CO(+) fluorescence in comets

Magnani, L.; A’Hearn, M. F.

doi:10.1086/164006

Cited by 56 publications

(33 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2. Their assignments were made using the Ultraviolet and Visible Spectroscopic Database for Atoms and Molecules in Celestial Objects compiled by Kim (1994Kim ( , 1998 and fluorescence calculations by Arpigny (1964) and Magnani & A'Hearn (1986).…”

Section: Resultsmentioning

confidence: 99%

Cometary activity of distant object C/2002 VQ94 (LINEAR)

Корсун

Ivanova

Afanasiev

2006

A&A

View full text Add to dashboard Cite

Aims. We have started a program of spectroscopic and photometric investigations of distant active comets in the optical domain. The comets with a significant level of activity-in particular, extended tails-are the objects of our observations. Methods. The observations were made at the 6-m telescope BTA (SAO RAS, Russia), with the focal reducer SCORPIO attached to the prime focus of the telescope. Long-slit and photometry modes were turned to perform our first observations. The spectral resolution in the spectroscopy mode was 10 Å. Results. The result of the spectrum analysis of comet C/2002 VQ94 (LINEAR) is of particular interest. The comet observed at the heliocentric distance of 6.8 AU clearly shows a rich molecular spectrum. We identified 14 vibrational bands of CO + (Comet Tail system), emissions of C 3 , and some tentatively assigned to N + 2 and CN. It should be emphasized that, for now, CO + and tentatively assigned N + 2 emissions are detected at a record heliocentric distance.

show abstract

Section: Resultsmentioning

confidence: 99%

Cometary activity of distant object C/2002 VQ94 (LINEAR)

Корсун

Ivanova

Afanasiev

2006

A&A

View full text Add to dashboard Cite

show abstract

“…In order to compare his intensity ratios with other observers' column density ratios, it is necessary to multiply by the ratio of the excitation factors, as before. Since the (2,0) CO + was used in our work and in other published ratios, we converted the intensity ratios in Table III by using the relationship I (4,0) = 0.6 × I (2,0), where I (4,0) is the intensity of the (4,0) band, I (2,0) is the intensity of the (2,0) band, and the factor is taken from Table 4 of Magnani and A'Hearn (1986). The resultant column density ratios are given in column 3 of Table III.…”

Section: /Comentioning

confidence: 99%

N+2 and CO+ in Comets 122P/1995 S1 (deVico) and C/1995 O1 (Hale–Bopp)

Cochran

Barker

2000

Icarus

View full text Add to dashboard Cite

“…A Pi band system calculated using the band fluorescence ef-2 ϩ X S ficiencies of Magnani & A'Hearn (1986). The strongest molecular ion features in comets Hyakutake, Hale-Bopp, and Halley are associated with CO ϩ and H 2 O ϩ .…”

Section: Observationsmentioning

confidence: 99%

“…Figure 2 illustrates that the 5310 Å unidentified emission features have a similar overall double structure extending from 5270 to 5350 Å in the five comets. Differences in the detailed band structure may have several causes, among them noise, spectral resolution differences (Table 1), and fluorescence excitation differences due to the Swings effect (Swings 1941;Magnani & A'Hearn 1986;Schleicher & A'Hearn 1988). Band flux ratios F 5310 (unident)/F 5420 (CO ϩ ) are listed for three comets in Table 3.…”

Section: Observationsmentioning

confidence: 99%

Unidentified Molecular Bands in the Plasma Tail of Comet Hyakutake (C/1996 B2)

Wyckoff

Heyd

Fox

1999

The Astrophysical Journal

View full text Add to dashboard Cite

Unidentified molecular emission bands first observed in optical spectra of the plasma tail of comet Halley (1P/1982 U1) have been discovered in pure ion tail spectra ( Å , ) of comet Dl ∼ 4700-6300 l/Dl ∼ 1000-4400 Hyakutake (C/1996 B2) and three other recent comets (Nakamura-Nishimura-Machholz P/1994 N1, Austin C/1989 X1, and Brorsen-Metcalf 32P/1989 N1), but not in comet Hale-Bopp (C/1995 O1). The strengths of the bands near 4940, 5310, and 6000 Å are correlated among the comets observed, indicative that the unidentified bands arise from a single molecular species. The bands have an asymmetric spatial distribution that extends in the antisolar direction, resembling molecular ions observed in comet plasma tails. Thus, the source of the unidentified bands is probably a single species of molecular ions. Of known laboratory molecular ion spectra, none can be attributed to the unidentified cometary emission bands. The absence of the unidentified ions in the tail of Hale-Bopp may be explained by a parent species of the unidentified ions that mimics the coma dynamics and photochemistry of H 2 O more closely than CO. This is inferred from the large tail CO ϩ /H 2 O ϩ ratio observed in Hale-Bopp, which arises from the comet's large production rate that extends the ionopause and coma collision zone. Our observations provide evidence that the source region for the ions in plasma tails of comets lies external to the magnetic field-free ionopause.

show abstract

CO(+) fluorescence in comets

Cited by 56 publications

References 0 publications

Cometary activity of distant object C/2002 VQ94 (LINEAR)

Cometary activity of distant object C/2002 VQ94 (LINEAR)

N+2 and CO+ in Comets 122P/1995 S1 (deVico) and C/1995 O1 (Hale–Bopp)

Unidentified Molecular Bands in the Plasma Tail of Comet Hyakutake (C/1996 B2)

Contact Info

Product

Resources

About