Volume 493, Number 2, January II 2009
|Page(s)||735 - 745|
|Published online||15 October 2008|
nicest, a near-infrared color excess method tailored to small-scale structures
European Southern Observatory, Karl-Schwarzschild-Straße 2, 85748 Garching bei München, Germany e-mail: firstname.lastname@example.org
2 University of Milan, Department of Physics, via Celoria 16, 20133 Milan, Italy
Accepted: 16 September 2008
Observational data and theoretical calculations show that significant small-scale substructures are present in dark molecular clouds. These inhomogeneities can provide useful clues to the physical conditions inside the clouds, but can also severely bias extinction measurements. We present nicest, a novel method to account and correct for inhomogeneities in molecular cloud extinction studies. The method, tested against numerical simulations, removes almost completely the biases introduced by sub-pixel structures and by the contamination of foreground stars. We applied nicest to 2MASS data of the Pipe molecular complex. The map thereby obtained shows significantly higher (up to in AK) extinction peaks than the standard nicer (Lombardi & Schneider 2001, A&A, 373, 359) map. This first application confirms that substructures in nearby molecular clouds, if not accounted for, can significantly bias extinction measurements in regions with ; the effect, moreover, is expected to increase in more distant molecular clouds, because of the poorer physical resolution achievable.
Key words: dust, extinction / methods: statistical / ISM: clouds / infrared: ISM / ISM: structure / ISM: individual objects: Pipe molecular complex
© ESO, 2009
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.