J/ApJ/867/79 NIR observations of GF 9/LDN 1082C field stars (Clemens+, 2018)
Magnetic field uniformity across the GF 9-2 YSO, L1082C dense core, and GF 9
filamentary dark cloud.
Clemens D.P., El-Batal A.M., Cerny C., Kressy S., Schroeder G., Pillai T.
<Astrophys. J., 867, 79 (2018)>
=2018ApJ...867...79C 2018ApJ...867...79C
ADC_Keywords: Polarization; Photometry, infrared; Molecular clouds;
Parallaxes, trigonometric; Optical
Keywords: instrumentation: polarimeters ; magnetic fields ; polarization ;
stars: formation ; stars: protostars ; techniques: polarimetric
Abstract:
The orientation of the magnetic field (B field) in the filamentary
dark cloud GF 9 was traced from the periphery of the cloud into the
L1082C dense core that contains the low-mass, low-luminosity Class 0
young stellar object (YSO) GF 9-2 (IRAS 20503+6006). This was done
using SOFIA HAWC+ dust thermal emission polarimetry (TEP) at 216µm
in combination with Mimir near-infrared background starlight
polarimetry (BSP) conducted in the H band (1.6µm) and K band
(2.2µm). These observations were augmented with published I-band
(0.77µm) BSP and Planck 850µm TEP to probe B-field orientations
with offset from the YSO in a range spanning 6000au to 3pc. No strong
B-field orientation change with offset was found, indicating
remarkable uniformity of the B-field from the cloud edge to the YSO
environs. This finding disagrees with weak-field models of cloud core
and YSO formation. The continuity of inferred B-field orientations for
both TEP and BSP probes is strong evidence that both are sampling a
common B field that uniformly threads the cloud, core, and YSO region.
Bayesian analysis of Gaia DR2 stars matched to the Mimir BSP stars
finds a distance to GF 9 of 270±10pc. No strong wavelength
dependence of B-field orientation angle was found, contrary to
previous claims.
Description:
SOFIA airborne observations of the GF 9-2 region using HAWC+ were
obtained on the nights of 2016 December 13 and 14, at altitudes in
excess of 12.5km, for the SOFIA Cycle 4 program 04_0026; in the E-band
(216um center wavelength, 43um bandwidth) polarimetry mode of HAWC+.
Observations of NIR background starlight polarimetry (BSP) were
obtained using Mimir on the 1.8m Perkins telescope, located in
northern Arizona, in the H (1.6um) and K (2.2um) bands during several
nights in 2011, 2013, 2014, 2015, and 2017. A total of 41 separate
observations were obtained. Key quantities for the 860 stars with
measured H- or K-band polarization values are reported in Table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 262 860 Photometry, polarimetry, and parallaxes
for GF 9/L1082C field stars
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
II/328 : AllWISE Data Release (Cutri+ 2013)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/110/268 : Red and infrared polarimetry in galactic plane (Creese+ 1995)
J/ApJ/650/945 : Polarisation around dark cloud GF 9 (Poidevin+, 2006)
J/ApJS/213/13 : Polarization maps of star-forming cores & SFRs (Hull+, 2014)
J/ApJ/833/176 : The magnetic field of L1544. I. NIR data (Clemens+, 2016)
J/ApJ/842/L9 : Polarized dust emission from Ser-emb 8 with ALMA (Hull+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/860] Running sequence number
5- 13 F9.5 deg RAdeg [312.69/313.1] Right Ascension (J2000)
15- 22 F8.5 deg DEdeg [60.2/60.4] Declination (J2000)
24- 29 F6.3 mag Hmag [7.8/19] Apparent H band magnitude
31- 36 F6.3 % PH [0/85.1] Fractional polarization in H band
38- 42 F5.1 deg PAH [0/179.8] Equatorial position angle of H band
polarization
44- 50 F7.3 % QH [-77.2/69] Stokes Q/I in the H band
52- 58 F7.3 % UH [-89.2/89.8] Stokes U/I in the H band
60- 65 F6.3 mag Kmag [7.3/18.5]?=30 Apparent K band magnitude
67- 72 F6.3 % PK [0.1/83.1]?=0 Fractional polarization in K band
74- 78 F5.1 deg PAK [0.2/177]?=0 Equatorial position angle of K band
polarization
80- 86 F7.3 % QK [-89.2/78.4]?=0 Stokes Q/I in the K band
88- 94 F7.3 % UK [-81.8/72.6]?=0 Stokes U/I in the K band
96-101 F6.3 mag Jmag2 [7.7/18.5]?=30 2MASS J band apparent magnitude
103-108 F6.3 mag Hmag2 [7.5/16.3]?=30 2MASS H band apparent magnitude
110-115 F6.3 mag Ksmag2 [7.5/16.6]?=30 2MASS Ks band apparent magnitude
117-122 F6.3 mag W1mag [7.3/18.1]?=30 WISE 3.4um band apparent magnitude
124-129 F6.3 mag W2mag [7.4/18]?=30 WISE 4.6um band apparent magnitude
131-136 F6.3 mag Gmag [8.5/21.3]?=30 Gaia DR2 apparent magnitude
138-143 F6.3 mas plx [-3/9.7]?=30 Gaia DR2 parallax
145-149 F5.3 mag e_Hmag [0/0.5] Uncertainty in Hmag
151-156 F6.3 % e_PH [0.04/99] Uncertainty in PH
158-162 F5.1 deg e_PAH [0.7/180] Uncertainty in PAH
164-169 F6.3 % e_QH [0.04/100] Uncertainty in QH
171-176 F6.3 % e_UH [0.04/96.5] Uncertainty in UH
178-183 F6.3 mag e_Kmag [0/0.7]?=90 Uncertainty in Kmag
185-191 F7.3 % e_PK [0.06/99]?=100 Uncertainty in PK
193-197 F5.1 deg e_PAK [1.9/180] Uncertainty in PAK
199-205 F7.3 % e_QK [0.04/93]?=100 Uncertainty in QK
207-213 F7.3 % e_UK [0.06/100]?=100 Uncertainty in UK
215-220 F6.3 mag e_Jmag2 [0.01/0.3]?=90 Uncertainty in Jmag
222-227 F6.3 mag e_Hmag2 [0.02/0.3]?=90 Uncertainty in Hmag
229-234 F6.3 mag e_Ksmag2 [0.01/0.4]?=90 Uncertainty in Ksmag
236-241 F6.3 mag e_W1mag [0.02/0.2]?=90 Uncertainty in W1mag
243-248 F6.3 mag e_W2mag [0.01/1]?=90 Uncertainty in W2mag
250-255 F6.3 mag e_Gmag [0/0.04]?=90 Uncertainty in Gmag
257-262 F6.3 mas e_plx [0.01/1.7]?=90 Uncertainty in plx
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Oct-2019