New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE

A. Pohl; E. Sissa; M. Langlois; A. Müller; C. Ginski; R. G. van Holstein; A. Vigan; D. Mesa; A. -L. Maire; Th Henning; R. Gratton; J. Olofsson; R. van Boekel; M. Benisty; B. Biller; A. Boccaletti; G. Chauvin; S. Daemgen; J. de Boer; S. Desidera; C. Dominik; A. Garufi; M. Janson; Q. Kral; F. Ménard; C. Pinte; T. Stolker; J. Szulágyi; A. Zurlo; M. Bonnefoy; A. Cheetham; M. Cudel; M. Feldt; M. Kasper; A. -M. Lagrange; C. Perrot; F. Wildi

doi:10.1051/0004-6361/201630234

New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE

A. Pohl
, E. Sissa
, M. Langlois
, A. Müller
, C. Ginski
, R. G. van Holstein
, A. Vigan
, D. Mesa
, A. -L. Maire
, Th Henning
, R. Gratton
, J. Olofsson
, R. van Boekel
, M. Benisty
, B. Biller
, A. Boccaletti
, G. Chauvin
, S. Daemgen
, J. de Boer
, S. Desidera

C. Dominik, A. Garufi, M. Janson, Q. Kral, F. Ménard, C. Pinte, T. Stolker, J. Szulágyi, A. Zurlo, M. Bonnefoy, A. Cheetham, M. Cudel, M. Feldt, M. Kasper, A. -M. Lagrange, C. Perrot, F. Wildi

Physics

Research output: Contribution to a Journal (Peer & Non Peer) › Article › peer-review

40 Citations (Scopus)

Abstract

Context. The transition disk around the T Tauri star T Cha possesses a large gap, making it a prime target for high-resolution imaging in the context of planet formation.
Aims: We aim to find signs of disk evolutionary processes by studying the disk geometry and the dust grain properties at its surface, and to search for companion candidates.
Methods: We analyze a set of VLT/SPHERE data at near-infrared and optical wavelengths. We performed polarimetric imaging of T Cha with IRDIS (1.6 μm) and ZIMPOL (0.5-0.9 μm), and obtained intensity images from IRDIS dual-band imaging with simultaneous spectro-imaging with IFS (0.9-1.3 μm).
Results: The disk around T Cha is detected in all observing modes and its outer disk is resolved in scattered light with unprecedented angular resolution and signal-to-noise. The images reveal a highly inclined disk with a noticeable east-west brightness asymmetry. The significant amount of non-azimuthal polarization signal in the U_φ images, with a U_φ/Q_φ peak-to-peak value of 14%, is in accordance with theoretical studies on multiple scattering in an inclined disk. Our optimal axisymmetric radiative transfer model considers two coplanar inner and outer disks, separated by a gap of 0.̋28 ( 30 au) in size, which is larger than previously thought. We derive a disk inclination of 69 deg and PA of 114 deg. In order to self-consistently reproduce the intensity and polarimetric images, the dust grains, responsible for the scattered light, need to be dominated by sizes of around ten microns. A point source is detected at an angular distance of 3.5'' from the central star. It is, however, found not to be co-moving.
Conclusions: We confirm that the dominant source of emission is forward scattered light from the near edge of the outer disk. Our point source analysis rules out the presence of a companion with mass larger than 8.5 M_jup between 0.̋1 and 0.̋3. The detection limit decreases to 2 M_jup for 0.̋3 to 4.0''.

Based on observations made with European Southern Observatory (ESO) telescopes at the Paranal Observatory in Chile, under program IDs 095.C-0298(B), 096.C-0248(B) and 096.C-0248(C)....

Original language	English
Journal	Astronomy and Astrophysics
DOIs	https://doi.org/10.1051/0004-6361/201630234
Publication status	Published - Sept 2017

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10.1051/0004-6361/201630234

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Pohl, A., Sissa, E., Langlois, M., Müller, A., Ginski, C., van Holstein, R. G., Vigan, A., Mesa, D., Maire, A. .-L., Henning, T., Gratton, R., Olofsson, J., van Boekel, R., Benisty, M., Biller, B., Boccaletti, A., Chauvin, G., Daemgen, S., de Boer, J., ... Wildi, F. (2017). New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE. Astronomy and Astrophysics. https://doi.org/10.1051/0004-6361/201630234

@article{7e27d90761b84547815453e4694166b5,

title = "New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE",

abstract = "Context. The transition disk around the T Tauri star T Cha possesses a large gap, making it a prime target for high-resolution imaging in the context of planet formation. Aims: We aim to find signs of disk evolutionary processes by studying the disk geometry and the dust grain properties at its surface, and to search for companion candidates. Methods: We analyze a set of VLT/SPHERE data at near-infrared and optical wavelengths. We performed polarimetric imaging of T Cha with IRDIS (1.6 μm) and ZIMPOL (0.5-0.9 μm), and obtained intensity images from IRDIS dual-band imaging with simultaneous spectro-imaging with IFS (0.9-1.3 μm). Results: The disk around T Cha is detected in all observing modes and its outer disk is resolved in scattered light with unprecedented angular resolution and signal-to-noise. The images reveal a highly inclined disk with a noticeable east-west brightness asymmetry. The significant amount of non-azimuthal polarization signal in the Uφ images, with a Uφ/Qφ peak-to-peak value of 14\%, is in accordance with theoretical studies on multiple scattering in an inclined disk. Our optimal axisymmetric radiative transfer model considers two coplanar inner and outer disks, separated by a gap of 0{\H .}28 ( 30 au) in size, which is larger than previously thought. We derive a disk inclination of 69 deg and PA of 114 deg. In order to self-consistently reproduce the intensity and polarimetric images, the dust grains, responsible for the scattered light, need to be dominated by sizes of around ten microns. A point source is detected at an angular distance of 3.5'' from the central star. It is, however, found not to be co-moving. Conclusions: We confirm that the dominant source of emission is forward scattered light from the near edge of the outer disk. Our point source analysis rules out the presence of a companion with mass larger than 8.5 Mjup between 0{\H .}1 and 0{\H .}3. The detection limit decreases to 2 Mjup for 0{\H .}3 to 4.0''. Based on observations made with European Southern Observatory (ESO) telescopes at the Paranal Observatory in Chile, under program IDs 095.C-0298(B), 096.C-0248(B) and 096.C-0248(C)....",

author = "A. Pohl and E. Sissa and M. Langlois and A. M{\"u}ller and C. Ginski and \{van Holstein\}, \{R. G.\} and A. Vigan and D. Mesa and Maire, \{A. -L.\} and Th Henning and R. Gratton and J. Olofsson and \{van Boekel\}, R. and M. Benisty and B. Biller and A. Boccaletti and G. Chauvin and S. Daemgen and \{de Boer\}, J. and S. Desidera and C. Dominik and A. Garufi and M. Janson and Q. Kral and F. M{\'e}nard and C. Pinte and T. Stolker and J. Szul{\'a}gyi and A. Zurlo and M. Bonnefoy and A. Cheetham and M. Cudel and M. Feldt and M. Kasper and Lagrange, \{A. -M.\} and C. Perrot and F. Wildi",

year = "2017",

month = sep,

doi = "10.1051/0004-6361/201630234",

language = "English",

journal = "Astronomy and Astrophysics",

}

Pohl, A, Sissa, E, Langlois, M, Müller, A, Ginski, C, van Holstein, RG, Vigan, A, Mesa, D, Maire, A-L, Henning, T, Gratton, R, Olofsson, J, van Boekel, R, Benisty, M, Biller, B, Boccaletti, A, Chauvin, G, Daemgen, S, de Boer, J, Desidera, S, Dominik, C, Garufi, A, Janson, M, Kral, Q, Ménard, F, Pinte, C, Stolker, T, Szulágyi, J, Zurlo, A, Bonnefoy, M, Cheetham, A, Cudel, M, Feldt, M, Kasper, M, Lagrange, A-M, Perrot, C & Wildi, F 2017, 'New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE', Astronomy and Astrophysics. https://doi.org/10.1051/0004-6361/201630234

TY - JOUR

T1 - New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE

AU - Pohl, A.

AU - Sissa, E.

AU - Langlois, M.

AU - Müller, A.

AU - Ginski, C.

AU - van Holstein, R. G.

AU - Vigan, A.

AU - Mesa, D.

AU - Maire, A. -L.

AU - Henning, Th

AU - Gratton, R.

AU - Olofsson, J.

AU - van Boekel, R.

AU - Benisty, M.

AU - Biller, B.

AU - Boccaletti, A.

AU - Chauvin, G.

AU - Daemgen, S.

AU - de Boer, J.

AU - Desidera, S.

AU - Dominik, C.

AU - Garufi, A.

AU - Janson, M.

AU - Kral, Q.

AU - Ménard, F.

AU - Pinte, C.

AU - Stolker, T.

AU - Szulágyi, J.

AU - Zurlo, A.

AU - Bonnefoy, M.

AU - Cheetham, A.

AU - Cudel, M.

AU - Feldt, M.

AU - Kasper, M.

AU - Lagrange, A. -M.

AU - Perrot, C.

AU - Wildi, F.

PY - 2017/9

Y1 - 2017/9

N2 - Context. The transition disk around the T Tauri star T Cha possesses a large gap, making it a prime target for high-resolution imaging in the context of planet formation. Aims: We aim to find signs of disk evolutionary processes by studying the disk geometry and the dust grain properties at its surface, and to search for companion candidates. Methods: We analyze a set of VLT/SPHERE data at near-infrared and optical wavelengths. We performed polarimetric imaging of T Cha with IRDIS (1.6 μm) and ZIMPOL (0.5-0.9 μm), and obtained intensity images from IRDIS dual-band imaging with simultaneous spectro-imaging with IFS (0.9-1.3 μm). Results: The disk around T Cha is detected in all observing modes and its outer disk is resolved in scattered light with unprecedented angular resolution and signal-to-noise. The images reveal a highly inclined disk with a noticeable east-west brightness asymmetry. The significant amount of non-azimuthal polarization signal in the Uφ images, with a Uφ/Qφ peak-to-peak value of 14%, is in accordance with theoretical studies on multiple scattering in an inclined disk. Our optimal axisymmetric radiative transfer model considers two coplanar inner and outer disks, separated by a gap of 0.̋28 ( 30 au) in size, which is larger than previously thought. We derive a disk inclination of 69 deg and PA of 114 deg. In order to self-consistently reproduce the intensity and polarimetric images, the dust grains, responsible for the scattered light, need to be dominated by sizes of around ten microns. A point source is detected at an angular distance of 3.5'' from the central star. It is, however, found not to be co-moving. Conclusions: We confirm that the dominant source of emission is forward scattered light from the near edge of the outer disk. Our point source analysis rules out the presence of a companion with mass larger than 8.5 Mjup between 0.̋1 and 0.̋3. The detection limit decreases to 2 Mjup for 0.̋3 to 4.0''. Based on observations made with European Southern Observatory (ESO) telescopes at the Paranal Observatory in Chile, under program IDs 095.C-0298(B), 096.C-0248(B) and 096.C-0248(C)....

AB - Context. The transition disk around the T Tauri star T Cha possesses a large gap, making it a prime target for high-resolution imaging in the context of planet formation. Aims: We aim to find signs of disk evolutionary processes by studying the disk geometry and the dust grain properties at its surface, and to search for companion candidates. Methods: We analyze a set of VLT/SPHERE data at near-infrared and optical wavelengths. We performed polarimetric imaging of T Cha with IRDIS (1.6 μm) and ZIMPOL (0.5-0.9 μm), and obtained intensity images from IRDIS dual-band imaging with simultaneous spectro-imaging with IFS (0.9-1.3 μm). Results: The disk around T Cha is detected in all observing modes and its outer disk is resolved in scattered light with unprecedented angular resolution and signal-to-noise. The images reveal a highly inclined disk with a noticeable east-west brightness asymmetry. The significant amount of non-azimuthal polarization signal in the Uφ images, with a Uφ/Qφ peak-to-peak value of 14%, is in accordance with theoretical studies on multiple scattering in an inclined disk. Our optimal axisymmetric radiative transfer model considers two coplanar inner and outer disks, separated by a gap of 0.̋28 ( 30 au) in size, which is larger than previously thought. We derive a disk inclination of 69 deg and PA of 114 deg. In order to self-consistently reproduce the intensity and polarimetric images, the dust grains, responsible for the scattered light, need to be dominated by sizes of around ten microns. A point source is detected at an angular distance of 3.5'' from the central star. It is, however, found not to be co-moving. Conclusions: We confirm that the dominant source of emission is forward scattered light from the near edge of the outer disk. Our point source analysis rules out the presence of a companion with mass larger than 8.5 Mjup between 0.̋1 and 0.̋3. The detection limit decreases to 2 Mjup for 0.̋3 to 4.0''. Based on observations made with European Southern Observatory (ESO) telescopes at the Paranal Observatory in Chile, under program IDs 095.C-0298(B), 096.C-0248(B) and 096.C-0248(C)....

U2 - 10.1051/0004-6361/201630234

DO - 10.1051/0004-6361/201630234

M3 - Article

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

ER -

New constraints on the disk characteristics and companion candidates around T Chamaeleontis with VLT/SPHERE

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