Hannah Gulick, Jessica R. Lu, Aryan Sood, Steven V. W. Beckwith, Joshua S. Bloom, Kodi Rider, Dan Werthimer, Wei Liu, Guy Nir, Harrison Lee, Jeremy McCauley
The rise of time-domain astronomy including electromagnetic counterparts to gravitational waves, gravitational microlensing, explosive phenomena, and even astrometry with Gaia, are showing the power and need for surveys with high-cadence, large area, and long time baselines to study the transient universe. A constellation of SmallSats or CubeSats providing wide, instantaneous sky coverage down to 21 Vega mag at optical wavelengths would be ideal for addressing this need. We are assembling CuRIOS-ED (CubeSats for Rapid Infrared and Optical Survey--Exploration Demo), an optical telescope payload which will act as a technology demonstrator for a larger constellation of several hundred 16U CubeSats known as CuRIOS. In preparation for CuRIOS, CuRIOS-ED will launch in late 2025 as part of the 12U Starspec InspireSat MVP payload. CuRIOS-ED will be used to demonstrate the StarSpec ADCS pointing capabilities to <1" and to space-qualify a commercial camera package for use on the full CuRIOS payload. The CuRIOS-ED camera system will utilize a Sony IMX455 CMOS detector delivered in an off-the-shelf Atik apx60 package which we modified to be compatible with operations in vacuum as well as the CubeSat form factor, power, and thermal constraints. By qualifying this commercial camera solution, the cost of each CuRIOS satellite will be greatly decreased (~100x) when compared with current space-qualified cameras with IMX455 detectors. We discuss the CuRIOS-ED mission design with an emphasis on the disassembly, repackaging, and testing of the Atik apx60 for space-based missions. Characterization of the apx60's read noise, dark current, patterned noise, and thermal behavior are reported for a range of temperatures (-35 C to 40 C) and exposure times (0.001s to 30 s). Additionally, we comment on preliminary environmental testing results from a successful thermal vacuum test.
{"title":"CuRIOS-ED: The Technology Demonstrator for the CubeSats for Rapid Infrared and Optical Surveys Mission","authors":"Hannah Gulick, Jessica R. Lu, Aryan Sood, Steven V. W. Beckwith, Joshua S. Bloom, Kodi Rider, Dan Werthimer, Wei Liu, Guy Nir, Harrison Lee, Jeremy McCauley","doi":"arxiv-2409.11471","DOIUrl":"https://doi.org/arxiv-2409.11471","url":null,"abstract":"The rise of time-domain astronomy including electromagnetic counterparts to\u0000gravitational waves, gravitational microlensing, explosive phenomena, and even\u0000astrometry with Gaia, are showing the power and need for surveys with\u0000high-cadence, large area, and long time baselines to study the transient\u0000universe. A constellation of SmallSats or CubeSats providing wide,\u0000instantaneous sky coverage down to 21 Vega mag at optical wavelengths would be\u0000ideal for addressing this need. We are assembling CuRIOS-ED (CubeSats for Rapid\u0000Infrared and Optical Survey--Exploration Demo), an optical telescope payload\u0000which will act as a technology demonstrator for a larger constellation of\u0000several hundred 16U CubeSats known as CuRIOS. In preparation for CuRIOS,\u0000CuRIOS-ED will launch in late 2025 as part of the 12U Starspec InspireSat MVP\u0000payload. CuRIOS-ED will be used to demonstrate the StarSpec ADCS pointing\u0000capabilities to <1\" and to space-qualify a commercial camera package for use on\u0000the full CuRIOS payload. The CuRIOS-ED camera system will utilize a Sony IMX455\u0000CMOS detector delivered in an off-the-shelf Atik apx60 package which we\u0000modified to be compatible with operations in vacuum as well as the CubeSat form\u0000factor, power, and thermal constraints. By qualifying this commercial camera\u0000solution, the cost of each CuRIOS satellite will be greatly decreased (~100x)\u0000when compared with current space-qualified cameras with IMX455 detectors. We\u0000discuss the CuRIOS-ED mission design with an emphasis on the disassembly,\u0000repackaging, and testing of the Atik apx60 for space-based missions.\u0000Characterization of the apx60's read noise, dark current, patterned noise, and\u0000thermal behavior are reported for a range of temperatures (-35 C to 40 C) and\u0000exposure times (0.001s to 30 s). Additionally, we comment on preliminary\u0000environmental testing results from a successful thermal vacuum test.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Alispach, A. Araudo, M. Balbo, V. Beshley, A. Biland, J. Blažek, J. Borkowski, T. Bulik, F. Cadoux, S. Casanova, A. Christov, J. Chudoba, L. Chytka, P. Dědič, D. della Volpe, Y. Favre, M. Garczarczyk, L. Gibaud, T. Gieras, P. Hamal, M. Heller, M. Hrabovský, P. Janeček, M. Jelínek, V. Jílek, J. Juryšek, V. Karas, B. Lacave, E. Lyard, E. Mach, D. Mandát, W. Marek, S. Michal, J. Michałowski, R. Moderski, T. Montaruli, A. Muraczewski, S. Muthyala, A. L. Müller, A. Nagai, K. Nalewajski, D. Neise, J. Niemiec, M. Nikołajuk, V. Novotný, M. Ostrowski, M. Palatka, M. Pech, M. Prouza, P. Rajda, P. Schovanek, K. Seweryn, V. Sliusar, Ł. Stawarz, R. Sternberger, M. Stodulska, J. Świerblewski, P. Świerk, J. Štrobl, T. Tavernier, P. Trávníček, I. Troyano Pujadas, J. Vícha, R. Walter, K. Zietara
The SST-1M is a Small-Sized Telescope (SST) designed to provide a cost-effective and high-performance solution for gamma-ray astrophysics, particularly for energies beyond a few TeV. The goal is to integrate this telescope into an array of similar instruments, leveraging its lightweight design, earthquake resistance, and established Davies-Cotton configuration. Additionally, its optical system is designed to function without a protective dome, allowing it to withstand the harsh atmospheric conditions typical of mountain environments above 2000 m. The SST-1M utilizes a fully digitizing camera system based on silicon photomultipliers (SiPMs). This camera is capable of digitizing all signals from the UV-optical light detectors, allowing for the implementation of various triggers and data analysis methods. We detail the process of designing, prototyping, and validating this system, ensuring that it meets the stringent requirements for gamma-ray detection and performance. An SST-1M stereo system is currently operational and collecting data at the Ondv{r}ejov observatory in the Czech Republic, situated at 500 m. Preliminary results from this system are promising. A forthcoming paper will provide a comprehensive analysis of the performance of the telescopes in detecting gamma rays and operating under real-world conditions.
SST-1M 是一种小型望远镜（SST），旨在为伽马射线天体物理学，特别是为超过几 TeV 的能量提供低成本、高性能的解决方案。其目标是将该望远镜集成到一系列类似仪器中，充分利用其轻巧的设计、抗震性和成熟的戴维斯-棉花配置。此外，其光学系统的设计可以在没有保护罩的情况下工作，使其能够承受 2000 米以上山区环境中典型的恶劣大气条件。该相机能够将紫外光-光学探测器发出的所有信号数字化，从而可以使用各种触发器和数据分析方法。我们详细介绍了这一系统的设计、原型制作和验证过程，确保它符合伽马射线探测和性能方面的严格要求。目前，一个SST-1M立体系统正在捷克共和国的Ondv{r}ejov天文台运行并收集数据，该天文台位于500米高空。即将发表的一篇论文将全面分析望远镜在探测伽马射线和在实际条件下工作的性能。
{"title":"The SST-1M imaging atmospheric Cherenkov telescope for gamma-ray astrophysics","authors":"C. Alispach, A. Araudo, M. Balbo, V. Beshley, A. Biland, J. Blažek, J. Borkowski, T. Bulik, F. Cadoux, S. Casanova, A. Christov, J. Chudoba, L. Chytka, P. Dědič, D. della Volpe, Y. Favre, M. Garczarczyk, L. Gibaud, T. Gieras, P. Hamal, M. Heller, M. Hrabovský, P. Janeček, M. Jelínek, V. Jílek, J. Juryšek, V. Karas, B. Lacave, E. Lyard, E. Mach, D. Mandát, W. Marek, S. Michal, J. Michałowski, R. Moderski, T. Montaruli, A. Muraczewski, S. Muthyala, A. L. Müller, A. Nagai, K. Nalewajski, D. Neise, J. Niemiec, M. Nikołajuk, V. Novotný, M. Ostrowski, M. Palatka, M. Pech, M. Prouza, P. Rajda, P. Schovanek, K. Seweryn, V. Sliusar, Ł. Stawarz, R. Sternberger, M. Stodulska, J. Świerblewski, P. Świerk, J. Štrobl, T. Tavernier, P. Trávníček, I. Troyano Pujadas, J. Vícha, R. Walter, K. Zietara","doi":"arxiv-2409.11310","DOIUrl":"https://doi.org/arxiv-2409.11310","url":null,"abstract":"The SST-1M is a Small-Sized Telescope (SST) designed to provide a\u0000cost-effective and high-performance solution for gamma-ray astrophysics,\u0000particularly for energies beyond a few TeV. The goal is to integrate this\u0000telescope into an array of similar instruments, leveraging its lightweight\u0000design, earthquake resistance, and established Davies-Cotton configuration.\u0000Additionally, its optical system is designed to function without a protective\u0000dome, allowing it to withstand the harsh atmospheric conditions typical of\u0000mountain environments above 2000 m. The SST-1M utilizes a fully digitizing\u0000camera system based on silicon photomultipliers (SiPMs). This camera is capable\u0000of digitizing all signals from the UV-optical light detectors, allowing for the\u0000implementation of various triggers and data analysis methods. We detail the\u0000process of designing, prototyping, and validating this system, ensuring that it\u0000meets the stringent requirements for gamma-ray detection and performance. An\u0000SST-1M stereo system is currently operational and collecting data at the\u0000Ondv{r}ejov observatory in the Czech Republic, situated at 500 m. Preliminary\u0000results from this system are promising. A forthcoming paper will provide a\u0000comprehensive analysis of the performance of the telescopes in detecting gamma\u0000rays and operating under real-world conditions.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shion Andrew, Calvin Leung, Alexander Li, Kiyoshi W. Masui, Bridget C. Andersen, Kevin Bandura, Alice P. Curtin, Jane Kaczmarek, Adam E. Lanman, Mattias Lazda, Juan Mena-Parra, Daniele Michilli, Kenzie Nimmo, Aaron B. Pearlman, Mubdi Rahman, Vishwangi Shah, Kaitlyn Shin, Haochen Wang
The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project has a new VLBI Outrigger at the Green Bank Observatory (GBO), which forms a 3300km baseline with CHIME operating at 400-800MHz. Using 100ms long full-array baseband "snapshots" collected commensally during FRB and pulsar triggers, we perform a shallow, wide-area VLBI survey covering a significant fraction of the Northern sky targeted at the positions of compact sources from the Radio Fundamental Catalog. In addition, our survey contains calibrators detected from two 1s long trial baseband snapshots for a deeper survey with CHIME and GBO. In this paper, we present the largest catalog of compact calibrators suitable for 30-milliarcsecond-scale VLBI observations at sub-GHz frequencies to date. Our catalog consists of 200 total calibrators in the Northern Hemisphere that are compact on 30-milliarcsecond scales with fluxes above 100mJy. This calibrator grid will enable the precise localization of hundreds of FRBs a year with CHIME/FRB-Outriggers.
{"title":"A VLBI Calibrator Grid at 600MHz for Fast Radio Transient Localizations with CHIME/FRB Outriggers","authors":"Shion Andrew, Calvin Leung, Alexander Li, Kiyoshi W. Masui, Bridget C. Andersen, Kevin Bandura, Alice P. Curtin, Jane Kaczmarek, Adam E. Lanman, Mattias Lazda, Juan Mena-Parra, Daniele Michilli, Kenzie Nimmo, Aaron B. Pearlman, Mubdi Rahman, Vishwangi Shah, Kaitlyn Shin, Haochen Wang","doi":"arxiv-2409.11476","DOIUrl":"https://doi.org/arxiv-2409.11476","url":null,"abstract":"The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst\u0000(CHIME/FRB) Project has a new VLBI Outrigger at the Green Bank Observatory\u0000(GBO), which forms a 3300km baseline with CHIME operating at 400-800MHz. Using\u0000100ms long full-array baseband \"snapshots\" collected commensally during FRB and\u0000pulsar triggers, we perform a shallow, wide-area VLBI survey covering a\u0000significant fraction of the Northern sky targeted at the positions of compact\u0000sources from the Radio Fundamental Catalog. In addition, our survey contains\u0000calibrators detected from two 1s long trial baseband snapshots for a deeper\u0000survey with CHIME and GBO. In this paper, we present the largest catalog of\u0000compact calibrators suitable for 30-milliarcsecond-scale VLBI observations at\u0000sub-GHz frequencies to date. Our catalog consists of 200 total calibrators in\u0000the Northern Hemisphere that are compact on 30-milliarcsecond scales with\u0000fluxes above 100mJy. This calibrator grid will enable the precise localization\u0000of hundreds of FRBs a year with CHIME/FRB-Outriggers.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexis Lau, Élodie Choquet, Lisa Altinier, Iva Laginja, Rémi Soummer, Laurent Pueyo, Nicolas Godoy, Arthur Vigan, David Mary
The Roman Space Telescope will be a critical mission to demonstrate high-contrast imaging technologies allowing for the characterisation of exoplanets in reflected light. It will demonstrate $10^{-7}$ contrast limits or better at 3--9 $lambda / D$ separations with active wavefront control for the first time in space. The detection limits for the Coronagraph Instrument are expected to be set by wavefront variations between the science target and the reference star observations. We are investigating methods to use the deformablel mirrors to methodically probe the impact of such variations on the coronagraphic PSF, generating a PSF library during observations of the reference star to optimise the starlight subtraction at post-processing. We are collaborating with STScI to test and validate these methods in lab using the HiCAT tested, a high-contrast imaging lab platform dedicated to system-level developments for future space missions. In this paper, we will present the first applications of these methods on HiCAT.
{"title":"ESCAPE project: testing active observing strategies for high-contrast imaging in space on the HiCAT testbed","authors":"Alexis Lau, Élodie Choquet, Lisa Altinier, Iva Laginja, Rémi Soummer, Laurent Pueyo, Nicolas Godoy, Arthur Vigan, David Mary","doi":"arxiv-2409.11062","DOIUrl":"https://doi.org/arxiv-2409.11062","url":null,"abstract":"The Roman Space Telescope will be a critical mission to demonstrate\u0000high-contrast imaging technologies allowing for the characterisation of\u0000exoplanets in reflected light. It will demonstrate $10^{-7}$ contrast limits or\u0000better at 3--9 $lambda / D$ separations with active wavefront control for the\u0000first time in space. The detection limits for the Coronagraph Instrument are\u0000expected to be set by wavefront variations between the science target and the\u0000reference star observations. We are investigating methods to use the\u0000deformablel mirrors to methodically probe the impact of such variations on the\u0000coronagraphic PSF, generating a PSF library during observations of the\u0000reference star to optimise the starlight subtraction at post-processing. We are\u0000collaborating with STScI to test and validate these methods in lab using the\u0000HiCAT tested, a high-contrast imaging lab platform dedicated to system-level\u0000developments for future space missions. In this paper, we will present the\u0000first applications of these methods on HiCAT.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shivam Pandey, Francois Lanusse, Chirag Modi, Benjamin D. Wandelt
We develop a transformer-based conditional generative model for discrete point objects and their properties. We use it to build a model for populating cosmological simulations with gravitationally collapsed structures called dark matter halos. Specifically, we condition our model with dark matter distribution obtained from fast, approximate simulations to recover the correct three-dimensional positions and masses of individual halos. This leads to a first model that can recover the statistical properties of the halos at small scales to better than 3% level using an accelerated dark matter simulation. This trained model can then be applied to simulations with significantly larger volumes which would otherwise be computationally prohibitive with traditional simulations, and also provides a crucial missing link in making end-to-end differentiable cosmological simulations. The code, named GOTHAM (Generative cOnditional Transformer for Halo's Auto-regressive Modeling) is publicly available at url{https://github.com/shivampcosmo/GOTHAM}.
我们为离散点物体及其属性开发了一个基于变换器的条件生成模型。我们用它建立了一个模型，用于在宇宙学模拟中填充被称为暗物质晕的引力塌缩结构。具体地说，我们用从快速近似模拟中获得的暗物质分布作为我们模型的条件，以恢复单个光环的正确三维位置和质量。这个训练有素的模型可以应用于体积很大的模拟，否则传统模拟的计算量将会非常大，同时也为端到端可分辨宇宙学模拟提供了一个关键的缺失环节。该代码被命名为GOTHAM（GenerativecOnditional Transformer for Halo's Auto-regressive Modeling），可在（url{https://github.com/shivampcosmo/GOTHAM}）上公开获取。
{"title":"Teaching dark matter simulations to speak the halo language","authors":"Shivam Pandey, Francois Lanusse, Chirag Modi, Benjamin D. Wandelt","doi":"arxiv-2409.11401","DOIUrl":"https://doi.org/arxiv-2409.11401","url":null,"abstract":"We develop a transformer-based conditional generative model for discrete\u0000point objects and their properties. We use it to build a model for populating\u0000cosmological simulations with gravitationally collapsed structures called dark\u0000matter halos. Specifically, we condition our model with dark matter\u0000distribution obtained from fast, approximate simulations to recover the correct\u0000three-dimensional positions and masses of individual halos. This leads to a\u0000first model that can recover the statistical properties of the halos at small\u0000scales to better than 3% level using an accelerated dark matter simulation.\u0000This trained model can then be applied to simulations with significantly larger\u0000volumes which would otherwise be computationally prohibitive with traditional\u0000simulations, and also provides a crucial missing link in making end-to-end\u0000differentiable cosmological simulations. The code, named GOTHAM (Generative\u0000cOnditional Transformer for Halo's Auto-regressive Modeling) is publicly\u0000available at url{https://github.com/shivampcosmo/GOTHAM}.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mario Casado Diezon behalf of the Gaia4Sustainability team
Light pollution is a growing environmental issue that affects astronomy, ecosystems, human health. To address this, we introduce the Free Dark Sky Meter (FreeDSM), an affordable IoT-based photometer designed for continuous light pollution monitoring. FreeDSM uses an ESP32 microcontroller with integrated sensors for light, temperature, and humidity, and operates on an open-source platform. Data from multiple devices are centralized and processed using the Gambons model, which leverages Gaia satellite data for accurate real-time assessments of natural light levels. This project is part of the Gaia4Sustainability initiative.
{"title":"FreeDSM and the Gaia4Sustaniability project: a light pollution meter based on IoT technologies","authors":"Mario Casado Diezon behalf of the Gaia4Sustainability team","doi":"arxiv-2409.10298","DOIUrl":"https://doi.org/arxiv-2409.10298","url":null,"abstract":"Light pollution is a growing environmental issue that affects astronomy,\u0000ecosystems, human health. To address this, we introduce the Free Dark Sky Meter\u0000(FreeDSM), an affordable IoT-based photometer designed for continuous light\u0000pollution monitoring. FreeDSM uses an ESP32 microcontroller with integrated\u0000sensors for light, temperature, and humidity, and operates on an open-source\u0000platform. Data from multiple devices are centralized and processed using the\u0000Gambons model, which leverages Gaia satellite data for accurate real-time\u0000assessments of natural light levels. This project is part of the\u0000Gaia4Sustainability initiative.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Ramirez, G. Pignata, Francisco Förster, Santiago Gonzáles-Gaitán, Claudia P. Gutiérrez, B. Ayala, Guillermo Cabrera-Vives, Márcio Catelan, A. M. Muñoz Arancibia, J. Pineda-García
This paper introduces a novel method for creating spectral time series, which can be used for generating synthetic light curves for photometric classification but also for applications like K-corrections and bolometric corrections. This approach is particularly valuable in the era of large astronomical surveys, where it can significantly enhance the analysis and understanding of an increasing number of SNe, even in the absence of extensive spectroscopic data. methods: By employing interpolations based on optimal transport theory, starting from a spectroscopic sequence, we derive weighted average spectra with high cadence. The weights incorporate an uncertainty factor, for penalizing interpolations between spectra with significant epoch differences and with poor match between the synthetic and observed photometry. results: Our analysis reveals that even with phase difference of up to 40 days between pairs of spectra, optical transport can generate interpolated spectral time series that closely resemble the original ones. Synthetic photometry extracted from these spectral time series aligns well with observed photometry. The best results are achieved in the V band, with relative residuals less than 10% for 87% and 84% of the data for type Ia and II, respectively. For the B, g, R and r bands the relative residuals are between 65% and 87% within the previously mentioned 10% threshold for both classes. The worse results correspond to the i and I bands where, in the case, of SN~Ia the values drop to 53% and 42%, respectively. conclusions: We introduce a new method to construct spectral time series for individual SN starting from a sparse spectroscopic sequence, demonstrating its capability to produce reliable light curves that can be used for photometric classification.
本文介绍了一种创建光谱时间序列的新方法，该方法不仅可用于生成用于测光分类的合成光曲线，还可用于 K 校正和测电校正等应用。这种方法在大型天文巡天时代尤为重要，即使在缺乏扩展光谱数据的情况下，它也能显著增强对越来越多的SNE的分析和理解：通过采用基于最优传输理论的内插法，从光谱序列出发，我们得出了加权平均高频率光谱。权重包含了一个不确定性因子，用于惩罚具有显著年代差异以及合成光度测量与观测光度测量之间匹配度较差的光谱之间的内插：我们的分析表明，即使光谱对之间的相位差高达 40 天，光传输也能产生与原始光谱非常相似的内插光谱时间序列。从这些光谱时间序列中提取的合成测光结果与观测到的测光结果非常吻合。V 波段的结果最好，Ia 型和 II 型分别有 87% 和 84% 的数据的相对残差小于 10%。在 B、g、R 和 r 波段，两类数据的相对残差都在 65% 到 87% 之间，不超过前面提到的 10% 的临界值。结果较差的是 i 和 I 波段，在 SN~Ia 的情况下，其值分别下降到 53% 和 42%：我们介绍了一种从稀疏光谱序列开始为单个SN构建光谱时间序列的新方法，证明了它能够产生可靠的光曲线，并可用于光度分类。
{"title":"A Novel Optimal Transport-Based Approach for Interpolating Spectral Time Series: Paving the Way for Photometric Classification of Supernovae","authors":"M. Ramirez, G. Pignata, Francisco Förster, Santiago Gonzáles-Gaitán, Claudia P. Gutiérrez, B. Ayala, Guillermo Cabrera-Vives, Márcio Catelan, A. M. Muñoz Arancibia, J. Pineda-García","doi":"arxiv-2409.10701","DOIUrl":"https://doi.org/arxiv-2409.10701","url":null,"abstract":"This paper introduces a novel method for creating spectral time series, which\u0000can be used for generating synthetic light curves for photometric\u0000classification but also for applications like K-corrections and bolometric\u0000corrections. This approach is particularly valuable in the era of large\u0000astronomical surveys, where it can significantly enhance the analysis and\u0000understanding of an increasing number of SNe, even in the absence of extensive\u0000spectroscopic data. methods: By employing interpolations based on optimal\u0000transport theory, starting from a spectroscopic sequence, we derive weighted\u0000average spectra with high cadence. The weights incorporate an uncertainty\u0000factor, for penalizing interpolations between spectra with significant epoch\u0000differences and with poor match between the synthetic and observed photometry.\u0000results: Our analysis reveals that even with phase difference of up to 40 days\u0000between pairs of spectra, optical transport can generate interpolated spectral\u0000time series that closely resemble the original ones. Synthetic photometry\u0000extracted from these spectral time series aligns well with observed photometry.\u0000The best results are achieved in the V band, with relative residuals less than\u000010% for 87% and 84% of the data for type Ia and II, respectively. For the B, g,\u0000R and r bands the relative residuals are between 65% and 87% within the\u0000previously mentioned 10% threshold for both classes. The worse results\u0000correspond to the i and I bands where, in the case, of SN~Ia the values drop to\u000053% and 42%, respectively. conclusions: We introduce a new method to construct\u0000spectral time series for individual SN starting from a sparse spectroscopic\u0000sequence, demonstrating its capability to produce reliable light curves that\u0000can be used for photometric classification.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Becker, F. C. Onyeagusi, J. Teiser, T. Jardiel, M. Peiteado, O. Munoz, J. Martikainen, J. C. Gomez Martin, J. Merrison, G. Wurm
Within the RoadMap project we investigated the microphysical aspects of particle collisions during saltation on the Martian surface in laboratory experiments. Following the size distribution of ejected particles, their aerodynamic properties and aggregation status upon ejection, we now focus on the electrification and charge distribution of ejected particles. We analyzed rebound and ejection trajectories of grains in a vacuum setup with a strong electric field of 100 kV/m and deduced particle charges from their acceleration. The ejected particles have sizes of about 10 to 100 microns. They carry charges up to $10^5$ e or charge densities up to $> 10^7$ e/mm$^2$. Within the given size range, we find a small bias towards positive charges.
{"title":"Ejected Particles after Impact Splash on Mars: Electrification","authors":"T. Becker, F. C. Onyeagusi, J. Teiser, T. Jardiel, M. Peiteado, O. Munoz, J. Martikainen, J. C. Gomez Martin, J. Merrison, G. Wurm","doi":"arxiv-2409.10287","DOIUrl":"https://doi.org/arxiv-2409.10287","url":null,"abstract":"Within the RoadMap project we investigated the microphysical aspects of\u0000particle collisions during saltation on the Martian surface in laboratory\u0000experiments. Following the size distribution of ejected particles, their\u0000aerodynamic properties and aggregation status upon ejection, we now focus on\u0000the electrification and charge distribution of ejected particles. We analyzed\u0000rebound and ejection trajectories of grains in a vacuum setup with a strong\u0000electric field of 100 kV/m and deduced particle charges from their\u0000acceleration. The ejected particles have sizes of about 10 to 100 microns. They\u0000carry charges up to $10^5$ e or charge densities up to $> 10^7$ e/mm$^2$.\u0000Within the given size range, we find a small bias towards positive charges.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Speckle polarimeter (SPP) is a facility instrument of the 2.5-m telescope of the Caucasian Mountain Observatory of SAI MSU. By design it is a combination of a speckle interferometer and a dual--beam polarimeter. In 2022 we performed a major upgrade of the instrument. New version of the instrument features Hamamatsu ORCA-Quest qCMOS C15550-20UP, having subelectron readout noise, as a main detector, as opposed to EMCCD Andor iXon 897 used in previous version. Optical distortions present in the instrument are considered as they directly affect the accuracy of the speckle interferometric astrometric measurements of binary stars. We identified the Atmospheric Dispersion Compensator (ADC) as the main source of distortions which are not constant and depend on the rotational angles of ADCs prisms. Distortions are estimated using internal calibration light source and multiple binary stars measurements. Method for their correction is developed. Flux ratio estimates are subject to CMOS-specific negative factors: spatially correlated noise and flux-dependent pixel-to-pixel sensitivity difference. We suggest ways to mitigate these factors. The use of speckle transfer function measured using a reference star further improves flux ratio estimation performance. We discuss the precision of the estimates of position angle, separation and flux ratio of binary stars.
{"title":"Precision speckle interferometry with CMOS detector","authors":"I. A. Strakhov, B. S. Safonov, D. V. Cheryasov","doi":"arxiv-2409.10249","DOIUrl":"https://doi.org/arxiv-2409.10249","url":null,"abstract":"Speckle polarimeter (SPP) is a facility instrument of the 2.5-m telescope of\u0000the Caucasian Mountain Observatory of SAI MSU. By design it is a combination of\u0000a speckle interferometer and a dual--beam polarimeter. In 2022 we performed a\u0000major upgrade of the instrument. New version of the instrument features\u0000Hamamatsu ORCA-Quest qCMOS C15550-20UP, having subelectron readout noise, as a\u0000main detector, as opposed to EMCCD Andor iXon 897 used in previous version.\u0000Optical distortions present in the instrument are considered as they directly\u0000affect the accuracy of the speckle interferometric astrometric measurements of\u0000binary stars. We identified the Atmospheric Dispersion Compensator (ADC) as the\u0000main source of distortions which are not constant and depend on the rotational\u0000angles of ADCs prisms. Distortions are estimated using internal calibration\u0000light source and multiple binary stars measurements. Method for their\u0000correction is developed. Flux ratio estimates are subject to CMOS-specific\u0000negative factors: spatially correlated noise and flux-dependent pixel-to-pixel\u0000sensitivity difference. We suggest ways to mitigate these factors. The use of\u0000speckle transfer function measured using a reference star further improves flux\u0000ratio estimation performance. We discuss the precision of the estimates of\u0000position angle, separation and flux ratio of binary stars.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. A. SemenikhinThe SNAD team, M. V. KornilovThe SNAD team, M. V. PruzhinskayaThe SNAD team, A. D. LavrukhinaThe SNAD team, E. RusseilThe SNAD team, E. GanglerThe SNAD team, E. E. O. IshidaThe SNAD team, V. S. KorolevThe SNAD team, K. L. MalanchevThe SNAD team, A. A. VolnovaThe SNAD team, S. SreejithThe SNAD team
In the task of anomaly detection in modern time-domain photometric surveys, the primary goal is to identify astrophysically interesting, rare, and unusual objects among a large volume of data. Unfortunately, artifacts -- such as plane or satellite tracks, bad columns on CCDs, and ghosts -- often constitute significant contaminants in results from anomaly detection analysis. In such contexts, the Active Anomaly Discovery (AAD) algorithm allows tailoring the output of anomaly detection pipelines according to what the expert judges to be scientifically interesting. We demonstrate how the introduction real-bogus scores, obtained from a machine learning classifier, improves the results from AAD. Using labeled data from the SNAD ZTF knowledge database, we train four real-bogus classifiers: XGBoost, CatBoost, Random Forest, and Extremely Randomized Trees. All the models perform real-bogus classification with similar effectiveness, achieving ROC-AUC scores ranging from 0.93 to 0.95. Consequently, we select the Random Forest model as the main model due to its simplicity and interpretability. The Random Forest classifier is applied to 67 million light curves from ZTF DR17. The output real-bogus score is used as an additional feature for two anomaly detection algorithms: static Isolation Forest and AAD. While results from Isolation Forest remained unchanged, the number of artifacts detected by the active approach decreases significantly with the inclusion of the real-bogus score, from 27 to 3 out of 100. We conclude that incorporating the real-bogus classifier result as an additional feature in the active anomaly detection pipeline significantly reduces the number of artifacts in the outputs, thereby increasing the incidence of astrophysically interesting objects presented to human experts.
{"title":"Real-bogus scores for active anomaly detection","authors":"T. A. SemenikhinThe SNAD team, M. V. KornilovThe SNAD team, M. V. PruzhinskayaThe SNAD team, A. D. LavrukhinaThe SNAD team, E. RusseilThe SNAD team, E. GanglerThe SNAD team, E. E. O. IshidaThe SNAD team, V. S. KorolevThe SNAD team, K. L. MalanchevThe SNAD team, A. A. VolnovaThe SNAD team, S. SreejithThe SNAD team","doi":"arxiv-2409.10256","DOIUrl":"https://doi.org/arxiv-2409.10256","url":null,"abstract":"In the task of anomaly detection in modern time-domain photometric surveys,\u0000the primary goal is to identify astrophysically interesting, rare, and unusual\u0000objects among a large volume of data. Unfortunately, artifacts -- such as plane\u0000or satellite tracks, bad columns on CCDs, and ghosts -- often constitute\u0000significant contaminants in results from anomaly detection analysis. In such\u0000contexts, the Active Anomaly Discovery (AAD) algorithm allows tailoring the\u0000output of anomaly detection pipelines according to what the expert judges to be\u0000scientifically interesting. We demonstrate how the introduction real-bogus\u0000scores, obtained from a machine learning classifier, improves the results from\u0000AAD. Using labeled data from the SNAD ZTF knowledge database, we train four\u0000real-bogus classifiers: XGBoost, CatBoost, Random Forest, and Extremely\u0000Randomized Trees. All the models perform real-bogus classification with similar\u0000effectiveness, achieving ROC-AUC scores ranging from 0.93 to 0.95.\u0000Consequently, we select the Random Forest model as the main model due to its\u0000simplicity and interpretability. The Random Forest classifier is applied to 67\u0000million light curves from ZTF DR17. The output real-bogus score is used as an\u0000additional feature for two anomaly detection algorithms: static Isolation\u0000Forest and AAD. While results from Isolation Forest remained unchanged, the\u0000number of artifacts detected by the active approach decreases significantly\u0000with the inclusion of the real-bogus score, from 27 to 3 out of 100. We\u0000conclude that incorporating the real-bogus classifier result as an additional\u0000feature in the active anomaly detection pipeline significantly reduces the\u0000number of artifacts in the outputs, thereby increasing the incidence of\u0000astrophysically interesting objects presented to human experts.","PeriodicalId":501163,"journal":{"name":"arXiv - PHYS - Instrumentation and Methods for Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：