Advances in optical engineering for future telescopes

Significant optical engineering advances at the University of Arizona are being made for design, fabrication, and construction of next generation astronomical telescopes. This summary review paper focuses on the technological advances in three key areas. First is the optical fabrication technique used for constructing next-generation telescope mirrors. Advances in ground-based telescope control and instrumentation comprise the second area of development. This includes active alignment of the laser truss-based Large Binocular Telescope(LBT) prime focus camera, the new MOBIUS modular cross-dispersion spectroscopy unit used at the prime focal plane of the LBT, and topological pupil segment optimization. Lastly, future space telescope concepts and enabling technologies are discussed. Among these, the Nautilus space observatory requires challenging alignment of segmented multi-order diffractive elements. The OASIS terahertz space telescope presents unique challenges for characterizing the inflatable primary mirror, and the Hyperion space telescope pushes the limits of high spectral resolution, far-UV spectroscopy. The Coronagraphic Debris and Exoplanet Exploring Pioneer(CDEEP) is a Small Satellite(Small Sat) mission concept for high-contrast imaging of circumstellar disks and exoplanets using vector vortex coronagraph. These advances in optical engineering technologies will help mankind to probe, explore, and understand the scientific beauty of our universe.

South Galactic Cap u-band Sky Survey(SCUSS):Project Overview

The South Galactic Cap u-band Sky Survey （SCUSS） was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） project. SCUSS is an international cooperative project between National Astronomical Observatories, Chinese Academy of Sciences, and Steward Observatory at the University of Arizona, using the 90 inch （2.3 m） Bok telescope on Kitt Peak. The telescope is equipped with a prime focus camera that is composed of a mosaic of four 4096 × 4096 CCDs and has a field of view of about 1 deg2. From 2009 to 2013, SCUSS performed a sky survey of an approximately 5000 deg2 field of the South Galactic Cap in u band, including the Galactic anticenter area and the SDSS-IV extended imaging area. The limiting magnitude of SCUSS is deeper than 23 mag （at a signal-to-noise ratio of 5）. In this paper, we briefly describe the goals of this project, method of observations and data reduction, and we also introduce current and potential scientific activities related to the SCUSS project.

Characterizing microlensing planetary system OGLE-2014-BLG-0676Lb with adaptive optics imaging

We constrain the host-star flux of the microlensing planet OGLE-2014-BLG-0676 Lb using adaptive optics(AO)images taken by the Magellan and Keck telescopes.We measure the flux of the light blended with the microlensed source to be K=16.79±0.04 mag and J=17.76±0.03 mag.Assuming that the blend is the lens star,we find that the host is a 0.73_(-0.29)^(+0.14)M_(⊙)star at a distance of2.67_(-1.41)^(+0.77)kpc,where the relatively large uncertainty in angular Einstein radius measurement is the major source of uncertainty.With mass of M_(p)=3.68_(-1.44)^(+0.69)M_J,the planet is likely a"super Jupiter"at a projected separation of r_(⊥)=4.53_(-2.50)^(+1.49)AU,and a degenerate model yields a similar M_p=3.73_(-1.47)^(+0.73)M_(J)at a closer separation of r_(⊥)=2.56_(-1.41)^(+0.84)AU.Our estimates are consistent with the previous Bayesian analysis based on a Galactic model.OGLE-2014-BLG-0676 Lb belongs to a sample of planets discovered in a"secondgeneration"planetary microlensing survey and we attempt to systematically constrain host properties of this sample with high-resolution imaging to study the distribution of planets.

Systematic Radio Telescope Alignment Using Portable Fringe Projection Profilometry

In 2019,the Event Horizon Telescope(EHT)released the first-ever image of a black hole event horizon.Astronomers are now aiming for higher angular resolutions of distant targets,like black holes,to understand more about the fundamental laws of gravity that govern our universe.To achieve this higher resolution and increased sensitivity,larger radio telescopes are needed to operate at higher frequencies and in larger quantities.Projects like the next-generation Very Large Array(ngVLA)and the Square-Kilometer Array(SKA)require building hundreds of telescopes with diameters greater than 10 ms over the next decade.This has a twofold effect.Radio telescope surfaces need to be more accurate to operate at higher frequencies,and the logistics involved in maintaining a radio telescope need to be simplified to support them properly in large quantities.Both of these problems can be solved with improved methods for surface metrology that are faster and more accurate with a higher resolution.This leads to faster and more accurate panel alignment and,therefore,a more productive observatory.In this paper,we present the use of binocular fringe projection profilometry as a solution to this problem and demonstrate it by aligning two panels on a 3-m radio telescope dish.The measurement takes only 10 min and directly delivers feedback on the tip,tilt,and piston of each panel to create the ideal reflector shape.

高红移类星体的观测

在宇宙大爆炸后10亿年以内的高红移(红移大于6)类星体为我们研究早期宇宙提供了重要的探针,这也使得对高红移类星体的观测研究成为星系宇宙学前沿研究领域的一大热点.本文对高红移类星体观测研究的重要性及其宇宙学意义,利用光学和近红外波段的观测发现早期宇宙中光度最高和中心黑洞质量最大的高红移类星体,以及利用亚毫米、毫米和射电波段观测对高红移类星体寄主星系所开展的研究等进行了较全面地总结,并对这一领域未来的研究前景与挑战进行了展望.

Adaptive Thermoforming and Structural Design of Millimeter-Wave Antenna Panels

Future large-scale radio telescope observatories,such as the next-generation Very Large Array,involve extremely large collection areas.These collection areas are divided into smaller shaped panels,which typically require their own unique molds to manufacture.For these projects to be cost-effective,an efficient fabrication method for the shaped panels is needed.This paper outlines the development and success of a novel adaptive freeform panel molding technology that greatly improves manufacturing efficiency due to its repeatable and reusable nature.Moreover,it presents an analysis of a proposed panel structural design for the shaped panels,which incorporates a study on surface deformation due to gravity and wind loading under realistic operational conditions.