Interstellar & Circumstellar Species in Ice

MOLECULES DETECTED IN ICE

NOTES: After being included along with gas phase ISM/CSM detections for 20+ years, I have decided to collect together detections of molecules found in astrophysical ices on its own page (as of April 2024). The primary reason for the change is the explosion of new ice detections and confirmations made possible by the James Webb Space Telescope. Some entries here will go into a bit more bibliographic detail than gas phase detections due to the often extended debates associated with claimed detections. Note that ALL current ice detections are based on vibrational spectra.
Recently added entries are highlighted; tentative detections are indicated with italic font.

NOTES: After being included along with gas phase ISM/CSM detections for 20+ years, I have decided to collect together detections of molecules found in astrophysical ices on its own page (as of April 2024). The primary reason for the change is the explosion of new ice detections and confirmations made possible by the James Webb Space Telescope. Some entries here will go into a bit more bibliographic detail than gas phase detections due to the often extended debates associated with claimed detections. Note that ALL current ice detections are based on vibrational spectra.

Recently added entries are highlighted; tentative detections are indicated with italic font.

RECENT ADDITIONS J. A. Noble+. Nat Astron 8:1169-1180 (2024) (H₂O)
2025.01	Ice inventory towards the protostar Ced 110 IRS4 observed with the James Webb Space Telescope - Results from the Early Release Science Ice Age program W. R. M. Rocha+. A&A 693:A288 (2025) (N₂O tentatively detected, as well as various known molecules and ions)

YEAR	SPECIES	CITATION	SOURCE(S)/LINES

1973	H₂O water	Spectra of the Becklin-Neugebauer point source and the Kleinmann-Low nebula from 2.8 to 13.5 microns F. C. Gillett and W. C. Forrest, ApJ 179:483-491 (1973). Absorption features in the 5-8 micron spectra of protostars. A. G. G. M. Tielens, L. J. Allamandola, J. Bregman, J. Goebbel, L. B. d'Hendecourt, and F. C Whittborn. ApJ 287:697-706 (1984). *The c2d Spitzer* spectroscopic survey of ices around low-mass young stellar objects. I. H₂O and the 5-8 μm bands. A. C. A. Boogert, K. M. Pontoppidan, C. Knez, F. Lahuis, J. Kessler-Silacci, E. F. van Dishoeck, G. A. Blake et al. ApJ 678:985-1004 (2008) An Ice Age JWST inventory of dense molecular cloud ices M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, F. Sun et al. Nat Astron 7:431-443 (2023). Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I with JWST NIRCam** J. A. Noble, H. J. Fraser, Z. L. Smith, E. Dartois, A. C. A. Boogert, H. M. Cuppen, H. J. Dickinson et al. Nat Astron 8:1169-1180 (2024).	Orion KL OH stretch 3.1 μm / 3220 cm^–1 W33A & others HOH bend 6 μm / 1667 cm^–1 41 Young Stellar Objects librations 13 μm / 770 cm^–1 NIR38 dangling OH stretch 2.73 μm / 3664 cm^–1 Chamaeleon I dangling OH stretch 2.703 μm / 3670 cm^–1 2.753 μm / 3632 cm^–1
Additional references for H₂O: 1978 - - - - - - - - - - - Is Water-Ice the Carrier of the 3 μm Absorption in Infrared Objects? T. Mukai, S. Mukai, and K. Noguchi. Astrophys Space Sci 53:77-84 (1978). 1979 - - - - - - - - - - - The 3.1 μm absorption in molecular clouds is probably due to amorphous H₂O ice. A. Léger, J. Klein, S. de Chevigne, C. Guinet, D. Defourneau, and M. Belin, A&A 79:256-259 (1979). 1996 - - - - - - - - - - - ISO-SWS observations of solid state features towards RAFGL 7009S L. d'Hendecourt, M. Jourdain de Muizon, E. Dartois, M. Breitfellner, P. Ehrenfreund, J. Benit, F. Boulanger, J. L. Puget, and H. J Habing. A&A 315:L365 (1996). 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000). 2024 - - - - - - - - - - - A JWST/MIRI analysis of the ice distribution and polycyclic aromatic hydrocarbon emission in the protoplanetary disk HH 48 NE J. A. Sturm, M. K. McClure, D. Harsono, J. B. Bergner, E. Dartois, A. C. A. Boogert et al. A&A 689:A92 (2024).

1979 NGC4945	OCN^– cyanate anion	The 4-8 micron spectrum of the infrared source W33A B. T. Soifer, R. C. Puetter, R. W. Russell, S. P. Willner, P. M. Harvey, and F. C. Gillett, ApJ 232:L53-L57 (1979). 4.6 micron absorption features due to solid phase CO and cyano group molecules toward compact infrared sources. J. H. Lacy, F. Baas, L. J. Allamandola, S. E. Persson, P. J. MacGregor, C. J. Lonsdale, T. R. Geballe, and C. E. P. van der Bult. ApJ 276:533-543 (1984). Spectroscopy of the 4.6-4.7 micon interstellar absroption features. T. R. Geballe. Occ Rep Royal Obs Edinburgh 12:56-60 (1984). JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	W33A OCN asymmetric stretch 4.62 μm / 2165 cm^–1 NGC 1333 IRAS 2A, IRAS 23385+6053 combination (2ν₂) 7.62 μm / 1312 cm^–1
Additional references for OCN^–: 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000).

1989	CO₂ carbon dioxide	The discovery of interstellar carbon dioxide L.B. d'Hendecourt and M. Jourdain de Muizon. A&A 223:L5 (1989). Detection of an absorption feature at the position of the 4.27-μm band of solid CO₂ J. Gürtler, T. Henning, C. Kömpe1, W. Pfau1, W. Krátschmer, and D. Lemke	3 IRAS sources bend 15.2 μm / 660 cm^–1 13 sources asymmetric stretch 4.27 μm / 2340 cm^–1
Additional references for CO₂: 1996 - - - - - - - - - - - SWS observations of solid CO₂ in molecular clouds T. de Graauw, D. C. B. Whittet, P. A. Gerakines, O. H. Bauer, D. A. Beintema, A. C. A. Boogert, D. R. Boxhoorn, J. E. Chiar, P. Ehrenfreund, H. Feuchtgruber, F. P. Helmich, A. M. Heras, R. Huygen, D. J. M. Kester, D. Kunze, F. Lahuis, K. J. Leech, D. Lutz, P. W. Morris, T. Prusti, P .R. Roelfsema, A. Salama, S. G. Schaeidt, W. A. Schutte, H. W. W. Spoon, A. G. G. M. Tielens, E. A. Valentijn, B. Vandenbusshe, E. F. van Dishoeck, P. R. Wesselius, E. Wieprecht, and C. M. Wright A&A 315:L345 (1996). 1996 - - - - - - - - - - - ISO-SWS observations of solid state features towards RAFGL 7009S L. d'Hendecourt, M. Jourdain de Muizon, E. Dartois, M. Breitfellner, P. Ehrenfreund, J. Benit, F. Boulanger, J. L. Puget, and H. J Habing. A&A 315:L365 (1996). 1998 - - - - - - - - - - - Detection of Abundant CO₂ Ice in the Quiescent Dark Cloud Medium toward Elias 16 D. C. B. Whittet, P. A. Gerakines, A. G. G. M. Tielens, A. J. Adamson, A. C. A. Boogert, J. E. Chiar, T. de Graauw, P. Ehrenfreund, T. Prusti, W. A. Schutte, B. Vandenbussche, and E. F. van Dishoeck. ApJ 498:L158 (1998). 1998 - - - - - - - - - - - Solid CO₂ towards NGC7538 IRS1 G. Strazzulla, B. Nisini, G. Leto, M. E. Palumbi, and P. Saraceno. A&A 334:1056 (1998). 1999 - - - - - - - - - - - Observations of Solid Carbon Dioxide in Molecular Clouds with the Infrared Space Observatory P. A. Gerakines, D. C. B. Whittet, P. Ehrenfreund, A. C. A. Boogert, A. G. G. M. Tielens, W. A. Schutte, J. E. Chiar, E. F. van Dishoeck, T. Prusti, F. P. Helmich, and T. de Graauw. ApJ 522:357-377 (1999). 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000). 2005 - - - - - - - - - - - Spitzer Observations of CO₂ Ice Towards Field Stars in the Taurus Molecular Cloud E. A. Bergin, G. J. Melnick, P. A. Gerakines, D. A. Neufeld, and D. C. B. Whittet. ApJ 627:L33-L36 (2005). 2008 - - - - - - - - - - - The c2d Spitzer Spectroscopic Survey of Ices around Low-Mass Young Stellar Objects. II. CO₂ K. M. Pontoppidan, A. C. A. Boogert, H. J. Fraser, E. F. van Dishoeck, G. A. Blake, F. Lahuis, K. I. Öberg, N. J. Evans II, and C. Salyk. ApJ 678:1032-1041 (2008). 2024 - - - - - - - - - - - A JWST/MIRI analysis of the ice distribution and polycyclic aromatic hydrocarbon emission in the protoplanetary disk HH 48 NE J. A. Sturm, M. K. McClure, D. Harsono, J. B. Bergner, E. Dartois, A. C. A. Boogert et al. A&A 689:A92 (2024).

1989	CO carbon monoxide	Infrared spectroscopy of dust in the Taurus dark clouds: solid carbon monoxide D. C. B. Whittet, A. J. Adamson, W. W. Duley, T. R. Geballe, and A. D. McFadzean. MNRAS 241:707-720 (1989).	TMC stretch 4.67 μm / 2140 cm^–1
Additional references for CO: 1995 - - - - - - - - - - - High-Resolution Studies of Solid CO in the Taurus Dark Cloud: Characterizing the Ices in Quiescent Clouds J. E. Chiar, A. J. Adamson, T. H. Kerr, and D. C. B. Whittet. ApJ 455:234-243 (1995). 1996 - - - - - - - - - - - ISO-SWS observations of solid state features towards RAFGL 7009S L. d'Hendecourt, M. Jourdain de Muizon, E. Dartois, M. Breitfellner, P. Ehrenfreund, J. Benit, F. Boulanger, J. L. Puget, and H. J Habing. A&A 315:L365 (1996). 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000).

1991	CH₃OH methanol	Detection of solid methanol toward W33A R. J. A. Grim, B. Bass, T. R. Geballe, J. M. Greenberg, and W. Schutte. A&A 243:473-477 (1991).	W33A CH₃ symmetric stretch 3.53 μm / 2830 cm^–1
Additional references for CH₃OH: 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000). 2010 - - - - - - - - - - - The c2d Spitzer Spectroscopic Survey of Ices Around Low-mass Young Stellar Objects. IV. NH₃ and CH₃OH S. Bottinelli, A. C. A. Boogert, J. Bouwman, M. Beckwith, E. F. van Dishoeck, K. I. Öberg, K. M. Pontoppidan, H. Linnartz, G. A. Blake, N. J. Evans II, and F. Lahuis. ApJ 718:1100-1117 (2010).

1991	CH₄ methane	Discovery of Interstellar Methane - Observations of Gaseous and Solid CH₄ Absorption Toward Young Stars in Molecular Clouds J. H. Lacy, J. S. Carr, N. J. Evans II, F. Baas, J. M. Achtermann, and J. F. Arens, ApJ 376:556-560 (1991). Methane abundance variations toward the massive protostar NGC 7538 IRS 9 A. C. A. Boogert, G. A. Blake, and K. Öberg. ApJ 615:344-353 (2004).	NGC 7538 IRS 9... bend 7.67 μm / 1300 cm^–1 NGC 7538 IRS 9 symmetric stretch 3.3 μm / 3030 cm^–1
Additional references for CH₄: 1996 - - - - - - - - - - - ISO-SWS observations of solid state features towards RAFGL 7009S L. d'Hendecourt, M. Jourdain de Muizon, E. Dartois, M. Breitfellner, P. Ehrenfreund, J. Benit, F. Boulanger, J. L. Puget, and H. J Habing. A&A 315:L365 (1996). 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000). 2008 - - - - - - - - - - - The c2d Spitzer Spectroscopic Survey of Ices around Low-Mass Young Stellar Objects. III. CH₄ K. I. Öberg, A. C. A. Boogert, K. M. Pontoppidan, G. A. Blake, N. J. Evans, F. Lahuis, and E. F. van Dishoeck. ApJ 678:1032-1041 (2008). 2024 - - - - - - - - - - - JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024). 2024 - - - - - - - - - - - A JWST/MIRI analysis of the ice distribution and polycyclic aromatic hydrocarbon emission in the protoplanetary disk HH 48 NE J. A. Sturm, M. K. McClure, D. Harsono, J. B. Bergner, E. Dartois, A. C. A. Boogert et al. A&A 689:A92 (2024).

1995	OCS carbonyl sulfide	Solid Carbonyl Sulphide (OCS) in W33A M. E. Palumbo, A. G. G. M. Tielens, and A. T. Tokunaga. ApJ 449:674-680 (1995).	W33A CO stretch 4.9 μm / 2041 cm^–1
Additional references for OCS: 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000). 2023 - - - - - - - - - - - An Ice Age JWST inventory of dense molecular cloud ices M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, F. Sun et al. Nat Astron 7:431-443 (2023).

1996	¹³CO₂ ¹³C-sub carbon dioxide	SWS observations of solid CO₂ in molecular clouds T. de Graauw, D. C. B. Whittet, P. A. Gerakines, O. H. Bauer, D. A. Beintema, A. C. A. Boogert, D. R. Boxhoorn, J. E. Chiar, P. Ehrenfreund, H. Feuchtgruber, F. P. Helmich, A. M. Heras, R. Huygen, D. J. M. Kester, D. Kunze, F. Lahuis, K. J. Leech, D. Lutz, P. W. Morris, T. Prusti, P .R. Roelfsema, A. Salama, S. G. Schaeidt, W. A. Schutte, H. W. W. Spoon, A. G. G. M. Tielens, E. A. Valentijn, B. Vandenbusshe, E. F. van Dishoeck, P. R. Wesselius, E. Wieprecht, and C. M. Wright A&A 315:L345 (1996).	Sgr A asymmetric stretch 4.38 μm / 2283 cm^–1
Additional references for ¹³CO₂: 1996 - - - - - - - - - - - ISO-SWS observations of solid state features towards RAFGL 7009S L. d'Hendecourt, M. Jourdain de Muizon, E. Dartois, M. Breitfellner, P. Ehrenfreund, J. Benit, F. Boulanger, J. L. Puget, and H. J Habing. A&A 315:L365 (1996). 2000 - - - - - - - - - - - ISO-SWS observations of interstellar solid ¹³CO₂: Heated ice and the Galactic ¹²C/¹³C abundance ratio A. C. A. Boogert, P. Ehrenfreund, P. A. Gerakines, A. G. G. M. Tielens, D. C. B. Whittet, W. A. Schutte, E. F. van Dishoeck, T. de Graauw, L. Decin, and T. Prust. A&A 353:349 (2000). 2024 - - - - - - - - - - - JWST observations of ¹³CO₂ ice - Tracing the chemical environment and thermal history of ices in protostellar envelopes N. G. C. Brunken, W. R. M. Rocha, E. F. van Dishoeck, R. Gutermuth, H. Tyagi, K. Slavicinska, P. Nazari, S. T. Megeath, N. J. Evans II, M. Narang et al. A&A 685:A27 (2024).

1998	NH₃ ammonia	Unraveling the 10 Micron "Silicate" Feature of Protostars: The Detection of Frozen Interstellar Ammonia J. H. Lacy, H. Faraji, S. A. Sandford, and L. J. Allamandola. ApJ 501:L105-L109 (1998). The Composition and Distribution of Dust along the Line of Sight toward the Galactic Center J. E. Chiar, A. G. G. M. Tielens, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, D. Lutz, E. F. van Dishoeck, and M. P. Bernstein. ApJ 537:749-762 (2000).	NGC 7538 IRS 9 inversion 9.0 μm / 1110 cm^–1 Galactic center NH stretch 2.95 μm / 3390 cm^–1
Additional references for NH₃: 2000 - - - - - - - - - - - An Inventory of Interstellar Ices toward the Embedded Protostar W33A E. L. Gibb, D. C. B. Whittet, W. A. Schutte, A. C. A. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. G. M. Tielens, E. F. van Dishoeck, and O. Kerkhof. ApJ 536:347-356 (2000). 2001 - - - - - - - - - - - Searching for Ammonia in Grain Mantles toward Massive Young Stellar Objects E. L. Gibb, D. C. B. Whittet, and J. E. Chiar. ApJ 558:702-716 (2001). 2010 - - - - - - - - - - - The c2d Spitzer Spectroscopic Survey of Ices Around Low-mass Young Stellar Objects. IV. NH₃ and CH₃OH S. Bottinelli, A. C. A. Boogert, J. Bouwman, M. Beckwith, E. F. van Dishoeck, K. I. Öberg, K. M. Pontoppidan, H. Linnartz, G. A. Blake, N. J. Evans II, and F. Lahuis. ApJ 718:1100-1117 (2010). 2024 - - - - - - - - - - - A JWST/MIRI analysis of the ice distribution and polycyclic aromatic hydrocarbon emission in the protoplanetary disk HH 48 NE J. A. Sturm, M. K. McClure, D. Harsono, J. B. Bergner, E. Dartois, A. C. A. Boogert et al. A&A 689:A92 (2024).

2023	NH+ 4 ammonium cation	An Ice Age JWST inventory of dense molecular cloud ices M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, F. Sun et al. Nat Astron 7:431-443 (2023).	NIR38, J110621 NH stretch 6.85 μm / 1459 cm^–1
Additional references for NH+ 4: 1989 - - - - - - - - - - - Ions in Grain Mantles: A New Explanation for the 6.86 Micron Absorption in W33A R. Grim, J. M. Greenberg, W. Schutte, and B. Schmitt. ApJ 341:L87-L90 (1989). 2003 - - - - - - - - - - - TOrigin of the 6.85 μm band near young stellar objects: The ammonium ion (NH+ 4) revisited W. A. Schutte and R. K. Khanna. A&A 398:1049-1062 (2003). 2006 - - - - - - - - - - - Theoretical Modeling of Formic Acid (HCOOH), Formate (HCOO^–), and Ammonium (NH+ 4) Vibrational Spectra in Astrophysical Ices J.-Y. Park and D. E. Woon. ApJ 638:1285-1290 (2006). 2010 - - - - - - - - - - - Ammonium and Formate Ions in Interstellar Ice Analogs O. Gálvez, B. Maté V. J. Herrero, and R. Escibanao. ApJ 724:539-545 (2010). 2024 - - - - - - - - - - - A JWST/MIRI analysis of the ice distribution and polycyclic aromatic hydrocarbon emission in the protoplanetary disk HH 48 NE J. A. Sturm, M. K. McClure, D. Harsono, J. B. Bergner, E. Dartois, A. C. A. Boogert et al. A&A 689:A92 (2024).

2024	SO₂ sulfur dioxide	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 asymmetric stretch 7.60 μm / 1320 cm^–1
Additional references for SO₂: 2023 - - - - - - - - - - - An Ice Age JWST inventory of dense molecular cloud ices M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, F. Sun et al. Nat Astron 7:431-443 (2023).

2024	HCOO^– formate anion	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 CO stretch 7.23 μm / 1383 cm^–1 CO stretch 7.38 μm / 55 cm^–1
Additional references for HCOO^–: TBD

2024	H₂CO formaldehyde	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 CH₂ rock 8.04 μm / 1244 cm^–1
Additional references for H₂CO: TBD

2024	HCOOH formic acid	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 CO stretch 8.22 μm / 1216 cm^–1
Additional references for HCOOH: TBD

2024	CH₃CHO acetaldehyde	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 CH₃ sym def/CH wag 7.41 μm / 1349 cm^–1
Additional references for CH₃CHO: 2023 - - - - - - - - - - - An Ice Age JWST inventory of dense molecular cloud ices M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, F. Sun et al. Nat Astron 7:431-443 (2023).

2024	C₂H₅OH ethanol	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 CH₃ sym def 7.23 μm / 1383 cm^–1
Additional references for C₂H₅OH: 2023 - - - - - - - - - - - An Ice Age JWST inventory of dense molecular cloud ices M. K. McClure, W. R. M. Rocha, K. M. Pontoppidan, N. Crouzet, L. E. U. Chu, E. Dartois, T. Lamberts, J. A. Noble, Y. J. Pendleton, G. Perotti, D. Qasim, M. G. Rachid, Z. L. Smith, F. Sun et al. Nat Astron 7:431-443 (2023).

2024	CH₃OCHO methyl formate	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 CO stretch 8.25 μm / 1211 cm^–1
Additional references for CH₃OCHO: TBD

2024	CH₃COOH acetic acid	JWST Observations of Young protoStars (JOYS+): Detecting icy complex organic molecules and ions - I. CH₄, SO₂, HCOO^–, OCN^–, H₂CO, HCOOH, CH₃CH₂OH, CH₃CHO, CH₃OCHO, and CH₃COOH W. R. M. Rocha, E. F. van Dishoeck, M. E. Ressler, M. L. van Gelder, K. Slavicinska, N. G. C. Brunken, H. Linnartz, T. P. Ray et al. A&A 683:A124 (2024).	NGC 1333 IRAS 2A, IRAS 23385+6053 OH bend 7.82 μm / 1278 cm^–1
Additional references for CH₃COOH: TBD

2024	CH₃CN methyl cyanide	Hunting for complex cyanides in protostellar ices with the JWST - A tentative detection of CH₃CN and C₂H₅CN P. Nazari, W. R. M. Rocha, A. E. Rubinstein, K. Slavicinska, M. G. Rachid, E. F. van Dishoeck, S. T. Megeath, R. Gutermuth, H. Tyagi, N. Brunken, M. Narang, P. Manoj, D. M. Watson, N. J. Evans II, S. Federman, J. Muzerolle, G. Anglada, H. Beuther, P. Klaassen, L. W. Looney, M. Osorio, T. Stanke, and Y.-L. Yang. A&A 686:A71 (2024).	HOPS 153, HOPS 370, IRAS 20126+4104 CN stretch 4.4 μm / 2273 cm^–1
Additional references for CH₃CN: TBD

2024	CH₃CH₂CN ethyl cyanide	Hunting for complex cyanides in protostellar ices with the JWST - A tentative detection of CH₃CN and C₂H₅CN P. Nazari, W. R. M. Rocha, A. E. Rubinstein, K. Slavicinska, M. G. Rachid, E. F. van Dishoeck, S. T. Megeath, R. Gutermuth, H. Tyagi, N. Brunken, M. Narang, P. Manoj, D. M. Watson, N. J. Evans II, S. Federman, J. Muzerolle, G. Anglada, H. Beuther, P. Klaassen, L. W. Looney, M. Osorio, T. Stanke, and Y.-L. Yang. A&A 686:A71 (2024).	HOPS 153, HOPS 370, IRAS 20126+4104 CN stretch
Additional references for CH₃CH₂CN: TBD

2024	N₂O nitrogen oxide	Hunting for complex cyanides in protostellar ices with the JWST - A tentative detection of CH₃CN and C₂H₅CN P. Nazari, W. R. M. Rocha, A. E. Rubinstein, K. Slavicinska, M. G. Rachid, E. F. van Dishoeck, S. T. Megeath, R. Gutermuth, H. Tyagi, N. Brunken, M. Narang, P. Manoj, D. M. Watson, N. J. Evans II, S. Federman, J. Muzerolle, G. Anglada, H. Beuther, P. Klaassen, L. W. Looney, M. Osorio, T. Stanke, and Y.-L. Yang. A&A 686:A71 (2024). Ice inventory towards the protostar Ced 110 IRS4 observed with the James Webb Space Telescope - Results from the Early Release Science Ice Age program W. R. M. Rocha, M. K. McClure, J. A. Sturm, T. L. Beck, Z. L. Smith, H. Dickinson, F. Sun, E. Egami, A. C. A. Boogert, H. J. Fraser, E. Dartois, I. Jimenez-Serra, J. A. Noble, J. Bergner, P. Caselli, S. B. Charnley, J. Chiar, L. Chu, I. Cooke, N. Crouzet, E. F. van Dishoeck, M. N. Drozdovskaya, R. Garrod, D. Harsono, S. Ioppolo, M. Jin, J. K. Jørgensen, T. Lamberts, D. C. Lis, G. J. Melnick, B. A. McGuire, K. I. Ïberg, M. E. Palumbo, Y. J. Pendleton, G. Perotti, D. Qasim, B. Shope, R. G. Urso, S. Viti, and H. Linnartz. A&A 693:A288 (2025).	HOPS 153, HOPS 370, IRAS 20126+4104 ? mode Ced 110 IRS4 1290 cm^–1
Additional references for N₂O: TBD

2024	HDO deuterated water	JWST detections of amorphous and crystalline HDO ice toward massive protostars K. Slavicinska, E. F. van Dishoeck, Ł. Tychoniec, P. Nazari, A. E. Rubinstein, R. Gutermuth, H. Tyagi, Y. Chen, N. G. C. Brunken, W. R. M. Rocha, P. Manoj, M. Narang, S. T. Megeath, Y.-L. Yang, L. W. Looney, J. J. Tobin, H. Beuther, T. L. Bourke, H. Linnartz, S. Federman, D. M. Watson, and H. Linz. A&A 688:A29 (2024).	HOPS 370, IRAS 20126+4104 OD stretch 4.1 μm / 2439 cm^–1
Additional references for HDO: TBD

infrared (vibrational)

Maintained by DE Woon

Updated 4 February 2025