance of 8.0 σ and 12.9 σ for the 2- and 4-cyanopyrene detections, respectively (right panels). The small features in the stacked simulated spectrum (pink) in the bottom left panel result from the densely populated 4-cyanopyrene lines (see Fig. A3) that add up in the stack. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Meteorites & Asteroids, Status Report

Detections Of Interstellar 2-cyanopyrene And 4-cyanopyrene In TMC-1

by Keith CowingOctober 4, 2024October 8, 2024

Polycyclic aromatic hydrocarbons (PAHs) are among the most ubiquitous compounds in the universe, accounting for up to ~25% of all interstellar carbon. Since most unsubstituted PAHs do not possess permanent […]

Top: Examples of the AKARI/IRC 2.5-5 µm spectra: (a) star-forming galaxy, (b) composite galaxy and (c) AGN-dominated galaxy. Bottom: Examples of the SED fitting results for star-forming galaxies: (a) IRG, (b) LIRG and (c) ULIRG. The observed flux densities are indicated with filled cyan circles. The SED model is composed of ionized PAHs (blue dotted line), neutral PAHs (purple dotted line), SamC (green dotted line), LamC (yellow dotted line), aSil (red dotted line) and near-IR continuum (purple dashed line). The total model spectrum and the model flux densities are shown with a solid cyan line and open red squares, respectively. -- astro-ph.GA

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

Processing of Hydrocarbon Dust In Star-forming Galaxies Revealed With AKARI

by Keith CowingJuly 26, 2024July 26, 2024

Hydrocarbon dust is one of the dominant components of interstellar dust, which mainly consists of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons. While hydrocarbon dust is thought to be processed in […]

NASA Raman Spectroscopic Database -- NASA

AI - Data - Apps - Cybernetics, Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Exploration Gear & Tech, Imaging & Spectroscopy, Missions & Hardware, Status Report, Tricorders & Sensors

Tricorder Tech: The NASA Raman Spectroscopic Database: Ramdb version 1.00

by Keith CowingJune 26, 2024June 26, 2024

The NASA Raman Spectroscopic Database (Ramdb) was developed to provide a publicly accessible, user-friendly database for spectra relevant to the planetary science community.

Composite computed anharmonic spectra of cyano-substituted PAHs (blue) and standard PAHs (black) from 700 - 950 cm−1 , the out-of-plane CH bending region, broadened using a Lorentzian line shape with a FWHM of 15 cm−1 (top) and 1 cm−1 (bottom). -- astro-ph.GA

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

The High-Resolution Far- to Near-Infrared Anharmonic Absorption Spectra of Cyano-Substituted Polycyclic Aromatic Hydrocarbons from 300-6200 cm−1

by Keith CowingJune 4, 2024June 4, 2024

Cyano-substituted polycyclic aromatic hydrocarbons (CN-PAHs) may contribute to the emission detected in the 7 – 9 μm (1430 – 1100 cm−1) and 11 – 15 μm (900 – 670 cm−1) […]

Dwarf galaxy NGC 4449 The orange-red areas indicate the distribution of a type of carbon-based compounds known as polycyclic aromatic hydrocarbons (or PAHs) — the MIRI F770W filter is particularly suited to imaging these important molecules. -- NASA

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

Webb Telescope Observes Organic Astrochemistry In Dwarf Galaxy NGC 4449

by Keith CowingMay 30, 2024May 30, 2024

Featured in this new image from the NASA/ESA/CSA James Webb Space Telescope is the dwarf galaxy NGC 4449. This galaxy, also known as Caldwell 21, resides roughly 12.5 million light-years […]

RPAH mapped in NGC 4303, with the F770W star subtraction described in Section 3.1 completed before incorperation of the F770W into the RPAH map. Yellow, pink, and blue contours show the location of the nucleus, bar, and spiral arms, respectively, as defined by the maps from Querejeta et al. (2021). Light green contours show the locations of the nebular regions from the PHANGS–MUSE nebular catalogs (Santoro et al. 2022; Groves et al. 2023). The black bar on the bottom left represents a scale of 5 kpc. Maps have been smoothed to 0. ′′9 to increase the signal to noise. -- astro-ph.GA

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

The Fraction of Dust Mass in the Form of PAHs on 10-50 pc Scales in Nearby Galaxies

by Keith CowingMay 27, 2024May 27, 2024

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous component of the interstellar medium (ISM) in z~0 massive, star-forming galaxies and play key roles in ISM energy balance, chemistry, and shielding.

The first two principal components for a data cube of H2 of NGC 3256 N. The left panels show the tomograms of each component which describes the spatial intensity of each eigenspectrum. The black crosses show the peak continuum position at this wavelength. The right panels show the eigenspectrum of each principal component. The horizontal dashed lines show where the weight is zero and the vertical dashed lines show the kinematic centre, determined by the peak wavelength of the first principal component. The first component describes the rest frame emission, while the second captures rotation of the gas. -- astro-ph.GA

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

The Kinematics of Polycyclic Aromatic Hydrocarbons (PAHs) in Galaxies revealed by Principal Component Analysis (PCA) tomography with JWST/NIRSpec

by Keith CowingMay 24, 2024May 24, 2024

Polycyclic Aromatic Hydrocarbons (PAHs) are organic molecules which comprise the smallest particles of dust in the interstellar medium (ISM). Due to their broad/complex emission profiles, obtaining kinematics is a challenge […]

Polycyclic Aromatic Hydrocarbons

A Study of Polycyclic Aromatic Hydrocarbon Emission in 30 Dor as seen by JWST

The Resolved Behavior of Dust Mass, Polycyclic Aromatic Hydrocarbon Fraction, and Radiation Field in ~ 800 Nearby Galaxies

Discovery Of Interstellar 1-cyanopyrene: A Four-ring Polycyclic Aromatic Hydrocarbon In TMC-1

Detections Of Interstellar 2-cyanopyrene And 4-cyanopyrene In TMC-1

Processing of Hydrocarbon Dust In Star-forming Galaxies Revealed With AKARI

Tricorder Tech: The NASA Raman Spectroscopic Database: Ramdb version 1.00

The High-Resolution Far- to Near-Infrared Anharmonic Absorption Spectra of Cyano-Substituted Polycyclic Aromatic Hydrocarbons from 300-6200 cm−1

Webb Telescope Observes Organic Astrochemistry In Dwarf Galaxy NGC 4449

The Fraction of Dust Mass in the Form of PAHs on 10-50 pc Scales in Nearby Galaxies

The Kinematics of Polycyclic Aromatic Hydrocarbons (PAHs) in Galaxies revealed by Principal Component Analysis (PCA) tomography with JWST/NIRSpec

Offworld Expedition Training: Astronauts Explore An Ancient Earth Volcano

Orbital Bioscience: Organoids Cultured In Microgravity

JWST Detection Of Methane Emission From A Young Brown Dwarf

Revealing The Shiny Nature Of Lava Worlds: Small Planet Phase Curves With TESS

Simulated Effects of Radioactive Elements on Magnetic Evolution and Atmospheric Mass Loss of Earth-like Planets