J/A+A/359/347 Reddening in open and globular clusters (Dutra+, 2000)
Foreground and background dust in star cluster directions.
Dutra C.M., Bica E.
<Astron. Astrophys. 359, 347 (2000)>
=2000A&A...359..347D 2000A&A...359..347D
ADC_Keywords: Clusters, globular ; Clusters, open ; Reddening ; Stars, distances
Keywords: Galaxy: globular clusters: general - ISM: dust, extinction -
Galaxy: open clusters and associations: general
Abstract:
This paper compares reddening values E(B-V) derived from the stellar
content of 103 old open clusters and 147 globular clusters of the
Milky Way with those derived from DIRBE/IRAS 100µm dust emission in
the same directions. Star clusters at |b|>20° show comparable
reddening values between the two methods, in agreement with the fact
that most of them are located beyond the disk dust layer. For very low
galactic latitude lines of sight, differences occur in the sense that
DIRBE/IRAS reddening values can be substantially larger, suggesting
effects due to the depth distribution of the dust. The differences
appear to arise from dust in the background of the clusters consistent
with a dust layer where important extinction occurs up to distances
from the Plane of ≃300pc. For 3% of the sample a significant
background dust contribution might be explained by higher dust clouds.
We find evidence that the Milky Way dust lane and higher dust clouds
are similar to those of several edge-on spiral galaxies recently
studied in detail by means of CCD imaging.
Description:
Table 2 lists the galactic globular cluster, as follows: (1) name of
object, (2) and (3) galactic coordinates, (4) distance from the sun,
(5) reddening derived from dust 100µm emission E(B-V)FIR, (6)
E(B-V) derived from the light emitted by the cluster members, and (7)
ΔE(B-V) which is the difference between E(B-V)FIR and
E(B-V).
Table 3 lists the galactic old open clusters, as follows: (1) name of
object, (2 and (3) galactic coordinates, (4) distance from the sun,
(5) age, (6) E(B-V)FIR, (7) E(B-V), and (8) ΔE(B-V). Assuming
the Milky Way dust layer height to be |Z'|=200pc, Table 4 presents the
60 clusters with ΔE(B-V)>0.30, showing their height from the
Plane |Z'|, the distance in the cluster line of sight from the true
Plane up to the dust layer edge dlayer, and the path length behind
the cluster up to the disk border dbck. They are separated in two
groups, one formed by clusters within the dust layer (10 globular and
33 old open clusters) and the other by clusters outside it (15
globular and 2 old open clusters).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 72 147 Properties of Galactic globular clusters
table3.dat 61 103 Properties of Galactic old open clusters
table4.dat 33 60 Distance from the plane and lines of sight for
clusters with ΔE(B-V)>0.30
tables.tex 455 403 LaTeX version of the tables
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Names
25 A1 --- n_Name [1] Note on Names (1)
27- 32 F6.2 deg GLON Galactic longitude
34- 39 F6.2 deg GLAT Galacitc latitude
41- 45 F5.1 kpc Dsun Distance from the sun
47- 51 A5 --- n_Dsun Notes on Dsun (1)
52- 56 F5.2 mag E(B-V)FIR Reddening derived from dust 100µm emission
58- 61 F4.2 mag E(B-V) E(B-V) derived from the light emitted by the
cluster members
63- 66 A4 -- n_E(B-V) Notes on E(B-V) (1)
68- 72 F5.2 mag DE(B-V) Difference between E(B-V)FIR and E(B-V)
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Note (1): Notes:
1: in Sagittarius Dwarf (Ibata et al., 1994Natur.370..194I 1994Natur.370..194I,
Da Costa & Armandroff, 1995AJ....109.2533D 1995AJ....109.2533D)
2: Barbuy et al. (1998A&A...333..117B 1998A&A...333..117B)
3: Bica et al. (1998A&AS..131..483B 1998A&AS..131..483B)
4: Ortolani et al. (1999A&A...350..840O 1999A&A...350..840O)
5: Barbuy et al. (1998A&AS..132..333B 1998A&AS..132..333B)
6: Ortolani et al. (1999A&AS..138..267O 1999A&AS..138..267O)
7: Barbuy et al. (1999A&A...348..783B 1999A&A...348..783B)
8: Ortolani et al. (1999A&AS..136..237O 1999A&AS..136..237O)
9: Kaisler et al. (1997PASP..109..920K 1997PASP..109..920K)
10: Rosino et al. (1997MNRAS.289..745R 1997MNRAS.289..745R)
11: Ortolani et al. (1993A&A...273..415O 1993A&A...273..415O)
12: Ortolani et al. (1995, Cat. J/A+A/300/726)
13: Bica et al. (1996, Cat. J/A+AS/120/153)
14: Ortolani et al. (1998, Cat. J/A+AS/127/471)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name Names
21- 26 F6.2 deg GLON Galactic longitude
28- 33 F6.2 deg GLAT Galacitc latitude
35- 39 F5.2 kpc Dsun Distance from the sun
41- 44 I4 Myr t Age
46- 50 F5.2 mag E(B-V)FIR Reddening derived from dust 100µm emission
52- 55 F4.2 mag E(B-V) E(B-V) derived from the light emitted by the
cluster members
57- 61 F5.2 mag DE(B-V) Difference between E(B-V)FIR and E(B-V)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- Note [wo] Cluster within (w) or outside (o)
dust layer
3- 16 A14 --- Name Name
18 A1 --- n_Name [*] Note on line of sight (1)
20- 23 I4 pc |Z'| Height from the Plane
25- 28 F4.1 kpc Dlayer Distance in the cluster line of sight from the
true Plane up to the dust layer edge
30- 33 F4.1 kpc Dbck Path length behind the cluster up to the disk
border
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Note (1): *: lines of sight are truncated considering a
galactic disk radius R=15kpc
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Acknowledgements: Carlos Maxmiliano Dutra
(End) Patricia Bauer [CDS] 14-Sep-2000