English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Young giant planets and brown dwarf companions emit near-infrared radiationthat can be linearly polarized up to several percent. This polarization canreveal the presence of a circumsubstellar accretion disk, rotation-inducedoblateness of the atmosphere, or an inhomogeneous distribution of atmosphericdust clouds. We measured the near-infrared linear polarization of 20 knowndirectly imaged exoplanets and brown dwarf companions with the high-contrastimager SPHERE-IRDIS at the VLT. We reduced the data using the IRDAP pipeline tocorrect for the instrumental polarization and crosstalk with an absolutepolarimetric accuracy <0.1% in the degree of polarization. We report the firstdetection of polarization originating from substellar companions, with apolarization of several tenths of a percent for DH Tau B and GSC 6214-210 B inH-band. By comparing the measured polarization with that of nearby stars, wefind that the polarization is unlikely to be caused by interstellar dust.Because the companions have previously measured hydrogen emission lines and redcolors, the polarization most likely originates from circumsubstellar disks.Through radiative transfer modeling, we constrain the position angles of thedisks and find that the disks must have high inclinations. The presence ofthese disks as well as the misalignment of the disk of DH Tau B with the diskaround its primary star suggest in situ formation of the companions. For the 18other companions, we do not detect significant polarization and placesubpercent upper limits on their degree of polarization. These non-detectionsmay indicate the absence of circumsubstellar disks, a slow rotation rate ofyoung companions, the upper atmospheres containing primarily submicron-sizeddust grains, and/or limited cloud inhomogeneity. Finally, we present images ofthe circumstellar disks of DH Tau, GQ Lup, PDS 70, Beta Pic, and HD 106906.

astronomy and astrophysics

A survey of the linear polarization of directly imaged exoplanets and  brown dwarf companions with SPHERE-IRDIS. First polarimetric detections  revealing disks around DH Tau B and GSC 6214-210 B