An upper limit for the water outgassing rate of the main-belt comet 176P/LINEAR observed with Herschel/HIFI

176P/LINEAR is a member of the new cometary class known as main-belt comets (MBCs). It displayed cometary activity shortly during its 2005 perihelion passage, which may be driven by the sublimation of subsurface ices. We have therefore searched for emission of the H2O 110-1 01 ground state rotationa...

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Detalles Bibliográficos
Autores: de Val-Borro, M., Rezac, Ladislav, Hartogh, P., Biver, N., Bockelée-Morvan, D., Crovisier, J., Küppers, M., Lis, D.C., Szutowicz, S., Blake, G.A., Emprechtinger, M., Jarchow, C., Jehin, E., Kidger, M., Lara, Luisa María, Lellouch, E., Moreno, R., Rengel, M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/413173
Acceso en línea:http://hdl.handle.net/10261/413173
Access Level:acceso abierto
Palabra clave:Comets: individual: 176P/LINEAR
Submillimeter: planetary systems
Techniques: spectroscopic
Descripción
Sumario:176P/LINEAR is a member of the new cometary class known as main-belt comets (MBCs). It displayed cometary activity shortly during its 2005 perihelion passage, which may be driven by the sublimation of subsurface ices. We have therefore searched for emission of the H2O 110-1 01 ground state rotational line at 557 GHz toward 176P/LINEAR with the Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory on UT 8.78 August 2011, about 40 days after its most recent perihelion passage, when the object was at a heliocentric distance of 2.58 AU. No H2O line emission was detected in our observations, from which we derive sensitive 3-σ upper limits for the water production rate and column density of <4 × 1025 mol≠s-1 and of <3 × 1010 cm-2, respectively. From the peak brightness measured during the object's active period in 2005, this upper limit is lower than predicted by the relation between production rates and visual magnitudes observed for a sample of comets at this heliocentric distance. Thus, 176P/LINEAR was most likely less active at the time of our observation than during its previous perihelion passage. The retrieved upper limit is lower than most values derived for the H2O production rate from the spectroscopic search for CN emission in MBCs. ©2012 ESO.