Mapping the release of volatiles in the inner comae of comets C/2012 f6 (LEMMON) and c/2012 s1 (ISON) using the Atacama large millimeter/Submillimeter array

M. A. Cordiner, A. J. Remijan, J. Boissier, S. N. Milam, M. J. Mumma, S. B. Charnley, L. Paganini, G. Villanueva, D. Bockelée-Morvan, Y. J. Kuan, Y. L. Chuang, D. C. Lis, N. Biver, J. Crovisier, D. Minniti, I. M. Coulson

Resultado de la investigación: Article

35 Citas (Scopus)

Resumen

Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially resolved distributions of HCN, HNC, H2CO, and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolution 0.″5), reveal an unprecedented level of detail in the distributions of these fundamental cometary molecules, and demonstrate the power of ALMA for quantitative measurements of the distributions of molecules and dust in the inner comae of typical bright comets. In both comets, HCN is found to originate from (or within a few hundred kilometers of) the nucleus, with a spatial distribution largely consistent with spherically symmetric, uniform outflow. By contrast, the HNC distributions are clumpy and asymmetrical, with peaks at cometocentric radii 500-1000 km, consistent with release of HNC in collimated outflow(s). Compared to HCN, the H2CO distribution in comet Lemmon is very extended. The interferometric visibility amplitudes are consistent with coma production of H2CO and HNC from unidentified precursor material(s) in both comets. Adopting a Haser model, the H2CO parent scale length is found to be a few thousand kilometers in Lemmon and only a few hundred kilometers in ISON, consistent with the destruction of the precursor by photolysis or thermal degradation at a rate that scales in proportion to the solar radiation flux.

Idioma originalEnglish
Número de artículoL2
PublicaciónAstrophysical Journal Letters
Volumen792
N.º1
DOI
EstadoPublished - 1 sep 2014

Huella dactilar

comets
comet
outflow
dust
thermal degradation
coma
solar radiation
photolysis
angular resolution
visibility
destruction
molecules
proportion
spatial distribution
distribution
degradation
nuclei
radii

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Citar esto

Cordiner, M. A. ; Remijan, A. J. ; Boissier, J. ; Milam, S. N. ; Mumma, M. J. ; Charnley, S. B. ; Paganini, L. ; Villanueva, G. ; Bockelée-Morvan, D. ; Kuan, Y. J. ; Chuang, Y. L. ; Lis, D. C. ; Biver, N. ; Crovisier, J. ; Minniti, D. ; Coulson, I. M. / Mapping the release of volatiles in the inner comae of comets C/2012 f6 (LEMMON) and c/2012 s1 (ISON) using the Atacama large millimeter/Submillimeter array. En: Astrophysical Journal Letters. 2014 ; Vol. 792, N.º 1.
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abstract = "Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially resolved distributions of HCN, HNC, H2CO, and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolution 0.″5), reveal an unprecedented level of detail in the distributions of these fundamental cometary molecules, and demonstrate the power of ALMA for quantitative measurements of the distributions of molecules and dust in the inner comae of typical bright comets. In both comets, HCN is found to originate from (or within a few hundred kilometers of) the nucleus, with a spatial distribution largely consistent with spherically symmetric, uniform outflow. By contrast, the HNC distributions are clumpy and asymmetrical, with peaks at cometocentric radii 500-1000 km, consistent with release of HNC in collimated outflow(s). Compared to HCN, the H2CO distribution in comet Lemmon is very extended. The interferometric visibility amplitudes are consistent with coma production of H2CO and HNC from unidentified precursor material(s) in both comets. Adopting a Haser model, the H2CO parent scale length is found to be a few thousand kilometers in Lemmon and only a few hundred kilometers in ISON, consistent with the destruction of the precursor by photolysis or thermal degradation at a rate that scales in proportion to the solar radiation flux.",
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author = "Cordiner, {M. A.} and Remijan, {A. J.} and J. Boissier and Milam, {S. N.} and Mumma, {M. J.} and Charnley, {S. B.} and L. Paganini and G. Villanueva and D. Bockel{\'e}e-Morvan and Kuan, {Y. J.} and Chuang, {Y. L.} and Lis, {D. C.} and N. Biver and J. Crovisier and D. Minniti and Coulson, {I. M.}",
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Cordiner, MA, Remijan, AJ, Boissier, J, Milam, SN, Mumma, MJ, Charnley, SB, Paganini, L, Villanueva, G, Bockelée-Morvan, D, Kuan, YJ, Chuang, YL, Lis, DC, Biver, N, Crovisier, J, Minniti, D & Coulson, IM 2014, 'Mapping the release of volatiles in the inner comae of comets C/2012 f6 (LEMMON) and c/2012 s1 (ISON) using the Atacama large millimeter/Submillimeter array', Astrophysical Journal Letters, vol. 792, n.º 1, L2. https://doi.org/10.1088/2041-8205/792/1/L2

Mapping the release of volatiles in the inner comae of comets C/2012 f6 (LEMMON) and c/2012 s1 (ISON) using the Atacama large millimeter/Submillimeter array. / Cordiner, M. A.; Remijan, A. J.; Boissier, J.; Milam, S. N.; Mumma, M. J.; Charnley, S. B.; Paganini, L.; Villanueva, G.; Bockelée-Morvan, D.; Kuan, Y. J.; Chuang, Y. L.; Lis, D. C.; Biver, N.; Crovisier, J.; Minniti, D.; Coulson, I. M.

En: Astrophysical Journal Letters, Vol. 792, N.º 1, L2, 01.09.2014.

Resultado de la investigación: Article

TY - JOUR

T1 - Mapping the release of volatiles in the inner comae of comets C/2012 f6 (LEMMON) and c/2012 s1 (ISON) using the Atacama large millimeter/Submillimeter array

AU - Cordiner, M. A.

AU - Remijan, A. J.

AU - Boissier, J.

AU - Milam, S. N.

AU - Mumma, M. J.

AU - Charnley, S. B.

AU - Paganini, L.

AU - Villanueva, G.

AU - Bockelée-Morvan, D.

AU - Kuan, Y. J.

AU - Chuang, Y. L.

AU - Lis, D. C.

AU - Biver, N.

AU - Crovisier, J.

AU - Minniti, D.

AU - Coulson, I. M.

PY - 2014/9/1

Y1 - 2014/9/1

N2 - Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially resolved distributions of HCN, HNC, H2CO, and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolution 0.″5), reveal an unprecedented level of detail in the distributions of these fundamental cometary molecules, and demonstrate the power of ALMA for quantitative measurements of the distributions of molecules and dust in the inner comae of typical bright comets. In both comets, HCN is found to originate from (or within a few hundred kilometers of) the nucleus, with a spatial distribution largely consistent with spherically symmetric, uniform outflow. By contrast, the HNC distributions are clumpy and asymmetrical, with peaks at cometocentric radii 500-1000 km, consistent with release of HNC in collimated outflow(s). Compared to HCN, the H2CO distribution in comet Lemmon is very extended. The interferometric visibility amplitudes are consistent with coma production of H2CO and HNC from unidentified precursor material(s) in both comets. Adopting a Haser model, the H2CO parent scale length is found to be a few thousand kilometers in Lemmon and only a few hundred kilometers in ISON, consistent with the destruction of the precursor by photolysis or thermal degradation at a rate that scales in proportion to the solar radiation flux.

AB - Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially resolved distributions of HCN, HNC, H2CO, and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolution 0.″5), reveal an unprecedented level of detail in the distributions of these fundamental cometary molecules, and demonstrate the power of ALMA for quantitative measurements of the distributions of molecules and dust in the inner comae of typical bright comets. In both comets, HCN is found to originate from (or within a few hundred kilometers of) the nucleus, with a spatial distribution largely consistent with spherically symmetric, uniform outflow. By contrast, the HNC distributions are clumpy and asymmetrical, with peaks at cometocentric radii 500-1000 km, consistent with release of HNC in collimated outflow(s). Compared to HCN, the H2CO distribution in comet Lemmon is very extended. The interferometric visibility amplitudes are consistent with coma production of H2CO and HNC from unidentified precursor material(s) in both comets. Adopting a Haser model, the H2CO parent scale length is found to be a few thousand kilometers in Lemmon and only a few hundred kilometers in ISON, consistent with the destruction of the precursor by photolysis or thermal degradation at a rate that scales in proportion to the solar radiation flux.

KW - comets: individual (C/2012 S1 (ISON), C/2012 F6 (Lemmon))

KW - techniques: interferometric

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U2 - 10.1088/2041-8205/792/1/L2

DO - 10.1088/2041-8205/792/1/L2

M3 - Article

AN - SCOPUS:84906334200

VL - 792

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

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