Multiband Imaging of the HD 36546 Debris Disk: A Refined View from SCExAO/CHARIS*

Abstract We present the first multiwavelength (near-infrared; 1.1–2.4 μm) imaging of HD 36546's debris disk, using the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). As a 3–10 Myr old star, HD 36546 presents a rare opportunity to study a debris disk at very early stages. SCExAO/CHARIS imagery resolves the disk over angular separations of ρ ∼ 0.″25–1.″0 (projected separations of rproj ∼ 25–101 au) and enables the first spectrophotometric analysis of the disk. The disk’s brightness appears symmetric between its eastern and western extents, and it exhibits slightly blue near-infrared colors on average (e.g., J−K = −0.4 ± 0.1)—suggesting copious submicron-sized or highly porous grains. Through detailed modeling adopting a Hong scattering phase function (SPF), instead of the more common Henyey–Greenstein function, and using the differential evolution optimization algorithm, we provide an updated schematic of HD 36546's disk. The disk has a shallow radial dust density profile (α in ≈ 1.0 and α out ≈ −1.5), a fiducial radius of r 0 ≈ 82.7 au, an inclination of i ≈ 79.°1, and a position angle of PA ≈ 80.°1. Through spine tracing, we find a spine that is consistent with our modeling, but also with a “swept-back wing” geometry. Finally, we provide constraints on companions, including limiting a companion responsible for a marginal Hipparcos–Gaia acceleration to a projected separation of ≲0.″2 and to a minimum mass of ≲11 M Jup.

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First scattered light detection of a nearly edge-on transition disk around the T Tauri star RY Lupi

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731624 ◽

2018 ◽

Vol 614 ◽

pp. A88 ◽

Cited By ~ 14

Author(s):

M. Langlois ◽

A. Pohl ◽

A.-M. Lagrange ◽

A.- L. Maire ◽

D. Mesa ◽

...

Keyword(s):

Adaptive Optics ◽

Near Infrared ◽

Planet Formation ◽

Scattered Light ◽

Emission Feature ◽

Point Sources ◽

Tauri Star ◽

Dual Band ◽

High Angular Resolution ◽

T Tauri

Context. Transition disks are considered sites of ongoing planet formation, and their dust and gas distributions could be signposts of embedded planets. The transition disk around the T Tauri star RY Lup has an inner dust cavity and displays a strong silicate emission feature. Aims. Using high-resolution imaging we study the disk geometry, including non-axisymmetric features, and its surface dust grain, to gain a better understanding of the disk evolutionary process. Moreover, we search for companion candidates, possibly connected to the disk. Methods. We obtained high-contrast and high angular resolution data in the near-infrared with the VLT/SPHERE extreme adaptive optics instrument whose goal is to study the planet formation by detecting and characterizing these planets and their formation environments through direct imaging. We performed polarimetric imaging of the RY Lup disk with IRDIS (at 1.6 μm), and obtained intensity images with the IRDIS dual-band imaging camera simultaneously with the IFS spectro-imager (0.9–1.3 μm). Results. We resolved for the first time the scattered light from the nearly edge-on circumstellar disk around RY Lup, at projected separations in the 100 au range. The shape of the disk and its sharp features are clearly detectable at wavelengths ranging from 0.9 to 1.6 μm. We show that the observed morphology can be interpreted as spiral arms in the disk. This interpretation is supported by in-depth numerical simulations. We also demonstrate that these features can be produced by one planet interacting with the disk. We also detect several point sources which are classified as probable background objects.

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Highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMA

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935034 ◽

2019 ◽

Vol 625 ◽

pp. A118 ◽

Cited By ~ 31

Author(s):

M. Keppler ◽

R. Teague ◽

J. Bae ◽

M. Benisty ◽

T. Henning ◽

...

Keyword(s):

Near Infrared ◽

Angular Resolution ◽

Dust Emission ◽

Mass Range ◽

Position Angle ◽

Circumstellar Disk ◽

High Angular Resolution ◽

Gas Kinematics ◽

Hydrodynamical Simulations ◽

Dust Ring

Context. Imaged in the gap of a transition disk and found at a separation of about 195 mas (~22 au) from its host star at a position angle of about 155°, PDS 70 b is the most robustly detected young planet to date. This system is therefore a unique laboratory for characterizing the properties of young planetary systems at the stage of their formation. Aims. We aim to trace direct and indirect imprints of PDS 70 b on the gas and dust emission of the circumstellar disk in order to study the properties of this ~5 Myr young planetary system. Methods. We obtained ALMA band 7 observations of PDS 70 in dust continuum and 12CO (3–2) and combined them with archival data. This resulted in an unprecedented angular resolution of about 70 mas (~8 au). Results. We derive an upper limit on circumplanetary material at the location of PDS 70 b of ~0.01 M⊕ and find a highly structured circumstellar disk in both dust and gas. The outer dust ring peaks at 0.65′′ (74 au) and reveals a possible second unresolved peak at about 0.53′′ (60 au). The integrated intensity of CO also shows evidence of a depletion of emission at ~0.2′′ (23 au) with a width of ~0.1′′ (11 au). The gas kinematics show evidence of a deviation from Keplerian rotation inside ≲0.8′′ (91 au). This implies a pressure gradient that can account for the location of the dust ring well beyond the location of PDS 70 b. Farther in, we detect an inner disk that appears to be connected to the outer disk by a possible bridge feature in the northwest region in both gas and dust. We compare the observations to hydrodynamical simulations that include a planet with different masses that cover the estimated mass range that was previously derived from near-infrared photometry (~5–9 MJup). We find that even a planet with a mass of 10 MJup may not be sufficient to explain the extent of the wide gap, and an additional low-mass companion may be needed to account for the observed disk morphology.

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A High Angular Resolution Survey of Massive Stars in Cygnus OB2: JHK Adaptive Optics Results from the Gemini Near-Infrared Imager

The Astronomical Journal ◽

10.3847/1538-3881/aba536 ◽

2020 ◽

Vol 160 (3) ◽

pp. 115

Author(s):

S. M. Caballero-Nieves ◽

D. R. Gies ◽

E. K. Baines ◽

A. H. Bouchez ◽

R. G. Dekany ◽

...

Keyword(s):

Adaptive Optics ◽

Near Infrared ◽

Angular Resolution ◽

Massive Stars ◽

High Angular Resolution ◽

Infrared Imager

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High-resolution imaging follow-up of doubly imaged quasars

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab532 ◽

2021 ◽

Vol 503 (2) ◽

pp. 1557-1567

Author(s):

Anowar J Shajib ◽

Eden Molina ◽

Adriano Agnello ◽

Peter R Williams ◽

Simon Birrer ◽

...

Keyword(s):

Adaptive Optics ◽

Time Delays ◽

Near Infrared ◽

High Resolution Imaging ◽

Modelling Uncertainty ◽

Model Predictions ◽

Smooth Model ◽

Resolution Imaging ◽

K Band

ABSTRACT We report upon 3 years of follow-up and confirmation of doubly imaged quasar lenses through imaging campaigns from 2016 to 2018 with the Near-Infrared Camera2 (NIRC2) on the W. M. Keck Observatory. A sample of 57 quasar lens candidates are imaged in adaptive-optics-assisted or seeing-limited K′-band observations. Out of these 57 candidates, 15 are confirmed as lenses. We form a sample of 20 lenses adding in a number of previously known lenses that were imaged with NIRC2 in 2013–14 as part of a pilot study. By modelling these 20 lenses, we obtain K′-band relative photometry and astrometry of the quasar images and the lens galaxy. We also provide the lens properties and predicted time delays to aid planning of follow-up observations necessary for various astrophysical applications, e.g. spectroscopic follow-up to obtain the deflector redshifts for the newly confirmed systems. We compare the departure of the observed flux ratios from the smooth-model predictions between doubly and quadruply imaged quasar systems. We find that the departure is consistent between these two types of lenses if the modelling uncertainty is comparable.

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Dust production in the debris disk around HR 4796 A

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935998 ◽

2019 ◽

Vol 630 ◽

pp. A142 ◽

Cited By ~ 3

Author(s):

J. Olofsson ◽

J. Milli ◽

P. Thébault ◽

Q. Kral ◽

F. Ménard ◽

...

Keyword(s):

Radiation Pressure ◽

Near Infrared ◽

High Angular Resolution ◽

Outer Planet ◽

Dust Grains ◽

Semi Major Axis ◽

Azimuthal Distribution ◽

Radial Profiles ◽

Debris Disk ◽

Small Dust

Context. Debris disks are the natural by-products of the planet formation process. Scattered or polarized light observations are mostly sensitive to small dust grains that are released from the grinding down of bigger planetesimals. Aims. High angular resolution observations at optical wavelengths can provide key constraints on the radial and azimuthal distribution of the small dust grains. These constraints can help us better understand where most of the dust grains are released upon collisions. Methods. We present SPHERE/ZIMPOL observations of the debris disk around HR 4796 A, and we modeled the radial profiles along several azimuthal angles of the disk with a code that accounts for the effect of stellar radiation pressure. This enabled us to derive an appropriate description for the radial and azimuthal distribution of the small dust grains. Results. Even though we only modeled the radial profiles along, or close to, the semi-major axis of the disk, our best-fit model is not only in good agreement with our observations but also with previously published datasets (from near-infrared to sub-mm wavelengths). We find that the reference radius is located at 76.4 ± 0.4 au, and the disk has an eccentricity of 0.076−0.010+0.016 with the pericenter located on the front side of the disk (north of the star). We find that small dust grains must be preferentially released near the pericenter to explain the observed brightness asymmetry. Conclusions. Even though parent bodies spend more time near the apocenter, the brightness asymmetry implies that collisions happen more frequently near the pericenter of the disk. Our model can successfully reproduce the shape of the outer edge of the disk without requiring an outer planet shaping the debris disk. With a simple treatment for the effect of the radiation pressure, we conclude that the parent planetesimals are located in a narrow ring of about 3.6 au in width.

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Adaptive Optics in Star Formation

Symposium - International Astronomical Union ◽

10.1017/s0074180900241740 ◽

2004 ◽

Vol 221 ◽

pp. 323-332

Author(s):

Wolfgang Brandner

Keyword(s):

Star Formation ◽

Adaptive Optics ◽

Near Infrared ◽

High Angular Resolution ◽

Full Potential ◽

Multiple Systems ◽

Infrared Telescope ◽

Reduction Strategies ◽

Under Construction ◽

Almost All

Over the past ten years, the concept of adaptive optics has evolved from early experimental stages to a standard observing tool now available at almost all major optical and near-infrared telescope facilities. Adaptive optics will also be essential in exploiting the full potential of the large optical/infrared interferometers currently under construction. Both observations with high-angular resolution and at high contrast, and with a high point source sensitivity are facilitated by adaptive optics. Among the areas which benefit most from the use of adaptive optics are studies of the circumstellar environment (envelopes, disks, outflows), substellar companions and multiple systems, and dense young stellar populations. This contribution highlights some of the recent advances in star formation studies facilitated by adaptive optics, and gives a brief tutorial on optimized observing and data reduction strategies.

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The Ophiuchus DIsc Survey Employing ALMA (ODISEA) – II. The effect of stellar multiplicity on disc properties

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1886 ◽

2020 ◽

Vol 496 (4) ◽

pp. 5089-5100 ◽

Cited By ~ 1

Author(s):

Alice Zurlo ◽

Lucas A Cieza ◽

Sebastián Pérez ◽

Valentin Christiaens ◽

Jonathan P Williams ◽

...

Keyword(s):

Adaptive Optics ◽

Binary Systems ◽

Near Infrared ◽

Position Angle ◽

Single Star ◽

Multiple Systems ◽

Dust Mass ◽

Low Mass ◽

The Masses ◽

Almost All

ABSTRACT We present adaptive optics (AO) near-infrared (NIR) observations using VLT/NACO and Keck/NIRC2 of Ophiuchus DIsc Survey Employing ALMA (ODISEA) targets. ODISEA is an ALMA survey of the entire population of circumstellar discs in the Ophiuchus molecular cloud. From the whole sample of ODISEA, we select all the discs that are not already observed in the NIR with AO and that are observable with NACO or NIRC2. The NIR-ODISEA survey consists of 147 stars observed in NIR AO imaging for the first time, as well as revisiting almost all the binary systems of Ophiuchus present in the literature (20 out of 21). In total, we detect 20 new binary systems and one triple system. For each of them, we calculate the projected separation and position angle of the companion, as well as their NIR and millimetre flux ratios. From the NIR contrast, we derived the masses of the secondaries, finding that nine of them are in the substellar regime (30–50 MJup ). Discs in multiple systems reach a maximum total dust mass of ∼50 M⊕, while discs in single stars can reach a dust mass of 200 M⊕. Discs with masses above 10 M⊕ are found only around binaries with projected separations larger than ∼110 au. The maximum disc size is also larger around single star than binaries. However, since most discs in Ophiuchus are very small and low-mass, the effect of visual binaries is relatively weak in the general disc population.

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OPTICAL AND MECHANICAL DESIGN OF THE CHARA ARRAY ADAPTIVE OPTICS

Journal of Astronomical Instrumentation ◽

10.1142/s2251171713400072 ◽

2013 ◽

Vol 02 (02) ◽

pp. 1340007 ◽

Cited By ~ 5

Author(s):

X. CHE ◽

L. STURMANN ◽

J. D. MONNIER ◽

T. A. TEN BRUMMELAAR ◽

J. STURMANN ◽

...

Keyword(s):

Adaptive Optics ◽

Near Infrared ◽

Angular Resolution ◽

Mechanical Design ◽

Wavefront Sensor ◽

High Angular Resolution ◽

Stellar Systems ◽

Tilt Correction ◽

Chara Array ◽

Adaptive Optics System

The CHARA array is an optical/near infrared interferometer consisting of six 1-meter diameter telescopes with the longest baseline of 331 m. With high angular resolution, the CHARA array provides a unique and powerful way of studying nearby stellar systems. In 2011, the CHARA array was funded by NSF-ATI for an upgrade of adaptive optics systems to all six telescopes to improve the sensitivity by several magnitudes. The initial grant covers Phase I of the adaptive optics system, which includes an on-telescope Wavefront Sensor and fast tip/tilt correction. We are currently seeking funding for Phase II which will add fast deformable mirrors at the telescopes to close the loop. This paper will describe the design of the project, and show simulations of how much improvement the array will gain after the upgrade.

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