Pub Date : 2024-05-09DOI: 10.1088/1538-3873/ad357c
Antonio C. Rodriguez
Galactic X-ray sources are diverse, ranging from active M dwarfs to compact object binaries, and everything in between. The X-ray landscape of today is rich, with point source catalogs such as those from XMM-Newton, Chandra, and Swift, each with ≳105 sources and growing. Furthermore, X-ray astronomy is on the verge of being transformed through data releases from the all-sky SRG/eROSITA survey. Many X-ray sources can be associated with an optical counterpart, which in the era of Gaia, can be determined to be Galactic or extragalactic through parallax and proper motion information. Here, I present a simple diagram—the “X-ray Main Sequence,” which distinguishes between compact objects and active stars based on their optical color and X-ray-to-optical flux ratio (FX/Fopt). As a proof of concept, I present optical spectroscopy of six exotic accreting WDs discovered using the X-ray Main Sequence as applied to the XMM-Newton catalog. Looking ahead to surveys of the near future, I additionally present SDSS-V optical spectroscopy of new systems discovered using the X-ray Main Sequence as applied to the SRG/eROSITA eFEDS catalog.
银河系的 X 射线源多种多样，从活跃的 M 矮星到紧凑的天体双星，以及介于两者之间的所有天体。当今的 X 射线天文资源非常丰富，有来自 XMM-牛顿、钱德拉和 Swift 的点源目录，每个目录都有≳105 个源，而且还在不断增加。此外，通过全天空 SRG/eROSITA 勘测发布的数据，X 射线天文学即将发生转变。许多 X 射线源都可以与光学对应源联系起来，在盖亚时代，光学对应源可以通过视差和适当运动信息确定是银河系还是河外星系。在这里，我介绍一个简单的图表--"X 射线主序"，它可以根据光学颜色和 X 射线光通量比（FX/Fopt）来区分紧凑天体和活动恒星。作为概念验证，我介绍了利用 X 射线主序列发现的六颗奇异吸积型 WD 的光学光谱，并将其应用于 XMM 牛顿星表。展望不久的将来的巡天观测，我还将介绍利用X射线主序发现的新系统的SDSS-V光学光谱，并将其应用到SRG/eROSITA eFEDS星表中。
{"title":"From Active Stars to Black Holes: A Discovery Tool for Galactic X-Ray Sources","authors":"Antonio C. Rodriguez","doi":"10.1088/1538-3873/ad357c","DOIUrl":"https://doi.org/10.1088/1538-3873/ad357c","url":null,"abstract":"Galactic X-ray sources are diverse, ranging from active M dwarfs to compact object binaries, and everything in between. The X-ray landscape of today is rich, with point source catalogs such as those from XMM-Newton, Chandra, and Swift, each with ≳105 sources and growing. Furthermore, X-ray astronomy is on the verge of being transformed through data releases from the all-sky SRG/eROSITA survey. Many X-ray sources can be associated with an optical counterpart, which in the era of Gaia, can be determined to be Galactic or extragalactic through parallax and proper motion information. Here, I present a simple diagram—the “X-ray Main Sequence,” which distinguishes between compact objects and active stars based on their optical color and X-ray-to-optical flux ratio (FX/Fopt). As a proof of concept, I present optical spectroscopy of six exotic accreting WDs discovered using the X-ray Main Sequence as applied to the XMM-Newton catalog. Looking ahead to surveys of the near future, I additionally present SDSS-V optical spectroscopy of new systems discovered using the X-ray Main Sequence as applied to the SRG/eROSITA eFEDS catalog.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"19 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-08DOI: 10.1088/1538-3873/ace6d9
S. R. Kulkarni, Charles Beichman, Michael E. Ressler
The Warm Ionized Medium (WIM) hosts most of the ionized gas in the Galaxy and occupies perhaps a quarter of the volume of the Galactic disk. Decoding the spectrum of the Galactic diffuse ionizing field is of fundamental interest. This can be done via direct measurements of ionization fractions of various elements. Based on current physical models for the WIM we predicted that mid-IR fine structure lines of Ne, Ar and S would be within the grasp of the Mid-Infrared Imager-Medium Resolution Spectrometer (MIRI-MRS), an Integral Field Unit (IFU) spectrograph, aboard the James Webb Space Telescope (JWST). Motivated thus we analyzed a pair of commissioning data sets and detected [Ne ii] 12.81 μm, [S iii] 18.71 μm and possibly [S iv] 10.51 μm. The inferred emission measure for these detections is about 10 cm−6 pc, typical of the WIM. These detections are broadly consistent with expectations of physical models for the WIM. The current detections are limited by uncorrected fringing (and to a lesser extent by baseline variations). In due course, we expect, as with other IFUs, the calibration pipeline to deliver photon-noise-limited spectra. The detections reported here bode well for the study of the WIM. Along most lines-of-sight hour-long MIRI-MRS observations should detect line emission from the WIM. When combined with optical observations by modern IFUs with high spectral resolution on large ground-based telescopes, the ionization fraction and temperature of neon and sulfur can be robustly inferred. Separately, the ionization of helium in the WIM can be probed by NIRspec. Finally, joint JWST and optical IFU studies will open up a new cottage industry of studying the WIM on arcsecond scales.
{"title":"Mid-infrared Fine Structure Lines from the Galactic Warm Ionized Medium","authors":"S. R. Kulkarni, Charles Beichman, Michael E. Ressler","doi":"10.1088/1538-3873/ace6d9","DOIUrl":"https://doi.org/10.1088/1538-3873/ace6d9","url":null,"abstract":"The Warm Ionized Medium (WIM) hosts most of the ionized gas in the Galaxy and occupies perhaps a quarter of the volume of the Galactic disk. Decoding the spectrum of the Galactic diffuse ionizing field is of fundamental interest. This can be done via direct measurements of ionization fractions of various elements. Based on current physical models for the WIM we predicted that mid-IR fine structure lines of Ne, Ar and S would be within the grasp of the Mid-Infrared Imager-Medium Resolution Spectrometer (MIRI-MRS), an Integral Field Unit (IFU) spectrograph, aboard the James Webb Space Telescope (JWST). Motivated thus we analyzed a pair of commissioning data sets and detected [Ne <sc>ii</sc>] 12.81 <italic toggle=\"yes\">μ</italic>m, [S <sc>iii</sc>] 18.71 <italic toggle=\"yes\">μ</italic>m and possibly [S <sc>iv</sc>] 10.51 <italic toggle=\"yes\">μ</italic>m. The inferred emission measure for these detections is about 10 cm<sup>−6</sup> pc, typical of the WIM. These detections are broadly consistent with expectations of physical models for the WIM. The current detections are limited by uncorrected fringing (and to a lesser extent by baseline variations). In due course, we expect, as with other IFUs, the calibration pipeline to deliver photon-noise-limited spectra. The detections reported here bode well for the study of the WIM. Along most lines-of-sight hour-long MIRI-MRS observations should detect line emission from the WIM. When combined with optical observations by modern IFUs with high spectral resolution on large ground-based telescopes, the ionization fraction and temperature of neon and sulfur can be robustly inferred. Separately, the ionization of helium in the WIM can be probed by NIRspec. Finally, joint JWST and optical IFU studies will open up a new cottage industry of studying the WIM on arcsecond scales.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"187 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-05DOI: 10.1088/1538-3873/ad3f4f
Gu Lim, Dohyeong Kim, Seonghun Lim, Myungshin Im, Hyeonho Choi, Jaemin Park, Keun-Hong Park, Junyeong Park, Chaudhary Muskaan, Donghyun Kim and Hayeong Jeong
We introduce a 0.7 m telescope system at the Miryang Arirang Astronomical Observatory (MAAO), a public observatory in Miryang, Korea. System integration and a scheduling program enable the 0.7 m telescope system to operate completely robotically during nighttime, eliminating the need for human intervention. Using the 0.7 m telescope system, we obtain atmospheric extinction coefficients and the zero-point magnitudes by observing standard stars. As a result, we find that atmospheric extinctions are moderate but they can sometimes increase depending on the weather conditions. The measured 5σ limiting magnitudes reach down to BVRI = 19.4–19.6 AB mag for a point source with a total integrated time of 10 minutes under clear weather conditions, demonstrating comparable performance with other observational facilities operating under similar specifications and sky conditions. We expect that the newly established MAAO 0.7 m telescope system will contribute significantly to the observational studies of astronomy. Particularly, with its capability for robotic observations, this system, although its primary duty is for public viewing, can be extensively used for the time-series observation of transients.
{"title":"The Robotic MAAO 0.7 m Telescope System: Performance and Standard Photometric System","authors":"Gu Lim, Dohyeong Kim, Seonghun Lim, Myungshin Im, Hyeonho Choi, Jaemin Park, Keun-Hong Park, Junyeong Park, Chaudhary Muskaan, Donghyun Kim and Hayeong Jeong","doi":"10.1088/1538-3873/ad3f4f","DOIUrl":"https://doi.org/10.1088/1538-3873/ad3f4f","url":null,"abstract":"We introduce a 0.7 m telescope system at the Miryang Arirang Astronomical Observatory (MAAO), a public observatory in Miryang, Korea. System integration and a scheduling program enable the 0.7 m telescope system to operate completely robotically during nighttime, eliminating the need for human intervention. Using the 0.7 m telescope system, we obtain atmospheric extinction coefficients and the zero-point magnitudes by observing standard stars. As a result, we find that atmospheric extinctions are moderate but they can sometimes increase depending on the weather conditions. The measured 5σ limiting magnitudes reach down to BVRI = 19.4–19.6 AB mag for a point source with a total integrated time of 10 minutes under clear weather conditions, demonstrating comparable performance with other observational facilities operating under similar specifications and sky conditions. We expect that the newly established MAAO 0.7 m telescope system will contribute significantly to the observational studies of astronomy. Particularly, with its capability for robotic observations, this system, although its primary duty is for public viewing, can be extensively used for the time-series observation of transients.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"17 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140882287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-28DOI: 10.1088/1538-3873/ad3eb2
Fang Wang
Capturing the characteristics of exoplanetary atmospheres (CEA) through transit spectroscopy (TS) holds profound implications for our understanding of planetary formation and evolution. However, TS, the method employed for detecting CEA, indirectly extracts these characteristics from the subtle variations in stellar spectra during the transit process, necessitating a high level of observational stability in optical instrumentation. To mitigate observational errors in spectral energy within the optical system, this dissertation delves into the optimal design of a high-stability optical system tailored for atmospheric spectra in transit observations. Initially, a theoretical model of transit signal-to-noise ratios (S/Ns) catered to the EAC retrievals is formulated based on transit observation strategies. Subsequently, the optimal parameters and design approach for the optical system are explored through an analysis of the optical factors influencing S/N. Leveraging an observation simulator for optical instruments, the detection feasibility of the optimized optical system for capturing CEA is validated.
通过凌日光谱（TS）捕捉系外行星大气（CEA）的特征对我们了解行星的形成和演化具有深远的意义。然而，TS 是用于探测 CEA 的方法，它间接地从凌日过程中恒星光谱的微妙变化中提取这些特征，这就要求光学仪器具有高度的观测稳定性。为了减少光学系统内光谱能量的观测误差，本论文深入研究了在凌日观测中为大气光谱量身定制的高稳定性光学系统的优化设计。首先，根据凌日观测策略，建立了一个适合 EAC 检索的凌日信噪比（S/N）理论模型。随后，通过分析影响信噪比的光学因素，探讨了光学系统的最佳参数和设计方法。利用光学仪器观测模拟器，验证了捕捉 CEA 的优化光学系统的探测可行性。
{"title":"Research on the Optimal Design of the High-stability Optical System for Atmospheric Spectra in Transit Observation","authors":"Fang Wang","doi":"10.1088/1538-3873/ad3eb2","DOIUrl":"https://doi.org/10.1088/1538-3873/ad3eb2","url":null,"abstract":"Capturing the characteristics of exoplanetary atmospheres (CEA) through transit spectroscopy (TS) holds profound implications for our understanding of planetary formation and evolution. However, TS, the method employed for detecting CEA, indirectly extracts these characteristics from the subtle variations in stellar spectra during the transit process, necessitating a high level of observational stability in optical instrumentation. To mitigate observational errors in spectral energy within the optical system, this dissertation delves into the optimal design of a high-stability optical system tailored for atmospheric spectra in transit observations. Initially, a theoretical model of transit signal-to-noise ratios (S/Ns) catered to the EAC retrievals is formulated based on transit observation strategies. Subsequently, the optimal parameters and design approach for the optical system are explored through an analysis of the optical factors influencing S/N. Leveraging an observation simulator for optical instruments, the detection feasibility of the optimized optical system for capturing CEA is validated.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"75 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140809756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1088/1538-3873/ad34fd
Taylor A. Hutchison, Brian D. Welch, Jane R. Rigby, Grace M. Olivier, Jack E. Birkin, Kedar A. Phadke, Gourav Khullar, Bernard J. Rauscher, Keren Sharon, Manuel Aravena, Matthew B. Bayliss, Lauren A. Elicker, Seonwoo Kim, Manuel Solimano, Joaquin D. Vieira, David Vizgan and On Behalf of the JWST TEMPLATES Early Release Science Team
We describe a custom outlier rejection algorithm for JWST/NIRSpec integral field spectroscopy. This method uses a layered sigma clipping approach that adapts clipping thresholds based upon the spatial profile of the science target. We find that this algorithm produces a robust outlier rejection while simultaneously preserving the signal of the science target. Originally developed as a response to unsatisfactory initial performance of the jwst pipeline outlier detection step, this method works either as a standalone solution, or as a supplement to the current pipeline software. Comparing leftover (i.e., not flagged) artifacts with the current pipeline’s outlier detection step, we find that our method results in one fifth as many residual artifacts as the jwst pipeline. However, we find a combination of both methods removes nearly all artifacts—an approach that takes advantage of both our algorithm’s robust outlier rejection and the pipeline’s use of individual dithers. This combined approach is what the TEMPLATES Early Release Science team has converged upon for our NIRSpec observations. Finally, we publicly release the code and Jupyter notebooks for the custom outlier rejection algorithm.
{"title":"TEMPLATES: A Robust Outlier Rejection Method for JWST/NIRSpec Integral Field Spectroscopy","authors":"Taylor A. Hutchison, Brian D. Welch, Jane R. Rigby, Grace M. Olivier, Jack E. Birkin, Kedar A. Phadke, Gourav Khullar, Bernard J. Rauscher, Keren Sharon, Manuel Aravena, Matthew B. Bayliss, Lauren A. Elicker, Seonwoo Kim, Manuel Solimano, Joaquin D. Vieira, David Vizgan and On Behalf of the JWST TEMPLATES Early Release Science Team","doi":"10.1088/1538-3873/ad34fd","DOIUrl":"https://doi.org/10.1088/1538-3873/ad34fd","url":null,"abstract":"We describe a custom outlier rejection algorithm for JWST/NIRSpec integral field spectroscopy. This method uses a layered sigma clipping approach that adapts clipping thresholds based upon the spatial profile of the science target. We find that this algorithm produces a robust outlier rejection while simultaneously preserving the signal of the science target. Originally developed as a response to unsatisfactory initial performance of the jwst pipeline outlier detection step, this method works either as a standalone solution, or as a supplement to the current pipeline software. Comparing leftover (i.e., not flagged) artifacts with the current pipeline’s outlier detection step, we find that our method results in one fifth as many residual artifacts as the jwst pipeline. However, we find a combination of both methods removes nearly all artifacts—an approach that takes advantage of both our algorithm’s robust outlier rejection and the pipeline’s use of individual dithers. This combined approach is what the TEMPLATES Early Release Science team has converged upon for our NIRSpec observations. Finally, we publicly release the code and Jupyter notebooks for the custom outlier rejection algorithm.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"101 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140805839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-16DOI: 10.1088/1538-3873/ad3122
Lindsay M. Berkhout, Daniel C. Jacobs, Zuhra Abdurashidova, Tyrone Adams, James E. Aguirre, Paul Alexander, Zaki S. Ali, Rushelle Baartman, Yanga Balfour, Adam P. Beardsley, Gianni Bernardi, Tashalee S. Billings, Judd D. Bowman, Richard F. Bradley, Philip Bull, Jacob Burba, Ruby Byrne, Steven Carey, Chris L. Carilli, Kai-Feng Chen, Carina Cheng, Samir Choudhuri, David R. DeBoer, Eloy de Lera Acedo, Matt Dexter, Joshua S. Dillon, Scott Dynes, Nico Eksteen, John Ely, Aaron Ewall-Wice, Nicolas Fagnoni, Randall Fritz, Steven R. Furlanetto, Kingsley Gale-Sides, Hugh Garsden, Bharat Kumar Gehlot, Abhik Ghosh, Brian Glendenning, Adelie Gorce, Deepthi Gorthi, Bradley Greig, Jasper Grobbelaar, Ziyaad Halday, Bryna J. Hazelton, Jacqueline N. Hewitt, Jack Hickish, Tian Huang, Alec Josaitis, Austin Julius, MacCalvin Kariseb, Nicholas S. Kern, Joshua Kerrigan, Honggeun Kim, Piyanat Kittiwisit, Saul A. Kohn, Matthew Kolopanis, Adam Lanman, Paul La Plante, Adrian Liu, Anita Loots, Yin-Zhe Ma, David Harold Edward MacMahon, Lourence Malan, Cresshim Malgas, Keith Malgas, Bradley Marero, Zachary E. Martinot, Andrei Mesinger, Mathakane Molewa, Miguel F. Morales, Tshegofalang Mosiane, Steven G. Murray, Abraham R. Neben, Bojan Nikolic, Chuneeta Devi Nunhokee, Hans Nuwegeld, Aaron R. Parsons, Robert Pascua, Nipanjana Patra, Samantha Pieterse, Yuxiang Qin, Eleanor Rath, Nima Razavi-Ghods, Daniel Riley, James Robnett, Kathryn Rosie, Mario G. Santos, Peter Sims, Saurabh Singh, Dara Storer, Hilton Swarts, Jianrong Tan, Nithyanandan Thyagarajan, Pieter van Wyngaarden, Peter K. G. Williams, Haoxuan Zheng, Zhilei Xu
This paper presents the design and deployment of the Hydrogen Epoch of Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements of the Epoch of Reionization. First results from the phase I array are published as of early 2022, and deployment of the phase II system is nearing completion. We describe the design of the phase II system and discuss progress on commissioning and future upgrades. As HERA is a designated Square Kilometre Array pathfinder instrument, we also show a number of “case studies” that investigate systematics seen while commissioning the phase II system, which may be of use in the design and operation of future arrays. Common pathologies are likely to manifest in similar ways across instruments, and many of these sources of contamination can be mitigated once the source is identified.
{"title":"Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning","authors":"Lindsay M. Berkhout, Daniel C. Jacobs, Zuhra Abdurashidova, Tyrone Adams, James E. Aguirre, Paul Alexander, Zaki S. Ali, Rushelle Baartman, Yanga Balfour, Adam P. Beardsley, Gianni Bernardi, Tashalee S. Billings, Judd D. Bowman, Richard F. Bradley, Philip Bull, Jacob Burba, Ruby Byrne, Steven Carey, Chris L. Carilli, Kai-Feng Chen, Carina Cheng, Samir Choudhuri, David R. DeBoer, Eloy de Lera Acedo, Matt Dexter, Joshua S. Dillon, Scott Dynes, Nico Eksteen, John Ely, Aaron Ewall-Wice, Nicolas Fagnoni, Randall Fritz, Steven R. Furlanetto, Kingsley Gale-Sides, Hugh Garsden, Bharat Kumar Gehlot, Abhik Ghosh, Brian Glendenning, Adelie Gorce, Deepthi Gorthi, Bradley Greig, Jasper Grobbelaar, Ziyaad Halday, Bryna J. Hazelton, Jacqueline N. Hewitt, Jack Hickish, Tian Huang, Alec Josaitis, Austin Julius, MacCalvin Kariseb, Nicholas S. Kern, Joshua Kerrigan, Honggeun Kim, Piyanat Kittiwisit, Saul A. Kohn, Matthew Kolopanis, Adam Lanman, Paul La Plante, Adrian Liu, Anita Loots, Yin-Zhe Ma, David Harold Edward MacMahon, Lourence Malan, Cresshim Malgas, Keith Malgas, Bradley Marero, Zachary E. Martinot, Andrei Mesinger, Mathakane Molewa, Miguel F. Morales, Tshegofalang Mosiane, Steven G. Murray, Abraham R. Neben, Bojan Nikolic, Chuneeta Devi Nunhokee, Hans Nuwegeld, Aaron R. Parsons, Robert Pascua, Nipanjana Patra, Samantha Pieterse, Yuxiang Qin, Eleanor Rath, Nima Razavi-Ghods, Daniel Riley, James Robnett, Kathryn Rosie, Mario G. Santos, Peter Sims, Saurabh Singh, Dara Storer, Hilton Swarts, Jianrong Tan, Nithyanandan Thyagarajan, Pieter van Wyngaarden, Peter K. G. Williams, Haoxuan Zheng, Zhilei Xu","doi":"10.1088/1538-3873/ad3122","DOIUrl":"https://doi.org/10.1088/1538-3873/ad3122","url":null,"abstract":"This paper presents the design and deployment of the Hydrogen Epoch of Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements of the Epoch of Reionization. First results from the phase I array are published as of early 2022, and deployment of the phase II system is nearing completion. We describe the design of the phase II system and discuss progress on commissioning and future upgrades. As HERA is a designated Square Kilometre Array pathfinder instrument, we also show a number of “case studies” that investigate systematics seen while commissioning the phase II system, which may be of use in the design and operation of future arrays. Common pathologies are likely to manifest in similar ways across instruments, and many of these sources of contamination can be mitigated once the source is identified.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"302 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140611001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-11DOI: 10.1088/1538-3873/ad2865
Edgar Marrufo Villalpando, Alex Drlica-Wagner, Andrés A. Plazas Malagón, Abhishek Bakshi, Marco Bonati, Julia Campa, Braulio Cancino, Claudio R. Chavez, Juan Estrada, Guillermo Fernandez Moroni, Luciano Fraga, Manuel E. Gaido, Stephen Holland, Rachel Hur, Michelle Jonas, Peter Moore, Javier Tiffenberg
We present results from the characterization and optimization of Skipper charge-coupled devices (CCDs) for use in a focal plane prototype for the Southern Astrophysical Research Integral Field Spectrograph (SIFS). We tested eight Skipper CCDs and selected six for SIFS based on performance results. The Skipper CCDs are 6k × 1k, 15 μm pixels, thick, fully depleted, p-channel devices that have been thinned to ∼250 μm, backside processed, and treated with an anti-reflective coating. We demonstrate a single-sample readout noise of <4.3 e− rms pixel−1 in all amplifiers. We optimize the readout sequence timing to achieve a readout noise of 0.5 e− rms pixel−1 after 74 non-destructive measurements, which can be accomplished in a region covering 5% of the detector area in a readout time of <4 minutes. We demonstrate single-photon-counting in all 24 amplifiers (four amplifiers per detector) with a readnoise of σN ∼ 0.18 e− rms pixel−1 after Nsamp = 400 samples, and we constrain the degree of nonlinearity to be ≲1% at low signal levels (0 e− to 50 e−). Clock-induced charge (CIC) remains an important issue when the Skipper CCD is configured to provide a large full-well capacity. We achieve a CIC rate of <1.45 × 10−3 e− pixel−1 frame−1 for a full-well capacity of ∼900 e−, which increases to a CIC rate of ∼3 e− pixel−1 frame−1 for full-well capacities ∼40,000–65,000 e−. We also perform conventional CCD characterization measurements such as charge transfer inefficiency (3.44 × 10−7 on average), dark current (∼2 × 10−4 e− pixel−1 s−1), photon transfer curves, cosmetic defects (<0.45% “bad” pixels), and charge diffusion (point-spread function < 7.5 μm) to verify that these properties are consistent with expectations from conventional p-channel CCDs used for astronomy. Furthermore, we provide the first measurements of the brighter-fatter effect and absolute quantum efficiency (≳80% between 450 and 980 nm; ≳90% between 600 and 900 nm) using Skipper CCDs.
{"title":"Characterization and Optimization of Skipper CCDs for the SOAR Integral Field Spectrograph","authors":"Edgar Marrufo Villalpando, Alex Drlica-Wagner, Andrés A. Plazas Malagón, Abhishek Bakshi, Marco Bonati, Julia Campa, Braulio Cancino, Claudio R. Chavez, Juan Estrada, Guillermo Fernandez Moroni, Luciano Fraga, Manuel E. Gaido, Stephen Holland, Rachel Hur, Michelle Jonas, Peter Moore, Javier Tiffenberg","doi":"10.1088/1538-3873/ad2865","DOIUrl":"https://doi.org/10.1088/1538-3873/ad2865","url":null,"abstract":"We present results from the characterization and optimization of Skipper charge-coupled devices (CCDs) for use in a focal plane prototype for the Southern Astrophysical Research Integral Field Spectrograph (SIFS). We tested eight Skipper CCDs and selected six for SIFS based on performance results. The Skipper CCDs are 6k × 1k, 15 <italic toggle=\"yes\">μ</italic>m pixels, thick, fully depleted, <italic toggle=\"yes\">p</italic>-channel devices that have been thinned to ∼250 <italic toggle=\"yes\">μ</italic>m, backside processed, and treated with an anti-reflective coating. We demonstrate a single-sample readout noise of <4.3 e<sup>−</sup> rms pixel<sup>−1</sup> in all amplifiers. We optimize the readout sequence timing to achieve a readout noise of 0.5 e<sup>−</sup> rms pixel<sup>−1</sup> after 74 non-destructive measurements, which can be accomplished in a region covering 5% of the detector area in a readout time of <4 minutes. We demonstrate single-photon-counting in all 24 amplifiers (four amplifiers per detector) with a readnoise of <italic toggle=\"yes\">σ</italic>\u0000<sub>\u0000<italic toggle=\"yes\">N</italic>\u0000</sub> ∼ 0.18 e<sup>−</sup> rms pixel<sup>−1</sup> after <italic toggle=\"yes\">N</italic>\u0000<sub>samp</sub> = 400 samples, and we constrain the degree of nonlinearity to be ≲1% at low signal levels (0 e<sup>−</sup> to 50 e<sup>−</sup>). Clock-induced charge (CIC) remains an important issue when the Skipper CCD is configured to provide a large full-well capacity. We achieve a CIC rate of <1.45 × 10<sup>−3</sup> e<sup>−</sup> pixel<sup>−1</sup> frame<sup>−1</sup> for a full-well capacity of ∼900 e<sup>−</sup>, which increases to a CIC rate of ∼3 e<sup>−</sup> pixel<sup>−1</sup> frame<sup>−1</sup> for full-well capacities ∼40,000–65,000 e<sup>−</sup>. We also perform conventional CCD characterization measurements such as charge transfer inefficiency (3.44 × 10<sup>−7</sup> on average), dark current (∼2 × 10<sup>−4</sup> e<sup>−</sup> pixel<sup>−1</sup> s<sup>−1</sup>), photon transfer curves, cosmetic defects (<0.45% “bad” pixels), and charge diffusion (point-spread function < 7.5 <italic toggle=\"yes\">μ</italic>m) to verify that these properties are consistent with expectations from conventional <italic toggle=\"yes\">p</italic>-channel CCDs used for astronomy. Furthermore, we provide the first measurements of the brighter-fatter effect and absolute quantum efficiency (≳80% between 450 and 980 nm; ≳90% between 600 and 900 nm) using Skipper CCDs.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"10 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140610872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-08DOI: 10.1088/1538-3873/ad2f4f
Varoujan Gorjian, Steven Levin, John Arballo, Virisha Timmaraju, Ryan Dorcey, Nancy Kreuser-Jenkins, Lisa Lamb, Joseph Lazio, Zoe Webb-Mack
This paper reports the results from a student-led Search for Extraterrestrial Intelligence (SETI), also known as technosignatures, targeting the plane of the Milky Way as a part of the Goldstone Apple Valley Radio Telescope (GAVRT) collaboration between the Lewis Center for Educational Research (LCER) and the Jet Propulsion Laboratory. Students associated with LCER submit analytic reports of spectral data targeting specific regions of the Milky Way, identifying interference, noise, and Candidate signals potentially originating from intelligent sources. GAVRT-SETI's search is guided by the assumption that a narrow-band radio signal (<1.5 Hz) from a fixed location in the sky, occurring across multiple observation periods, is unlikely to be caused by instrument noise or by a natural source. Thus, we searched the reported data for similar signals occurring during different observation periods within the same region of sky. No such signals were found. However, our analysis of the frequency distribution of Candidates suggests that at least a few percent of the Candidates are associated with low-level radio-frequency interference.
{"title":"The Goldstone Apple Valley Radio Telescope (GAVRT) Search for Extra Terrestrial Intelligence (SETI)","authors":"Varoujan Gorjian, Steven Levin, John Arballo, Virisha Timmaraju, Ryan Dorcey, Nancy Kreuser-Jenkins, Lisa Lamb, Joseph Lazio, Zoe Webb-Mack","doi":"10.1088/1538-3873/ad2f4f","DOIUrl":"https://doi.org/10.1088/1538-3873/ad2f4f","url":null,"abstract":"This paper reports the results from a student-led Search for Extraterrestrial Intelligence (SETI), also known as technosignatures, targeting the plane of the Milky Way as a part of the Goldstone Apple Valley Radio Telescope (GAVRT) collaboration between the Lewis Center for Educational Research (LCER) and the Jet Propulsion Laboratory. Students associated with LCER submit analytic reports of spectral data targeting specific regions of the Milky Way, identifying interference, noise, and Candidate signals potentially originating from intelligent sources. GAVRT-SETI's search is guided by the assumption that a narrow-band radio signal (<1.5 Hz) from a fixed location in the sky, occurring across multiple observation periods, is unlikely to be caused by instrument noise or by a natural source. Thus, we searched the reported data for similar signals occurring during different observation periods within the same region of sky. No such signals were found. However, our analysis of the frequency distribution of Candidates suggests that at least a few percent of the Candidates are associated with low-level radio-frequency interference.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"96 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140610859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.1088/1538-3873/ad2c95
Nathan W. Galliher, Thomas Procter, Nicholas M. Law, Hank Corbett, Ward S. Howard, Alan Vasquez Soto, Ramses Gonzalez, Lawrence Machia, Jonathan Carney, William J. Marshall
ArgusSpec is a prototype autonomous spectroscopic follow-up instrument designed to characterize flares detected by the Argus Pathfinder telescope array by taking short exposure (30 s) broadband spectra (370–750 nm) at low resolutions (R ∼ 150 at 500 nm). The instrument is built from consumer off-the-shelf astronomical equipment, assembled inside a shipping container, and deployed alongside the Argus Pathfinder at a dark sky observing site in Western North Carolina. In this paper, we describe the hardware design, system electronics, custom control software suite, automated target acquisition procedure, and data reduction pipeline. We present initial on-sky test data used to evaluate system performance and show a series of spectra taken of a small flare from AD Leonis. The $35k prototype ArgusSpec was designed, built, and deployed in under a year, largely from existing parts, and has been operating on-sky since 2023 March. With current hardware and software, the system is capable of receiving an observation, slewing, performing autonomous slit acquisition, and beginning data acquisition within an average of 32 s. With Argus Pathfinder’s 1 s cadence survey reporting alerts of rising sources within 2 s of onset, ArgusSpec can reach new targets well within a minute of the start of the event. As built, ArgusSpec can observe targets down to a 20σ limiting magnitude of mV ≈ 13 at 30 s cadence with an optical resolution of R ∼ 150 (at 500 nm). With automated rapid acquisition demonstrated, later hardware upgrades will be based on a clean-sheet optical design, solving many issues in the current system, significantly improving the limiting magnitude, and potentially enabling deep spectroscopy by the coaddition of data from an array of ArgusSpec systems. The primary science driver behind ArgusSpec is the characterization of the blackbody evolution of flares from nearby M-dwarfs. Large flares emitted by these stars could have significant impacts on the potential habitability of any orbiting exoplanets, but our current understanding of these events is in large part built on observations from a handful of active stars. ArgusSpec will characterize large numbers of flares from across the night sky, building a spectroscopic library of the most extreme events from a wide variety of stellar masses and ages.
ArgusSpec 是一个自主光谱跟踪仪器原型，旨在通过以低分辨率（500 nm 处 R ∼ 150）拍摄短时间曝光（30 秒）宽带光谱（370-750 nm）来描述 Argus 探路者望远镜阵列探测到的耀斑。该仪器使用现成的天文设备，组装在一个集装箱内，与阿格斯探路者一起部署在北卡罗来纳州西部的一个暗天观测点。在本文中，我们将介绍硬件设计、系统电子设备、定制控制软件套件、自动目标获取程序和数据缩减管道。我们介绍了用于评估系统性能的初始星空测试数据，并展示了从 AD Leonis 拍摄的一系列小型耀斑光谱。耗资 3.5 万美元的原型 ArgusSpec 在不到一年的时间内完成了设计、制造和部署，主要是利用现有部件，自 2023 年 3 月以来一直在星上运行。由于 Argus Pathfinder 的 1 秒周期巡天会在开始后 2 秒内报告上升源警报，ArgusSpec 可以在事件开始后一分钟内到达新目标。目前，ArgusSpec 能以 30 秒的频率观测到 mV ≈ 13 的 20σ 极限量级目标，光学分辨率为 R ∼ 150（500 纳米）。在演示了自动快速采集之后，以后的硬件升级将以简洁的光学设计为基础，解决目前系统中的许多问题，显著提高极限量级，并有可能通过对 ArgusSpec 系统阵列中的数据进行叠加来实现深度光谱分析。ArgusSpec 背后的主要科学驱动力是鉴定附近 M 型矮星耀斑的黑体演化。这些恒星发射的大型耀斑可能会对任何环绕系外行星的潜在宜居性产生重大影响，但我们目前对这些事件的了解在很大程度上是建立在对少数活跃恒星的观测基础上的。ArgusSpec 将对夜空中的大量耀斑进行定性分析，建立一个包含各种质量和年龄恒星的最极端事件的光谱库。
{"title":"The ArgusSpec Prototype: Autonomous Spectroscopic Follow-up of Flares Detected by Large Array Telescopes","authors":"Nathan W. Galliher, Thomas Procter, Nicholas M. Law, Hank Corbett, Ward S. Howard, Alan Vasquez Soto, Ramses Gonzalez, Lawrence Machia, Jonathan Carney, William J. Marshall","doi":"10.1088/1538-3873/ad2c95","DOIUrl":"https://doi.org/10.1088/1538-3873/ad2c95","url":null,"abstract":"ArgusSpec is a prototype autonomous spectroscopic follow-up instrument designed to characterize flares detected by the Argus Pathfinder telescope array by taking short exposure (30 s) broadband spectra (370–750 nm) at low resolutions (<italic toggle=\"yes\">R</italic> ∼ 150 at 500 nm). The instrument is built from consumer off-the-shelf astronomical equipment, assembled inside a shipping container, and deployed alongside the Argus Pathfinder at a dark sky observing site in Western North Carolina. In this paper, we describe the hardware design, system electronics, custom control software suite, automated target acquisition procedure, and data reduction pipeline. We present initial on-sky test data used to evaluate system performance and show a series of spectra taken of a small flare from AD Leonis. The $35k prototype ArgusSpec was designed, built, and deployed in under a year, largely from existing parts, and has been operating on-sky since 2023 March. With current hardware and software, the system is capable of receiving an observation, slewing, performing autonomous slit acquisition, and beginning data acquisition within an average of 32 s. With Argus Pathfinder’s 1 s cadence survey reporting alerts of rising sources within 2 s of onset, ArgusSpec can reach new targets well within a minute of the start of the event. As built, ArgusSpec can observe targets down to a 20<italic toggle=\"yes\">σ</italic> limiting magnitude of <italic toggle=\"yes\">m</italic>\u0000<sub>\u0000<italic toggle=\"yes\">V</italic>\u0000</sub> ≈ 13 at 30 s cadence with an optical resolution of <italic toggle=\"yes\">R</italic> ∼ 150 (at 500 nm). With automated rapid acquisition demonstrated, later hardware upgrades will be based on a clean-sheet optical design, solving many issues in the current system, significantly improving the limiting magnitude, and potentially enabling deep spectroscopy by the coaddition of data from an array of ArgusSpec systems. The primary science driver behind ArgusSpec is the characterization of the blackbody evolution of flares from nearby M-dwarfs. Large flares emitted by these stars could have significant impacts on the potential habitability of any orbiting exoplanets, but our current understanding of these events is in large part built on observations from a handful of active stars. ArgusSpec will characterize large numbers of flares from across the night sky, building a spectroscopic library of the most extreme events from a wide variety of stellar masses and ages.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"280 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140580924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The darkness of the sky is a critical parameter for assessing the suitability of an astronomical site. Among various sources of light pollution, urban lights pose the most significant threat to ground-based optical astronomical and planetary observations. Quantitatively assessing the impact of urban lights with varying scales and fluxes is indispensable for selecting an ideal optical observation site. In order to quantitatively assess the changes in Night Sky Brightness (NSB) relative to the distance from urban areas and to establish a foundation for safeguarding the light environment at the newly developed Lenghu astronomical site on the Tibetan Plateau, we employed both a Sky Quality Meter and a pre-calibrated smartphone. These instruments were used to measure the NSB in the vicinity of two cities, Da Qaidam and Delingha, which vary in size and radiant flux, on the Tibetan Plateau. The findings indicate that the NSB around both cities decreases significantly as the distance from the city center increases, although the rate of decrease varies between the two locations. This decline can be effectively modeled using an exponential decay function. Notably, the influence of city lights on NSB becomes negligible at distances exceeding 30 km from Da Qaidam, while for Delingha, this distance extends to 50 km due to its larger city size and higher total radiant flux. The methodologies and results presented in this paper offer valuable insights for the selection of astronomical observation sites and the development of light pollution management policies.
{"title":"Assessing the Influence of Urban Lights on Night Sky Brightness with a Smartphone","authors":"Yingqiang Wang, Yong Zhao, Weijia Sun, Fan Yang, Licai Deng, Fei He, Zhaojin Rong, Yong Wei","doi":"10.1088/1538-3873/ad332a","DOIUrl":"https://doi.org/10.1088/1538-3873/ad332a","url":null,"abstract":"The darkness of the sky is a critical parameter for assessing the suitability of an astronomical site. Among various sources of light pollution, urban lights pose the most significant threat to ground-based optical astronomical and planetary observations. Quantitatively assessing the impact of urban lights with varying scales and fluxes is indispensable for selecting an ideal optical observation site. In order to quantitatively assess the changes in Night Sky Brightness (NSB) relative to the distance from urban areas and to establish a foundation for safeguarding the light environment at the newly developed Lenghu astronomical site on the Tibetan Plateau, we employed both a Sky Quality Meter and a pre-calibrated smartphone. These instruments were used to measure the NSB in the vicinity of two cities, Da Qaidam and Delingha, which vary in size and radiant flux, on the Tibetan Plateau. The findings indicate that the NSB around both cities decreases significantly as the distance from the city center increases, although the rate of decrease varies between the two locations. This decline can be effectively modeled using an exponential decay function. Notably, the influence of city lights on NSB becomes negligible at distances exceeding 30 km from Da Qaidam, while for Delingha, this distance extends to 50 km due to its larger city size and higher total radiant flux. The methodologies and results presented in this paper offer valuable insights for the selection of astronomical observation sites and the development of light pollution management policies.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"280 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140581000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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