Near-Infrared Circular Polarization Survey in Star-Forming Regions: Correlations and Trends

Kwon, Jungmi; Tamura, Motohide; Hough, J. H.; Kusakabe, Nobuhiko; Nagata, T.; Lucas, P. W.; Nagayama, Takahiro; Kandori, Ryo

doi:10.1088/2041-8205/795/1/l16

Cited by 21 publications

(21 citation statements)

References 38 publications

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“…Our previous studies, which have included a systematic near-infrared survey of circular polarization in star-forming regions of various luminosities, presented the relationships between luminosities, extents, and the degree of circular polarization. We found that a high degree of circular polarization, generated in some starforming regions, was consistent with a dichroic extinction mechanism (Chrysostomou et al 2007;Fukue et al 2009;Kwon et al 2013Kwon et al , 2014. Therefore, it is important to extend this survey for various star-forming regions, in particular bipolar nebulae such as GGD 27 IRS, and to determine how often significant circular polarization is observed.…”

Section: Introductionmentioning

confidence: 66%

Near-Infrared Imaging Polarimetry of GGD 27: Circular Polarization and Magnetic Field Structures

Kwon

Tamura

Hough

et al. 2016

ApJ

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Near-infrared imaging polarimetry in the J, H, and K s bands was carried out for GGD 27 in the dark cloud Lynds 291. Details of an infrared reflection nebula associated with the optical nebulosity GGD 27 and the infrared nebula GGD 27 IRS are presented. Aperture photometry of 1263 point-like sources, detected in all three bands, was used to classify them based on a color-color diagram, and the linear polarization of several hundred sources was determined, with the latter used to map the magnetic field structure around GGD 27. This field, around GGD 27 IRS, appears to be associated with the extended CO outflow of IRAS 18162-2048; however, there are partly distorted or bent components in the field. The Chandrasekhar-Fermi method gives an estimate of the magnetic field strength as ∼90 μG. A region associated with GGD 27 IRS is discovered to have a circular polarization in the range of ∼2%-11% in the K s band. The circular polarization has an asymmetric positive/negative pattern and extends out to ∼ 120″ or 1.0 pc. The circular and linear polarization patterns are explained as resulting from a combination of dense inner and fainter outer lobes, suggesting episodic outflow.

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Section: Introductionmentioning

confidence: 66%

Near-Infrared Imaging Polarimetry of GGD 27: Circular Polarization and Magnetic Field Structures

Kwon

Tamura

Hough

et al. 2016

ApJ

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“…One is photolysis of enantiomers by circularly polarized UV light (UV CPL) (39). UV CPL is also suggested as a possible interstellar mechanism for the production of EE (40,41). Laboratory experiments with UV CPL have demonstrated a slight preferential destruction of one enantiomer, which resulted in relatively small but reversible EE (depending on the direction of the CPL) from an initially racemic mixture of amino acids (39).…”

Section: Discussionmentioning

confidence: 99%

Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites

Cooper

Rios

2016

Proc. Natl. Acad. Sci. U.S.A.

123

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Biological polymers such as nucleic acids and proteins are constructed of only one-the D or L-of the two possible nonsuperimposable mirror images (enantiomers) of selected organic compounds. However, before the advent of life, it is generally assumed that chemical reactions produced 50:50 (racemic) mixtures of enantiomers, as evidenced by common abiotic laboratory syntheses. Carbonaceous meteorites contain clues to prebiotic chemistry because they preserve a record of some of the Solar System's earliest (∼4.5 Gy) chemical and physical processes. In multiple carbonaceous meteorites, we show that both rare and common sugar monoacids (aldonic acids) contain significant excesses of the D enantiomer, whereas other (comparable) sugar acids and sugar alcohols are racemic. Although the proposed origins of such excesses are still tentative, the findings imply that meteoritic compounds and/or the processes that operated on meteoritic precursors may have played an ancient role in the enantiomer composition of life's carbohydrate-related biopolymers.carbonaceous meteorites | sugar acids | enantiomer excesses | aldonic acids | polyols T he organic phase of carbonaceous meteorites comprises an insoluble "macromolecular" material (1-3), a complex mixture of largely uncharacterized solvent-extractable compounds (4), as well as discrete (identified) soluble organic compounds such as amino acids (3, 5) nucleobases (6, 7), and sugar derivatives (8). Analyses of this prebiotic organic carbon have been important in understanding its early Solar System synthesis and history: Characteristics of the organic phase suggest that it consists of both products and survivors of interstellar/presolar grain irradiation (9) and subsequent encapsulation and aqueous reactions (10, 11) in asteroids "parent bodies."Several identified meteoritic organic compounds are chiral: They can exist as two nonsuperimposable mirror image compounds called enantiomers, commonly designated D and L. To date, most chiral meteoritic compounds are reported to be racemic mixtures, i.e., their D and L enantiomers are equal in abundance (3). Racemic compounds are expected in nature because typical abiotic synthetic processes are (historically) thought to occur in the absence of asymmetric influences. Racemic mixtures are equated with pristine/uncontaminated abiotic samples when discussing meteoritic compounds. However, some meteoritic amino acids that are rare on Earth, i.e., they are not constituents of proteins and therefore less likely to be contaminants, have been confirmed to contain L enantiomer excesses (EE) (3, 12, 13). The origins of such excesses are unknown.Sugars, aldehydes, or ketones that contain multiple carbon hydroxyl (carbon alcohol) groups, are also chiral and were likely necessary for the origin of life. In the majority of extant biological sugars and derivatives ("polyols"), the D enantiomers are significantly more abundant than the L enantiomers (we will note exceptions in Results and Natural Occurrence of Relevant Sugar Derivatives and Enantiomers)...

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“…In this case, circular polarization traces the overall geometry of the setup as well as properties of the medium. Examples include circular polarization of starlight [10] or of diffuse radiation in star-forming regions [11], and the circular polarization observed from solar system planets [12,13]. An alternative source of circular polarization (relevant for both foregrounds and new physics) involves magnetized media, where the intrinsic emission can be circularly polarized due to the preferred handedness of particle trajectories, as occurs in masers [14,15], GRB afterglows [16,17], and (we expect) in the diffuse synchrotron emission from our Galaxy.…”

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confidence: 89%

“…Due to our choice of thex-axis, no further rotation is necessary. 11 We follow the convention of CLASS for the transfer functions, e.g. T E = − 5 4 √ 6 (G (0) +G (2) ), see Eq.…”

Section: )mentioning

confidence: 99%

Exploring circular polarization in the CMB due to conventional sources of cosmic birefringence

Montero-Camacho

Hirata

2018

J. Cosmol. Astropart. Phys.

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The circular polarization of the cosmic microwave background (CMB) is usually taken to be zero since it is not generated by Thomson scattering. Here we explore the actual level of circular polarization in the CMB generated by conventional cosmological sources of birefringence. We consider two classes of mechanisms for birefringence. One is alignment of the matter to produce an anisotropic susceptibility tensor: the hydrogen spins can be aligned either by density perturbations or CMB anisotropies themselves. The other is anisotropy of the radiation field coupled to the non-linear response of the medium to electromagnetic fields: this can occur either via photon-photon scattering (non-linear response of the vacuum); atomic hyperpolarizability (non-linear response of neutral atoms); or plasma delay (non-linear response of free electrons). The strongest effect comes from photon-photon scattering from recombination at a level of ∼ 10 −14 K. Our results are consistent with a negligible circular polarization of the CMB in comparison with the linear polarization or the sensitivity of current and near-term experiments.

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Near-Infrared Circular Polarization Survey in Star-Forming Regions: Correlations and Trends

Cited by 21 publications

References 38 publications

Near-Infrared Imaging Polarimetry of GGD 27: Circular Polarization and Magnetic Field Structures

Near-Infrared Imaging Polarimetry of GGD 27: Circular Polarization and Magnetic Field Structures

Enantiomer excesses of rare and common sugar derivatives in carbonaceous meteorites

Exploring circular polarization in the CMB due to conventional sources of cosmic birefringence

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