High-contrast observations of brown dwarf companion HR 2562 B with the vector Apodizing Phase Plate coronagraph

InstrumentationStars and planetary system

On-sky Performance Analysis of the Vector Apodizing Phase Plate Coronagraph on MagAO/Clio2

Stars and planetary systemsInstrumentatio

Improved companion mass limits for Sirius A with thermal infrared coronagraphy using a vector-apodizing phase plate and time-domain starlight-subtraction techniques

Stars and planetary system

Vector-apodizing phase plate coronagraph: design, current performance, and future development [Invited]

Instrumentatio

Performance of the Gemini Planet Imager Non-redundant Mask and Spectroscopy of Two Close-separation Binaries: HR 2690 and HD 142527

Instrumentatio

Companion mass limits for 17 binary systems obtained with binary differential imaging and MagAO/Clio

Improving direct detection capability close to the star through improved star subtraction and post-processing techniques is vital for discovering new low-mass companions and characterizing known ones at longer wavelengths. We present results of 17 binary star systems observed with the Magellan adaptive optics system (MagAO) and the Clio infrared camera on the Magellan Clay Telescope using binary differential imaging (BDI). BDI is an application of reference differential imaging (RDI) and angular differential imaging (ADI) applied to wide binary star systems (2 arcsec <Δρ < 10 arcsec) within the isoplanatic patch in the infrared. Each star serves as the point spread function (PSF) reference for the other, and we performed PSF estimation and subtraction using principal component analysis. We report contrast and mass limits for the 35 stars in our initial survey using BDI with MagAO/Clio in L′ and 3.95 μm bands. Our achieved contrasts varied between systems, and spanned a range of contrasts from 3.0 to 7.5 magnitudes and a range of separations from 0.2 to 2 arcsec. Stars in our survey span a range of masses, and our achieved contrasts correspond to late-type M-dwarf masses down to ∼10 MJup. We also report detection of a candidate companion signal at 0.2 arcsec (18 au) around HIP 67506 A (SpT G5V, mass ∼1.2 M⊙), which we estimate to be ∼ 60-90, MJup. We found that the effectiveness of BDI is highest for approximately equal brightness binaries in high-Strehl conditions. © 2022 The Author(s).Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

High-contrast Imaging with Fizeau Interferometry: The Case of Altair

The Large Binocular Telescope (LBT) has two 8.4 m primary mirrors that produce beams that can be combined coherently in a "Fizeau"interferometric mode. In principle, the Fizeau point-spread function (PSF) enables the probing of structure at a resolution up to three times better than that of the adaptive-optics-corrected PSF of a single 8.4 m telescope. In this work, we examined the nearby star Altair (5.13 pc, type A7V, hundreds of Myr to ≈1.4 Gyr) in the Fizeau mode with the LBT at Brα (4.05 μm) and carried out angular differential imaging to search for companions. This work presents the first filled-aperture LBT Fizeau science data set to benefit from a correcting mirror that provides active phase control. In the analysis of the λ/D angular regime, the sensitivity of the data set is down to ≈0.5 M o˙ at 1″ for a 1.0 Gyr system. This sensitivity remains limited by the small amount of integration time, which is in turn limited by the instability of the Fizeau PSF. However, in the Fizeau fringe regime we attain sensitivities of Δm ≈ 5 at 0.″2 and put constraints on companions of 1.3 M o˙ down to an inner angle of ≈0.″15, closer than any previously published direct imaging of Altair. This analysis is a pathfinder for future data sets of this type, and represents some of the first steps to unlocking the potential of the first Extremely Large Telescope. Fizeau observations will be able to reach dimmer targets with upgrades to the instrument, in particular the phase detector. © 2022. The Author(s). Published by the American Astronomical Society..Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Applying a temporal systematics model to vector Apodizing Phase Plate coronagraphic data:TRAP4vAPP

Context. The vector Apodizing Phase Plate (vAPP) is a pupil plane coronagraph that suppresses starlight by forming a dark hole in its point spread function (PSF). The unconventional and non-axisymmetrical PSF arising from the phase modification applied by this coronagraph presents a special challenge to post-processing techniques. Aims. We aim to implement a recently developed post-processing algorithm, temporal reference analysis of planets (TRAP) on vAPP coronagraphic data. The property of TRAP that uses non-local training pixels, combined with the unconventional PSF of vAPP, allows for more flexibility than previous spatial algorithms in selecting reference pixels to model systematic noise. Methods. Datasets from two types of vAPPs are analysed: a double grating-vAPP (dgvAPP360) that produces a single symmetric PSF and a grating-vAPP (gvAPP180) that produces two D-shaped PSFs. We explore how to choose reference pixels to build temporal systematic noise models in TRAP for them. We then compare the performance of TRAP with previously implemented algorithms that produced the best signal-to-noise ratio (S/N) in companion detections in these datasets. Results. We find that the systematic noise between the two D-shaped PSFs is not as temporally associated as expected. Conversely, there is still a significant number of systematic noise sources that are shared by the dark hole and the bright side in the same PSF. We should choose reference pixels from the same PSF when reducing the dgvAPP360 dataset or the gvAPP180 dataset with TRAP. In these datasets, TRAP achieves results consistent with previous best detections, with an improved S/N for the gvAPP180 dataset

Improved Orbital Constraints and H α Photometric Monitoring of the Directly Imaged Protoplanet Analog HD 142527 B

Companions embedded in the cavities of transitional circumstellar disks have been observed to exhibit excess luminosity at Hα, an indication that they are actively accreting. We report 5 yr (2013-2018) of monitoring of the position and Hα excess luminosity of the embedded, accreting low-mass stellar companion HD 142527 B from the MagAO/VisAO instrument. We use pyklip, a Python implementation of the Karhunen-Loeve Image Processing algorithm, to detect the companion. Using pyklip forward modeling, we constrain the relative astrometry to 1-2 mas precision and achieve sufficient photometric precision (±0.2 mag, 3% error) to detect changes in the Hα contrast of the companion over time. In order to accurately determine the relative astrometry of the companion, we conduct an astrometric calibration of the MagAO/VisAO camera against 20 yr of Keck/NIRC2 images of the Trapezium cluster. We demonstrate agreement of our VisAO astrometry with other published positions for HD 142527 B, and use orbitize! to generate a posterior distribution of orbits fit to the relative astrometry of HD 142527 B. Our data suggest that the companion is close to periastron passage, on an orbit significantly misaligned with respect to both the wide circumbinary disk and the recently observed inner disk encircling HD 142527 A. We translate observed Hα contrasts for HD 142527 B into mass accretion rate estimates on the order of 4-9 × 10-10 M yr-1. Photometric variation in the Hα excess of the companion suggests that the accretion rate onto the companion is variable. This work represents a significant step toward observing accretion-driven variability onto protoplanets, such as PDS 70 b © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Characterizing deformable mirrors for the MagAO-X instrument

The MagAO-X instrument is an extreme adaptive optics system for high-contrast imaging at visible- and near-infrared wavelengths on the Magellan Clay Telescope. A central component of this system is a 2040-actuator microelectromechanical deformable mirror (DM) from Boston Micromachines Corp. that operates at 3.63 kHz for high-order wavefront control (the tweeter). Two additional DMs from ALPAO perform the low-order (the woofer) and non-common-path science-arm wavefront correction (the NCPC DM). Prior to integration with the instrument, we characterized these devices using a Zygo Verifire Interferometer to measure each DM surface. We present the results of the characterization effort here, demonstrating the ability to drive the tweeter to a flat of 6.9 nm root-mean-square (RMS) surface (and 0.56 nm RMS surface within its control bandwidth), the woofer to 2.2-nm RMS surface, and the NCPC DM to 2.1-nm RMS surface over the MagAO-X beam footprint on each device. Using focus-diversity phase retrieval on the MagAO-X science cameras to estimate the internal instrument wavefront error, we further show that the integrated DMs correct the instrument WFE to 18.7 nm RMS, which, combined with a 11.7% pupil amplitude RMS, produces a Strehl ratio of 0.94 at Hα. © 2021 Society of Photo-Optical Instrumentation Engineers (SPIE).Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]