Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.024002
Manuel Indaco, Kanak Parmar, Ryan Long, James Whitehead, Russell W. Mailen, Davide Guzzetti
Flat-fabrication technology may enable the next generation of gigantic deployable architectures devoted to the detection of faint cosmological signals. We assess the applicability of a multifunctional roll-out structure based on shape memory polymer technology for the realization of a large space observatory to measure the cosmological Dark Ages radio signal. Roll-out solutions offer advantageous properties for probe class missions, such as the capability to morph the shape to achieve sufficient structural performance while ensuring high packaging efficiency. We characterize the feasibility of a roll-out observatory in the context of a 5 years-long heliocentric mission scenario. Our preliminary study demonstrates how a four-250 m-long arms architecture with 150 evenly spaced short dipole antennas potentially meets the basic mission requirements dictated by the Dark Ages science case. We conduct a quasi-static structural analysis considering axial and bending loads acting on the arms to assess the structural properties of the proposed architecture, identifying geometric ranges which enable the structure to withstand expected loads while satisfying mass and size constraints. Printable electronics are considered in the design due to the ease of integration with the polymer substrate. In this regard, we explore two distinct electronics configuration options—centralized and decentralized—discussing their benefits in terms of power demand and data management. If successful, such a design may set the stage for future technological development aiming to realize tomographic measurements of the cosmological Dark Ages.
{"title":"Lessons learned from an NIAC Phase I study for the flat-fabrication of a Dark Ages observatory","authors":"Manuel Indaco, Kanak Parmar, Ryan Long, James Whitehead, Russell W. Mailen, Davide Guzzetti","doi":"10.1117/1.jatis.10.2.024002","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.024002","url":null,"abstract":"Flat-fabrication technology may enable the next generation of gigantic deployable architectures devoted to the detection of faint cosmological signals. We assess the applicability of a multifunctional roll-out structure based on shape memory polymer technology for the realization of a large space observatory to measure the cosmological Dark Ages radio signal. Roll-out solutions offer advantageous properties for probe class missions, such as the capability to morph the shape to achieve sufficient structural performance while ensuring high packaging efficiency. We characterize the feasibility of a roll-out observatory in the context of a 5 years-long heliocentric mission scenario. Our preliminary study demonstrates how a four-250 m-long arms architecture with 150 evenly spaced short dipole antennas potentially meets the basic mission requirements dictated by the Dark Ages science case. We conduct a quasi-static structural analysis considering axial and bending loads acting on the arms to assess the structural properties of the proposed architecture, identifying geometric ranges which enable the structure to withstand expected loads while satisfying mass and size constraints. Printable electronics are considered in the design due to the ease of integration with the polymer substrate. In this regard, we explore two distinct electronics configuration options—centralized and decentralized—discussing their benefits in terms of power demand and data management. If successful, such a design may set the stage for future technological development aiming to realize tomographic measurements of the cosmological Dark Ages.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.025005
Nicolas Erasmus, Iain A. Steele, Andrzej S. Piascik, Stuart D. Bates, Chris. J. Mottram, Kathryn A. Rosie, Carel H. D. R. van Gend, Ulrich Geen, Magaretha L. Pretorius, Stephen B. Potter, Egan Loubser, Willie Koorts, Hitesh Gajjar, Keegan Titus, Hannah L. Worters, Amanda A. Sickafoose, Sunil Chandra, James E. O’Connor, Kgothatso Matlala, Justine Crook-Mansour, Ali Ranjbar, Robert J. Smith, Helen Jermak, Shalom Abiodun, Okwudili D. Egbo
We present Mookodi (meaning “rainbow” in Sesotho), a multipurpose instrument with a low-resolution spectrograph mode and a multi-filter imaging mode for quick-reaction astronomical observations. The instrument, mounted on the 1-m Lesedi telescope at the South African Astronomical Observatory in Sutherland (South Africa), is based on the low-resolution spectrograph for the rapid acquisition of transients (SPRAT) instrument in operation on the 2-m Liverpool Telescope in La Palma (Canary Islands, Spain). Similar to SPRAT, Mookodi has a resolution R≈350 and an operating wavelength range in the visible (∼4000 to 8000 Å). The linear optical design, as in SPRAT, is made possible through the combination of a volume phase holographic transmission grating as the dispersive element and a prism pair (grism), which makes it possible to rapidly and seamlessly switch to an imaging mode by pneumatically removing the slit and grism from the beam and using the same detector as in spectrographic mode to image the sky. This imaging mode is used for auto-target acquisition, but the inclusion of filter slides in Mookodi’s design also provides the capability to perform imaging with a field-of-view ≈10′×10′ (∼0.6″/px) in the complete Sloan Digital Sky Survey filter set.
{"title":"Mookodi: multi-purpose low-resolution spectrograph and multi-filter photometric imager for rapid follow-up observations of astronomical transient events","authors":"Nicolas Erasmus, Iain A. Steele, Andrzej S. Piascik, Stuart D. Bates, Chris. J. Mottram, Kathryn A. Rosie, Carel H. D. R. van Gend, Ulrich Geen, Magaretha L. Pretorius, Stephen B. Potter, Egan Loubser, Willie Koorts, Hitesh Gajjar, Keegan Titus, Hannah L. Worters, Amanda A. Sickafoose, Sunil Chandra, James E. O’Connor, Kgothatso Matlala, Justine Crook-Mansour, Ali Ranjbar, Robert J. Smith, Helen Jermak, Shalom Abiodun, Okwudili D. Egbo","doi":"10.1117/1.jatis.10.2.025005","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.025005","url":null,"abstract":"We present Mookodi (meaning “rainbow” in Sesotho), a multipurpose instrument with a low-resolution spectrograph mode and a multi-filter imaging mode for quick-reaction astronomical observations. The instrument, mounted on the 1-m Lesedi telescope at the South African Astronomical Observatory in Sutherland (South Africa), is based on the low-resolution spectrograph for the rapid acquisition of transients (SPRAT) instrument in operation on the 2-m Liverpool Telescope in La Palma (Canary Islands, Spain). Similar to SPRAT, Mookodi has a resolution R≈350 and an operating wavelength range in the visible (∼4000 to 8000 Å). The linear optical design, as in SPRAT, is made possible through the combination of a volume phase holographic transmission grating as the dispersive element and a prism pair (grism), which makes it possible to rapidly and seamlessly switch to an imaging mode by pneumatically removing the slit and grism from the beam and using the same detector as in spectrographic mode to image the sky. This imaging mode is used for auto-target acquisition, but the inclusion of filter slides in Mookodi’s design also provides the capability to perform imaging with a field-of-view ≈10′×10′ (∼0.6″/px) in the complete Sloan Digital Sky Survey filter set.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140805561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large-field telescopes play a significant role in cutting-edge astronomical research fields, such as time-domain astronomy and cosmology. For such telescopes, ensuring symmetrical and uniform imaging across the entire field-of-view (FoV) is pivotal, particularly for areas such as astronomical photometry and astrometry. However, conventional image quality evaluation methods for telescope optical systems have mainly focused on imaging spot size. Other alternative methods, such as ellipticity based methods, also face the challenges of high computational requirements and limited assessment parameters. In addition, establishing a coherent link between the telescope structure and research domains such as photometry has remained a challenge. In response to these challenges, we introduce an assessment approach termed the ray tracing, spot-vector index, and angle (RSVA) approach. This approach offers a fresh perspective on optical systems, prioritizing the depiction of imaging spot shapes. It acts as a valuable supplement to traditional methods and has been effectively employed to analyze four 1-m aperture telescopes with an f-ratio of 3 for a 3 deg FoV. Building on this foundation, the RSVA can be further expanded to explore other research avenues, including exploring the interplay between photometry and telescope systems and guiding large FoV optical design.
大视场望远镜在时域天文学和宇宙学等尖端天文研究领域发挥着重要作用。对于这类望远镜来说，确保整个视场（FoV）的对称和均匀成像至关重要，尤其是在天文测光和天体测量等领域。然而，传统的望远镜光学系统图像质量评估方法主要侧重于成像光斑的大小。其他替代方法，如基于椭圆度的方法，也面临着计算要求高和评估参数有限的挑战。此外，在望远镜结构和光度测量等研究领域之间建立连贯的联系仍然是一项挑战。为了应对这些挑战，我们引入了一种评估方法，即光线跟踪、光斑矢量指数和角度（RSVA）方法。这种方法为光学系统提供了一个全新的视角，优先考虑成像光斑形状的描述。它是对传统方法的重要补充，已被有效地用于分析四台 1 米孔径的望远镜，其 f 比为 3，视场角为 3 度。在此基础上，RSVA 可以进一步扩展，探索其他研究途径，包括探索光度测量与望远镜系统之间的相互作用，以及指导大视场光学设计。
{"title":"Imaging quality evaluation method for large field-of-view telescope optical systems","authors":"Chao Chen, Zhengyang Li, Zhixu Wu, Yiming Zhang, Xiangyan Yuan","doi":"10.1117/1.jatis.10.2.025003","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.025003","url":null,"abstract":"Large-field telescopes play a significant role in cutting-edge astronomical research fields, such as time-domain astronomy and cosmology. For such telescopes, ensuring symmetrical and uniform imaging across the entire field-of-view (FoV) is pivotal, particularly for areas such as astronomical photometry and astrometry. However, conventional image quality evaluation methods for telescope optical systems have mainly focused on imaging spot size. Other alternative methods, such as ellipticity based methods, also face the challenges of high computational requirements and limited assessment parameters. In addition, establishing a coherent link between the telescope structure and research domains such as photometry has remained a challenge. In response to these challenges, we introduce an assessment approach termed the ray tracing, spot-vector index, and angle (RSVA) approach. This approach offers a fresh perspective on optical systems, prioritizing the depiction of imaging spot shapes. It acts as a valuable supplement to traditional methods and has been effectively employed to analyze four 1-m aperture telescopes with an f-ratio of 3 for a 3 deg FoV. Building on this foundation, the RSVA can be further expanded to explore other research avenues, including exploring the interplay between photometry and telescope systems and guiding large FoV optical design.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140613967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.024001
Nicholas Nell, Nicholas Kruczek, Kevin France, Stefan Ulrich, Patrick Behr, Emily Farr
The Far- and Lyman-ultraviolet imaging demonstrator (FLUID) is a rocket-borne arcsecond-level ultraviolet (UV) imaging instrument covering four bands between 92 and 193 nm. FLUID will observe nearby galaxies to find and characterize the most massive stars that are the primary drivers of the chemical and dynamical evolution of galaxies and the co-evolution of the surrounding galactic environment. The FLUID short wave channel is designed to suppress efficiency at Lyman-α (121.6 nm) while enhancing the reflectivity of shorter wavelengths. Utilizing this technology, FLUID will take the first ever images of local galaxies isolated in the Lyman UV (90–120 nm). As a pathfinder instrument, FLUID will employ and increase the technology readiness level of band-selecting UV coatings and solar-blind UV detector technologies, including microchannel plate and solid-state detectors; technologies that are prioritized in the 2022 NASA Astrophysical Biennial Technology Report. These technologies enable high throughput and high sensitivity observations in the four co-aligned UV imaging bands that make up the FLUID instrument. We present the design of FLUID, status on the technology development, and results from initial assembly and calibration of the FLUID instrument.
{"title":"Far- and Lyman-ultraviolet imaging demonstrator: a rocket-borne pathfinder instrument for high efficiency ultraviolet band selection imaging","authors":"Nicholas Nell, Nicholas Kruczek, Kevin France, Stefan Ulrich, Patrick Behr, Emily Farr","doi":"10.1117/1.jatis.10.2.024001","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.024001","url":null,"abstract":"The Far- and Lyman-ultraviolet imaging demonstrator (FLUID) is a rocket-borne arcsecond-level ultraviolet (UV) imaging instrument covering four bands between 92 and 193 nm. FLUID will observe nearby galaxies to find and characterize the most massive stars that are the primary drivers of the chemical and dynamical evolution of galaxies and the co-evolution of the surrounding galactic environment. The FLUID short wave channel is designed to suppress efficiency at Lyman-α (121.6 nm) while enhancing the reflectivity of shorter wavelengths. Utilizing this technology, FLUID will take the first ever images of local galaxies isolated in the Lyman UV (90–120 nm). As a pathfinder instrument, FLUID will employ and increase the technology readiness level of band-selecting UV coatings and solar-blind UV detector technologies, including microchannel plate and solid-state detectors; technologies that are prioritized in the 2022 NASA Astrophysical Biennial Technology Report. These technologies enable high throughput and high sensitivity observations in the four co-aligned UV imaging bands that make up the FLUID instrument. We present the design of FLUID, status on the technology development, and results from initial assembly and calibration of the FLUID instrument.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.025004
Leonid Pogorelyuk, Mason Black, Nicholas Belsten, Eleonora Polini, Jonah T. Hansen, Michael Ireland, John D. Monnier, Kerri Cahoy
Space interferometers could, in principle, exploit the relatively stable space environment and ease of baseline reconfiguration to collect measurements beyond the limitations of ground-based interferometers. In particular, a two-element interferometer could provide excellent uv-plane coverage over a few tens of low Earth orbits. One of the challenges for free-flying interferometers is controlling the optical path distance with subwavelength accuracies despite the collectors flying up to hundreds of meters apart. We consider two approaches: an artificial in-orbit laser guide star (LGS) that provides a phase reference for the space interferometer and fringe tracking on the science target itself. The two approaches (LGS versus no LGS) would require different image processing techniques. In this work, we explore image processing with LGS phase residuals due to global positioning system (GPS) uncertainties. We use GPS uncertainties from the Gravity Recovery and Climate Experiment Follow-On mission to simulate image retrieval with a 300-m baseline laser-guided space interferometer. This is done by fitting the slowly varying phase errors of complex visibility measurements. We also consider a 40-m baseline interferometer with visibility(-modulus)-only measurements. In this case, we simulate the bias in visibility due to fringe tracking in the presence of parasitic forces acting on the spacecraft. We then use a modified version of the hybrid input–output phase retrieval algorithm for image reconstruction. We conclude that under our optimistic assumptions, both approaches could enable general imaging of a few large stars even with CubeSats, although an LGS would significantly improve the best resolution obtainable.
{"title":"Space interferometer imaging limitations due to Global Positioning System uncertainties and parasitic forces in Low Earth Orbit","authors":"Leonid Pogorelyuk, Mason Black, Nicholas Belsten, Eleonora Polini, Jonah T. Hansen, Michael Ireland, John D. Monnier, Kerri Cahoy","doi":"10.1117/1.jatis.10.2.025004","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.025004","url":null,"abstract":"Space interferometers could, in principle, exploit the relatively stable space environment and ease of baseline reconfiguration to collect measurements beyond the limitations of ground-based interferometers. In particular, a two-element interferometer could provide excellent uv-plane coverage over a few tens of low Earth orbits. One of the challenges for free-flying interferometers is controlling the optical path distance with subwavelength accuracies despite the collectors flying up to hundreds of meters apart. We consider two approaches: an artificial in-orbit laser guide star (LGS) that provides a phase reference for the space interferometer and fringe tracking on the science target itself. The two approaches (LGS versus no LGS) would require different image processing techniques. In this work, we explore image processing with LGS phase residuals due to global positioning system (GPS) uncertainties. We use GPS uncertainties from the Gravity Recovery and Climate Experiment Follow-On mission to simulate image retrieval with a 300-m baseline laser-guided space interferometer. This is done by fitting the slowly varying phase errors of complex visibility measurements. We also consider a 40-m baseline interferometer with visibility(-modulus)-only measurements. In this case, we simulate the bias in visibility due to fringe tracking in the presence of parasitic forces acting on the spacecraft. We then use a modified version of the hybrid input–output phase retrieval algorithm for image reconstruction. We conclude that under our optimistic assumptions, both approaches could enable general imaging of a few large stars even with CubeSats, although an LGS would significantly improve the best resolution obtainable.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140635169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.025001
Yinzi Xin, Daniel Echeverri, Nemanja Jovanovic, Dimitri Mawet, Sergio Leon-Saval, Rodrigo Amezcua-Correa, Stephanos Yerolatsitis, Michael P. Fitzgerald, Pradip Gatkine, Yoo Jung Kim, Jonathan Lin, Barnaby Norris, Garreth Ruane, Steph Sallum
Photonic lantern nulling (PLN) is a method for enabling the detection and characterization of close-in exoplanets by exploiting the symmetries of the ports of a mode-selective photonic lantern (MSPL) to cancel out starlight. A six-port MSPL provides four ports where on-axis starlight is suppressed, while off-axis planet light is coupled with efficiencies that vary as a function of the planet’s spatial position. We characterize the properties of a six-port MSPL in the laboratory and perform the first testbed demonstration of the PLN in monochromatic light (1569 nm) and in broadband light (1450 to 1625 nm), each using two orthogonal polarizations. We compare the measured spatial throughput maps with those predicted by simulations using the lantern’s modes. We find that the morphologies of the measured throughput maps are reproduced by the simulations, though the real lantern is lossy and has lower throughputs overall. The measured ratios of on-axis stellar leakage to peak off-axis throughput are around 10−2, likely limited by testbed wavefront errors. These null-depths are already sufficient for observing young gas giants at the diffraction limit using ground-based observatories. Future work includes using wavefront control to further improve the nulls, as well as testing and validating the PLN on-sky.
{"title":"Laboratory demonstration of a Photonic Lantern Nuller in monochromatic and broadband light","authors":"Yinzi Xin, Daniel Echeverri, Nemanja Jovanovic, Dimitri Mawet, Sergio Leon-Saval, Rodrigo Amezcua-Correa, Stephanos Yerolatsitis, Michael P. Fitzgerald, Pradip Gatkine, Yoo Jung Kim, Jonathan Lin, Barnaby Norris, Garreth Ruane, Steph Sallum","doi":"10.1117/1.jatis.10.2.025001","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.025001","url":null,"abstract":"Photonic lantern nulling (PLN) is a method for enabling the detection and characterization of close-in exoplanets by exploiting the symmetries of the ports of a mode-selective photonic lantern (MSPL) to cancel out starlight. A six-port MSPL provides four ports where on-axis starlight is suppressed, while off-axis planet light is coupled with efficiencies that vary as a function of the planet’s spatial position. We characterize the properties of a six-port MSPL in the laboratory and perform the first testbed demonstration of the PLN in monochromatic light (1569 nm) and in broadband light (1450 to 1625 nm), each using two orthogonal polarizations. We compare the measured spatial throughput maps with those predicted by simulations using the lantern’s modes. We find that the morphologies of the measured throughput maps are reproduced by the simulations, though the real lantern is lossy and has lower throughputs overall. The measured ratios of on-axis stellar leakage to peak off-axis throughput are around 10−2, likely limited by testbed wavefront errors. These null-depths are already sufficient for observing young gas giants at the diffraction limit using ground-based observatories. Future work includes using wavefront control to further improve the nulls, as well as testing and validating the PLN on-sky.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.025002
Malachi Noel, Jason J. Wang, Bruce Macintosh, Katie Crotts, Christian Marois, Eric L. Nielsen, Robert J. De Rosa, Katie Scalzo, Kent Wallace
The atmospheric dispersion corrector (ADC) of the Gemini Planet Imager (GPI) corrects the chromatic dispersion caused by differential atmospheric refraction (DAR), making it an important optic for exoplanet observation. Despite requiring <5 mas of residual DAR to avoid potentially affecting the coronagraph, the GPI ADC averages ∼7 and ∼11 mas of residual DAR in H and J band, respectively. We analyzed GPI data in those bands to find explanations for the underperformance. We found the model GPI uses to predict DAR underestimates humidity’s impact on incident DAR, causing on average a 0.54 mas increase in H band residual DAR. Additionally, the GPI ADC consistently undercorrects in H band by about 7 mas, causing almost all the H band residual DAR. J band does not have such an offset. Perpendicular dispersion induced by the GPI ADC, potentially from a misalignment in the prisms’ relative orientation, causes 86% of the residual DAR in J band. Correcting these issues could reduce residual DAR, thereby improving exoplanet detection. We also made an approximation for the index of refraction of air from 0.7 to 1.36 microns that more accurately accounts for the effects of humidity.
双子座行星成像仪（GPI）的大气色散校正器（ADC）可以校正由大气折射差（DAR）引起的色散，是观测系外行星的重要光学设备。尽管为了避免对日冕仪造成潜在影响，要求残余 DAR 小于 5mas，但 GPI ADC 在 H 波段和 J 波段的平均残余 DAR 分别为 7mas 和 11mas 。我们对这些波段的 GPI 数据进行了分析，以找出性能不佳的原因。我们发现，GPI用来预测DAR的模型低估了湿度对入射DAR的影响，导致H波段的残余DAR平均增加了0.54mas。此外，GPI ADC 在 H 波段的校正一直不足约 7mas，导致几乎所有 H 波段的残余 DAR。J 波段则没有这种偏移。GPI ADC 引起的垂直色散（可能是棱镜相对方向的偏差）造成了 J 波段 86% 的残余 DAR。纠正这些问题可以减少残余 DAR，从而改进系外行星探测。我们还对 0.7 至 1.36 微米的空气折射率进行了近似，以更准确地考虑湿度的影响。
{"title":"Analyzing the atmospheric dispersion correction of the Gemini Planet Imager: residual dispersion above design requirements","authors":"Malachi Noel, Jason J. Wang, Bruce Macintosh, Katie Crotts, Christian Marois, Eric L. Nielsen, Robert J. De Rosa, Katie Scalzo, Kent Wallace","doi":"10.1117/1.jatis.10.2.025002","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.025002","url":null,"abstract":"The atmospheric dispersion corrector (ADC) of the Gemini Planet Imager (GPI) corrects the chromatic dispersion caused by differential atmospheric refraction (DAR), making it an important optic for exoplanet observation. Despite requiring <5 mas of residual DAR to avoid potentially affecting the coronagraph, the GPI ADC averages ∼7 and ∼11 mas of residual DAR in H and J band, respectively. We analyzed GPI data in those bands to find explanations for the underperformance. We found the model GPI uses to predict DAR underestimates humidity’s impact on incident DAR, causing on average a 0.54 mas increase in H band residual DAR. Additionally, the GPI ADC consistently undercorrects in H band by about 7 mas, causing almost all the H band residual DAR. J band does not have such an offset. Perpendicular dispersion induced by the GPI ADC, potentially from a misalignment in the prisms’ relative orientation, causes 86% of the residual DAR in J band. Correcting these issues could reduce residual DAR, thereby improving exoplanet detection. We also made an approximation for the index of refraction of air from 0.7 to 1.36 microns that more accurately accounts for the effects of humidity.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.026003
Jared E. Fuchs, Peter Veres, Michael S. Briggs, Peter Jenke
The study of gamma-ray burst (GRB) jets has focused predominantly on the gamma-ray portion of the spectral energy distribution (SED) to understand jet properties and their physics. Recent theoretical development has turned to the lower-energy side of the SED to test competing jet models. We considered the application of wide-field X-ray detectors to extend the observation of the SED and for better distinguishing spectral models, aimed at resolving theoretical features existing at or below the sensitivity of missions such as Fermi and Swift. A proposed SmallSat reference mission is introduced, and analysis is conducted on simulated GRBs to determine its improvement in understanding the SED compared with the Fermi-gamma-ray burst monitor (GBM). Detection rates of the reference mission are simulated using a GRB population model and convolved with the energy flux needed to resolve models to find estimated rates of GRBs that the reference mission can resolve better than Fermi-GBM. We discuss the methods and results along with the scientific context for this type of mission.
对伽马射线暴（GRB）喷流的研究主要集中在光谱能量分布（SED）的伽马射线部分，以了解喷流的特性及其物理学原理。最近的理论发展转向了 SED 的低能量部分，以测试相互竞争的喷流模型。我们考虑应用宽视场 X 射线探测器来扩大 SED 的观测范围，并更好地区分光谱模型，目的是解决费米和雨燕等飞行任务灵敏度或低于灵敏度时存在的理论特征。介绍了拟议的小卫星参考任务，并对模拟的 GRB 进行了分析，以确定与费米-伽马射线暴监测器（GBM）相比，小卫星在理解 SED 方面的改进。利用 GRB 群体模型模拟参考任务的探测率，并与解析模型所需的能量通量相联系，以找到参考任务能比 Fermi-GBM 更好地解析 GRB 的估计率。我们将讨论这些方法和结果以及这类任务的科学背景。
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Complementary metal-oxide-semiconductor (CMOS) detectors are a competitive choice for current and upcoming astronomical missions. To understand the performance variations of CMOS detectors in the space environment, we investigate the total ionizing dose effects on custom-made large-format X-ray CMOS detectors. Three CMOS detector samples were irradiated with a Co60 source with a total dose of 70 and 105 krad. We test and compare the performance of these detectors before and after irradiation. After irradiation, the dark current increases by roughly 20∼100 times, and the readout noise increases from 3 e− to 6 e−. The bias level at 50 ms integration time decreases by 13 to 18 digital number (DN) at −30°C. The energy resolution increases from ∼150 to ∼170 eV at 4.5 keV at −30°C. The conversion gain of the detectors varies for <2% after the irradiation. Furthermore, there are about 50 pixels in which bias at 50 ms has changed by more than 20 DN after the exposure to the radiation and about 30 to 140 pixels in which the readout noise has increased by over 20 e− at −30°C at 50 ms integration time. These results demonstrate that the performances of large-format CMOS detectors do not suffer significant degeneration in space environment.
{"title":"Radiation effects on scientific complementary metal-oxide-semiconductor detectors for x-ray astronomy: II. Total ionizing dose irradiation","authors":"Mengxi Chen, Zhixing Ling, Mingjun Liu, Qinyu Wu, Chen Zhang, Jiaqiang Liu, Zhenlong Zhang, Weimin Yuan, Shuang-Nan Zhang","doi":"10.1117/1.jatis.10.2.026001","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.026001","url":null,"abstract":"Complementary metal-oxide-semiconductor (CMOS) detectors are a competitive choice for current and upcoming astronomical missions. To understand the performance variations of CMOS detectors in the space environment, we investigate the total ionizing dose effects on custom-made large-format X-ray CMOS detectors. Three CMOS detector samples were irradiated with a Co60 source with a total dose of 70 and 105 krad. We test and compare the performance of these detectors before and after irradiation. After irradiation, the dark current increases by roughly 20∼100 times, and the readout noise increases from 3 e− to 6 e−. The bias level at 50 ms integration time decreases by 13 to 18 digital number (DN) at −30°C. The energy resolution increases from ∼150 to ∼170 eV at 4.5 keV at −30°C. The conversion gain of the detectors varies for <2% after the irradiation. Furthermore, there are about 50 pixels in which bias at 50 ms has changed by more than 20 DN after the exposure to the radiation and about 30 to 140 pixels in which the readout noise has increased by over 20 e− at −30°C at 50 ms integration time. These results demonstrate that the performances of large-format CMOS detectors do not suffer significant degeneration in space environment.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1117/1.jatis.10.2.028001
Marcelo Tala Pinto, Adrian Kaminski, Andreas Quirrenbach, Mathias Zechmeister
We present moes, a ray tracing software package that computes the path of rays through echelle spectrographs. Our algorithm is based on sequential direct tracing with Seidel aberration corrections applied at the detector plane. As a test case, we model the CARMENES VIS spectrograph. After subtracting the best model from the data, the residuals yield an rms of 0.024 pix, setting a new standard for the precision of the wavelength solution of state-of-the-art radial velocity (RV) instruments. By including the influence of the changes of the environment in ray propagation, we are able to predict instrumental RV systematics at the 1 m/s level.
我们介绍的 moes 是一款光线跟踪软件包，可计算光线通过埃歇尔摄谱仪的路径。我们的算法基于顺序直接追踪，并在探测器平面应用塞德尔像差校正。作为测试案例，我们对 CARMENES VIS 摄谱仪进行了建模。从数据中减去最佳模型后，残差的均方根值为 0.024 像素，为最先进的径向速度（RV）仪器的波长解算精度设定了新标准。通过将射线传播中环境变化的影响考虑在内，我们能够预测 1 米/秒级别的仪器径向速度系统性。
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