Hipparcos distance estimates of the Ophiuchus and the Lupus cloud complexes

Author(s)
M. Lombardi, C. J. Lada, J. Alves
Abstract

We combine extinction maps from the Two Micron All Sky Survey (2MASS)with Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based on a rigorous maximum-likelihood approach, shows that the ρ-Ophiuchi cloud is located at (119± 6) pc and the Lupus complex is located at (155 ± 8) pc;in addition, we are able to put constraints on the thickness of the clouds and on their orientation on the sky (both these effects are not included in the error estimate quoted above). For Ophiuchus, we find some evidence that the streamers are closer to us than the core. The method applied in this paper is currently limited to nearby molecular clouds, but it will find many natural applications in the GAIA-era, when it will be possible to pin down the distance and three-dimensional structure of virtually every molecular cloud in the Galaxy.

Organisation(s)
Department of Astrophysics
External organisation(s)
Harvard-Smithsonian Center for Astrophysics
Journal
Astronomy & Astrophysics
Volume
480
Pages
785-792
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361:20079110
Publication date
03-2008
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/964c932d-2f4b-497d-baad-196fd96ef620