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We present a new method to constrain the grain size in protoplanetary disks with polarization observations at millimeter wavelengths. If dust grains are grown to the size comparable to the wavelengths, the dust grains are expected to have a…

Dust grains emit intrinsic polarized emission if they are elongated and aligned in the same direction. The direction of the grain alignment is determined by external forces, such as magnetic fields, radiation, and gas flow against the dust…

Earth and Planetary Astrophysics · Physics 2019-04-03 Akimasa Kataoka , Satoshi Okuzumi , Ryo Tazaki

Spatially resolved polarized (sub-)mm emission has been observed for example in the protoplanetary disk around HL Tau. Magnetically aligned grains are commonly interpreted as the source of polarization. However, self-scattering by large…

Earth and Planetary Astrophysics · Physics 2016-08-31 A. Pohl , A. Kataoka , P. Pinilla , C. P. Dullemond , Th. Henning , T. Birnstiel

ALMA observations revealed recently polarised radiation of several protoplanetary disks in the (sub-)millimetre wavelength range. Besides self-scattering of large particles, thermal emission by elongated grains is a potential source for the…

Earth and Planetary Astrophysics · Physics 2019-07-10 Florian Kirchschlager , Gesa H. -M. Bertrang , Mario Flock

Observations of protoplanetary disks (PPDs) at sub-mm wavelengths suggest that polarisation is caused by scattering of thermal radiation. Most of the dust models that are used to explain these observations have major drawbacks: They either…

Solar and Stellar Astrophysics · Physics 2021-04-21 Robert Brunngräber , Sebastian Wolf

We theoretically analyze protoplanetary disks consisting of porous dust grains. In the analysis of observations of protoplanetary disks the dust phase is often assumed to consist of spherical grains, allowing one to apply the Mie scattering…

Solar and Stellar Astrophysics · Physics 2014-09-05 F. Kirchschlager , S. Wolf

Scattering of re-emitted flux is considered to be at least partially responsible for the observed polarisation in the (sub-)millimetre wavelength range of several protoplanetary disks. Although the degree of polarisation produced by…

Solar and Stellar Astrophysics · Physics 2020-08-26 Robert Brunngräber , Sebastian Wolf

Polarization at millimeter wavelengths provides a powerful diagnostic of dust grain properties in protoplanetary disks. Standard models based on solid spherical grains often struggle to reproduce the observed polarization fractions and…

The size of dust grains, $a$, is key to the physical and chemical processes in circumstellar disks, but observational constraints of grain size remain challenging. (Sub)millimeter continuum observations often show a percent-level…

The origin of polarized emission from protoplanetary disks is uncertain. Three mechanisms have been proposed for such polarized emission: grain alignment with magnetic fields, grain alignment with radiation gradients, and self-scattering of…

The investigation of polarized light of protoplanetary disks is key for constraining the dust properties, disk morphology and embedded magnetic fields. However, different polarization mechanisms and the diversity of dust grain shapes and…

Solar and Stellar Astrophysics · Physics 2019-07-17 Robert Brunngräber , Sebastian Wolf

(Sub)millimeter dust polarization in protoplanetary disks has revealed the presence of large (~ 100 um) dust grains that are aligned along their long axis following the azimuthal direction of the disk. The novel Badminton Birdie-like…

The mechanisms causing millimeter-wave polarization in protoplanetary disks are under debate. To disentangle the polarization mechanisms, we observe the protoplanetary disk around HL Tau at 3.1 mm with the Atacama Large…

Earth and Planetary Astrophysics · Physics 2017-07-26 Akimasa Kataoka , Takashi Tsukagoshi , Adriana Pohl , Takayuki Muto , Hiroshi Nagai , Ian W. Stephens , Kohji Tomisaka , Munetake Momose

(Sub-)Millimeter observations of the polarized emission of aligned aspherical dust grains enable us to study the magnetic fields within protoplanetary disk. However, the interpretation of these observations is complex. One must consider the…

Solar and Stellar Astrophysics · Physics 2017-06-21 G. H. -M. Bertrang , S. Wolf

The azimuthal polarization patterns observed in some protoplanetary disks by ALMA at millimeter wavelength have raised doubts about their being produced by dust grains aligned with the magnetic field lines. These conclusions were based on…

Astrophysics of Galaxies · Physics 2020-02-26 V. Guillet , J. M. Girart , A. J. Maury , F. O. Alves

Dust coagulation in a protoplanetary disk is the first step of planetesimal formation. However, a pathway from dust aggregates to planetesimals remains unclear. Both numerical simulations and laboratory experiments have suggested the…

Earth and Planetary Astrophysics · Physics 2020-01-08 Ryo Tazaki , Hidekazu Tanaka , Akimasa Kataoka , Satoshi Okuzumi , Takayuki Muto

Our aim is to study the polarization of thermal dust emission to see if the alignment of grain by radiative torques could explain the observed relation between the degree of polarization and the intensity in dense cores. Predictions are…

Astrophysics · Physics 2009-11-11 V. -M. Pelkonen , M. Juvela , P. Padoan

Polarization carries information about the magnetic fields in interstellar clouds. The observations of polarized dust emission are used to study the role of magnetic fields in the evolution of molecular clouds and the initial phases of…

Astrophysics of Galaxies · Physics 2015-05-13 V. -M. Pelkonen , M. Juvela , P. Padoan

Magnetic fields ($\textbf{B}$) are an important factor that controls the star formation process. The leading method to observe $\textbf{B}$ is using polarized thermal emission from dust grains aligned with $\textbf{B}$. However, in dense…

Astrophysics of Galaxies · Physics 2023-06-16 Nguyen Chau Giang , Thiem Hoang , Jeong-Gyu Kim , Le Ngoc Tram

Millimeter and sub-millimeter observations of continuum linear dust polarization provide insight into dust grain growth in protoplanetary disks, which are the progenitors of planetary systems. We present the results of the first survey of…

Solar and Stellar Astrophysics · Physics 2024-04-17 Rachel E. Harrison , Zhe-Yu Daniel Lin , Leslie W. Looney , Zhi-Yun Li , Haifeng Yang , Ian Stephens , Manuel Fernández-López
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