CDROM/AJ/V105/P0258
Polarization in the Carina Nebula (Marraco+ 1993)
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Intracluster Dust Polarization in the Carina Nebula
H. G. Marraco, E. I. Vega, F. J. Vrba
<1993, AJ, 105, 258>
=1993AJ....105..258M
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Abstract:
We have obtained new UBVRI polarimetric observations of 25 stars and BV
polarimetric observations of 60 stars which are embedded in the Carina
Nebula. Using these data and photometric data from the literature we
have modeled and subtracted the foreground dust contribution in the
color excess E(B-V) and the visual polarization. The resulting
intracluster dust component is found to have a polarization efficiency
less than the maximum observed for the interstellar medium. The
intracluster dust is also characterized by a ratio of E(V-K)/E(B-V) to
Lambda(max) higher than the canonical value for the interstellar
medium. This result is consistent with the anomalous extinction for
this region, reported by Tapia et al. [MNRAS, 232, 661 (1988a)], which
increases above normal values color excess ratios that are normalized
at wavelengths shorter than the V band.
File Summary:
------------------------------------------------------------------------------File Name
Lrecl
Records
Explanations
------------------------------------------------------------------------------table1.dat
62
61
BV polarimetric observations
table2.dat
47
147
UBVRI polarimetric observations
table4.dat
92
54
Observed, foreground, and intracluster
color
excesses and visual polarizations
table5.dat
47
105
UBVRI intracluster polarization
table6.dat
86
18
UBVRI polarization results
table125.tex
111
644
TeX version of tables 1, 2, and 5
table46.tex
141
282
TeX version of landscape tables 4 and 6
------------------------------------------------------------------------------Comments for file: table1.dat
------------------------------------------------------------------------------Table 1 presents data for 60 high luminosity stars (plus Eta Carina)
that were observed polarimetrically in the Johnson B and V bandpasses in
the years 1978 to 1980. The observations were obtained with the
rotating analyzer polarimeter at La Plata Observatory using the 83 cm
telescope and also at the "Felix Aguilar" Observatory (San Juan) using
the "Perrine" 76 cm telescope.
------------------------------------------------------------------------------Byte-by-byte Description of file: table1.dat
------------------------------------------------------------------------------Bytes Format Units
Label
Explanations
------------------------------------------------------------------------------1
A1
--Front
*Asterisk, "*" if this is a "frontside" star
2
1X
----Blank
3- 8
A6
--HD
*Henry Draper (HD) number
91X
----Blank
10-13
A4
--LS
*Luminous Star (LS) number
14
1X
----Blank
15-22
A8
--Fein
*Identification from Feinstein, et al.
23-27
F5.2 %
P_V
Percentage of polarization in V
28-31
F4.2 %
e_P_V
Error in P_V
32-37
F6.1 deg
PA_V
Equatorial position angle in V
38-42
F5.2 deg
e_PA_V
Error in PA_V
43-47
F5.2 %
P_B
Percentage of polarization in B
48-51
F4.2 %
e_P_B
Error in P_B
52-57
F6.1 deg
PA_B
Equatorial position angle in B
58-62
F5.2 deg
e_PA_B
Error in PA_B
------------------------------------------------------------------------------Notes for file: table1.dat
------------------------------------------------------------------------------Front:
"Front-side" stars are 22 stars determined to be cluster members and
which appear to be least affected by reddening
HD:
One star is identified as "RT Car", instead
LS:
Reference: Stephenson & Sanduleak 1971
Fein:
Identification from Feinstein, Marraco & Muzzio [1973, A&AS, 12, 331],
Feinstein, Marraco & Forte [1976, A&AS, 24, 389], Feinstein,
Fitzgerald & Moffat [1980, AJ, 85, 708] and Feinstein [1982, AJ, 87,
1012]: 14-, 15-, 16- and C- indicate respectively Tr 14, Tr 15, Tr 16
and Collinder 228; SRN- from van den Bergh & Herbst (1975).
------------------------------------------------------------------------------Comments for file: table2.dat
------------------------------------------------------------------------------The data for each star in Table 2 is arranged in groups of 5, one each
for wavelengths 0.374, 0.443, 0.563, 0.670, and 0.792 um,
respectively. The first record in a group contains the
identification, and each group is separated by a blank line. See the
example below. Stars 15-23 and 15-5 do not have data for 0.374 um.
------------------------------------------------------------------------------Byte-by-byte Description of file: table2.dat
------------------------------------------------------------------------------Bytes Format Units
Label
Explanations
------------------------------------------------------------------------------1
A1
--Front
Asterisk, "*" if this is a "frontside" star
2
1X
----Blank
3- 8
A6
--HD
*Henry Draper (HD) number
9
1X
----Blank
10-13
A4
--LS
*Luminous Star (LS) number
14
1X
----Blank
15-22
A8
--Fein
*Identification from Feinstein, et al.
23-27
F5.3 um
lam
Wavelength
28-32
F5.2 %
P_lam
Percentage of polarization in lambda
33-37
F5.2 %
e_P_lam
Error in P_lam
38-43
F6.1 deg
PA_lam
Equatorial position angle in lambda
44-47
F4.1 deg
e_PA_lam
Error in PA_lam
------------------------------------------------------------------------------Notes for file: table2.dat
------------------------------------------------------------------------------Front:
"Front-side" stars are 22 stars determined to be cluster members
and least affected by reddening
HD:
One star is identified as "RT Car", instead
LS:
Reference: Stephenson & Sanduleak 1971
Fein:
Identification from Feinstein, Marraco & Muzzio [1973, A&AS, 12, 331],
Feinstein, Marraco & Forte [1976, A&AS, 24, 389], Feinstein,
Fitzgerald & Moffat [1980, AJ, 85, 708] and Feinstein [1982, AJ, 87,
1012]: 14-, 15-, 16- and C- indicate respectively Tr 14, Tr 15, Tr 16
and Collinder 228; FO- from Forte & Orsatti (1981)
------------------------------------------------------------------------------Comments for file: table4.dat
------------------------------------------------------------------------------Table 4 lists results for stars with two-color polarization data.
Together with Table 5, these data represent the observed polarization
of the intracluster material. Note that neither Table 4 nor 5 include
data for the "frontside" stars, as the residual reddening and
polarizations for those stars are meaningless. Note also that the
errors quoted for the intracluster polarization in Tables 4 and 5 are
internal errors.
------------------------------------------------------------------------------Byte-by-byte Description of file: table4.dat
------------------------------------------------------------------------------Bytes Format Units Label
Explanations
------------------------------------------------------------------------------1- 6
A6
--HD
*Henry Draper (HD) number
7
1X
----Blank
8-11
A4
--LS
*Luminous Star (LS) number
12
1X
----Blank
13-20
A8
--Fein
*Identification from Feinstein, et al.
21-25
F5.2 --E(B-V)o
[]? Observed B-V color excess
26-30
F5.2 --E(B-V)f
[]? Foreground B-V color excess
31-35
F5.2 --E(B-V)i
[]? Intracluster B-V color excess
36-41
F6.2 %
P_V
Observed polarization in V
42-45
F4.2 %
e_P_V
Error in observed P_V
46-52
F7.1 deg
PA_V
Observed equatorial position angle in
V
53-57
F5.1 deg
e_PA_V
Error in observed PA_V
58-63
F6.2 %
P_Vf
Foreground polarization in V
64-70
F7.1 deg
PA_Vf
Foreground equatorial position angle
in V
71-76
F6.2 %
P_Vi
Intracluster polarization in V
77-80
F4.2 %
e_P_Vi
Error in intracluster P_Vi
81-87
F7.1 deg
PA_P_Vi
Intracluster equatorial position angle
in V
88-92
F5.1 deg
e_PA_P_Vi Error in intracluster PA_P_Vi
------------------------------------------------------------------------------Notes for file: table4.dat
------------------------------------------------------------------------------HD:
One star is identified as "RT Car", instead
LS:
Reference: Stephenson & Sanduleak 1971
Fein:
Identification from Feinstein, Marraco & Muzzio [1973, A&AS, 12, 331],
Feinstein, Marraco & Forte [1976, A&AS, 24, 389], Feinstein,
Fitzgerald & Moffat [1980, AJ, 85, 708] and Feinstein [1982, AJ, 87,
1012]: 14-, 15-, 16- and C- indicate respectively Tr 14, Tr 15, Tr 16
and Collinder 228; FO- from Forte & Orsatti (1981) SRN- from van den
Bergh & Herbst (1975)
------------------------------------------------------------------------------Comments for file: table5.dat
------------------------------------------------------------------------------The data for each star in Table 5 is arranged in groups of 5, one each
for wavelengths 0.374, 0.443, 0.563, 0.670, and 0.792 um,
respectively. The first record in a group contains the
identification, and each group is separated by a blank line. See the
example below. Stars 15-23 and 15-5 do not have data for 0.374 um.
------------------------------------------------------------------------------Byte-by-byte Description of file: table5.dat
------------------------------------------------------------------------------Bytes Format Units Label
Explanations
------------------------------------------------------------------------------1- 2
2X
----Blank
3- 8
A6
--HD
*Henry Draper (HD) number
9
1X
----Blank
10-13
A4
--LS
*Luminous Star (LS) number
14
1X
----Blank
15-22
A8
--Fein
*Identification from Feinstein, et al.
23-27
F5.3 um
lam
Wavelength
28-32
F5.2 %
P_lam
Percentage of polarization in lambda
33-37
F5.2 %
e_P_lam
Error in P_lam
38-43
F6.1 deg
PA_lam
Equatorial position angle in lambda
44-47
F4.1 deg
e_PA_lam
Error in PA_lam
------------------------------------------------------------------------------Notes for file: table5.dat
------------------------------------------------------------------------------HD:
One star is identified as "RT Car", instead
LS:
Reference: Stephenson & Sanduleak 1971
Fein:
Identification from Feinstein, Marraco & Muzzio [1973, A&AS, 12, 331],
Feinstein, Marraco & Forte [1976, A&AS, 24, 389], Feinstein,
Fitzgerald & Moffat [1980, AJ, 85, 708] and Feinstein [1982, AJ, 87,
1012]: 14-, 15-, 16- and C- indicate respectively Tr 14, Tr 15, Tr 16
and Collinder 228; FO- from Forte & Orsatti (1981)
------------------------------------------------------------------------------Comments for file: table6.dat
------------------------------------------------------------------------------Table 6 contains results for those nonfrontside stars with five-color
polarimetric data.
------------------------------------------------------------------------------Byte-by-byte Description of file: table6.dat
------------------------------------------------------------------------------Bytes Format Units Label
Explanations
------------------------------------------------------------------------------1- 6
A6
--HD
*Henry Draper (HD) number
7
1X
----Blank
8-11
A4
--LS
*Luminous Star (LS) number
12
1X
----Blank
13-20
A8
--Fein
*Identification from Feinstein, et al.
21-25
F5.2 --Disp_O
*Observed dispersion of position angle
26-31
F6.2 --Disp_I
*Intracluster dispersion of position
angle
32
A1
--u_Disp_I *See notes
33-38
F6.3 um
lam_O
Observed wavelength of maximum
polarization
39-43
F5.3 um
e_lam_O
Error in lam_O
44-49
F6.2 %
P_O
Observed polarization
50-53
F4.2 %
e_P_O
Error in P_O
54-59
F6.2 %
sig_O
Observed unit wgt error, least-squares
fit
60-65
F6.3 um
lam_I
Intracluster wavelength of max.
polarization
66-70
F5.3 um
e_lam_I
Error in lam_I
71-76
F6.2 %
P_I
Intracluster polarization
77A1
--u_P_I
A colon, ':', for one star, Tr15-16
(RT Car)
78-80
F3.2 %
e_P_I
[]? Error in P_I (null for one star,
Tr15-16)
81-86
F6.2 %
sig_I
Intraclus. unit wgt error, leastsquares fit
------------------------------------------------------------------------------Notes for file: table6.dat
------------------------------------------------------------------------------HD:
One star is identified as "RT Car", instead
LS:
Reference: Stephenson & Sanduleak 1971
Fein:
Identification from Feinstein, Marraco & Muzzio [1973, A&AS, 12, 331],
Feinstein, Marraco & Forte [1976, A&AS, 24, 389], Feinstein,
Fitzgerald & Moffat [1980, AJ, 85, 708] and Feinstein [1982, AJ, 87,
1012]: 14-, 15-, 16- and C- indicate respectively Tr 14, Tr 15, Tr 16
and Collinder 228
Disp_O:
Observed dispersion of position angle normalized by the average of
the position angle errors
Disp_I:
Intracluster dispersion of position angle normalized by the average
of the position angle errors
u_Disp_I:
A colon, ':', flags two stars that have computed intracluster P(max)
< 0.5%, and, hence, small intracluster polarizations in relation to
the external errors. The authors have chosen not to extract results
from these stars.
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(End)
Lee Brotzman [ADS] 26Feb-1995