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Abstract:

MOSAIC is the multi-object spectrograph and IFU for the ESO ELT, currently in its design phase leading up to PDR. The GLAO subsystem is a key component to improve coupling of flux into the fibre apertures over the 7.8arcmin field of view. The apertures are positioned by 261 robot positioners which are attached to a > 1.5m Focal Plate that is mounted onto the Instrument Core Structure barrel which rotates for sky tracking. The four MOSAIC GLAO sensing units are also mounted on the barrel, and this entire assembly flexes under gravity and temperature changes. The ELT itself is expected to flex and its mirror positions will deviate from nominal locations leading to focal surface aberrations and distortions. Each GLAO unit then has three measurement goals: pupil plane wavefronts from LGS and NGS, focal surface distortions based on measurements from NGS, and Focal Plate distortions from artificial sources. All measurements pass to the AO Control Module which computes the fast control signal for the ELT M4 deformable mirror from LGS and NGS, while slower offsets allow the ELT to compensate focal surface distortions on-demand, and the instrument control updates knowledge of aperture positioning geometry from NGS and the artificial sources. The NGS WFS architecture combines high-speed tip/tilt (> 10Hz) from the ELT and low-order modes (< 10Hz) from NGS WFSs. The GLAO NGS WFSs enable the > 99% sky coverage of the instrument and have three measurement roles: telescope control modes, ELT focus surface distortions, and correcting LGS NCPA WFE due to their finite conjugate. The GLAO LGS WFSs use sky tracking LGS to measure the high-order WFE modes. The third GLAO modules are the metrology cameras which monitor the positions of the focal plate artificial sources, with one set per GLAO unit.

Abstract:

We report the direct imaging discovery of a third exoplanet in the β Pictoris (β Pic) system. We detect β Pictoris d (β Pic d) in noncoronagraphic observations obtained with the Very Large Telescope (VLT) Enhanced Resolution Imager and Spectrograph (ERIS), as well as multi-epoch archival datasets from the JWST Near Infrared Camera (NIRCam) and VLT/SPHERE. Astrometric measurements over an 11 yr baseline demonstrate that it is consistent with a gravitationally bound source with orbital motion. Joint multi-planet orbit fits of all three planets in the system yield a semimajor axis of 26.0−6.1+2.2 au and inclination 89.0−0.6+0.7 deg for planet d. β Pic d has a larger orbital semimajor axis than the other known planets in the system, but is coplanar with the inner two planets, and its orbit is consistent with sculpting the inner edge of the debris disk. β Pic d has a contrast of ΔL′=12.11±0.15 mag, with colors and luminosity that closely match those of 51 Eri b, another exoplanet in the β Pic moving group. Its VLT/ERIS and JWST/NIRCam colors are distinct from those of free-floating planetary-mass objects of a similar age and temperature. Its red F410M − F444W color indicates strong CO2 absorption in its atmosphere and suggests significant enhancement in metals compared to free-floating objects. From the ATMO hot-start evolutionary models, we estimate an effective temperature of 600−60+45 K and mass of 2.4 ± 0.6 MJup, which also closely matches similar estimates for 51 Eri b. β Pic d is among the lowest-mass exoplanets imaged from the ground. This discovery highlights the deep sensitivity achievable with ground-based imaging in the mid-infrared and the discovery potential of future high-contrast observations with the Extremely Large Telescope.

Abstract:

Dynamical modelling can be used to constrain the masses of central black holes, but it is challenging to model massive galaxies because of their complex kinematics. We report six new measurements of supermassive black hole masses of massive early-type galaxies from stellar kinematics, which were extracted from adaptive-optics-assisted SINFONI and MUSE observations. We combined the stellar kinematics with HST photometry to build triaxial Schwarzschild orbit-superposition models. Our Schwarzschild models can recover the complex triaxial features of the galaxies and constrain the black hole masses of all six galaxies. We found that strong triaxial kinematic features can bias the mass measurements and corrected for this effect. The derived black hole masses are $(1.14^ DYNAMITE +0.41 _ -0.63 ) _ 10^9$ M_⊙ for NGC 3706, $(1.19^ +1.34 -0.80 ) _ 10^9$ M_⊙ for NGC 3923, $(1.14^ +1.08 -0.95 ) _ 10^9$ M_⊙ for NGC 4261, $(4.68^ +2.99 -4.26 ) _ 10^8$ M_⊙ for NGC 4636, $(3.51^ +3.37 -2.57 ) _ 10^9$ M_⊙ for IC 4296, and $(2.43^ +1.53 -1.65 ) 10^9$ M_⊙ for IC 4329 at a confidence level of 3σ. We compared our measurements with published results from axisymmetric Schwarzschild modelling and with our JAM Jeans Anisotropic models and obtained mostly consistent black hole masses. Most of our black hole mass estimates can be well constrained using MUSE observations alone. All of our mass measurements agree with local black hole scaling relations.