Astronomical School’s Report, 2011, Volume 7, Issue 2, Pages 208–220
UDC 523.6
The optical spectra of comets
Churyumov K.І.1, Chubko L.S.2, Ponomarenko V.O.1
1Astronomical Observatory, Kyiv Shevchenko National University, Ukraine
2National Aviation University, Ukraine
Abstract
We present an analytical overview of the spectral studies of comets with medium and high resolution. The article briefly laid out the stages of formation of modern ideas about the physics of comets and the influence on the process of spectral data. Examined in detail the main types of cometary emissions, namely: C2, C3, CN, NH, NH2, OH, H, O, Na and the emission of molecular ions. Revealed the most reasoned opinions on the “grandfather”, “parent” and “daughter” molecules of cometary atmospheres. Accentuated the problem areas and discussion issues.
Keywords: spectroscopy of comets; physical properties of comets
References
- Donati G.B. (1864). Comete II. 1864. Astronomische Nachrichten, 62(1488), 378. https://doi.org/10.1002/asna.18640622404
- Shul’man B.S. (1947). Spektrofotometricheskoe issledovanie nekotorykh komet. Izv. Gl. astron. observ. v Pulkove., 5(17), 1.
- Poloskov S.M. (1948). Rol’ releevskogo rasseyaniya v obschem protsesse otrazheniya i rasseyaniya radiatsii yadrom komety. Vestn. Mosk. un-ta.– 1948. – № 2., 37–39.
- Houziaux L. (1959). Sur l'origine du spectre continu des cométes. Bull. Acad. Roy. Belgique. Class Sciences., 45, 375–394.
- Swings P., Haser L. (1956). Atlas of Representative Cometary Spectra. Impr.Ceuterick. – Louvain..
- Rreston G.W. (1967). The spectrum of Ikeya-Seki (1965f). Astrophys. J., 147, 718–742.
- Churyumov K.I., Luk'yanyk I.V., Berezhnoy A.A., Chavushyan V.H., Sandoval L., Palma A., Kleshchonok V.V., Chubko L.S. (2002). Exploration of spectra comet C/2000 WM1 (LINEAR) obtained in Mexico on November 22 and 24, 2001 and April 5, 2002. Abstract book of CAMMAC. – Vinnytsia, Ukraine, 2002., 11.
- Cochran A.L., Cochran W.D. (2002). A high spectral resolution atlas of Comet 122P/de Vico. Icarus, 157, 297–308. https://doi.org/10.1006/icar.2002.6850
- Jackson W.M. (1976). The photochemical formation of cometary radicals. J.Photochem., 5, 107–118.
- O'Dell C.R. et al. (1988). C2 in Comet Halley – Evidence for its being third generation and resolution of the vibrational population discrepancy. Astrophys. J., 334, 476–488.
- Sombi M.R., Fink U. (1997). A critical study of molecular photodissociation and CHON grain sources for cometary C2. Astrophys. J., 484, 879–890. https://doi.org/10.1086/304349
- Sorkhabi O., et al. (1997). Using photochemistry to explain the formation and observation of C2 in comets. Planet. Space Sci., 45, 721–730.
- Bus S.J., A'Hearn M.F., Schleicher D.G., Bowell E. (1991). Detection of CN emission from (2060) Chiron. Science, 251, 774–777. https://doi.org/10.1126/science.251.4995.774
- Kleine M., Wysckoff S., Wehinger P.A., Peterson B.A. (1994). The cometary fluorescence spectrum of cyanogen: A model. Astrophys. J., 436, 885–906. https://doi.org/10.1086/174966
- Kleine M., Wysckoff S., Wehinger P.A., Peterson B.A. (1995). The carbon isotope abundance ratio in comet Halley. Astrophys. J., 439, 1021–1033. https://doi.org/10.1086/175239
- Lambert D.L., Danks A.C. (1983). High-resolution spectra of C2 Swan bands from comet West 1976 VI. Astrophys. J., 268, 428–446. https://doi.org/10.1086/160969
- Lambert D.L., et al. (1990). High-resolution spectroscopy of the C2 Swan 0–0 band from Comet P/Halley. Astrophys. J., 353, 640–653.
- Arpigny C., et al. (2003). Anomalous nitrogen isotope ratio in comets. Science, 301, 1522–1524. https://doi.org/10.1126/science.1086711
- Bockelee-Morvan D., Crovisier J. (1985). Possible parents for the cometary CN radical – Photochemistry and excitation conditions. Astron.Astrophys., 151, 90–100.
- Ziurys L.M., et al. (1994). Cyanide chemistry in Comet Hale-Bopp (C/1995 O1). Astrophys. J.Lett., 527, L67–L71. https://doi.org/10.1086/312388
- Woodney L.M., et al. (2002). Morphology of HCN and CN in Comet Hale-Bopp (1995 O1). Icarus, 157, 193–204. https://doi.org/10.1006/icar.2001.6798
- Festou M.C., et al. (1998). Tentative identification of the parent of CN radicals in comets := C2N2. Bull. Am. Astron. Soc., 30, 1089.
- Bonev B., Komitov B. (2000). New two-variable fits for the scale lengths of CN and its parent molecule in cometary atmospheres: Application to the identification of the CN parent. Bull. Am. Astron.Soc., 32, 1072.
- Douglas A.E. (1951). Laboratory studies of the λ4050 group of cometary spectra. Astrophys. J., 114, 466–468. https://doi.org/10.1086/145486
- Rousselot P., et al. (2001). A fluorescence model of the C3 radical in comets. Astron. Astrophys., 368, 689–699.
- Randall C.E., Schleicher D.G., Ballou R.G., Osip D.J. (1992). Observational constraints on molecular scalelengths and lifetimes in comets. Bull. Am. Astron. Soc., 24, 1002.
- Singh P.D., Dalgarno A. Photodissociation lifetimes of CH and CD radicals in comets Diversity and Similarity of Comets (E.J.Rolfe and B.Battrick, eds.) – ESA SP-278, Noordwijk, The Netherlands, 1987, P.177–179.
- Swings P., Elvey C.T., Babcock H.W. (1941). The spectrum of Comet Cunningham, 1940C. Astrophys. J., 94, 320–343. https://doi.org/10.1086/144336
- Palmer P., et al. (1996). Comet Hyakutake: First secure detection of ammonia in a comet. Bull. Am. Astron. Soc., 28, 927.
- Bird M.K., et al. (1997). Radio detection of ammonia in comet Hale-Bopp. Astron. Astrophys., 325, L5-L8.
- Mogee-Sauer K., et al. (2002). Spatial distribution of O1(D) from Comet Halley. Icarus, 76, 89–99.
- Tegler S., Wyckoff S. (1989). NH2 fluorescence efficiencies and the NH3 abundance in Comet Halley. Astrophys. J., 343, 445–449.
- Krasnopolsky V.A., Tkachuk A.Y. (1991). TKS-Vega experiment – NH and NH2 bands in Comet Halley. Astrophys. J., 101, 1915–1919. https://doi.org/10.1086/115816
- Fink U., Combi M.R., DiSanti M.A. (1991). Comet P/Halley – Spatial distributions and scale lengths for C2, CN, NH2, and H2O. Astrophys. J., 383, 356–371.
- Kawakita H., et al. (2001). High-dispersion spectra of NH2 in the Comet C/1999 S4 (LINEAR): Excitation mechanism of the NH2 molecule. Publ. Astron. Soc. Japan., 53, L5-L8. https://doi.org/10.1093/pasj/53.1.l5
- Korsun P.P., Jockers K. (2002). CN, NH2, and dust in the atmosphere of comet C/1993 J3 (LINEAR). Astron. Astrophys., 381, 703–708. https://doi.org/10.1051/0004-6361:20011557
- Kim S.J., A'Hearn M.F., Cochran W.D. (1989). NH emissions in comets – Fluorescence vs. Collisions. Icarus, 77, 98–108. https://doi.org/10.1016/0019-1035(89)90009-2
- Feldman P.D., Fournier K.B., Grinin V.P., Zvereva A.M. (1993). The abundance of ammonia in Comet P/Halley derived from ultraviolet spectrophotometry of NH by ASTRON and IUE. Astrophys. J., 404, 348–355. https://doi.org/10.1086/172284
- Kawakita H., et al. (2001). The spin temperature of NH3 in Comet C/1999 S4 (LINEAR). Science, 294, 1089–1091.
- A'Hearn M.F., Millis R.L., Schleicher D.G., Osip D.J., Birch P.V. (1995). The ensemble properties of comets: Results from narrowband photometry of 85 comets, 1976-1992. Icarus, 118, 223–270. https://doi.org/10.1006/icar.1995.1190
- Crovisier J., Colom P., Gérard E., Bockelee-Morvan D., Bourgois G. (2002). Observations at Nancay of the OH 18-cm lines in comets. The data base. Observations made from 1982 to 1999. Astron. Astrophys., 393, 1053–1064. https://doi.org/10.1051/0004-6361:20020673
- Schleicher D.G., A'Hearn M.F. (1988). The fluorescence of cometary OH. Astrophys. J., 331, 1058–1077.
- Bockelée-Morvan D., Gérard E. (1984). Radio observations of the hydroxyl radical in comets with high spectral resolution – Kinematics and asymmetries of the OH coma in C/Meier (1978 XXI), C/Bradfield (1979X), and C/Austin (1982g). Astron.Astrophys., 131, 111–122.
- Bockelée-Morvan D. Crovisier J., Gérard E. (1990). Retrieving the coma gas expansion velocity in P/Halley, Wilson (1987 VII) and several other comets from the 18-cm OH line shapes. Astron. Astrophys., 238, 382–400.
- Tacconi-Garman L.E., Schloerb F.P., Claussen M.J. (1990). High spectral resolution observations and kinematic modeling of the 1667 MHz hyperfine transition of OH in Comets Halley (1982i), Giacobini-Zinner (1984e), Hartley-Good (1985l), Thiele (1985m), and Wilson (1986l). Astrophys. J., 364, 672–686. https://doi.org/10.1086/169450
- Gérard E. (1990). The discrepancy between OH production rates deduced from radio and ultraviolet observations of comets. I. – A comparative study of OH radio and UV observations of P/Halley 1986 III in late November and early December 1985. Astron. Astrophys., 230, 489–503.
- Combi M.R., Feldman P.D. (1993). Water production rates in Comet P/Halley from IUE observations of HI Lyman-alpha. Icarus, 105, 557–567. https://doi.org/10.1006/icar.1993.1149
- Combi M.R., Feldman P.D. (1992). IUE observations of H Lyman-alpha in Comet P/Giacobini-Zinner. Icarus, 97, 260–268. https://doi.org/10.1016/0019-1035(92)90132-q
- A'Hearn M.F., Schleicher D.G. (1988). Comet P/Encke's non-gravitational force. Astrophys. J. Lett., 331, L47–L51.
- Brooke, et al. (1996). Detection of acetylene in the infrared spectrum of Comet Hyakutake. Nature, 383, 606–608. https://doi.org/10.1038/383606a0
- Mumma, et al. (2001). A survey of organic volatile species in Comet C/1999 H1 (Lee) using NIRSPEC at the Keck Observatory. Astrophys. J., 546, 1183–1193.
- A'Hearn M.F., Schleicher D.G., West R.A. (1985). Emision by OD in comets. Astrophys. J., 297, 826–836.
- Code A.D., Houck T.E., Lillie C.F. Ultraviolet observations of comets Scientific Results from the Orbiting Astronomical Observatory (OAO-2) (A.D.Code, ed.). NASA SP-310, 1972, P.109–114.
- Bertaux J.L., Blamont J.E., Festou M. (1973). Interpretation of hydrogen Lyman-alpha observations of Comets Bennett and Encke. Astron.Astrophys., 25, 415–430.
- Keller H.U. (1976). The interpretations of ultraviolet observations of comets. Space Sci. Rev., 18, 641–684.
- Huppler D., Reynolds R.J., Roesler F.L., Scherb F., Trauger J. (1975). Observations of comet Kohoutel (1973f) with a ground-based Fabry-Perot spectrometer. Astrophys. J., 202, 276–282. https://doi.org/10.1086/153974
- Scherb F. (1981). Hydrogen production rates from ground-based Fabry-Perot observations of comet Kohoutek. Astrophys. J., 368, 689–699. https://doi.org/10.1086/158630
- Brown M.E., Spinrad H. (1993). The velocity distribution of cometary hydrogen – Evidence for high velocities? Icarus, 104, 197–205. https://doi.org/10.1006/icar.1993.1095
- Combi M.R., Cochran A.L., Cochran W.D., Lambert D.L., Johns-Krull C.M. (1999). Observation and analysis of high-resolution optical line profiles in Comet Hyakutake (C/1996 B2). Astrophys. J., 512, 961–968. https://doi.org/10.1086/306798
- Combi M.R., et al. (1998). Hubble Space Telescope ultraviolet imaging and high-resolution spectroscopy of water photo-dissociation products in Comet Hyakutake (C/1996 B2). Astrophys. J., 494, 816–821.
- Richter K., Combi M.R., Keller H.U., Meier R.R. (2000). Multiple scattering of hydrogen Lyman-alpha radiation in the coma of Comet Hyakutake (C/1996 B2). Astrophys. J., 531, 599–611. https://doi.org/10.1086/308433
- Festou M., Feldman P.D. (1981). The forbidden oxygen lines in comets. Astron. Astrophys., 103, 154–159.
- Cochran W.D. (1984). Detection of forbidden OI 1S–1D in comet IRAS-Araki-Alcock. Icarus, 58, 440–445.
- Morisson N.D., Knauth D.C., Mulliss C.L., Lee W. (1997). High-resolution optical spectra of the head of the Comet C/1996 B2 (Hyakutake). Publ. Astron. Soc. Pac., 109, 676–681. https://doi.org/10.1086/133931
- Smith W.H., Schempp W.V. (1989). [OI] in Comet Halley. Icarus, 82, 61–66. https://doi.org/10.1016/0019-1035(89)90023-7
- Cochran A.L., Cochran W.D. (2001). Observations of O(1S) and O(1D) in spectra of C/1999 S4 (LINEAR). Icarus, 154, 381–390.
- Storey P.J., Zeippen C.J. (2000). Theoretical values for the [OIII] 5007/4959 line-intensity ratio and homologous cases. Mon. Not. R. Astron. Soc., 312, 813–816. https://doi.org/10.1046/j.1365-8711.2000.03184.x
- Magee-Sauer K., Roesler F.L., Scherb F., Harlander J., Oliversen R.J. (1988). Spatial distribution of O(1D) from Comet Halley. Icarus, 76, 89–99. https://doi.org/10.1016/0019-1035(88)90141-8
- Combi M.R., McCrosky R.E. (1991). High-resolution spectra of the 6300 Å region of Comet P/Halley. Icarus, 91, 270–279. https://doi.org/10.1016/0019-1035(91)90024-n
- Jockers K., et al. (2000). Water production of comets derived from observations of [OI] (6300 Å) and H2O+ (6150 Å): comets C/1998 U5 (LINEAR) and C/1999 J3 (LINEAR). Kinematika i Fizika Nebesnykh Tel, Suppl, 2000(.3), 261–265.
- Spinrad H. (1982). Observations of the red auroral oxygen lines in nine comets. Publ. Astron. Soc. Pac., 94, 1008–1016. https://doi.org/10.1086/131101
- Fink U., Hicks M.D. (1996). A survey of 39 comets using CCD spectroscopy. Astrophys. J., 459, 729–743. https://doi.org/10.1086/176938
- Arpigny, et al. (1987). Resolution of the [OI]+NH2 blend in Comet P/Halley. Astron.Astrophys., 187, 485–488.
- Huebner W.F., Keady J.J., Lyon S.P., eds. (1992). Solar Photo Rates for Planetary Atmospheres and Atmospheric Pollutants. – Kluwer, Dordrecht. 292 p.
- Levin B.J. (1964). On the reported Na tails of comets. Icarus, 3, 497–498. https://doi.org/10.1016/0019-1035(64)90010-7
- Newall H.F. (1910). On the spectrum of the daylight comet 1910a. Mon. Not. R. Astron. Soc., 70, 459–461.
- Brown R.A., Chaffee F.H. (1974). High-resolution spectra of sodium emission from Io. AstrophysJ.Lett., 187, L125-L126. https://doi.org/10.1086/181413
- Potter A., Morgan T. (1985). Discovery of sodium in the atmosphere of Mercury. Science, 229, 651–653. https://doi.org/10.1126/science.229.4714.651
- Potter A., Morgan T. (1988). Discovery of sodium and potassium vapor in the atmosphere of the Moon. Science, 241, 675–680. https://doi.org/10.1126/science.241.4866.675
- Baranovs’ky E.A., Taraschuk V.P. (2004). Fotonnoe vozbuzhdenie svecheniya natriya v kometakh. Pis’ma v AZH, 30(11), 874.
- Bappu M.K.V., Sivaraman K.R. (1969). Some characteristics of the solar wind inferred from the study of sodium emission from cometary nuclei. Sol.Phys., 10, 496–501. https://doi.org/10.1007/bf00145536
- Preston G.W. (1967). The spectrum of Ikeya-Seki (1965f). Astrophys. J., 147, 718–742. https://doi.org/10.1086/149049
- Spinrad H., Miner E.D. (1968). Sodium velocity fields in Comet 1965f. Astrophys. J., 153, 355–366. https://doi.org/10.1086/149672
- Huebner W.F. (1970). Dust from cometary nuclei. Astron.Astrophys., 5, 286–297.
- Slaughter C.D. (1969). The emission spectrum of Comet Ikeya-Seki 1965f at perihelion passage. Astrophys. J., 74, 929–943. https://doi.org/10.1086/110884
- Combi M.R., Fink U. (1997). A critical study of molecular photodissociation and CHON grain sources for cometary C2. Astrophys. J., 484, 879–890. https://doi.org/10.1086/304349
- Delsemme A.H., Combi M.R. (1983). Neutral cometary atmospheres. IV. – Brightness profiles in the inner coma of comet Kohoutek 1973 XII. Astrophys. J., 271, 388–397. https://doi.org/10.1086/161204
- Oppenheimer M. (1980). Sodium D-line emission in Comet West (1975n) and the sodium source in comets. Astrophys. J., 240, 923–928. https://doi.org/10.1086/158305
- Combi M.R., DiSanti M.A., Fink U. (1997). The spatial distribution of gaseous atomic sodium in the comae of comets: Evidence for direct nucleus and extended plasma sources. Icarus, 130, 336–354. https://doi.org/10.1006/icar.1997.5832
- Cremonese G., et al. (1997). Neutral sodium from Comet Hale-Bopp: A third type of tail. Astrophys. J.Lett., 409, L199-L202. https://doi.org/10.1086/311040
- Wilson J.K., Baumgardner J., Mendillo M. (1998). Three tails of comets Hale-Bopp. Geophys. Res. Lett., 25, 225–228. https://doi.org/10.1029/97gl03704
- Brown M.E., Bouchez A.H., Spinrad H., Misch A. (1998). Sodium velocities and sources in Hale-Bopp. Icarus, 134, 228–234. https://doi.org/10.1006/icar.1998.5941
- Rauer H., Arpigny C., Manfroid J., Cremonese G., Lemme C. (1998). The spatial sodium distribution in the coma of comet Hale-Bopp (C/1995 O1). Astron.Astrophys., 334, L61-L64.
- Jessberger E.K., Kissel J. Chemical properties of cometary dust and a note on carbon isotopes Comets in the Post-Halley Era (R.Newburn, et al., eds) – IAU Colloquium No 116, ASSL – Kluwer, Dordrecht, 1991, 167, P.1075–1092.
- Wright M.C.H., et al. (1998). Mosaicked images and spectra of J=1>0 HCN and HCO+ emission from Comet Hale-Bopp (1995 O1). Astrophys. J., 116, 3018–3028.
- Lis D.C., et al. (1999). New molecular species in Comet C/1995 O1 (Hale-Bopp) observed with the Catech Submillimeter Observatory. Earth Moon Planets, 78, 13–20.
- Umbach R., Jockers K., Geyer E.H. (1998). Spatial distribution of neutral and ionic constituents in comet P/Halley. Astron.Astrophys., 127, 479–495.
- Jackson W.M., Donn B. (1968). Photochemical effects in the production of cometary radicals and ions. Icarus, 8, 270–280. https://doi.org/10.1016/0019-1035(68)90079-1
- Cochran A.L., Cochran W.D. (1991). The first detection of CN and the distribution of CO+ gas in the coma of Comet P/Schwassmann-Wachmann 1. Icarus, 90, 172–175. https://doi.org/10.1016/0019-1035(91)90077-7
- Magnani L., A'Hearn M.F. (1986). CO+ fluorescence in comets. Astrophys. J., 302, 477–489.
- Herzberg G., Lew H. (1974). Tentative identification of the H2O+ ion in Comet Kohoutek. Astron.Astrophys., 31, 123–124.
- Wegmann R., Jockers K., Bonev T. (1999). H2O+ ions in comets: Models and observations. Planet.Space Sci., 47, 745–763. https://doi.org/10.1016/s0032-0633(98)00114-7
- Lutz B.L., Womack M., Wagner R.M. (1993). Ion abundances and implications for photochemistry in Comets Halley (1986 III) and Bradfield (1987 XXIX). Astrophys. J., 407, 402–411. https://doi.org/10.1086/172523
- Arpigny C. Physical chemistry of comets: Models, uncertainties, data needs Molecules and Grains in Space (I.Nenner, ed.) – AIP Conference Proceedings 312, 1994, P.205–238.
- Lew H. (1976). Electronic spectrum of H2O+. Can. J. Phys., 54, 2028–2049.
- Bonev T., Jockers K. (1994). H2O+ ions in the inner plasma tail of Comet Austin 1990 V. Icarus, 107, 335–357. https://doi.org/10.1006/icar.1994.1028
- Swings P., Page T. (1950). The spectrum of Comet Bester (1947k). Astrophys. J., 111, 530–554. https://doi.org/10.1086/145295
- Feldman P.D., Brune W.H. (1976). Carbon production in comet West 1975n. Astrophys. J.Lett., 209, L45-L48. https://doi.org/10.1086/182263
- Festou M.C., Feldman P.D., Weaver H.A. (1982). The ultraviolet bands of the CO2+ ion in comets. Astrophys. J., 256, 331–338.
- Feldman P.D., Weaver H.A., A'Hearn M.F., Festou M.C., McFadden L.A. (1986). Is CO2 responsible for the outburst of comet Halley? Nature, 324, 433–436. https://doi.org/10.1038/324433a0
- Leach S. (1987). Electronic spectroscopy and relaxation of some molecular cations of cometary interest. Astron.Astrophys., 187, 195–200.
- Fox J.L., Dalgarno A. (1979). Ionization, luminosity, and heating of the upper atmosphere of Mars. J.Geophys.Res., 84, 7315–7333. https://doi.org/10.1029/ja084ia12p07315
- Marconi M.L., et al. (1990). The identification of H3S+ with the ion of mass per charge (m/q) 35 observed in the coma of Comet Halley. Astrophys. J. Lett., 352, L17-L20. https://doi.org/10.1086/185683
- Eberhardt P., Krankowsky D. (1995). The electron temperature in the inner coma of comet P/Halley. Astron. Astrophys., 295, 795–806.
- Sochran A.L., Cochran W.D., Barker E.S. (2000). N2+ and CO+ in Comets 122P/1995 S1 (de Vico) and C/1995 O1 (Hale-Bopp). Icarus, 146, 583–593. https://doi.org/10.1006/icar.2000.6413
- Cochran A.L. (2002). A search for N2+ in spectra of Comet C/2002 C1 (Ikea-Jang). Astrophys. J. Lett., 576, L165-L168. https://doi.org/10.1086/343763
- Iro N., Gautier D., Hersant F., Bockelee-Morvan D., Lunine J.I. (2003). An interpretation of the nitrogen deficiency in comets. Icarus, 161, 511–532. https://doi.org/10.1016/s0019-1035(02)00038-6
Download PDF