Detection of a Magnetized Disk Around a Very Young Protostar

Rao, Ramprasad; Girart, J. M.; Lai, Shih-Ping; Marrone, Daniel P.

doi:10.1088/2041-8205/780/1/l6

Cited by 81 publications

(95 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is usually interpreted as coming from magnetically aligned dust grains (e.g., Cho & Lazarian 2007). This interpretation appears consistent with the data on IRAS 16293-2422B and L1527, where the observed polarization patterns are broadly similar to those expected from grains aligned by a predominantly toroidal magnetic field (Rao et al 2014;Segura-Cox et al 2015; see § 5 for more discussion). In contrast, the polarization vectors in the disk of HL Tau (which is inclined with respect to the line of sight by ∼ 45…”

Section: Introductionsupporting

confidence: 87%

See 1 more Smart Citation

Inclination-induced polarization of scattered millimetre radiation from protoplanetary discs: the case of HL Tau

Yang

Looney

et al. 2015

Monthly Notices of the Royal Astronomical Society

126

174

View full text Add to dashboard Cite

Spatially resolved polarized millimeter/submillimeter emission has been observed in the disk of HL Tau and two other young stellar objects. It is usually interpreted as coming from magnetically aligned grains, but can also be produced by dust scattering, as demonstrated explicitly by Kataoka et al. for face-on disks. We extend their work by including the polarization induced by disk inclination with respect to the line of sight. Using a physically motivated, semi-analytic model, we show that the polarization fraction of the scattered light increases with the inclination angle i, reaching 1/3 for edge-on disks. The inclination-induced polarization can easily dominate that intrinsic to the disk in the face-on view. It provides a natural explanation for the two main features of the polarization pattern observed in the tilted disk of HL Tau (i ∼ 45• ): the polarized intensity concentrating in a region elongated more or less along the major axis, and polarization in this region roughly parallel to the minor axis. This broad agreement provides support to dust scattering as a viable mechanism for producing, at least in part, polarized millimeter radiation. In order to produce polarization at the observed level (∼ 1%), the scattering grains must have grown to a maximum size of tens of microns. However, such grains may be too small to produce the opacity spectral index of β 1 observed in HL Tau and other sources; another population of larger, millimeter/centimeter-sized, grains may be needed to explain the bulk of the unpolarized continuum emission.

show abstract

Section: Introductionsupporting

confidence: 87%

“…Polarized millimeter/sub-millimeter emission has been observed in the disks around 3 young stellar objects: IRAS 16293-2422B (Rao et al 2014), HL Tau (Stephens et al 2014) and L1527 (SeguraCox et al 2015). It is usually interpreted as coming from magnetically aligned dust grains (e.g., Cho & Lazarian 2007).…”

Section: Introductionmentioning

confidence: 99%

Inclination-induced polarization of scattered millimetre radiation from protoplanetary discs: the case of HL Tau

Yang

Looney

et al. 2015

Monthly Notices of the Royal Astronomical Society

126

174

View full text Add to dashboard Cite

show abstract

“…The millimeter-wave polarization observations toward starforming regions and protoplanetary disks have been interpreted as an indicator of the morphology of the magnetic field (Girart et al 2006(Girart et al , 2009Hull et al 2013Hull et al , 2014Rao et al 2014;Stephens et al 2014;Segura-Cox et al 2015). The elongated dust grains have a preferential direction perpendicular to the magnetic field, which results in the polarization of the thermal dust emission (Davis & Greenstein 1951).…”

Section: Introductionmentioning

confidence: 99%

Grain Size Constraints on Hl Tau With Polarization Signature

Kataoka

Muto

Momose

et al. 2016

ApJ

119

147

View full text Add to dashboard Cite

The millimeter-wave polarization of the protoplanetary disk around HL Tau has been interpreted as the emission from elongated dust grains aligned with the magnetic field in the disk. However, the self-scattering of thermal dust emission may also explain the observed millimeter-wave polarization. In this paper, we report a modeling of the millimeter-wave polarization of the HL Tau disk with the self-polarization. Dust grains are assumed to be spherical and to have a power-law size distribution. We change the maximum grain size with a fixed dust composition in a fixed disk model to find the grain size to reproduce the observed signature. We find that the direction of the polarization vectors and the polarization degree can be explained with the self-scattering. Moreover, the polarization degree can be explained only if the maximum grain size is ∼150 μm. The obtained grain size from the polarization is different from that which has been previously expected from the spectral index of the dust opacity coefficient (a millimeter or larger) if the emission is optically thin. We discuss that porous dust aggregates may solve the inconsistency of the maximum grain size between the two constraints.

show abstract

“…The properties of the accretion disks are better studied in the T Tauri stage since the surrounding material has already infallen into the disk-protostar system or has been dispersed by the strong outflow activity (e.g., Hogerheijde et al 1998;André et al 2004). Still recent works have found disks even in the earliest embedded stages of Class 0 protostars (e.g., Tobin et al 2012;Murillo & Lai 2013;Rao et al 2014). Class 0 disks are, in general, also smaller in size ( 50 AU; e.g., Tobin et al 2013;Segura-Cox et al 2016) than T Tauri disks (200-300 AU; e.g., Takakuwa et al 2012;Harsono et al 2014;Piétu et al 2014).…”

Section: Introductionmentioning

confidence: 99%

The Circumestellar Disk of the B0 Protostar Powering the HH 80-81 Radio Jet

Girart

Estalella

Fernández-López

et al. 2017

ApJ

View full text Add to dashboard Cite

We present subarcsecond angular resolution observations carried out with the Submillimeter Array (SMA) at 880 µm centered at the B0-type protostar GGD27 MM1, the driving source of the parsec scale HH 80-81 jet. We constrain its polarized continuum emission to be 0.8% at this wavelength. Its submm spectrum is dominated by sulfur-bearing species tracing a rotating disk-like structure (SO and SO 2 isotopologues mainly), but also shows HCN-bearing and CH 3 OH lines, which trace the disk and the outflow cavity walls excavated by the HH 80-81 jet. The presence of many sulfurated lines could indicate the presence of shocked gas at the disk's centrifugal barrier or that MM1 is a hot core at an evolved stage. The resolved SO 2 emission traces very well the disk kinematics and we fit the SMA observations using a thin-disk Keplerian model, which gives the inclination (47 • ), the inner ( 170 AU) and outer (∼ 950 − 1300 AU) radii and the disk's rotation velocity (3.4 km s −1 at a putative radius of 1700 AU). We roughly estimate a protostellar dynamical mass of 4-18 M ⊙ . MM2 and WMC cores show, comparatively, an almost empty spectra suggesting that they are associated with extended emission detected in previous low-angular resolution observations, and therefore indicating youth (MM2) or the presence of a less massive object (WMC).

show abstract

Detection of a Magnetized Disk Around a Very Young Protostar

Cited by 81 publications

References 50 publications

Inclination-induced polarization of scattered millimetre radiation from protoplanetary discs: the case of HL Tau

Inclination-induced polarization of scattered millimetre radiation from protoplanetary discs: the case of HL Tau

Grain Size Constraints on Hl Tau With Polarization Signature

The Circumestellar Disk of the B0 Protostar Powering the HH 80-81 Radio Jet

Contact Info

Product

Resources

About