J/MNRAS/462/2266 RCW121 stars polarimetric study (Seron Navarrete+, 2016)
Optical and near-infrared polarimetric study of the RCW121 Galactic H II region.
Seron Navarrete J.C., Roman-Lopes A., Santos F.P., Franco G.A.P., Reis W.
<Mon. Not. R. Astron. Soc. 462, 2266 (2016)>
=2016MNRAS.462.2266S 2016MNRAS.462.2266S (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Polarization ; Magnetic fields
Keywords: techniques: polarimetric - stars: formation - dust, extinction -
H II regions - ISM: individual objects: RCW121 - ISM: magnetic fields
Abstract:
We present a polarimetric study of the RCW121 star-forming region to
derive the orientation of the sky-projected magnetic field component
traced by the polarization vectors, the morphology of which tends to
follow the cloud's structure. Individual polarization-angle values
are consistent across the different bands, having a broad distribution
towards the RCW121 HII region. We estimate the corresponding magnetic
field orientation in the HII region to have a mean value of
-12±7°. RCW121 shows an elongated shape in the same direction as
the magnetic field orientation, which may be evidence that magnetic
pressure opposes the HII region expansion. Serkowski's relation was
used to determine individual values of the total-to-selective
extinction ratio (RV ) distribution and a weighted mean value of
RV=3.17±0.05. We derive a foreground component of the polarization
degree that is consistent with the literature value for this Galactic
region.
Description:
Linear polarimetric measurements for 1253 stars with data in at least
1 filter (VRIH) towards the RCW121 Galactic HII region are presented,
all of these have at least polarization degree 3 times its associated
error.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
rcw121po.dat 313 1253 Polarimetric parameters for 2655 stars
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Byte-by-byte Description of file: rcw121po.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- StarIDV ?=- Star unique ID, when V data (1)
11- 19 F9.5 deg RAVdeg ?=- Right ascension (J2000.0) for a star with
V filter data
21- 29 F9.5 deg DEVdeg ?=- Declination (J2000.0) for a star with
V filter data
31- 38 E8.5 --- qV ?=- q Stoke parameter in V filter
40- 47 E8.5 --- uV ?=- u Stoke parameter in V filter
49- 56 F8.6 % PdpV ?=- Debiassed polarization degree value for
V filter
58- 62 F5.3 % e_PdpV ?=- Error of PdpV
64- 68 F5.1 deg thetaFV ?=- Corrected polarization angle for V filter
70- 77 F8.6 deg e_thetaFV ?=- Error of polarization angle for V filter
79- 87 I9 --- StarIDR ?=- Star unique ID, when R data (1)
89- 97 F9.5 deg RARdeg ?=- Right ascension (J2000.0) for a star with
R filter data
99-107 F9.5 deg DERdeg ?=- Declination (J2000.0) for a star with
R filter data
109-116 E8.5 --- qR ?=- q Stoke parameter in R filter
118-125 E8.5 --- uR ?=- u Stoke parameter in R filter
127-134 F8.6 % PdpR ?=- Debiassed polarization degree value for
R filter
136-140 F5.3 % e_PdpR ?=- Error of PdpR in percentage
142-146 F5.1 deg thetaFR ?=- Corrected polarization angle for R filter
148-155 F8.6 deg e_thetaFR ?=- Error of polarization angle for R filter
157-165 I9 --- StarIDVI ?=- Star unique ID, when I data (1)
167-175 F9.5 deg RAIdeg ?=- Right ascension (J2000.0) for a star with
I filter data
177-185 F9.5 deg DEIdeg ?=- Declination (J2000.0) for a star with
I filter data
187-194 E8.5 --- qI ?=- q Stoke parameter in I filter
196-203 E8.5 --- uI ?=- u Stoke parameter in I filter
205-213 F9.6 % PdpI ?=- Debiassed polarization degree value for
I filter
215-219 F5.3 % e_PdpI ?=- Error of PdpI
221-225 F5.1 deg thetaFI ?=- Corrected polarization angle for I filter
227-234 F8.6 deg e_thetaFI ?=- Error of polarization angle for I filter
236-244 I9 --- StarIDVH ?=- Star unique ID, when H data (1)
246-254 F9.5 deg RAHdeg ?=- Right ascension (J2000.0) for a star with
H filter data
256-264 F9.5 deg DEHdeg ?=- Declination (J2000.0) for a star with
H filter data
266-273 E8.5 --- qH ?=- q Stoke parameter in H filter
275-282 E8.5 --- uH ?=- u Stoke parameter in H filter
284-292 F9.6 % PdpH ?=- Debiassed polarization degree value for
H filter
294-298 F5.3 % e_PdpH ?=- Error of PdpH
300-304 F5.1 deg thetaFH ?=- Corrected polarization angle for H filter
306-313 F8.6 deg e_thetaFH ?=- Error of polarization angle for H filter
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Note (1): Star unique identification number (same number in each band).
First number 4 is because our data set has 4 filters, the next 4 numbers
indicate whether the star has good polarimetric measurements in the bands
VRIH respectively (1 indicate it is present and 0 that it is not).
The next 4 numbers as sequential number.
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Acknowledgements:
Jacqueline Seron, jacqueline.seron.navarrete(at)gmail.com
(End) Patricia Vannier [CDS] 08-Aug-2016