Interstellar Polycyclic Aromatic Hydrocarbon Molecules

Large polycyclic aromatic hydrocarbon (PAH) molecules carry the infrared (IR) emission features that dominate the spectra of most galactic and extragalactic sources. This review surveys the observed mid-IR characteristics of these emission features and summarizes laboratory and theoretical studies of the spectral characteristics of PAHs and the derived intrinsic properties of emitting interstellar PAHs. Dedicated experimental studies have provided critical input for detailed astronomical models that probe the origin and evolution of interstellar PAHs and their role in the universe. The physics and chemistry of PAHs are discussed, emphasizing the contribution of these species to the photoelectric heating and the ionization balance of the interstellar gas and to the formation of small hydrocarbon radicals and carbon chains. Together, these studies demonstrate that PAHs are abundant, ubiquitous, and a dominant force in the interstellar medium of galaxies.

[1]  J. Augereau,et al.  C2D Spitzer-IRS spectra of disks around T Tauri stars IV Crystalline silicates , 2009, 0908.4153.

[2]  G. Helou,et al.  The Spitzer View of the Extragalactic Universe , 2008 .

[3]  A. Tielens,et al.  Chemical Rates on Small Grains and PAHs: C+ Recombination and H2 Formation , 2008, 0803.0138.

[4]  E. Peeters,et al.  The Infrared Spectra of Very Large, Compact, Highly Symmetric, Polycyclic Aromatic Hydrocarbons (PAHs) , 2008, 0802.1071.

[5]  E. Peeters,et al.  Variations of the Mid-IR Aromatic Features inside and among Galaxies , 2008, 0801.4955.

[6]  C. Joblin,et al.  Extended Red Emission and the evolution of carbonaceous nanograins in NGC 7023 , 2008, 0801.3400.

[7]  Caltech,et al.  Spatially extended polycyclic aromatic hydrocarbons in circumstellar disks around T Tauri and Herbig Ae stars , 2007, 0710.2825.

[8]  C. Joblin,et al.  Thermochemistry and infrared spectroscopy of neutral and cationic iron-polycyclic aromatic hydrocarbon complexes of astrophysical interest: fundamental density functional theory studies. , 2007, The journal of physical chemistry. A.

[9]  J. Lemaire,et al.  Infrared spectra of isolated protonated polycyclic aromatic hydrocarbons: protonated naphthalene. , 2007, Angewandte Chemie.

[10]  P. Chanial,et al.  Stellar Evolutionary Effects on the Abundances of Polycyclic Aromatic Hydrocarbons and Supernova-Condensed Dust in Galaxies , 2007, 0708.0790.

[11]  Gaspard Duchêne,et al.  HD 97048: a closer look at the disk , 2007 .

[12]  P. Theulé,et al.  Rotational Spectra of Small PAHs: Acenaphthene, Acenaphthylene, Azulene, and Fluorene , 2007 .

[13]  Astronomy,et al.  The Calibration of Mid-Infrared Star Formation Rate Indicators , 2007, 0705.3377.

[14]  J. Bernard-Salas,et al.  The Unusual Hydrocarbon Emission from the Early Carbon Star HD 100764: The Connection between Aromatics and Aliphatics , 2007, 0705.0905.

[15]  O. Shemmer,et al.  PAH Emission and Star Formation in the Host of the z ~ 2.56 Cloverleaf QSO , 2007, 0704.0133.

[16]  D. Calzetti,et al.  Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample , 2007, astro-ph/0703213.

[17]  Y. Deville,et al.  Analysis of the emission of very small dust particles from Spitzer spectro-imagery data using blind signal separation methods , 2007, astro-ph/0703072.

[18]  J. Augereau,et al.  PAH chemistry and IR emission from circumstellar disks , 2007, astro-ph/0701606.

[19]  C. Joblin,et al.  On-line database of the spectral properties of polycyclic aromatic hydrocarbons , 2007, astro-ph/0701254.

[20]  K. Sellgren,et al.  The 15-20 μm Spitzer Spectra of Interstellar Emission Features in NGC 7023 , 2006, astro-ph/0612544.

[21]  Jr.,et al.  The Mid-Infrared Spectrum of Star-forming Galaxies: Global Properties of Polycyclic Aromatic Hydrocarbon Emission , 2006, astro-ph/0610913.

[22]  B. Draine,et al.  Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era , 2006, astro-ph/0608003.

[23]  A. Tielens,et al.  Infrared Molecular Starburst Fingerprints in Deeply Obscured (Ultra)Luminous Infrared Galaxy Nuclei , 2006, astro-ph/0612748.

[24]  J. Bernard-Salas,et al.  The Mid-Infrared Properties of Starburst Galaxies from Spitzer-IRS Spectroscopy , 2006 .

[25]  B. Rowe,et al.  Laboratory measurements of the recombination of PAH ions with electrons: implications for the PAH charge state in interstellar clouds. , 2006, Faraday discussions.

[26]  V. Bierbaum,et al.  Gas-Phase Study of Coronene Cation Reactivity of Interstellar Relevance , 2006 .

[27]  C. Joblin,et al.  Theoretical evaluation of PAH dications properties , 2006, astro-ph/0609681.

[28]  C. Joblin,et al.  Formation and destruction of polycyclic aromatic hydrocarbon clusters in the interstellar medium , 2006, astro-ph/0609186.

[29]  J. Augereau,et al.  C2D Spitzer-IRS spectra of disks around T Tauri stars. II. PAH emission features , 2006, astro-ph/0609157.

[30]  J. Rho,et al.  Shock Processing of Interstellar Dust and Polycyclic Aromatic Hydrocarbons in the Supernova Remnant N132D , 2006, astro-ph/0609133.

[31]  J. Bernard-Salas,et al.  The Mid-IR Properties of Starburst Galaxies from Spitzer-IRS Spectroscopy , 2006, astro-ph/0609024.

[32]  G. Williger,et al.  What Is the Total Deuterium Abundance in the Local Galactic Disk? , 2006, astro-ph/0608308.

[33]  Olivier Pirali,et al.  Far-infrared spectroscopy of small polycyclic aromatic hydrocarbons. , 2006, Physical chemistry chemical physics : PCCP.

[34]  A. Tielens,et al.  Infrared Spectroscopy of Gas-Phase Complexes of Fe+ and Polycyclic Aromatic Hydrocarbon Molecules , 2006 .

[35]  M. V. D. Ancker,et al.  A survey for nanodiamond features in the 3 micron spectra of Herbig Ae/Be stars , 2006, astro-ph/0606650.

[36]  C. Joblin,et al.  A general model for the identification of specific PAHs in the far-IR , 2006, astro-ph/0606264.

[37]  C. Joblin,et al.  Diagnostics for specific PAHs in the far-IR: Searching neutral naphthalene and anthracene in the Red Rectangle , 2006, astro-ph/0605411.

[38]  Pasadena,et al.  Spitzer/IRAC and ISOCAM/CVF insights on the origin of the near to mid-IR Galactic diffuse emission , 2006, astro-ph/0604238.

[39]  G. Walker,et al.  The Gas Phase Spectrum of Cyclic C18 and the Diffuse Interstellar Bands , 2006 .

[40]  D. Calzetti,et al.  Extended Mid-Infrared Aromatic Feature Emission in M82 , 2006, astro-ph/0603551.

[41]  B. Rowe,et al.  Reaction of anthracene with CH radicals: an experimental study of the kinetics between 58 and 470 K. , 2006, The journal of physical chemistry. A.

[42]  S. Hony,et al.  UIR bands in the ISO SWS spectrum of the carbon star TU Tauri , 2006 .

[43]  J. Bernard-Salas,et al.  Mid-Infrared Properties of Low-Metallicity Blue Compact Dwarf Galaxies from the Spitzer Infrared Spectrograph , 2005, astro-ph/0510856.

[44]  J. Rho,et al.  A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy , 2005, astro-ph/0510630.

[45]  L. Testi,et al.  Spatially resolved PAH emission in the inner disks of Herbig Ae/Be stars , 2005, astro-ph/0503105.

[46]  Hydrogen dissociation of naphthalene cations: a theoretical study , 2005 .

[47]  D. Hudgins,et al.  Variations in the Peak Position of the 6.2 μm Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population , 2005 .

[48]  M. Sauvage,et al.  ISM properties in low-metallicity environments I. mid-infrared spectra of dwarf galaxies , 2005, astro-ph/0510086.

[49]  C. Bréchignac,et al.  Photoinduced products from cold coronene clusters. A route to hydrocarbonated nanograins , 2005 .

[50]  P. Ehrenfreund,et al.  A quantitative study of proton irradiation and UV photolysis of benzene in interstellar environments , 2005 .

[51]  A. Tielens.  The Physics and Chemistry of the Interstellar Medium , 2005 .

[52]  G. Rieke,et al.  Metallicity Effects on Mid-Infrared Colors and the 8 μm PAH Emission in Galaxies , 2005, astro-ph/0506214.

[53]  P. Ehrenfreund,et al.  Formation and photostability of N-heterocycles in space. I. The effect of nitrogen on the photostability of small aromatic molecules , 2005 .

[54]  J. Le Garrec,et al.  The reaction of anthracene with OH radicals: an experimental study of the kinetics between 58 and 470 K. , 2005, The Journal of chemical physics.

[55]  A. Abergel,et al.  Are PAHs precursors of small hydrocarbons in photo-dissociation regions? The Horsehead case , 2005, astro-ph/0501339.

[56]  P. Temi,et al.  Variations of the Mid-Infrared Emission Spectrum in Reflection Nebulae , 2004, astro-ph/0412100.

[57]  D. Wales,et al.  Stacked clusters of polycyclic aromatic hydrocarbon molecules. , 2004, The journal of physical chemistry. A.

[58]  C. Joblin,et al.  Spectroscopy of polycyclic aromatic hydrocarbons and very small grains in photodissociation regions , 2005 .

[59]  C. Grillmair,et al.  Observations of Ultraluminous Infrared Galaxies with the Infrared Spectrograph on the Spitzer Space Telescope. II. The IRAS Bright Galaxy Sample , 2006, astro-ph/0610218.

[60]  E. Peeters,et al.  Polycyclic Aromatic Hydrocarbon Emission in the 15-21 Micron Region , 2004 .

[61]  E. Peeters,et al.  Polycyclic Aromatic Hydrocarbons as a Tracer of Star Formation? , 2004 .

[62]  L. Kewley,et al.  Spitzer Infrared Nearby Galaxies Survey (SINGS) Imaging of NGC 7331: A Panchromatic View of a Ringed Galaxy , 2004 .

[63]  E. Peeters,et al.  The Profiles of the 3-12 Micron Polycyclic Aromatic Hydrocarbon Features , 2004 .

[64]  K. Sellgren,et al.  New Infrared Emission Features and Spectral Variations in NGC 7023 , 2004, astro-ph/0407213.

[65]  Bram AckeMario E. van den Ancker.  ISO spectroscopy of disks around Herbig Ae/Be stars , , 2004, astro-ph/0406050.

[66]  J. Cernicharo.  The Polymerization of Acetylene, Hydrogen Cyanide, and Carbon Chains in the Neutral Layers of Carbon-rich Proto-planetary Nebulae , 2004 .

[67]  É. Habart,et al.  PAHs in circumstellar disks around Herbig Ae/Be stars , 2004, astro-ph/0405195.

[68]  E. Peeters,et al.  The profiles of the 3 to 12 $\mu$m PAH features , 2004, astro-ph/0405098.

[69]  S. Sandford,et al.  Deuterated Interstellar Polycyclic Aromatic Hydrocarbons , 2004 .

[70]  G. Walker,et al.  On the Possible Role of Carbon Chains as Carriers of Diffuse Interstellar Bands , 2004 .

[71]  A. Abergel,et al.  Carbon budget and carbon chemistry in Photon Dominated Regions , 2004, astro-ph/0401309.

[72]  A. Tielens,et al.  Laboratory Infrared Spectroscopy of Cationic Polycyclic Aromatic Hydrocarbon Molecules , 2003 .

[73]  V. Bierbaum,et al.  Hydrogenation and Charge States of Polycyclic Aromatic Hydrocarbons in Diffuse Clouds. II. Results , 2003 .

[74]  H. Liszt.  Gas - phase recombination, grain neutralization and cosmic - ray ionization in diffuse gas , 2002, astro-ph/0211369.

[75]  Francoise Combes,et al.  SF2A-2003: Semaine de l'Astrophysique Franaise , 2003 .

[76]  R. Saykally,et al.  Single-Photon Infrared Emission Spectroscopy of Gaseous Polycyclic Aromatic Hydrocarbon Cations: A Direct Test for Proposed Carriers of the Unidentified Infrared Emission Bands , 2002 .

[77]  Richard N. Zare,et al.  Side Group Addition to the Polycyclic Aromatic Hydrocarbon Coronene by Ultraviolet Photolysis in Cosmic Ice Analogs , 2002 .

[78]  P. Cau.  Formation of carbon grains in the atmosphere of IRC+10216 I. The role of periodic shocks in the formation of PAHs and their dimers , 2002 .

[79]  B. Foing,et al.  Spectroscopy of large PAHs Laboratory studies and comparison to the Diffuse Interstellar Bands , 2002 .

[80]  Eric Herbst,et al.  The Synthesis of Benzene in the Proto-planetary Nebula CRL 618 , 2002 .

[81]  A. A. Kaas,et al.  Evolution of very small particles in the southern part of Orion B observed by ISOCAM , 2002 .

[82]  C. Joblin,et al.  The profiles of the aromatic infrared bands explained with molecular carriers , 2002 .

[83]  C. Bauschlicher,et al.  The rich 6 to 9 vec mu m spectrum of interstellar PAHs , 2002, astro-ph/0205400.

[84]  J. Bauschlicher.  The Infrared Spectra of C96H24, C96H24+, and C96H25+ , 2002 .

[85]  B. Draine,et al.  Do the Infrared Emission Features Need Ultraviolet Excitation? The Polycyclic Aromatic Hydrocarbon Model in UV-poor Reflection Nebulae , 2002, astro-ph/0201060.

[86]  C. Bauschlicher,et al.  The rich 6 to 9m spectrum of interstellar PAHs , 2002 .

[87]  A. Tielens,et al.  Gas-Phase Infrared Spectrum of the Coronene Cation , 2001 .

[88]  A. Tielens,et al.  Theoretical Modeling of Infrared Emission from Neutral and Charged Polycyclic Aromatic Hydrocarbons. II. , 2001 .

[89]  R. Saykally,et al.  Single photon infrared emission spectroscopy of the gas phase pyrene cation: support for a polycyclic aromatic hydrocarbon origin of the unidentified infrared emission bands. , 2001, Physical review letters.

[90]  S. Drapatz,et al.  The Aromatic Infrared Bands as seen by ISO-SWS: Probing the PAH model , 2001, astro-ph/0104144.

[91]  V. Bierbaum,et al.  Hydrogenation and Charge States of PAHs in Diffuse Clouds. I. Development of a Model , 2001 .

[92]  Ana Heras,et al.  Infrared Space Observatory's Discovery of C4H2, C6H2, and Benzene in CRL 618 , 2001 .

[93]  J. Bouwman,et al.  ISO spectroscopy of circumstellar dust in 14 Herbig Ae/Be systems: Towards an understanding of dust processing , 2000, astro-ph/0012295.

[94]  Infrared Emission from Interstellar Dust. I. Stochastic Heating of Small Grains , 2000, astro-ph/0011318.

[95]  E. Peeters,et al.  The CH out of plane bending modes of PAH molecules in astrophysical environments , 2001, astro-ph/0103035.

[96]  R. Saykally,et al.  Peripherally Hydrogenated Neutral Polycyclic Aromatic Hydrocarbons as Carriers of the 3 Micron Interstellar Infrared Emission Complex: Results from Single-Photon Infrared Emission Spectroscopy , 2000, The Astrophysical journal.

[97]  J. Oomens,et al.  Gas-Phase Infrared Photodissociation Spectroscopy of Cationic Polyaromatic Hydrocarbons , 2000 .

[98]  I. Gatley,et al.  High-Resolution Imaging of Photodissociation Regions in NGC 6334 , 2000 .

[99]  Saclay,et al.  Mid-infrared diagnostics to distinguish AGNs from starbursts , 2000, astro-ph/0005376.

[100]  K. Sellgren,et al.  Infrared Space Observatory Mid-Infrared Spectra of Reflection Nebulae , 2000 .

[101]  P. Cox,et al.  The C-C-C bending modes of PAHs : a new emission plateau from 15 to 20 mu m , 2000 .

[102]  Farid Salama,et al.  Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: A Survey , 2011, The Astrophysical journal.

[103]  C. Bauschlicher,et al.  Carbon chain abundance in the diffuse interstellar medium. , 1999, Astronomy and astrophysics.

[104]  Y. Keheyan,et al.  Reactions of Cations Derived from Naphthalene with Molecules and Atoms of Interstellar Interest , 1999 .

[105]  J. Weingartner,et al.  Photoelectric Emission from Interstellar Dust: Grain Charging and Gas Heating , 1999, astro-ph/9907251.

[106]  G. Meijer,et al.  Infrared Spectroscopy of Jet-cooled Cationic Polyaromatic Hydrocarbons: Naphthalene+ , 1999 .

[107]  K. Sellgren,et al.  Upper limit on C60 and C60+ features in the ISO-SWS spectrum of the reflection nebula NGC 7023 , 1999, astro-ph/9905374.

[108]  D. Hudgins,et al.  Interstellar PAH Emission in the 11-14 Micron Region: New Insightsfrom Laboratory Data and a Tracer of Ionized PAHs , 1999, The Astrophysical journal.

[109]  Y. Keheyan,et al.  Gas phase chemistry of pyrene and related cations with molecules and atoms of interstellar interest , 1999 .

[110]  D. Hudgins,et al.  The Spacing of the Interstellar 6.2 and 7.7 Micron Emission Features as an Indicator of Polycyclic Aromatic Hydrocarbon Size , 1999, The Astrophysical journal.

[111]  H. Baumgärtel,et al.  Structure-dependent Photostability of Polycyclic Aromatic Hydrocarbon Cations: Laboratory Studies and Astrophysical Implications , 1999 .

[112]  S. Sandford,et al.  Modeling the Unidentified Infrared Emission with Combinations of Polycyclic Aromatic Hydrocarbons , 1999, The Astrophysical journal.

[113]  Alexander G. G. M. Tielens,et al.  Photodissociation Regions in the Interstellar Medium of Galaxies , 1999 .

[114]  T. Henning,et al.  2D RADIATIVE TRANSFER WITH TRANSIENTLY HEATED PARTICLES FOR THE CIRCUMSTELLAR ENVIRONMENT OF HERBIG AE/BE STARS , 1999 .

[115]  A. Tielens,et al.  The Effects of Polycyclic Aromatic Hydrocarbons on the Chemistry of Photodissociation Regions , 1998 .

[116]  S. Schlemmer,et al.  Single photon infrared emission spectroscopy: a study of IR emission from UV laser excited PAHs between 3 and 15 micrometers. , 1998, The journal of physical chemistry. A.

[117]  A. Lazarian,et al.  Electric Dipole Radiation from Spinning Dust Grains , 1998, astro-ph/9802239.

[118]  R. Saykally,et al.  Simulated Infrared Emission Spectra of Highly Excited Polyatomic Molecules: A Detailed Model of the PAH-UIR Hypothesis , 1998, The Astrophysical journal.

[119]  Y. Keheyan,et al.  The interstellar chemistry of PAH cations , 1998, Nature.

[120]  T. Prusti,et al.  Infrared Spectroscopy of Dust in the Diffuse Interstellar Medium toward Cygnus OB2 No. 12 , 1997 .

[121]  D. Kunze,et al.  What Powers Ultraluminous IRAS Galaxies? , 1997, astro-ph/9711255.

[122]  M. Barlow,et al.  UIR Bands in Carbon Star Spectra , 1997 .

[123]  Eric Herbst,et al.  The Formation of Large Hydrocarbons and Carbon Clusters in Dense Interstellar Clouds , 1997 .

[124]  D. Talbi,et al.  The PAH hypothesis: a computational experiment on the combined effects of ionization and dehydrogenation on the IR signatures. , 1997 .

[125]  G. Sloan,et al.  Variations in the 3 Micron Spectrum across the Orion Bar: Polycyclic Aromatic Hydrocarbons and Related Molecules , 1997, The Astrophysical journal.

[126]  S. Sandford,et al.  Hydrogenated Polycyclic Aromatic Hydrocarbons and the 2940 and 2850 Wavenumber (3.40 and 3.51 micron) Infrared Emission Features , 1996, The Astrophysical journal.

[127]  A. Tielens,et al.  Grain Shattering in Shocks: The Interstellar Grain Size Distribution , 1996 .

[128]  C. Moutou,et al.  FAR-INFRARED EMISSION OF PAH MOLECULES (14-40 MU M) : A PREPARATION FOR ISO SPECTROSCOPY , 1996 .

[129]  Charles L. Bennett,et al.  High-Latitude Galactic Emission in the COBE Differential Microwave Radiometer 2 Year Sky Maps , 1996 .

[130]  S. Langhoff.  Theoretical Infrared Spectra for Polycyclic Aromatic Hydrocarbon Neutrals, Cations and Anions , 1996 .

[131]  A. Tielens,et al.  Assessment of the polycyclic aromatic hydrocarbon-diffuse interstellar band proposal. , 1996, The Astrophysical journal.

[132]  C. Joblin,et al.  Spatial variation of the 3.29 and 3.40 micron emission bands within reflection nebulae and the photochemical evolution of methylated polycyclic aromatic hydrocarbons. , 1996, The Astrophysical journal.

[133]  E. Sedlmayr,et al.  PHOTODESTRUCTION OF PAHS IN THE INTERSTELLAR MEDIUM. I. PHOTODISSOCIATION RATES FOR THE LOSS OF AN ACETYLENIC GROUP , 1996 .

[134]  H. Baumgärtel,et al.  PHOTOIONIZATION QUANTUM YIELDS OF POLYCYCLIC AROMATIC HYDROCARBONS , 1996 .

[135]  P. Marty,et al.  Contribution of metal-bonded polycyclic aromatic hydrocarbons to the interstellar depletion. , 1995 .

[136]  B. Rowe,et al.  Reaction of anthracene with atomic ions of interstellar interest. A FALP measurement at room temperature , 1995 .

[137]  George H. Herbig,et al.  The Diffuse Interstellar Bands , 1995 .

[138]  T. Snow.  Diffuse Interstellar Bands , 1995 .

[139]  B. Rowe,et al.  Electron attachment to anthracene. A FALP measurement of the rate coefficient at room temperature , 1994 .

[140]  S. Schlemmer,et al.  The unidentified interstellar infrared bands: PAHs as carriers? , 1994, Science.

[141]  A. Tielens,et al.  THE PHOTOELECTRIC HEATING MECHANISM FOR VERY SMALL GRAPHITIC GRAINS AND POLYCYCLIC AROMATIC HYDROCARBONS , 1994 .

[142]  S. Tobita,et al.  SIZE EFFECTS ON DISSOCIATION RATES OF POLYCYCLIC AROMATIC HYDROCARBON CATIONS : LABORATORY STUDIES AND ASTROPHYSICAL IMPLICATIONS , 1994 .

[143]  M. Naor,et al.  Time-dependent mass spectra and breakdown graphs. 17. Naphthalene and phenanthrene , 1993 .

[144]  T. Märk,et al.  Electron attachment to C60 at low energies , 1993 .

[145]  P. P. van der Werf,et al.  Anatomy of the Photodissociation Region in the Orion Bar , 1993, Science.

[146]  A. Tielens,et al.  Theoretical modeling of the infrared fluorescence from interstellar polycyclic aromatic hydrocarbons , 1993 .

[147]  A. Tielens,et al.  Infrared spectra of transition objects and the composition and evolution of carbon dust , 1993 .

[148]  M. Vala,et al.  Infrared frequencies and intensities for astrophysically important polycyclic aromatic hydrocarbon cations , 1993 .

[149]  J. Mitchell,et al.  Measurements of C3H3(+), C5H3(+), C6H6(+), C7H5(+), and C10H8(+) dissociative recombination rate coefficients , 1993 .

[150]  D. Talbi,et al.  Theoretical infrared spectra of some model polycyclic aromatic hydrocarbons: effect of ionization. , 1993, The Astrophysical journal.

[151]  A. Tielens,et al.  Polycyclic aromatic hydrocarbon formation in carbon-rich stellar envelopes , 1992 .

[152]  F. Boulanger,et al.  Fine structure lines of C+ and N+ in the galaxy. , 1992 .

[153]  D. Bohme.  PAH and Fullerene Ions and Ion/Molecule Reactions in Interstellar and Circumstellar Chemistry , 1992 .

[154]  L. Christophorou,et al.  Polycyclic aromatic hydrocarbons : negative ion formation following low energy (0-15 eV) electron impact , 1992 .

[155]  A. Omont,et al.  Physics of the rotation of a PAH molecule in interstellar environments , 1992 .

[156]  W. Latter.  Large Molecule Production by Mass-losing Carbon Stars: The Primary Source of Interstellar Polycyclic Aromatic Hydrocarbons? , 1991 .

[157]  A. Tielens,et al.  The mid-infrared spectrum of the carbon star HD 38218 and its possible relation to polycyclic aromatic hydrocarbons , 1991 .

[158]  R. Buss,et al.  Hydrocarbon emission features in the IR spectra of warm supergiants , 1990 .

[159]  F. Boulanger,et al.  Interstellar dust models for extinction and emission , 1990 .

[160]  K. Sellgren,et al.  The excitation of 12 micron emission from very small particles , 1990 .

[161]  L. Verstraete,et al.  Ionization cross-section measurements for two PAH molecules: implications for the heating of diffuse interstellar gas , 1990 .

[162]  A. Tielens,et al.  Interstellar polycyclic aromatic hydrocarbons: the infrared emission bands, the excitation/emission mechanism, and the astrophysical implications. , 1989, The Astrophysical journal. Supplement series.

[163]  A. Tielens,et al.  The infrared emission bands. II. A spatial and spectral study of the Orion Bar. , 1989, The Astrophysical journal.

[164]  E. Feigelson,et al.  Formation of polycyclic aromatic hydrocarbons in circumstellar envelopes , 1989 .

[165]  A. Tielens,et al.  Spatial variations of the 3 micron emission features within UV-excited nebulae: photochemical evolution of interstellar polycyclic aromatic hydrocarbons. , 1989, The Astrophysical journal.

[166]  J. Puget,et al.  A New Component of the Interstellar Matter: Small Grains and Large Aromatic Molecules , 1989 .

[167]  J. Black,et al.  Large molecules in diffuse interstellar clouds , 1988 .

[168]  A. Dalgarno,et al.  Polycyclic aromatic hydrocarbons in interstellar chemistry , 1988 .

[169]  A. Tielens,et al.  Anharmonicity and the interstellar polycyclic aromatic hydrocarbon infrared emission spectrum , 1987 .

[170]  S. Leach.  Photophysics, Electronic Spectroscopy and Relaxation of Molecular Ions and Radicals with Special Reference to Polycyclic Aromatic Hydrocarbons , 1987 .

[171]  John H. Black,et al.  Comprehensive models of diffuse interstellar clouds : physical conditions and molecular abundances , 1986 .

[172]  Alexander G. G. M. Tielens,et al.  Polycyclic aromatic hydrocarbons and the unidentified infrared emission bands - Auto exhaust along the Milky Way , 1985 .

[173]  F. J. Low,et al.  INFRARED CIRRUS - NEW COMPONENTS OF THE EXTENDED INFRARED-EMISSION , 1984 .

[174]  K. Sellgren,et al.  The near-infrared continuum emission of visual reflection nebulae , 1984 .

[175]  A. Douglas.  Origin of diffuse interstellar lines , 1977, Nature.

[176]  G. Herbig.  The diffuse interstellar bands. IV. The region 4400--6850 A , 1975 .