Mapping the aliphatic hydrocarbon content of interstellar dust in the Galactic plane

Abstract

We implement a new observational method for mapping the aliphatic hydrocarbon content in the solid phase in our Galaxy, based on spectrophotometric imaging of the 3.4 $\mu$m absorption feature from interstellar dust. We previously demonstrated this method in a field including the Galactic Centre cluster. We applied the method to a new field in the Galactic centre where the 3.4 $\mu$m absorption feature has not been previously measured and we extended the measurements to a field in the Galactic plane to sample the diffuse local interstellar medium, where the 3.4 $\mu$m absorption feature has been previously measured. We have analysed 3.4 $\mu$m optical depth and aliphatic hydrocarbon column density maps for these fields. Optical depths are found to be reasonably uniform in each field, without large source-to-source variations. There is, however, a weak trend towards increasing optical depth in a direction towards $b=0^{\circ }$ in the Galactic centre. The mean value of column densities and abundances for aliphatic hydrocarbon were found to be about several $\times 10^{18}\mathrm{c}{\mathrm{m}}^{-2}$ and several tens $\times 10^{-6}$, respectively for the new sightlines in the Galactic plane. We conclude that at least 10-20% of the carbon in the Galactic plane lies in aliphatic form.

References in corpus (79)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The chemical composition of the Sun
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Correcting for the Effects of Interstellar Extinction
• Interstellar Dust Grains
• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• The Wavelength Dependence of Interstellar Extinction from 1.25 to 8.0 microns Using GLIMPSE Data
• Planck 2013 results. XI. All-sky model of thermal dust emission
• The chemical make-up of the Sun: A 2020 vision
• Modelling the Galactic Interstellar Extinction Distribution in Three Dimensions
• The evolution of amorphous hydrocarbons in the ISM: dust modelling from a new vantage point
• 2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• Observations of Protoplanetary Disk Structures
• An Analysis of the Shapes of Interstellar Extinction Curves. VII. Milky Way Spectrophotometric Optical-through-Ultraviolet Extinction and Its R-Dependence
• Oxygen, Carbon and Nitrogen evolution in galaxies
• Line derived infrared extinction towards the Galactic Center
• The structure of the nuclear stellar cluster of the Milky Way
• Astrochemistry and compositions of planetary systems
• The solar chemical composition
• A cosmic abundance standard: chemical homogeneity of the solar neighbourhood and the ISM dust-phase composition
• Tracing the Ingredients for a Habitable Earth from Interstellar Space through Planet Formation
• The Chemical Homogeneity of Sun-like Stars in the Solar Neighborhood
• Three-dimensional interstellar dust reddening maps of the Galactic plane
• Astrochemistry of dust, ice and gas: introduction and overview
• Interstellar Extinction Law toward the Galactic Center II: V, J, H, and Ks Bands
• The origin and chemical evolution of carbon in the Galactic thin and thick disks
• HST Paschen alpha and 1.9 micron imaging of Sgr A West
• Extinction Map of the Galactic center: OGLE-II Galactic bulge fields
• Observational Constraints on the Physical Properties of Interstellar Dust in the Post-Planck Era
• The gas-to-extinction ratio and the gas distribution in the Galaxy
• Milky Way Mid-Infrared Spitzer Spectroscopic Extinction Curves: Continuum and Silicate Features
• A 3D extinction map of the Northern Galactic Plane based on IPHAS photometry
• Variations on a theme - the evolution of hydrocarbon solids: I. Compositional and spectral modelling - the eRCN and DG models
• Variations on a theme - the evolution of hydrocarbon solids: II. Optical property modelling - the optEC(s) model
• Variations on a theme - the evolution of hydrocarbon solids: III. Size-dependent properties - the optEC(s)(a) model
• GALACTICNUCLEUS: A high angular resolution $JH{K}_s$ imaging survey of the Galactic Centre. I. Methodology, performance, and near-infrared extinction towards the Galactic Centre
• The Dielectric Function of "Astrodust" and Predictions for Polarization in the 3.4$\mu$m and 10$\mu$m Features
• Point Sources from a Spitzer IRAC Survey of the Galactic Center
• Very Large Interstellar Grains as Evidenced by the Mid-Infrared Extinction
• A Correction to the Standard Galactic Reddening Map: Passive Galaxies as Standard Crayons
• Microgravity experiments on the collisional behavior of Saturnian ring particles
• Destruction of Refractory Carbon in Protoplanetary Disks
• First proper motions of thin dust filaments at the Galactic Center
• A Cool Accretion Disk around the Galactic Centre Black Hole
• Interstellar gas within $\sim 10$ pc of Sgr A${}^{\ast }$
• Large Metallicity Variations in the Galactic Interstellar Medium
• Stellar Bowshocks in the Northern Arm of the Galactic Center: More Members and Kinematics of the Massive Star Population
• Mantle formation, coagulation and the origin of cloud/core-shine: II. Comparison with observations
• L- and M-band imaging observations of the Galactic Center region
• The Interstellar Oxygen Crisis, or Where Have All the Oxygen Atoms Gone?
• Mantle formation, coagulation and the origin of cloud/core shine: I. Modelling dust scattering and absorption in the infra-red
• Dust Embedded Sources at the Galactic Center. 2 to 4$\mu$m imaging and spectroscopy in the central parsec
• Two New and Remarkable Sightlines through the Galactic Center's Molecular Gas
• VLT L-band mapping of the Galactic Center IRS 3-IRS 13 region Evidence for new Wolf-Rayet type stars
• Possible in situ Tests of the Evolution of Elemental and Isotopic Abundances in the Solar Convection Zone
• Sticky or not sticky? Measurements of the tensile strength of micro-granular organic materials
• The essential elements of dust evolution: A viable solution to the interstellar oxygen depletion problem?
• M-Band Spectra of Dust Embedded Sources at the Galactic Center
• Rocky Planetesimal Formation Aided by Organics
• Interstellar Silicon Depletion and the Ultraviolet Extinction
• 3D Galactic dust extinction mapping with multi-band photometry
• Aliphatic hydrocarbon content of the interstellar dust
• Interstellar Extinction and Elemental Abundances
• The enigma of GCIRS 3 - Constraining the properties of the mid-infrared reference star of the central parsec of the Milky Way with optical long baseline interferometry
• Toward understanding physical origin of 2175Å extinction bump in interstellar medium
• Growth of Aggregates with Liquid-Like Ice-Shells in Protoplanetary Discs
• ALMA and VLA observations of emission from the environment of Sgr A*
• How Much Graphene in Space?
• Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre I. Catalog of Variable Sources
• Complex small-scale structure in the infrared extinction towards the Galactic Centre
• Interstellar Extinction and Elemental Abundances: Individual Sight Lines
• IRAS 18511+0146: a proto Herbig Ae/Be cluster?
• Onset of planet formation in the warm inner disk -- Colliding dust aggregates at high temperatures
• A Zero-Gravity Instrument to Study Low Velocity Collisions of Fragile Particles at Low Temperatures
• The Interstellar Medium toward the Galactic Center Source 2MASS J17470898-2829561
• A method for mapping the aliphatic hydrocarbon content of interstellar dust towards the Galactic Centre
• Collisions of small ice particles under microgravity conditions (II): Does the chemical composition of the ice change the collisional properties?
• High-spectral resolution M-band observations of CO Rot-Vib absorption lines towards the Galactic center
• Dust and Gas environment of the young embedded cluster IRAS 18511+0146

Cited by in corpus (2)

• JWST reveals widespread CO ice and gas absorption in the Galactic Center cloud G0.253+0.016
• Photometric Mapping of Carbonaceous/Siliceous Dust and Water Ice in the ISM with JWST: Applications to the Dense Sightlines