HIGH-RESOLUTION 8 mm AND 1 cm POLARIZATION OF IRAS 4A FROM THE VLA NASCENT DISK AND MULTIPLICITY (VANDAM) SURVEY

Cox, Erin G.; Harris, Robert J.; Looney, Leslie W.; Segura-Cox, Dominique; Tobin, John J.; Li, Zhi Yun; Tychoniec, Łukasz; Chandler, Claire J.; Dunham, Michael M.; Kratter, Kaitlin M.; Melis, Carl; Pérez, Laura; Sadavoy, Sarah

doi:10.1088/2041-8205/814/2/l28

Cited by 58 publications

(76 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The distance of theNGC 1333 cloud is 235±18 pc from the very long baseline interferometry parallax measurements of H 2 O masers (Hirota et al 2008). The magnetic field in the IRAS 4A core mapped with dust polarization exhibits an overall hourglass morphology and a toroidal field in the pseudodisk, consistent with the theoretical expectation of a magnetized rotating core during its collapse phase (Girart et al 2006;Goncalves et al 2008;Frau et al 2011;Cox et al 2015; H.-Y. Liu et al, submitted; S.-P. Lai et al 2016, in preparation).…”

Section: Introductionsupporting

confidence: 62%

Helical Magnetic Fields in the NGC 1333 Iras 4a Protostellar Outflows

Ching

Lai

Zhang

et al. 2016

ApJ

View full text Add to dashboard Cite

We present Submillimeter Array polarization observations of the CO J = 3-2 line towardNGC 1333 IRAS 4A. The CO Stokes I maps at an angular resolution of ∼1″ reveal two bipolar outflows from the binary sources ofNGC 1333 IRAS 4A. The kinematic features of the CO emission can be modeled by wind-driven outflows at ∼20°i nclined from the plane of the sky. Close to the protostars the CO polarization, at an angular resolution of ∼2 3, has a position angle approximately parallel to the magnetic field direction inferred from the dust polarizations. The CO polarization direction appears to vary smoothly from an hourglass field around the core to an arc-like morphology wrapping around the outflow, suggesting a helical structure of magnetic fields that inherits the poloidal fields at the launching point and consists of toroidal fields at a farther distance of outflow. The helical magnetic field is consistent with the theoretical expectations for launching and collimating outflows from a magnetized rotating disk. Considering that the CO polarized emission is mainly contributed from the low-velocity and low-resolution data, the helical magnetic field is likely a product of the wind-envelope interaction in the winddriven outflows. The CO data reveal a PA of ∼30°deflection in the outflows. The variation in the CO polarization angle seems to correlate with the deflections. We speculate that the helical magnetic field contributes to ∼10°d eflection of the outflows by means of Lorentz force.

show abstract

Section: Introductionsupporting

confidence: 62%

Helical Magnetic Fields in the NGC 1333 Iras 4a Protostellar Outflows

Ching

Lai

Zhang

et al. 2016

ApJ

View full text Add to dashboard Cite

show abstract

“…At IRAS4A1, the 6.9 mm polarization observations may probe the B-field in a region nearer to the protostar than what was probed by the 0.88 mm observations. Due to the high optical depth, the presented 6.9 mm, and the optical thicker 0.88 mm polarization observations may not yet probe the B-field inside the circumstellar disk in IRAS4A1 as seen by Cox et al (2015).…”

Section: Discussionmentioning

confidence: 85%

“…Furthermore, recent sub-arcsecond resolution millimeter and submillimeter observations have inferred the toroidal B-field components in the circumstellar disks embedded in the two class 0 YSOs IRAS 16293-2422B (Rao et al 2014), in the class 0 YSO L1527 (Segura- Cox et al 2015), and in the T Tauri object HL Tau (Stephens et al 2014). The toroidal B-field components can arise from the dragging of B-fields by differential rotation.…”

Section: Introductionmentioning

confidence: 99%

DETECTION OF LINEARLY POLARIZED 6.9 mm CONTINUUM EMISSION FROM THE CLASS 0 YOUNG STELLAR OBJECT NGC 1333 IRAS4A

Liu

Lai

Hasegawa

et al. 2016

ApJ

View full text Add to dashboard Cite

We report new Karl G. Jansky Very Large Array (JVLA),  0. 5 angular resolution observations of linearly polarized continuum emission at 6.9 mm, toward the class 0 young stellar object NGC 1333 IRAS4A. This target source is a collapsing dense molecular core that was resolved at short wavelengths to have an hourglass shaped B-field configuration. We compare these 6.9 mm observations with previous polarization Submillimeter Array observations at 0.88 mm, which have a comparable angular resolution (∼  0. 7). We find that at the same resolution, the observed polarization position angles at 6.9 mm are slightly deviated from those observed at 0.88 mm. Due to the lower optical depth of the emission at 6.9 mm, and the potential effect of dust grain growth, the new JVLA observations are likely probing B-field alignments in regions interior to those sampled by the previous polarization observations at higher frequencies. Our understanding can be improved with more sensitive observations, and with observations for the more extended spatial scales.

show abstract

“…At millimeter wavelengths, polarimetric observations of disks have been performed so far (e.g., Hughes et al 2009;Hughes et al 2013;Cox et al 2015;Rao et al 2014;Stephens et al 2014;Kataoka et al 2016b). Polarized emission from a circumstellar disk has been detected in the Class 0 phase (Cox et al 2015;Rao et al 2014). More evolved disks do not show a degree of linear polarization larger than 0.5% (Hughes et al 2009;Hughes et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Radiative Grain Alignment in Protoplanetary Disks: Implications for Polarimetric Observations

Tazaki

Lazarian

Nomura

2017

ApJ

126

200

View full text Add to dashboard Cite

We apply the theory of radiative torque (RAT) alignment for studying protoplanetary disks around a T-Tauri star and perform 3D radiative transfer calculations to provide the expected maps of polarized radiation to be compared with observations, such as with ALMA. We revisit the issue of grain alignment for large grains expected in the protoplanetary disks and find that mm-sized grains at midplane do not align with magnetic field as the Larmor precession timescale for such large grains becomes longer than the gaseous damping timescale. Hence, for these grains the RAT theory predicts that the alignment axis is determined by the grain precession with respect to the radiative flux. As a result, we expect that the polarization will be in the azimuthal direction for a face-on disk. It is also shown that if dust grains have superparamagnetic inclusions, magnetic field alignment is possible for (sub-)micron grains at the surface layer of disks, and this can be tested by mid-infrared polarimetric observations.

show abstract

HIGH-RESOLUTION 8 mm AND 1 cm POLARIZATION OF IRAS 4A FROM THE VLA NASCENT DISK AND MULTIPLICITY (VANDAM) SURVEY

Cited by 58 publications

References 39 publications

Helical Magnetic Fields in the NGC 1333 Iras 4a Protostellar Outflows

Helical Magnetic Fields in the NGC 1333 Iras 4a Protostellar Outflows

DETECTION OF LINEARLY POLARIZED 6.9 mm CONTINUUM EMISSION FROM THE CLASS 0 YOUNG STELLAR OBJECT NGC 1333 IRAS4A

Radiative Grain Alignment in Protoplanetary Disks: Implications for Polarimetric Observations

Contact Info

Product

Resources

About