J/A+A/495/157 Interstellar extinction in Galactic Center (Schultheis+, 2009)
Interstellar extinction and long-period variables in the Galactic centre.
Schultheis M., Sellgren K., Ramirez S., Stolovy S., Ganesh S., Glass I.S.,
Girardi L.
<Astron. Astrophys. 495, 157 (2009)>
=2009A&A...495..157S 2009A&A...495..157S
ADC_Keywords: Stars, variable ; Milky Way ; Extinction
Keywords: ISM: dust, extinction - Galaxy: stellar content -
stars: AGB and post-AGB
Abstract:
We use the Spitzer IRAC catalogue of the Galactic Center (GC) point
sources (Ramirez et al., 2008ApJS..175..147R 2008ApJS..175..147R) and combine it with new
isochrones (Marigo et al., 2008A&A...482..883M 2008A&A...482..883M) to derive extinctions
based on photometry of red giants and asymptotic giant branch (AGB)
stars. This new extinction map extends to much higher values of Av
than previously available. Our new extinction map of the GC region
covers 2.0x1.4deg2 (280x200pc at a distance of 8kpc). We apply it to
deredden the LPVs found by Glass et al. (2001, Cat. J/MNRAS/321/77)
near the GC. We make period-magnitude diagrams and compare them to
those from other regions of different metallicity. The Glass-LPVs
follow well-defined period-luminosity relations (PL) in the IRAC
filter bands at 3.6 , 4.5, 5.8, and 8.0um. The period-luminosity
relations are similar to those in the Large Magellanic Cloud,
suggesting that the PL relation in the IRAC bands is universal. We use
ISOGAL data to derive mass-loss rates and find for the Gl ass-LPV
sample some correlation between mass-loss and pulsation period, as
expected theoretically. The GC has an excess of high luminosity and
long period LPVs compared to the Bulge, which supports previous
suggestions that it contains a younger stellar population.
Description:
Interstellar extinction maps (Av) of the galactic center region are
provided as FITS files using the 2MASS JK bands, the IRAC/SPitzer
bands [3.6]-[5.8] and a "combined map" where for Av<20 2MASS is used
and for Av>20 the Spitzer bands. We recommend to use the "combined
extinction map".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
maps.dat 92 3 List of images
fig/* . 3 FITS images
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Byte-by-byte Description of file: maps.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- FileName Name of the FITS file in subdirectory fig
25- 92 A68 --- Title Title of the file
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Acknowledgements:
Mathias Schultheis,
(End) Patricia Vannier [CDS] 20-Feb-2009