Herschel observations of the debris disc around HIP 92043
Journal article, 2013
Context. Typical debris discs are composed of particles ranging from several micron sized dust grains to km sized asteroidal bodies, and their infrared emission peaks at wavelengths 60-100 mu m. Recent Herschel DUNES observations have identified several debris discs around nearby Sun-like stars (F, G and K spectral type) with significant excess emission only at 160 mu m.
Aims. We observed HIP 92043 (110 Her, HD 173667) at far-infrared and sub-millimetre wavelengths with Herschel PACS and SPIRE. Identification of the presence of excess emission from HIP 92043 and the origin and physical properties of any excess was undertaken through analysis of its spectral energy distribution (SED) and the PACS images.
Methods. The PACS and SPIRE images were produced using the HIPE photProject map maker routine. Fluxes were measured using aperture photometry. A stellar photosphere model was scaled to optical and near infrared photometry and subtracted from the far-infared and sub-mm fluxes to determine the presence of excess emission. Source radial profiles were fitted using a 2D Gaussian and compared to a PSF model based on Herschel observations of alpha Boo to check for extended emission.
Results. Clear excess emission from HIP 92043 was observed at 70 and 100 mu m. Marginal excess was observed at 160 and 250 mu m. Analysis of the images reveals that the source is extended at 160 mu m. A fit to the source SED is inconsistent with a photosphere and single temperature black body.
Conclusions. The excess emission from HIP 92043 is consistent with the presence of an unresolved circumstellar debris disc at 70 and 100 mu m, with low probability of background contamination. The extended 160 mu m emission may be interpreted as an additional cold component to the debris disc or as the result of background contamination along the line of sight. The nature of the 160 mu m excess cannot be determined absolutely from the available data, but we favour a debris disc interpretation, drawing parallels with previously identified cold disc sources in the DUNES sample.
Stars: individual: HIP 92043 (110 Her
HD 173667)
circumstellar matter
Infrared: stars
Author
J. P. Marshall
Universidad Autonoma de Madrid (UAM)
A. Krivov
Friedrich Schiller University Jena
C. del Burgo
UNINOVA-CA3
National Institute of Astrophysics, Optics and Electronics
C. Eiroa
Universidad Autonoma de Madrid (UAM)
A. Mora
European Space Agency (ESA)
B. Montesinos
Centro de Astrobiologia (CAB)
S. Ertel
Grenoble Alpes University
University of Kiel
G. Bryden
California Institute of Technology (Caltech)
René Liseau
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
Chalmers, Earth and Space Sciences, Onsala Space Observatory
J. C. Augereau
Grenoble Alpes University
A. Bayo
European Space Observatory
W. Danchi
National Aeronautics and Space Administration (NASA)
T. Lohne
Friedrich Schiller University Jena
J. Maldonado
Universidad Autonoma de Madrid (UAM)
G.L. Pilbratt
European Space Agency (ESA)
K. R. Stapelfeldt
National Aeronautics and Space Administration (NASA)
P. Thebault
Observatoire de Paris-Meudon
Grenoble Alpes University
G. J. White
Open University
STFC Rutherford Appleton Laboratory
S. Wolf
University of Kiel
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 557 A58Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/201218976