Pub Date : 2024-05-13DOI: 10.1088/1538-3873/ad430c
Dana I. Casetti-Dinescu, Roberto Baena-Gallé, Terrence M. Girard, Alejandro Cervantes-Rovira and Sebastian Todeasa
We present an expanded and improved deep-learning (DL) methodology for determining centers of star images on Hubble Space Telescope/Wide-Field Planetary Camera 2 (WFPC2) exposures. Previously, we demonstrated that our DL model can eliminate the pixel-phase bias otherwise present in these undersampled images; however that analysis was limited to the central portion of each detector. In the current work we introduce the inclusion of global positions to account for the point-spread function (PSF) variation across the entire chip and instrumental magnitudes to account for nonlinear effects such as charge transfer efficiency. The DL model is trained using a unique series of WFPC2 observations of globular cluster 47 Tuc, data sets comprising over 600 dithered exposures taken in each of two filters—F555W and F814W. It is found that the PSF variations across each chip correspond to corrections of the order of ∼100 mpix, while magnitude effects are at a level of ∼10 mpix. Importantly, pixel-phase bias is eliminated with the DL model; whereas, with a classic centering algorithm, the amplitude of this bias can be up to ∼40 mpix. Our improved DL model yields star-image centers with uncertainties of 8–10 mpix across the full field of view of WFPC2.
{"title":"Star Image Centering with Deep Learning. II. HST/WFPC2 Full Field of View","authors":"Dana I. Casetti-Dinescu, Roberto Baena-Gallé, Terrence M. Girard, Alejandro Cervantes-Rovira and Sebastian Todeasa","doi":"10.1088/1538-3873/ad430c","DOIUrl":"https://doi.org/10.1088/1538-3873/ad430c","url":null,"abstract":"We present an expanded and improved deep-learning (DL) methodology for determining centers of star images on Hubble Space Telescope/Wide-Field Planetary Camera 2 (WFPC2) exposures. Previously, we demonstrated that our DL model can eliminate the pixel-phase bias otherwise present in these undersampled images; however that analysis was limited to the central portion of each detector. In the current work we introduce the inclusion of global positions to account for the point-spread function (PSF) variation across the entire chip and instrumental magnitudes to account for nonlinear effects such as charge transfer efficiency. The DL model is trained using a unique series of WFPC2 observations of globular cluster 47 Tuc, data sets comprising over 600 dithered exposures taken in each of two filters—F555W and F814W. It is found that the PSF variations across each chip correspond to corrections of the order of ∼100 mpix, while magnitude effects are at a level of ∼10 mpix. Importantly, pixel-phase bias is eliminated with the DL model; whereas, with a classic centering algorithm, the amplitude of this bias can be up to ∼40 mpix. Our improved DL model yields star-image centers with uncertainties of 8–10 mpix across the full field of view of WFPC2.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937571","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 : 2024-05-09DOI: 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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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 : 2024-05-01DOI: 10.1088/1538-3873/ad4592
Lynne A. Valencic, Kimberly A. Weaver, K. D. Kuntz, J. Cann, R. Pfeifle
The recently discovered non-magnetic cataclysmic variable TUVO-21acq was serendipitously observed in a quiescent state during an XMM-Newton observing campaign for the starburst galaxy NGC 4945. Data from this campaign was combined with archival serendipitous XMM observations to examine its X-ray and UV/optical characteristics. TUVO-21acq was found to have X-ray flux FX(0.4–3.0 keV) ∼ 1.3 × 10−14 erg s−1 cm−2 and features similar to other quiescent dwarf novae, with X-ray luminosity LX(0.4–3.0 keV) ∼ 8 × 1030 erg s−1 and a white dwarf mass MWD=0.78−0.27+0.37M⊙. Its UV/optical spectrum was variable between observations, possibly due to changes in the accretion disk or the visibility of the bright spot.
{"title":"A Serendipitous Observation of the Recently Discovered Cataclysmic Variable TUVO-21acq","authors":"Lynne A. Valencic, Kimberly A. Weaver, K. D. Kuntz, J. Cann, R. Pfeifle","doi":"10.1088/1538-3873/ad4592","DOIUrl":"https://doi.org/10.1088/1538-3873/ad4592","url":null,"abstract":"\u0000 <jats:p>The recently discovered non-magnetic cataclysmic variable TUVO-21acq was serendipitously observed in a quiescent state during an XMM-Newton observing campaign for the starburst galaxy NGC 4945. Data from this campaign was combined with archival serendipitous XMM observations to examine its X-ray and UV/optical characteristics. TUVO-21acq was found to have X-ray flux <jats:italic>F</jats:italic>\u0000 <jats:sub>X</jats:sub>(0.4–3.0 keV) ∼ 1.3 × 10<jats:sup>−14</jats:sup> erg s<jats:sup>−1</jats:sup> cm<jats:sup>−2</jats:sup> and features similar to other quiescent dwarf novae, with X-ray luminosity <jats:italic>L</jats:italic>\u0000 <jats:sub>X</jats:sub>(0.4–3.0 keV) ∼ 8 × 10<jats:sup>30</jats:sup> erg s<jats:sup>−1</jats:sup> and a white dwarf mass <jats:inline-formula>\u0000 <jats:tex-math>\u0000\u0000</jats:tex-math>\u0000 <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\">\u0000 <mml:msub>\u0000 <mml:mrow>\u0000 <mml:mi>M</mml:mi>\u0000 </mml:mrow>\u0000 <mml:mrow>\u0000 <mml:mi>WD</mml:mi>\u0000 </mml:mrow>\u0000 </mml:msub>\u0000 <mml:mo>=</mml:mo>\u0000 <mml:msubsup>\u0000 <mml:mrow>\u0000 <mml:mn>0.78</mml:mn>\u0000 </mml:mrow>\u0000 <mml:mrow>\u0000 <mml:mo>−</mml:mo>\u0000 <mml:mn>0.27</mml:mn>\u0000 </mml:mrow>\u0000 <mml:mrow>\u0000 <mml:mo>+</mml:mo>\u0000 <mml:mn>0.37</mml:mn>\u0000 </mml:mrow>\u0000 </mml:msubsup>\u0000 <mml:mspace width=\"0.25em\"/>\u0000 <mml:msub>\u0000 <mml:mrow>\u0000 <mml:mi>M</mml:mi>\u0000 </mml:mrow>\u0000 <mml:mrow>\u0000 <mml:mo>⊙</mml:mo>\u0000 </mml:mrow>\u0000 </mml:msub>\u0000 </mml:math>\u0000 <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"paspad4592ieqn1.gif\" xlink:type=\"simple\"/>\u0000 </jats:inline-formula>. Its UV/optical spectrum was variable between observations, possibly due to changes in the accretion disk or the visibility of the bright spot.</jats:p>","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141139214","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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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}
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