J/ApJ/707/89 Variation of mid-IR extinction (Gao+, 2009)
Mid-infrared extinction and its variation with galactic longitude.
Gao J., Jiang B.W., Li A.
<Astrophys. J., 707, 89-102 (2009)>
=2009ApJ...707...89G 2009ApJ...707...89G
ADC_Keywords: Extinction ; Galactic plane ; Interstellar medium ; Stars, giant ;
Photometry, infrared ; Surveys
Keywords: dust, extinction - Galaxy: bulge - Galaxy: structure - infrared: ISM -
infrared: stars
Abstract:
Based on the data obtained from the Spitzer/Galactic Legacy Infrared
Midplane Survey Extraordinaire (GLIPMSE) Legacy Program and the Two
Micron All Sky Survey (2MASS) project, we derive the extinction in the
four IRAC bands, [3.6], [4.5], [5.8], and [8.0]um, relative to the
2MASS Ks band (at 2.16um) for 131 GLIPMSE fields along the Galactic
plane within |l|≤65°, using red giants and red clump giants as
tracers. As a whole, the mean extinction in the IRAC bands (normalized
to the 2MASS Ks band), A[3.6]/AKs∼0.63±0.01,
A[4.5]/AKs∼0.57±0.03, A[5.8]/AKs_∼0.49±0.03,
A[8.0]/AKs∼0.55±0.03, exhibits little variation with wavelength
(i.e., the extinction is somewhat flat or gray). As far as individual
sightline is concerned, however, the wavelength dependence of the
mid-infrared interstellar extinction Aλ/AKs varies from one
sightline to another, suggesting that there may not exist a
"universal" IR extinction law.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 126 131 Extinction ratios A(λ)/A(Ks) of the 131
GLIMPSE fields
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See also:
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJ/658/1264 : IR-excess sources in GLIMPSE and MSX (Uzpen+, 2007)
J/A+A/446/551 : Extinctions at 7um + 15um from ISOGAL survey (Jiang+, 2006)
J/MNRAS/338/253 : K extinction near the Galactic Centre (Dutra+, 2003)
J/A+A/349/L69 : Interstellar extinction (Schultheis+, 1999)
http://www.astro.wisc.edu/sirtf/glimpsedata.html : GLIMPSE data home page
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- FName Field name (1)
13- 17 F5.1 deg GLONl Lower Galactic longitude degree
19- 23 F5.1 deg GLONu Upper Galactic longitude degree
25- 28 F4.1 deg GLATl Lower Galactic latitude degree
30- 33 F4.1 deg GLATu Upper Galactic latitude degree
35- 39 F5.3 --- GA3.6 IRAC [3.6] band to Ks band extinction ratio
from Red Giants (2)
41- 45 F5.3 --- e_GA3.6 Uncertainty in GA3.6
47- 51 F5.3 --- GA4.5 IRAC [4.5] band to Ks band extinction ratio
from Red Giants (2)
53- 57 F5.3 --- e_GA4.5 Uncertainty in GA4.5
59- 63 F5.3 --- GA5.8 IRAC [5.8] band to Ks band extinction ratio
from Red Giants (2)
65- 69 F5.3 --- e_GA5.8 Uncertainty in GA5.8
71- 75 F5.3 --- GA8.0 IRAC [8.0] band to Ks band extinction ratio
from Red Giants (2)
77- 81 F5.3 --- e_GA8.0 Uncertainty in GA8.0
83- 86 F4.2 --- CA3.6 IRAC [3.6] band to Ks band extinction ratio
from Red Clump Giants (2)
88- 91 F4.2 --- e_CA3.6 Uncertainty in CA3.6
93- 96 F4.2 --- CA4.5 IRAC [4.5] band to Ks band extinction ratio
from Red Clump Giants (2)
98-101 F4.2 --- e_CA4.5 Uncertainty in CA4.5
103-106 F4.2 --- CA5.8 IRAC [5.8] band to Ks band extinction ratio
from Red Clump Giants (2)
108-111 F4.2 --- e_CA5.8 Uncertainty in CA5.8
113-116 F4.2 --- CA8.0 IRAC [8.0] band to Ks band extinction ratio
from Red Clump Giants (2)
118-121 F4.2 --- e_CA8.0 Uncertainty in CA8.0
123-126 F4.1 mag Ksmax Maximum Ks band magnitude for Red Clump Giants
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Note (1): GLMXC_l009, GLMXC_l350, GLMIC_l064 and GLMIC_l295 are the combined
fields (see Section 2 in the paper).
Note (2): The effective wavelengths of the four Spitzer/IRAC bands [3.6],
[4.5], [5.8] and [8.0] are actually 3.545, 4.442, 5.675 and 7.760
microns, respectively.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 29-Dec-2011