Pith. sign in

REVIEW 4 major objections 3 minor 56 references

Graphene Oxide Nanoparticles in the Interstellar Medium

T0 review · 4 major / 3 minor · reviewed 2026-08-14 · deepseek-v4-flash

Pith's one-line read Graphene oxide nanoparticles are proposed as the carrier of interstellar Extended Red Emission.

desk verdict A genuinely new ERE carrier candidate, honestly presented, but the abstract oversells the identification. read the letter →

arxiv 1908.07787 v1 pith:42AESMRN submitted 2019-08-21 astro-ph.GA physics.chem-ph

classification astro-ph.GAphysics.chem-ph
keywords grapheneoxideextendedredemissioninterstellardustpolycyclicaromatichydrocarbonsphotoluminescenceRectangleinfraredspectroscopyastrochemistry
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper identifies graphene oxide (GO) nanoparticles—tiny flakes of carbon decorated with oxygen functional groups—as the long-sought carrier of Extended Red Emission (ERE), a broad red glow seen in reflection nebulae, planetary nebulae, galactic cirrus, and external galaxies. The case rests on a close match between laboratory photoluminescence of GO and the ERE spectrum in the Red Rectangle, supported by infrared features at 6.0 and 8 µm that trace the same gas as ERE in NGC 2023. If the proposal is right, GO is not a laboratory curiosity but a significant component of interstellar dust, with implications for carbon and oxygen budgets, surface chemistry, and the identity of several long-unexplained astronomical emission bands.

What carries the argument

The central object is graphene oxide (GO), a single-layer graphene sheet bearing oxygen-containing groups—carbonyl (>C=O), epoxide (–O–), carboxyl (–COOH), and hydroxyl (–OH)—attached to the carbon framework. Its key property is that the oxygen sites open an optical band gap in otherwise gapless graphene, creating localized electronic states whose radiative recombination emits in the red part of the spectrum. The argument is carried by two comparisons: the overlap of GO photoluminescence with the Red Rectangle ERE profile, and the coincidence of ERE with the 6.0 µm carbonyl and 8 µm epoxy infrared features in NGC 2023, which ties the optical emission to oxygen chemistry on large carbon flakes.

What would settle it

Measure photoluminescence of size- and oxidation-controlled graphene oxide nanoparticles at cryogenic temperatures (10–100 K) under UV and broad-band excitation, and compare peak wavelength and width to ERE observations. If the emission shifts substantially, narrows, or disappears under these conditions, or if its quantum yield falls below the roughly 10% lower limit inferred for ERE, the proposed carrier fails; a spatial map of an ERE source in which the 6.0 µm and 8 µm features anticorrelate with ERE would also falsify the link.

Watch

Extended reading notes

Core claim

The paper's central claim is that emission from graphene oxide nanoparticles is the origin of ERE, and that these nanoparticles are a significant component of interstellar dust. In the Red Rectangle, the ERE peaks near 670 nm at 6 arcsec south and 645 nm at 10 arcsec south of HD 44179, closely matching the 630–660 nm photoluminescence of laboratory graphene oxide, with comparable width. The paper adds supporting evidence from space-based infrared spectra: the 6.0 µm band attributed to carbonyl C=O stretching and the broader 8 µm feature from epoxy C-O-C groups, whose spatial distributions in NGC 2023 follow the ERE rather than the usual polycyclic aromatic hydrocarbon bands. On this evidence the author proposes that oxidized graphene, formed by UV-driven decomposition of multilayer graphite oxide or by photo-removal of hydrogen from PAHs followed by oxygen attachment, is present wherever ERE is seen, and that its blue luminescence near 400 nm may have a separate astrophysical counterpart.

Load-bearing premise

The argument depends on the assumption that graphene oxide photoluminescence measured in the laboratory—for specific samples, laser-excited at room temperature—is representative of what interstellar GO nanoparticles emit under UV or broad-band excitation, at low interstellar temperatures, and at realistic particle sizes and oxidation levels.

Editorial extensions

If this is right

  • ERE would be understood as luminescence from an identifiable, oxygen-bearing carbonaceous grain population rather than an unidentified material.
  • The 6.0 µm and 8 µm astronomical emission features would gain a physical carrier—carbonyl and epoxy groups on graphene oxide—explaining why their spatial distributions differ from standard PAH bands.
  • The unidentified Red Rectangle emission bands near 5800 and 6600 Å could be decomposition products of the ERE-emitting GO, linking two long-standing spectral mysteries.
  • Interstellar GO formation would require UV irradiation, consistent with the established need for UV excitation of ERE, and would place GO nanoparticle sizes in the same range as very small grains being evaporated into PAHs.
  • Oxygen incorporated into GO would become part of interstellar dust budgets, relevant to the known missing-oxygen problem in the diffuse interstellar medium.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A direct extension of the proposal is a quantitative prediction: ERE peak wavelength should correlate with the relative strength of the 6.0 µm and 8 µm GO infrared features within a source, because more oxidized GO should emit at shorter wavelengths; existing Spitzer maps can test this.
  • If GO is as widespread as ERE, the same nanoparticles may act as catalytic surfaces in interstellar clouds; the paper mentions catalytic reactions only in passing, but a large GO population would make surface-mediated formation of molecules such as H2 a natural follow-up to test.
  • The GO carrier also suggests that the blue luminescence near 400 nm from sp2 carbon islands should appear in ERE sources, possibly as the astronomical Blue Luminescence, so a targeted search for a correlated 400 nm component would either strengthen or weaken the identification.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 3 minor

Summary. This Letter proposes that graphene oxide (GO) nanoparticles are the carrier of the long-unidentified Extended Red Emission (ERE) and constitute a significant component of interstellar dust. The argument rests on two pillars: (i) a qualitative comparison between laboratory photoluminescence (PL) spectra of GO (Gokus et al. 2009; Li et al. 2012) and ERE in the Red Rectangle at 6″ and 10″ south of HD 44179, and (ii) a claimed spatial and spectroscopic association of interstellar infrared features at 6.0 μm and near 8 μm with oxygen-containing functional groups in GO, using ISO and Spitzer data for the Red Rectangle and NGC 2023. The paper also discusses formation routes for interstellar GO, notes a blue 400 nm GO emission feature that might relate to astronomical Blue Luminescence, and suggests connections to unidentified Red Rectangle bands, the 2175 Å bump, and the missing oxygen problem.

Significance. If the identification were established, GO would be the first widely accepted ERE carrier, solving a forty-year-old problem in interstellar dust physics and linking carbonaceous nanoparticles to a broad set of observations. The proposal is attractive because it connects specific laboratory PL data to a recurrent astronomical spectral feature, and because it generates concrete, testable predictions. Credit is due for using independent laboratory spectra as external benchmarks, for noting explicitly in Section 4 that temperature and particle-size effects on GO emission are unknown, and for proposing laboratory experiments that could test the hypothesis. However, the evidence as presented is predominantly qualitative and the laboratory conditions differ substantially from those in interstellar ERE regions, so the central claim in the abstract outstrips the support in the body of the Letter.

major comments (4)
  1. [Section 2, Figs 1–2] The central spectral comparison is qualitative. Laboratory GO PL peaks at 630–660 nm and Red Rectangle ERE peaks at 670 nm (6″) and 645 nm (10″), but no line-profile fitting, no uncertainty analysis, and no quantitative similarity metric are provided. Because ERE is a broad feature whose peak and width vary widely between and within objects, an eye-level overlap of two broad emissions carries little discriminatory power. The authors should either perform a quantitative comparison using the same spectral binning and include FWHM values, or explicitly restrict the claim to 'a plausible candidate spectrum'.
  2. [Section 4 with Section 2] The laboratory PL data were obtained at room temperature with 473 nm laser excitation on supported GO flakes, whereas interstellar ERE is excited by UV photons (wavelengths short of ~118 nm in NGC 7023) and emitted by cold grains. The paper acknowledges in Section 4 that the effects of temperature and particle size on GO emission are unknown, and Cuong et al. (2011) directly show that GO PL peaks shift with temperature and reduction level. In addition, Gokus et al. (2009) show that their GO sample photobleaches under intense irradiation, and the required ~10% photon conversion efficiency of ERE has not been measured for GO under UV excitation. These gaps are load-bearing: until low-temperature, UV-excited, size-controlled GO PL is measured, the spectral match cannot support the abstract's claim that GO is the origin of ERE.
  3. [Section 3] The infrared evidence is not discriminative for GO specifically. The 6.0 μm feature is attributed by Peeters et al. (2002) to a C=O stretch in quinone-type PAHs, and Hsia et al. (2016) suggest an olefinic double-bond origin; ordinary oxygenated PAHs also contain carbonyl groups, so the presence of 6.0 μm emission does not distinguish GO from other oxygenated PAH species. The same band is used both as a fingerprint of GO and as supporting evidence for the GO–ERE association, a circularity. The 8 μm 'bump' in NGC 2023 is not a formally identified PAH band, and its spatial coincidence with the 6.0 μm feature is suggestive but not sufficient to identify a chemical carrier. A GO-specific infrared diagnostic or quantitative band-strength prediction is needed.
  4. [Abstract and Section 4] The claim that GO nanoparticles are 'a significant component of interstellar dust' is unsupported by any abundance or formation model. The two formation routes suggested in Section 4—UV decomposition of multilayer graphite oxide and photo-removal of H from PAHs followed by O addition—are stated without rates, yields, or destruction pathways, and no dust mass fraction is estimated from ERE intensities or infrared band strengths. At minimum, the abstract should be worded as a hypothesis rather than an established identification unless such a model is supplied.
minor comments (3)
  1. [Figure 1 caption] The caption describes the sample as 'GO produced by an oxygen plasma treatment of graphene', while Gokus et al. refer to oxidized graphene; the terminology should be clarified to match the original work exactly.
  2. [Section 3, first paragraph] The text notes that the ISO spectra cover a 14″×20″ aperture and therefore cannot be compared directly with the bipolar ERE distribution, but later comparisons use Spitzer data with a different field of view; these instrument and aperture differences should be stated explicitly where the spatial correlation is discussed.
  3. [Section 2, second paragraph] The statement that the laboratory PL and the Red Rectangle ERE have 'very similar' peak wavelength and FWHM would be more useful if the numerical FWHM values for the laboratory GO spectra were given, since only peak wavelengths are cited in the text.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the GO–ERE comparison rests on independent laboratory and astronomical spectra, with acknowledged untested assumptions rather than fitted inputs.

full rationale

The central claim is that graphene oxide nanoparticles emit the Extended Red Emission feature because laboratory photoluminescence spectra of graphene oxide (Gokus et al. 2009; Li et al. 2012) resemble Red Rectangle ERE (Witt & Boroson 1990). These are external benchmarks, not quantities derived from the ERE spectrum itself, and no parameter of the GO model is fitted to ERE and then renamed a prediction. The supporting infrared argument likewise compares the astronomical 6.0 and 8.0 µm features with independent GO absorption measurements and with NIST-based carbonyl stretching frequencies shifted by a literature value of 15 cm−1; this is an external consistency check, not a circular reduction. The paper explicitly states in Section 4 that temperature, particle size, and broad-band excitation effects on GO emission remain to be tested, which is an acknowledged limitation of the proposal rather than a circular step. The author's self-citations (Sarre 1991, 1995, 2006) concern diffuse interstellar bands and are not load-bearing for the ERE identification. No equation in the paper reduces the conclusion to its own inputs, so no circularity meeting the required evidentiary standard is present.

Assumptions & free parameters 0 free parameters · 4 assumptions · 1 invented entities

The central claim rests on no fitted constants, but on several domain assumptions about ERE's carbon origin, the chemical attribution of the 6.0 micrometer band, the adopted spectral shift, and an ad hoc GO formation scenario. One new entity (interstellar GO) is postulated with testable but unperformed predictions.

assumptions (4)
  • domain assumption ERE is luminescence of dust grains and is carbon-related, as inferred from its absence in oxygen-rich nebulae.
    Adopted from Witt & Vijh 2004 and Furton & Witt 1990, 1992; it frames why GO is a plausible carrier.
  • domain assumption The 6.0 micrometer astronomical emission band is due to a C=O stretch in oxygenated aromatic molecules.
    Based on Peeters et al. 2002 and Wallace 2019; the paper notes an alternative olefinic origin (Hsia et al. 2016) but relies on the C=O interpretation to support GO.
  • domain assumption A 15 cm^-1 redward shift from gas-phase absorption to astronomical emission applies to carbonyl aromatics.
    Invoked in Section 3 via Bauschlicher et al. 2009 to map lab absorption to observed 6.0 micrometer emission.
  • ad hoc to paper GO can form in interstellar environments, either by UV decomposition of multilayer graphite oxide or by photo-removal of H from PAHs followed by O addition.
    Introduced in Section 4 to reconcile the observed need for UV excitation with the fact that lab GO luminescence is excited by visible light; no formation model or abundance calculation is given.
invented entities (1)
  • Interstellar graphene oxide nanoparticles independent evidence
    purpose: Carrier of extended red emission and a proposed significant carbonaceous dust component.
    The paper offers falsifiable tests: spatial correlation of 6.0 and 8.0 micrometer bands with ERE, and laboratory studies varying oxidation, temperature, and particle size. These are predictions not used to derive the entity, though none are yet performed.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Graphene Oxide Nanoparticles in the Interstellar Medium." pith.science (2026). https://pith.science/paper/42AESMRN

@misc{pith2026190807787,
  author       = {Pith},
  title        = {Pith review of: Graphene Oxide Nanoparticles in the Interstellar Medium},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/42AESMRN}},
  note         = {Machine review of arXiv:1908.07787}
}
read the original abstract

Dust particles play a major role in the formation, evolution and chemistry of interstellar clouds, stars and planetary systems. Commonly identified forms include amorphous and crystalline carbon-rich particles and silicates. Also present in many astrophysical environments are polycyclic aromatic hydrocarbons (PAHs), detected through their infrared emission, and which are essentially small flakes of graphene. Astronomical observations over the past four decades have revealed a widespread unassigned Extended Red Emission (ERE) feature which is attributed to luminescence of dust grains. Numerous potential carriers for ERE have been proposed but none has gained general acceptance. In this Letter it is shown that there is a strong similarity between laboratory optical emission spectra of graphene oxide and ERE, leading to this proposal that emission from graphene oxide nanoparticles is the origin of ERE and that these are a significant component of interstellar dust. The proposal is supported by infrared emission features detected by the Infrared Space Observatory (ISO) and the Spitzer Space Telescope.

Figures

Figures reproduced from arXiv: 1908.07787 by the authors.

Figure 1
Figure 1. PL spectra of GO produced by an oxygen plasma treatment of graphene and excited by laser radiation at 473 nm. Spectra for three irradiated positions (Pos 1, 2 and 3) on the GO sample are shown. Reprinted with permission from Gokus et al. (2009). Copyright 2009 American Chemical Society. < 10,000 K as described by Darbon et al. (1999), a lower limit on the estimated photon (not energy) conversion effi￾ciency of about… view at source ↗
Figure 2
Figure 2. FIG. 2. (Color online) Schematic illus structures of GOCRGand TRG ‘unique’ spatial distribution is also found for the Northern [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

56 extracted references · 40 canonical work pages

  1. [1]

    J., Sandford S

    Allamandola L. J., Sandford S. A., Wopenka B., 1987, @doi [Science] 10.1126/science.237.4810.56 , https://ui.adsabs.harvard.edu/abs/1987Sci...237...56A 237, 56

  2. [2]

    J., Chhowalla M., Shenoy V

    Bagri A., Mattevi C., Acik M., Chabal Y. J., Chhowalla M., Shenoy V. B., 2010, Nature Chemistry, 2, 581

  3. [3]

    J., Peeters E., Allamandola L

    Bauschlicher Charles W. J., Peeters E., Allamandola L. J., 2009, @doi [ ] 10.1088/0004-637X/697/1/311 , https://ui.adsabs.harvard.edu/abs/2009ApJ...697..311B 697, 311

  4. [4]

    Bern \'e O., et al., 2007, @doi [ ] 10.1051/0004-6361:20066282 , https://ui.adsabs.harvard.edu/abs/2007A&A...469..575B 469, 575

  5. [5]

    C., Deville Y., 2008, @doi [ ] 10.1051/0004-6361:20079158 , https://ui.adsabs.harvard.edu/abs/2008A&A...479L..41B 479, L41

    Bern \'e O., Joblin C., Rapacioli M., Thomas J., Cuillandre J. C., Deville Y., 2008, @doi [ ] 10.1051/0004-6361:20079158 , https://ui.adsabs.harvard.edu/abs/2008A&A...479L..41B 479, L41

  6. [6]

    Cesarsky D., Lequeux J., Ryter C., G \'e rin M., 2000, , https://ui.adsabs.harvard.edu/abs/2000A&A...354L..87C 354, L87

  7. [7]

    Chien C.-T., et al., 2012, Angewandte Chemie-International Edition, 51, 6662

  8. [8]

    Cohen M., et al., 1975, @doi [ ] 10.1086/153403 , http://adsabs.harvard.edu/abs/1975ApJ...196..179C 196, 179

Show all 56 references
  1. [9]

    A., Candian A., Bern \'e O., Tielens A

    Croiset B. A., Candian A., Bern \'e O., Tielens A. G. G. M., 2016, @doi [ ] 10.1051/0004-6361/201527714 , https://ui.adsabs.harvard.edu/abs/2016A&A...590A..26C 590, A26

  2. [10]

    V., et al., 2011, @doi [App

    Cuong T. V., et al., 2011, @doi [App. Phys. Lett.] 10.1063/1.3616142 , 99, 041905

  3. [11]

    Darbon S., Perrin J.-M., Sivan J.-P., 1999, , http://adsabs.harvard.edu/abs/1999A

  4. [12]

    R., Park S., Bielawski C

    Dreyer D. R., Park S., Bielawski C. W., Ruoff R. S., 2010, @doi [Chem. Soc. Rev.] 10.1039/b917103g , 39, 228

  5. [13]

    J., 1991, @doi [ ] 10.1038/353393b0 , https://ui.adsabs.harvard.edu/abs/1991Natur.353..393F 353, 393

    Fossey S. J., 1991, @doi [ ] 10.1038/353393b0 , https://ui.adsabs.harvard.edu/abs/1991Natur.353..393F 353, 393

  6. [14]

    G., Witt A

    Furton D. G., Witt A. N., 1990, @doi [ ] 10.1086/185871 , http://adsabs.harvard.edu/abs/1990ApJ...364L..45F 364, L45

  7. [15]

    G., Witt A

    Furton D. G., Witt A. N., 1992, @doi [ ] 10.1086/171041 , http://adsabs.harvard.edu/abs/1992ApJ...386..587F 386, 587

  8. [16]

    Gao X., Jang J., Nagase S., 2010, J. Phys. Chem C, 114, 832

  9. [17]

    Gokus T., et al., 2009, ACS nano, 3, 3963

  10. [18]

    D., Witt A

    Gordon K. D., Witt A. N., Friedmann B. C., 1998, @doi [ ] 10.1086/305571 , https://ui.adsabs.harvard.edu/abs/1998ApJ...498..522G 498, 522

  11. [19]

    Holmlid L., 2018, @doi [ ] 10.3847/1538-4357/aadda1 , http://adsabs.harvard.edu/abs/2018ApJ...866..107H 866, 107

  12. [20]

    Hsia C.-H., Sadjadi S., Zhang Y., Kwok S., 2016, @doi [ ] 10.3847/0004-637X/832/2/213 , https://ui.adsabs.harvard.edu/abs/2016ApJ...832..213H 832, 213

  13. [21]

    Krishnamoorthy K., Veerapandian M., Yun K., Kim S.-J., 2013, Carbon, 53, 38

  14. [22]

    S.-Y., Witt A

    Lai T. S.-Y., Witt A. N., Crawford K., 2017, @doi [ ] 10.1093/mnras/stx1124 , http://adsabs.harvard.edu/abs/2017MNRAS.469.4933L 469, 4933

  15. [23]

    Ledoux G., Guillois O., Huisken F., Kohn B., Porterat D., Reynaud C., 2001, @doi [ ] 10.1051/0004-6361:20011136 , https://ui.adsabs.harvard.edu/abs/2001A&A...377..707L 377, 707

  16. [24]

    K., Zhou X., Guo S., Wu N., 2012, @doi [J

    Li M., Cushing S. K., Zhou X., Guo S., Wu N., 2012, @doi [J. Mat. Chem.] 10.1039/c2jm35417a , 22, 23374

  17. [25]

    M., Mele E

    Luo Z., Vora P. M., Mele E. J., Johnson A. T. C., Kikkawa J. M., 2009 a, App. Phys. Lett. , 94

  18. [26]

    A., Johnson A

    Luo Z., Lu Y., Somers L. A., Johnson A. T. C., 2009 b, @doi [ JACS ] 10.1021/ja807934n , 131 , 898

  19. [27]

    McCartney M. S. K., Brand P. W. J. L., Burton M. G., Chrysostomou A., 1999, @doi [ ] 10.1046/j.1365-8711.1999.02602.x , 307, 315

  20. [28]

    Peeters E., Hony S., Van Kerckhoven C., Tielens A. G. G. M., Allamandola L. J., Hudgins D. M., Bauschlicher C. W., 2002, @doi [ ] 10.1051/0004-6361:20020773 , https://ui.adsabs.harvard.edu/abs/2002A&A...390.1089P 390, 1089

  21. [29]

    W., Allamandola L

    Peeters E., Bauschlicher C. W., Allamandola L. J., Tielens A. G. G. M., Ricca A., Wolfire M. G., 2017, @doi [ ] 10.3847/1538-4357/836/2/198 , 836, 198

  22. [30]

    Pilleri P., 2010, PhD thesis, L'Universit\'e de Toulouse

  23. [31]

    Quirico E., Borg J., Raynal P., Montagnac G., d'Hendecourt L., 2005, Planetary and Space Science, 53, 1443

  24. [32]

    M., Lee T

    Rhee Y. M., Lee T. J., Gudipati M. S., Allamandola L. J., Head-Gordon M., 2007, @doi [Proceedings of the National Academy of Science] 10.1073/pnas.0609396104 , https://ui.adsabs.harvard.edu/abs/2007PNAS..104.5274R 104, 5274

  25. [33]

    1st Franco-British Meeting on the Physics and Chemistry of the Interstellar Medium, Newsletter on Analysis of Astronomical Spectra

    Rouan D., Lecoupanec P., L\'eger A., 1995, in Jeffery C., ed., Proc. 1st Franco-British Meeting on the Physics and Chemistry of the Interstellar Medium, Newsletter on Analysis of Astronomical Spectra. No. 22 in 1. p. 37

  26. [34]

    J., 1991, @doi [ ] 10.1038/351356a0 , https://ui.adsabs.harvard.edu/abs/1991Natur.351..356S 351, 356

    Sarre P. J., 1991, @doi [ ] 10.1038/351356a0 , https://ui.adsabs.harvard.edu/abs/1991Natur.351..356S 351, 356

  27. [35]

    J., 2006, @doi [ Journal of Molecular Spectroscopy ] 10.1016/j.jms.2006.03.009 , https://ui.adsabs.harvard.edu/abs/2006JMoSp.238....1S 238, 1

    Sarre P. J., 2006, @doi [ Journal of Molecular Spectroscopy ] 10.1016/j.jms.2006.03.009 , https://ui.adsabs.harvard.edu/abs/2006JMoSp.238....1S 238, 1

  28. [36]

    J., Miles J

    Sarre P. J., Miles J. R., Scarrott S. M., 1995, @doi [Science] 10.1126/science.269.5224.674 , https://ui.adsabs.harvard.edu/abs/1995Sci...269..674S 269, 674

  29. [37]

    D., Witt A

    Schmidt G. D., Witt A. N., 1991, @doi [ ] 10.1086/170826 , https://ui.adsabs.harvard.edu/abs/1991ApJ...383..698S 383, 698

  30. [38]

    D., Cohen M., Margon B., 1980, @doi [ ] 10.1086/183309 , https://ui.adsabs.harvard.edu/abs/1980ApJ...239L.133S 239, L133

    Schmidt G. D., Cohen M., Margon B., 1980, @doi [ ] 10.1086/183309 , https://ui.adsabs.harvard.edu/abs/1980ApJ...239L.133S 239, L133

  31. [39]

    D., Evans A., Rawlings J

    Scott A. D., Evans A., Rawlings J. M. C., 1994, @doi [ ] 10.1093/mnras/269.1.L21 , https://ui.adsabs.harvard.edu/abs/1994MNRAS.269L..21S 269, L21

  32. [40]

    L., Witt A

    Smith T. L., Witt A. N., 2002, @doi [ ] 10.1086/324542 , https://ui.adsabs.harvard.edu/abs/2002ApJ...565..304S 565, 304

  33. [41]

    Szomoru A., Guhathakurta P., 1998, @doi [ ] 10.1086/311156 , https://ui.adsabs.harvard.edu/abs/1998ApJ...494L..93S 494, L93

  34. [42]

    Tielens A. G. G. M., 2008, @doi [ ] 10.1146/annurev.astro.46.060407.145211 , https://ui.adsabs.harvard.edu/abs/2008ARA&A..46..289T 46, 289

  35. [43]

    Tielens A. G. G. M., 2013, @doi [Reviews of Modern Physics] 10.1103/RevModPhys.85.1021 , https://ui.adsabs.harvard.edu/abs/2013RvMP...85.1021T 85, 1021

  36. [44]

    P., Witt A

    Vijh U. P., Witt A. N., Gordon K. D., 2005, @doi [ ] 10.1086/447763 , https://ui.adsabs.harvard.edu/abs/2005ApJ...633..262V 633, 262

  37. [45]

    E., 2019, in Linstrom P

    Wallace W. E., 2019, in Linstrom P. J., Mallard W. G., eds, NIST Chemistry WebBook, NIST Standard Reference Database Number 69, https://doi.org/10.18434/T4D303. https://doi.org/10.18434/T4D303

  38. [46]

    N., 2014, in Cami J., Cox N

    Witt A. N., 2014, in Cami J., Cox N. L. J., eds, IAU Symposium Vol. 297, The Diffuse Interstellar Bands. pp 173--179, @doi 10.1017/S1743921313015810

  39. [47]

    N., Boroson T

    Witt A. N., Boroson T. A., 1990, @doi [ ] 10.1086/168752 , https://ui.adsabs.harvard.edu/abs/1990ApJ...355..182W 355, 182

  40. [48]

    N., Malin D

    Witt A. N., Malin D. F., 1989, , 347, 25

  41. [49]

    N., Schild R

    Witt A. N., Schild R. E., 1988, @doi [ ] 10.1086/166054 , https://ui.adsabs.harvard.edu/abs/1988ApJ...325..837W 325, 837

  42. [50]

    N., Vijh U

    Witt A. N., Vijh U. P., 2004, in Witt A. N., Clayton G. C., Draine B. T., eds, Astronomical Society of the Pacific Conference Series Vol. 309, Astrophysics of Dust. p. 115 ( @eprint arXiv astro-ph/0309674 )

  43. [51]

    N., Gordon K

    Witt A. N., Gordon K. D., Vijh U. P., Sell P. H., Smith T. L., Xie R.-H., 2006, @doi [ ] 10.1086/498052 , https://ui.adsabs.harvard.edu/abs/2006ApJ...636..303W 636, 303

  44. [52]

    N., Mandel S., Sell P

    Witt A. N., Mandel S., Sell P. H., Dixon T., Vijh U. P., 2008, @doi [ ] 10.1086/587131 , https://ui.adsabs.harvard.edu/abs/2008ApJ...679..497W 679, 497

  45. [53]

    Wopenka B., 1988, @doi [Earth and Planetary Science Letters] 10.1016/0012-821X(88)90079-9 , https://ui.adsabs.harvard.edu/abs/1988E&PSL..88..221W 88, 221

  46. [54]

    Yuan T., Meng T., He P., Shi Y., Li Y., Li X., Fan L., Yang S., 2019, J. Mat. Chem. , 7, 6820

  47. [55]

    Springer

    Zhao J., Liu L., Li F., 2015, Graphene Oxide, Physics and Applications. Springer

  48. [56]

    write newline

    " write newline "" before.all 'output.state := FUNCTION fin.entry write newline FUNCTION new.block output.state before.all = 'skip after.block 'output.state := if FUNCTION new.sentence output.state after.block = 'skip output.state before.all = 'skip after.sentence 'output.stat...

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.