53 research outputs found
Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project
Get PDFIn the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory
The Software Architecture and development approach for the ASTRI Mini-Array gamma-ray air-Cherenkov experiment at the Observatorio del Teide
Get PDFThe ASTRI Mini-Array is an international collaboration led by the Italian National Institute for Astrophysics (INAF) and devoted to the imaging of atmospheric Cherenkov light for very-high gamma-ray astronomy. The project is deploying an array of 9 telescopes sensitive above 1 TeV. In this contribution, we present the architecture of the software that covers the entire life cycle of the observatory, from scheduling to remote operations and data dissemination. The high-speed networking connection available between the observatory site, at the Canary Islands, and the Data Center in Rome allows for ready data availability for stereo triggering and data processing
A user-friendly simulation tool to facilitate writing of complex part programs for laser micromachining
No full textExcimer micromachining tools used to produce micromachined parts are often controlled by manually written numerical control (NC) part programs in RS-274 “G” and “M” codes, or NC-code. The manual creation of the part programs in NC-code is a time-consuming process for users and relies on their expertise. This often results in a trial-and-error approach to producing a part program for the desired shape because a user rarely gets it ‘right the first time’. Furthermore, writing programs to machine complex microstructures is difficult. As few CAD/CAM tools are available to assist programming for laser micromachining, the aim of the research was to develop a user-friendly CAM tool to assist programmers. A simulation tool has been written to interpret a part program and to display the intended part. With this simulation tool, the part programmer works more effectively by being able to view the machined surface and check the program using the simulation tool before trialling it on an expensive laser machine. The simulator allows the user to easily modify and retry a program during its development. The simulator provides a number of debugging features to enable the user to step through the program and determine what is happening at each instruction. The capability of the simulator tools is demonstrated through several part programs
Positioning and orienting a drill axis on a curved surface
No full textA novel technique, referred to as a vector setting in the aerospace industry, has been developed for positioning and orienting drilling bushes on curved surfaces. The position and orientation of holes and their axes in parts and tooling in the aerospace industry must conform to strict tolerances; however, the process of locating and orienting the bushes in drilling plates having curved surfaces is slow and time consuming. This is because the existing process used is a trial and error one, and past research in automated drilling in the aerospace industry has not covered this area. A prototype device has been developed which reduces the setting time. The device has two angular adjustments, which are computed using specially written software. The device is used in conjunction with a 3D spatial measurement system in order to determine reference points on the part or tooling and the device. Experimental results on a prototype indicate a substantial time saving as well as good accuracy in orienting the drill axis at a given point on a surface
Preliminary test results on factors affecting model accuracy for the FDM rapid prototyping process
No full textAbstract not available
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