Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012astl...38...12g&link_type=abstract
Astronomy Letters, Volume 38, Issue 1, pp.12-24
Astronomy and Astrophysics
Astronomy
1
Interstellar Dust Grains, Galactic Solar Neighborhood, Color-Color Diagrams, Main Sequence: Early-Type (O And B) Stars, Giants And Subgiants
Scientific paper
Multicolor photometry from the Tycho-2 and 2MASS catalogues for 11 990 OB and 30 671 K-type red giant branch stars is used to detect systematic large-scale variations of the interstellar extinction law within the nearest kiloparsec. The characteristic of the extinction law, the total-to-selective extinction ratio Rv, which also characterizes the size and other properties of interstellar dust grains, has been calculated for various regions of space by the extinction law extrapolation method. The results for the two classes of stars agree: the standard deviation of the "red giants minus OB" Rv differences within 500 pc of the Sun is 0.2. The detected Rv variations between 2.2 and 4.4 not only manifest themselves in individual clouds but also span the entire space near the Sun, following Galactic structures. In the Local Bubble within about 100 pc of the Sun, Rv has a minimum. In the inner part of the Gould Belt and at high Galactic latitudes, at a distance of about 150 pc from the Sun, Rv reaches a maximum and then decreases to its minimum in the outer part of the Belt and other directions at a distance of about 500 pc from the Sun, returning to its mean values far from the Sun. The detected maximum of Rv at high Galactic latitudes is important when allowance is made for the interstellar extinction toward extragalactic objects. In addition, a monotonic increase in Rv by 0.3 per kpc toward the Galactic center has been found near the Galactic equator. It is consistent with the result obtained by Zasowski et al. (2009) for much of the Galaxy. Ignoring the Rv variations and traditionally using a single value for the entire space must lead to systematic errors in the calculated distances reaching 10%.
No associations
LandOfFree
Variations of the interstellar extinction law within the nearest kiloparsec does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Variations of the interstellar extinction law within the nearest kiloparsec, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variations of the interstellar extinction law within the nearest kiloparsec will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-908104