Extremely Large Telescope

Abstract:

We explore the nucleus of the nearby 109 M⊙ early-type galaxy, NGC 404, using Hubble Space Telescope (HST)/STIS spectroscopy and WFC3 imaging. We first present evidence for nuclear variability in UV, optical, and infrared filters over a time period of 15 years. This variability adds to the already substantial evidence for an accreting black hole at the center of NGC 404. We then redetermine the dynamical black hole mass in NGC 404 including modeling of the nuclear stellar populations. We combine HST/STIS spectroscopy with WFC3 images to create a local color-M/L relation derived from stellar population modeling of the STIS data. We then use this to create a mass model for the nuclear region. We use Jeans modeling to fit this mass model to adaptive optics stellar kinematic observations from Gemini/NIFS. From our stellar dynamical modeling, we find a 3σ upper limit on the black hole mass of 1.5 × 105 M⊙. Given the accretion evidence for a black hole, this upper limit makes NGC 404 the lowest mass central black hole with dynamical mass constraints. We find that the kinematics of H2 emission line gas show evidence for non-gravitational motions preventing the use of gas dynamical modeling to constrain the black hole mass. Our stellar population modeling also reveals that the central, counter-rotating region of the nuclear cluster is dominated by ∼1 Gyr old populations.

Abstract:

As high pixel count Microwave Kinetic Inductance Detector (MKID) arrays become widely adopted, there is a growing demand for automated device readout calibration. These calibrations include ascertaining the optimal driving power for best pixel sensitivity, which, because of large variations in MKID behavior, is typically performed by manual inspection. This process takes roughly 1 hour per 1000 MKIDs, making the manual characterization of ten-kilopixel scale arrays unfeasible. We propose the concept of using a machine-learning algorithm, based on a convolution neural network (CNN) architecture, which should reliably tune ten-kilopixel scale MKID arrays on the order of several minutes.

Abstract:

Within the VLT instrumentation program, the second generation instrument ERIS (Enhanced Resolution Imager and Spectrograph) combines two key scientifically successful elements of the VLT first generation instrumentation program: It consists of a full renovation of the integral field spectrograph SPIFFI and a new near-IR camera NIX, implementing the most scientifically important imaging modes offered so far by NACO (imaging in the J to M bands, astrometry, Sparse Aperture Masking and Apodizing Phase Plate (APP) coronagraphy). Both diffraction limited sub-systems of ERIS make use of the latest AO technologies with the newly installed AOF (AO Facility) Deformable Secondary Mirror with 1170 actuators and a new laser guide star system. We will describe the changes that will be implemented, give a summary of what SINFONI is currently achieving, and present what to expect from the performance upgrade. With instruments becoming more complex and therefore increasing development times, we describe the challenges to improve image quality, spectral and spatial resolution on the same focus of a VLT UT, which could become valuable lessons for the extension of the life of actual instruments and of future ones. We will address the impact of the aging of the instrument and what critical parts to consider in the design in view of future upgrades, to possibly extend the performances, capabilities and lifetime at lower development costs.