J/ApJS/234/42 JHKs polarimetry in Circinus Molecular Cloud (Kwon+, 2018)
First near-infrared imaging polarimetry of young stellar objects in the
Circinus Molecular Cloud.
Kwon J., Nakagawa T., Tamura M., Hough J.H., Choi M., Kandori R., Nagata T.,
Kang M.
<Astrophys. J. Suppl. Ser., 234, 42 (2018)>
=2018ApJS..234...42K 2018ApJS..234...42K
ADC_Keywords: Molecular clouds ; YSOs ; Polarization ; Interstellar medium ;
Photometry, infrared
Keywords: circumstellar matter; infrared: stars; ISM: structure; polarization;
ISM: individual objects (Circinus); stars: formation
Abstract:
We present the results of near-infrared (NIR) linear imaging
polarimetry in the J, H, and Ks bands of the low-mass star
cluster-forming region in the Circinus Molecular Cloud Complex. Using
aperture polarimetry of point-like sources, positive detection of 314,
421, and 164 sources in the J, H, and Ks bands, respectively, was
determined from among 749 sources whose photometric magnitudes were
measured. For the source classification of the 133 point-like sources
whose polarization could be measured in all 3 bands, a color-color
diagram was used. While most of the NIR polarizations of point-like
sources are well-aligned and can be explained by dichroic polarization
produced by aligned interstellar dust grains in the cloud, 123 highly
polarized sources have also been identified with some criteria. The
projected direction on the sky of the magnetic field in the Cir-MMS
region is indicated by the mean polarization position angles (70°)
of the point-like sources in the observed region, corresponding to
approximately 1.6x1.6pc2. In addition, the magnetic field direction
is compared with the outflow orientations associated with Infrared
Astronomy Satellite sources, in which two sources were found to be
aligned with each other and one source was not. We also show prominent
polarization nebulosities over the Cir-MMS region for the first time.
Our polarization data have revealed one clear infrared reflection
nebula (IRN) and several candidate IRNe in the Cir-MMS field. In
addition, the illuminating sources of the IRNe are identified with
near- and mid-infrared sources.
Description:
The observations in the direction of the Cir-MMS cluster region (see
Cir-MMSs 1-4 in Reipurth+ 1996A&A...314..258R 1996A&A...314..258R) were carried out using
the SIRPOL imaging polarimeter mounted on the 1.4m Infrared Survey
Facility (IRSF) telescope at the South African Astronomical
Observatory (SAAO).
Our IRSF/SIRPOL observations were made on the night of 2011 March 19,
during which we performed 10s exposures at 4 wave plate angles in the
sequence of 0°, 45°, 22.5°, and 67.5° at 10 dithered
positions for each set.
The typical seeing size during the observations was approximately
3 pixels (corresponding to 1.4") in the JHKs band.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 137 749 Photometry and polarimetry of point-like sources
in the Circinus Molecular Cloud Complex
table2.dat 60 785 Polarizations of additional sources detected in
the J and H bands
table3.dat 60 701 Polarizations of additional sources detected in
the H and Ks bands
table4.dat 92 95 Polarization degrees and polarization
position angles of highly polarized sources
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See also:
J/AJ/136/621 : Near-infrared polarimetry of M42 (Kusakabe+, 2008)
J/ApJ/708/758 : Polarimetry of HH1-2 region (Kwon+, 2010)
J/ApJ/741/35 : NIR photometry and polarization in NGC 2264 (Kwon+, 2011)
J/ApJ/733/L2 : YSOs from WISE in Western Circinus cloud (Liu+, 2011)
J/ApJ/743/54 : Polarization around star-forming regions (Targon+, 2011)
J/ApJS/220/17 : Wide-field NIR polarimetry of ρ Oph cloud (Kwon+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/749] Source identifier
5- 6 I2 h RAh [14/15] Hour of Right Ascension (J2000) (1)
8- 9 I2 min RAm Minute of Right Ascension (J2000) (1)
11- 15 F5.2 s RAs Second of Right Ascension (J2000) (1)
17 A1 --- DE- [-] Sign of the Declination (J2000)(1)
18- 19 I2 deg DEd [63] Degree of Declination (J2000) (1)
21- 22 I2 arcmin DEm [2/10] Arcminute of Declination (J2000) (1)
24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000) (1)
29- 34 F6.3 mag Jmag [10.8/18.3] IRSF/SIRPOL apparent J band mag
36- 40 F5.3 mag e_Jmag [0/0.1] Uncertainty in Jmag
42- 47 F6.3 mag Hmag [9.9/16.6] IRSF/SIRPOL apparent H band mag
49- 53 F5.3 mag e_Hmag [0/0.05] Uncertainty in Hmag
55- 60 F6.3 mag Ksmag [9.3/16.3] IRSF/SIRPOL apparent Ks band mag
62- 66 F5.3 mag e_Ksmag [0/0.1] Uncertainty in Ksmag
68- 72 F5.2 % PJ [0.1/41] Polarization in J band (2)
74- 78 F5.2 % e_PJ [0.03/17] Uncertainty in PJ (2)
80- 84 F5.2 % PH [0.07/14.1] Polarization in H band (2)
86- 89 F4.2 % e_PH [0.02/5] Uncertainty in PH (2)
91- 95 F5.2 % PKs [0.2/34] Polarization in Ks band (2)
97-101 F5.2 % e_PKs [0.03/14] Uncertainty in PKs (2)
103-107 F5.1 deg thetaJ [0.4/179] Polarization angle in J band
109-113 F5.1 deg e_thetaJ [0.2/266] Uncertainty in thetaJ
115-119 F5.1 deg thetaH [1.8/180] Polarization angle in H band
121-125 F5.1 deg e_thetaH [0.1/155] Uncertainty in thetaH
127-131 F5.1 deg thetaKs [1.4/180] Polarization angle in Ks band
133-137 F5.1 deg e_thetaKs [0.3/478] Uncertainty in thetaKs
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Note (1): Positions are from the JHKs image (Figure 1: Color-composite
Stokes I image of the Circinus region in the J (blue), H (green), and
Ks (red) bands from the IRSF/SIRPOL observations), and these sources
are sorted by their declination.
Note (2): In this paper, sources with P/e_P≥3 and e_P<median(P) are
used. Note that in this table, some sources show very large degrees
of polarization (>20%), especially in the J band, but the degrees of
polarization of such sources also show very large errors.
Accordingly, special care is necessary when using these large-error
and low-S/N data.
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Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Det Source detection type (1)
4- 11 A8 --- Source Source identifier (2)
13- 14 I2 h RAh [14/15] Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 23 F5.2 s RAs Second of Right Ascension (J2000)
25 A1 --- DE- [-] Sign of the Declination (J2000)
26- 27 I2 deg DEd [63] Degree of Declination (J2000)
29- 30 I2 arcmin DEm [2/10] Arcminute of Declination (J2000)
32- 35 F4.1 arcsec DEs Arcsecond of Declination (J2000)
37- 41 F5.2 % Pol [0.2/33] Polarization in Det
43- 46 F4.2 % e_Pol [0.01/7] Uncertainty in Pol
48- 52 F5.1 deg theta [1/180] Polarization angle in Det
54- 56 F3.1 deg e_theta [0.1/9] Uncertainty in theta
58- 60 I3 --- ID [3/746]? Identifier from Table 1
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Note (1): Detection as follows:
J = J-band sources detected in the J and H bands.
H = H-band sources detected in the J and H bands (for table 2).
H = H-band sources detected in the H and Ks bands (for table 3).
Ks = Ks-band sources detected in the H and Ks bands.
Note (2): Missing numbers are the sources whose polarizations do not
satisfy the selection criteria of P/e_P≥3 and e_P<median(P)
in the J, H and Ks bands.
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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- 3 I3 --- ID [36/732] Source identifier (1)
5- 6 I2 h RAh [14/15] Hour of Right Ascension (J2000)
8- 9 I2 min RAm Minute of Right Ascension (J2000)
11- 15 F5.2 s RAs Second of Right Ascension (J2000)
17 A1 --- DE- [-] Sign of the Declination (J2000)
18- 19 I2 deg DEd [63] Degree of Declination (J2000)
21- 22 I2 arcmin DEm [2/10] Arcminute of Declination (J2000)
24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000)
29- 33 F5.2 % PJ [2/20] Polarization in J band
35- 38 F4.2 % e_PJ [0.06/6] Uncertainty in PJ
40- 44 F5.2 % PH [1/12] Polarization in H band
46- 49 F4.2 % e_PH [0.02/3] Uncertainty in PH
51- 55 F5.2 % PKs [0.8/18] Polarization in Ks band
57- 60 F4.2 % e_PKs [0.03/8] Uncertainty in PKs
62- 66 F5.1 deg thetaJ [35/118] Polarization angle in J band
68- 71 F4.1 deg e_thetaJ [0.2/39] Uncertainty in thetaJ
73- 76 F4.1 deg thetaH [27/97] Polarization angle in H band
78- 81 F4.1 deg e_thetaH [0.1/91] Uncertainty in thetaH
83- 87 F5.1 deg thetaKs [25.9/172] Polarization angle in Ks band
89- 92 F4.1 deg e_thetaKs [0.3/53] Uncertainty in thetaKs
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Note (1): The sources listed in Table 1 include highly polarized sources with
the criteria P>Pmax and P>median(P) in at least one of the
three bands.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Mar-2018