J/AJ/153/126 NIR polarimetric study in the LMC N159/N160 field (Kim+, 2017)
Near-infrared polarimetric study of the N159/N160 star-forming complex in
the Large Magellanic Cloud.
Kim J., Jeong W.-S., Pyo J., Pak S., Park W.-K., Kwon J., Tamura M.
<Astron. J., 153, 126 (2017)>
=2017AJ....153..126K 2017AJ....153..126K
ADC_Keywords: Magellanic Clouds ; Star Forming Region ; H II regions ;
Photometry, infrared ; Extinction
Keywords: infrared: ISM - infrared: stars -
ISM: individual objects (N159, N160) - ISM: magnetic fields -
ISM: structure - Magellanic Clouds
Abstract:
We present near-infrared polarimetric results for the N159/N160
star-forming complex in the Large Magellanic Cloud with SIRPOL, the
polarimeter of the Infrared Survey Facility. We separated foreground
sources using their visual extinction derived from near-infrared
photometric data. The 45 young stellar candidates and 2 high-excitation
blobs were matched with our sources, and 12 of them showed high
polarization that did not originate from the interstellar dust. We
made a polarimetric catalog of 252, 277, and 89 sources at the J, H,
and Ks bands, respectively. Based on the ratios of the polarization
degree between these bands, we verify that the origin of these
polarized sources is the dichroic extinction from the interstellar
dust aligned by the magnetic field and that the ratios follow a
power-law dependence of Pλ~λ-0.9. The linear
polarization vectors projected onto the Hα image of the complex
turned out to follow the local magnetic field structure. The vector
map overlaid on dust and gas emissions shows the close correlation
between the magnetic field structure and surrounding interstellar
medium. We suggest that the derived magnetic field structure supports
the sequential formation scenario of the complex.
Description:
Simultaneous JHKs polarimetric observations of the N159/N160 complex
were performed on 2007 February 3 and 5. We used the near-infrared
camera SIRIUS (Nagayama et al. 2003SPIE.4841..459N 2003SPIE.4841..459N) and the polarimeter
SIRPOL (Kandori et al. 2006SPIE.6269E..51K 2006SPIE.6269E..51K) of the Infrared Survey Facility
(IRSF) 1.4 m telescope at the South African Astronomical Observatory
in Sutherland, South Africa. The camera has a field of view of 7.7"x7.7"
and a pixel scale of 0.45"/pixel. One set of observations for a target
field consisted of 20 s exposures at 10 dithered positions for four
wave-plate angles (0°, 45°, 22.5°, and 67.5°) in
the J, H, and Ks bands, and the whole sequence is repeated 10 and 9
times for the N159 and N160 fields centered at
(α, δ)2000=(5h39m37.1s, -69°43'45.1") and
(5h40m05.6s, -69°36'25.8"), respectively.
Objects:
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RA (ICRS) DE Designation(s)
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05 39 46.65 -69 45 39.9 N159 = LHA 120-N 159
05 39 47.9 -69 37 08 N160 = LHA 120-N 160
05 23 34.6 -69 45 22 Large Magellanic Cloud = NAME LMC
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . this file
table1.dat 164 47 Photometric and polarimetric catalog of YSOs and
HPSs in the N159/N160 Field
table3.dat 179 418 Photometric and polarimetric catalog of the sources
in the N159/N160 Field of the LMC
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See also:
J/A+A/422/129 : JHKs photometry in N159 (LMC) (Meynadier+, 2004)
J/A+A/453/517 : JKs photometry of N159A (Testor+, 2006)
J/A+A/469/459 : K magnitudes of N159-5 (LMC) (Testor+, 2007)
J/AJ/138/510 : Spectral classification of N159/N160 stars (Farina+, 2009)
J/A+A/542/A66 : YSOs in 9 LMC star forming regions (Carlson+, 2012)
J/AJ/144/179 : AKARI-LMC Point-source catalog (Kato+, 2012)
J/ApJ/834/122 : Massive star formation in the LMC. I. N159 + N160
(Gordon+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 1 I1 h RAh Hour of Right Ascension (J2000)
3- 4 I2 min RAm Minute of Right Ascension (J2000)
6- 10 F5.2 s RAs Second of Right Ascension (J2000)
12 A1 --- DE- Sign of the Declination (J2000)
13- 14 I2 deg DEd Degree of Declination (J2000)
16- 17 I2 arcmin DEm Arcminute of Declination (J2000)
19- 23 F5.2 arcsec DEs Arcsecond of Declination (J2000)
25- 30 F6.3 mag Jmag [13.64/19.334] IRSF J band magnitude
32- 36 F5.3 mag e_Jmag [0.007/0.09] Error in Jmag
38- 43 F6.3 mag Hmag [12.975/18.145] IRSF H band magnitude
45- 49 F5.3 mag e_Hmag [0.003/0.083] Error in Hmag
51- 56 F6.3 mag Ksmag [11.156/17.551] IRSF Ks band magnitude
58- 62 F5.3 mag e_Ksmag [0.003/0.096] Error in Ksmag
64- 68 F5.2 % JPdeg [1.58/27.67]? Polarization degree in J band
70- 73 F4.2 % e_JPdeg [0.33/6.71]? Error in JPdeg
75- 79 F5.2 % HPdeg [0.92/24.38]? Polarization degree in H band
81- 84 F4.2 % e_HPdeg [0.34/6.14]? Error in HPdeg
86- 90 F5.2 % KsPdeg [0.41/52.79]? Polarization degree in Ks band
92- 95 F4.2 % e_KsPdeg [0.23/6.99]? Error in KsPdeg
97-102 F6.2 deg JPang [2.54/179.34]? Polarization position angle
in J band
104-108 F5.2 deg e_JPang [4.40/20.2]? Error in JPang
110-115 F6.2 deg HPang [4.49/176.29]? Polarization position angle
in H band
117-121 F5.2 deg e_HPang [4.20/20.09]? Error in HPang
123-128 F6.2 deg KsPang [7.03/176.72]? Polarization position angle
in Ks band
130-134 F5.2 deg e_KsPang [2.59/19.63]? Error in KsPang
136-140 F5.2 mag Av [-0.39/13.64] Visual extinction
142-144 A3 --- Ref Reference code(s) (1)
146-151 A6 --- Type Type of matched objects in literature (2)
153-154 I2 --- Num [1/12]? Numbering of highly polarized sources
that matched with YSO candidate
156-159 F4.2 mag S7-S11 [0.58/1.78]? AKARI/IRC mid-IR point-source LMC
catalog (S7-S11) color of Kato et al. (2012,
J/AJ/144/179)
161-164 F4.2 mag N3-S7 [3.20/5.04]? AKARI/IRC mid-IR point-source LMC
catalog (N3-S7) color of Kato et al. (2012,
J/AJ/144/179)
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Note (1): Reference as follows:
1 = Chen et al. (2010ApJ...721.1206C 2010ApJ...721.1206C);
2 = Carlson et al. (2012, J/A+A/542/A66);
3 = Kato et al. (2012, J/AJ/144/179);
4 = Martin-Hernandez et al. (2008A&A...489.1189M 2008A&A...489.1189M).
Note (2): Evolutionary stages for YSO candidates are labeled as "ya", "yb", and
"yc" indicating their stages from I to III as referred to in
Chen et al. (2010ApJ...721.1206C 2010ApJ...721.1206C) and Carlson et al. (2012,
J/A+A/542/A66). The label "ysc", "HEB", and "YSO" indicate young
stellar cluster (Chen et al. 2010ApJ...721.1206C 2010ApJ...721.1206C), HEB objects and
massive YSO from Martin-Hernandez et al. (2008A&A...489.1189M 2008A&A...489.1189M),
respectively. The label "CC5" indicates YSO candidates with water
ice absorption, classified by Kato et al. (2012, J/AJ/144/179).
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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- 5 A5 --- Field [N159 N160] Target field name
6- 17 F12.7 deg RAdeg Right Ascension in decimal degrees (J2000)
18- 29 F12.7 deg DEdeg Declination in decimal degrees (J2000)
30- 38 F9.3 mag Jmag [11.698/18.057] IRSF J band magnitude
39- 47 F9.3 mag e_Jmag [0.002/0.057] Error in Jmag
48- 56 F9.3 mag Hmag [10.499/17.153] IRSF H band magnitude
57- 65 F9.3 mag e_Hmag [0.001/0.056] Error in Hmag
66- 74 F9.3 mag Ksmag [9.918/16.93] IRSF Ks band magnitude
75- 83 F9.3 mag e_Ksmag [0.001/0.109] Error in Ksmag
84- 90 F7.2 % JPdeg [0.42/27.67]? Polarization degree in J band
91- 97 F7.2 % e_JPdeg [0.07/6.71]? Error in JPdeg
98-104 F7.2 % HPdeg [0.27/13.03]? Polarization degree in H band
105-111 F7.2 % e_HPdeg [0.11/3.48]? Error in HPdeg
112-118 F7.2 % KsPdeg [0.27/21.38]? Polarization degree in Ks band
119-125 F7.2 % e_KsPdeg [0.07/8.64]? Error in KsPdeg
126-132 F7.2 deg JPang [0.11/179.6]? Polarization position angle
in J band
133-139 F7.2 deg e_JPang [0.67/19.36]? Error in JPang
140-146 F7.2 deg HPang [0.05/179.95]? Polarization position angle
in H band
147-153 F7.2 deg e_HPang [1.45/20.03]? Error in HPang
154-160 F7.2 deg KsPang [0.3/179.98]? Polarization position angle
in Ks band
161-167 F7.2 deg e_KsPang [1.55/20.19]? Error in KsPang
168-173 F6.2 mag Av [0.48/13.64] Visual extinction
174-179 F6.2 mag e_Av [0.9/1.12] Error in Av
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau 18-Apr-2018