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Astro arXiv | astro-ph.IM

Daily Astro papers on the arXiv in astro-ph.IM.

  1. 30/11/2022

    3UCubed: The IMAP Student Collaboration CubeSat Project

    3UCubed: The IMAP Student Collaboration CubeSat Project by Marcus Alfred et al. on Wednesday 30 November The 3UCubed project is a 3U CubeSat being jointly developed by the University of New Hampshire, Sonoma State University, and Howard University as a part of the NASA Interstellar Mapping and Acceleration Probe, IMAP, student collaboration. This project comprises of a multidisciplinary team of undergraduate students from all three universities. The mission goal of the 3UCubed is to understand how Earths polar upper atmosphere the thermosphere in Earths auroral regions, responds to particle precipitation and solar wind forcing, and internal magnetospheric processes. 3UCubed includes two instruments with rocket heritage to achieve the science mission: an ultraviolet photomultiplier tube, UVPMT, and an electron retarding potential analyzer ERPA. The spacecraft bus consists of the following subsystems: Attitude Determination and Control, Command and Data Handling, Power, Communication, Structural, and Thermal. Currently, the project is in the post-PDR stage, starting to build and test engineering models to develop a FlatSat prior to critical design review in 2023. The goal is to launch at least one 3U CubeSat to collect science data close to the anticipated peak of Solar Cycle 25 around July 2025. Our mother mission, IMAP, is also projected to launch in 2025, which will let us jointly analyze the science data of the main mission, providing the solar wind measurements and inputs to the magnetosphere with that of 3UCubed, providing the response of Earths cusp to these inputs. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15781v1

    1 phút

  2. 30/11/2022

    A Bayesian approach to RFI mitigation

    A Bayesian approach to RFI mitigation by S. A. K. Leeney et al. on Wednesday 30 November Radio Frequency Interference (RFI) is an endemic problem in radio astronomy. Information in contaminated frequency channels is lost and it can lead to significant systematic error if not properly modelled. In this paper we propose a RFI mitigation methodology that takes a Bayesian approach, where contaminated data is both flagged and managed as part of a single step fitting process. To the authors knowledge, our approach is first-of-its-kind. We provide a proof-of-concept of our methods which are also tested and shown to be effective on both a simple toy model and when incorporated into the Bayesian data analysis pipeline for REACH (a modern cosmological radio experiment). arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15448v1

    25 giây

  3. 30/11/2022

    ASTENA: a mission concept for a deep study of the transient gamma-ray sky and for nuclear astrophysics

    ASTENA: a mission concept for a deep study of the transient gamma-ray sky and for nuclear astrophysics by E. Virgilli et al. on Wednesday 30 November Gamma-ray astronomy is a branch whose potential has not yet been fully exploited. The observations of elemental and isotopic abundances in supernova (SN) explosions are key probes not only of the stellar structure and evolution but also for understanding the physics that makes Type-Ia SNe as standard candles for the study of the Universe expansion properties. In spite of its crucial role, nuclear astrophysics remains a poorly explored field mainly for the typical emission lines intensity which are vanishing small and requires very high sensitivities of the telescopes. Furthermore, in spite that the Galactic bulge-dominated intensity of positron annihilation line at 511 keV has been measured, its origin is still a mystery due to the poor angular resolution and insufficient sensitivity of the commonly employed instrumentation in the sub-MeV energy domain. To answer these scientific issues a jump in sensitivity and angular resolution with respect to the present instrumentation is required. Conceived within the EU project AHEAD, a new high energy mission, capable of tackling the previously mentioned topics, has been proposed. This concept of mission named ASTENA (Advanced Surveyor of Transient Events and Nuclear Astrophysics), includes two instruments: a Wide Field Monitor with Imaging and Spectroscopic (WFM-IS, 2 keV - 20 MeV) capabilities and a Narrow Field Telescope (NFT, 50 - 700 keV). Thanks to the combination of angular resolution, sensitivity and large FoV, ASTENA will be a breakthrough in the hard X and soft gamma--ray energy band, also enabling polarimetry in this energy band. In this talk the science goals of the mission are discussed, the payload configuration is described and expected performances in observing key targets are shown. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16916v1

    1 phút

  4. 30/11/2022

    Adding Workflow Management Flexibility to LSST Pipelines Execution

    Adding Workflow Management Flexibility to LSST Pipelines Execution by Michelle Gower et al. on Wednesday 30 November Data processing pipelines need to be executed at scales ranging from small runs up through large production data release runs resulting in millions of data products. As part of the Rubin Observatory's pipeline execution system, BPS is the abstraction layer that provides an interface to different Workflow Management Systems (WMS) such as HTCondor and PanDA. During the submission process, the pipeline execution system interacts with the Data Butler to produce a science-oriented execution graph from algorithmic tasks. BPS converts this execution graph to a workflow graph and then uses a WMS-specific plugin to submit and manage the workflow. Here we will discuss the architectural design of this interface and report briefly on the recent production of the Data Preview 0.2 release and how the system is used by pipeline developers. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15795v1

    29 giây

  5. 30/11/2022

    Bayesian modelling of scattered light in the LIGO interferometers

    Bayesian modelling of scattered light in the LIGO interferometers by Rhiannon Udall et al. on Wednesday 30 November Excess noise from scattered light poses a persistent challenge in the analysis of data from gravitational wave detectors such as LIGO. We integrate a physically motivated model for the behavior of these "glitches" into a standard Bayesian analysis pipeline used in gravitational wave science. This allows for the inference of the free parameters in this model, and subtraction of these models to produce glitch-free versions of the data. We show that this inference is an effective discriminator of the presence of the features of these glitches, even when those features may not be discernible in standard visualizations of the data. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15867v1

    24 giây

  6. 30/11/2022

    Elements of effective machine learning datasets in astronomy

    Elements of effective machine learning datasets in astronomy by Bernie Boscoe et al. on Wednesday 30 November In this work, we identify elements of effective machine learning datasets in astronomy and present suggestions for their design and creation. Machine learning has become an increasingly important tool for analyzing and understanding the large-scale flood of data in astronomy. To take advantage of these tools, datasets are required for training and testing. However, building machine learning datasets for astronomy can be challenging. Astronomical data is collected from instruments built to explore science questions in a traditional fashion rather than to conduct machine learning. Thus, it is often the case that raw data, or even downstream processed data is not in a form amenable to machine learning. We explore the construction of machine learning datasets and we ask: what elements define effective machine learning datasets? We define effective machine learning datasets in astronomy to be formed with well-defined data points, structure, and metadata. We discuss why these elements are important for astronomical applications and ways to put them in practice. We posit that these qualities not only make the data suitable for machine learning, they also help to foster usable, reusable, and replicable science practices. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.14401v2

    1 phút

  7. 30/11/2022

    Estimating effective wind speed from Gemini Planet Imager's adaptive optics data using covariance maps

    Estimating effective wind speed from Gemini Planet Imager's adaptive optics data using covariance maps by Daniel M. Levinstein et al. on Wednesday 30 November The Earth's turbulent atmosphere results in speckled and blurred images of astronomical objects when observed by ground based visible and near-infrared telescopes. Adaptive optics (AO) systems are employed to reduce these atmospheric effects by using wavefront sensors (WFS) and deformable mirrors. Some AO systems are not fast enough to correct for strong, fast, high turbulence wind layers leading to the wind butterfly effect, or wind-driven halo, reducing contrast capabilities in coronagraphic images. Estimating the effective wind speed of the atmosphere allows us to calculate the atmospheric coherence time. This is not only an important parameter to understand for site characterization but could be used to help remove the wind butterfly in post processing. Here we present a method for estimating the atmospheric effective wind speed from spatio-temporal covariance maps generated from pseudo open-loop (POL) WFS data. POL WFS data is used as it aims to reconstruct the full wavefront information when operating in closed-loop. The covariance maps show how different atmospheric turbulent layers traverse the telescope. Our method successfully recovered the effective wind speed from simulated WFS data generated with the soapy python library. The simulated atmospheric turbulence profiles consist of two turbulent layers of ranging strengths and velocities. The method has also been applied to Gemini Planet Imager (GPI) AO WFS data. This gives insight into how the effective wind speed can affect the wind-driven halo seen in the AO image point spread function. In this paper, we will present results from simulated and GPI WFS data. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16441v1

    1 phút

  8. 30/11/2022

    Estimating effective wind speed from Gemini Planet Imager's adaptive optics data using covariance maps

    Estimating effective wind speed from Gemini Planet Imager's adaptive optics data using covariance maps by Daniel M. Levinstein et al. on Wednesday 30 November The Earth's turbulent atmosphere results in speckled and blurred images of astronomical objects when observed by ground based visible and near-infrared telescopes. Adaptive optics (AO) systems are employed to reduce these atmospheric effects by using wavefront sensors (WFS) and deformable mirrors. Some AO systems are not fast enough to correct for strong, fast, high turbulence wind layers leading to the wind butterfly effect, or wind-driven halo, reducing contrast capabilities in coronagraphic images. Estimating the effective wind speed of the atmosphere allows us to calculate the atmospheric coherence time. This is not only an important parameter to understand for site characterization but could be used to help remove the wind butterfly in post processing. Here we present a method for estimating the atmospheric effective wind speed from spatio-temporal covariance maps generated from pseudo open-loop (POL) WFS data. POL WFS data is used as it aims to reconstruct the full wavefront information when operating in closed-loop. The covariance maps show how different atmospheric turbulent layers traverse the telescope. Our method successfully recovered the effective wind speed from simulated WFS data generated with the soapy python library. The simulated atmospheric turbulence profiles consist of two turbulent layers of ranging strengths and velocities. The method has also been applied to Gemini Planet Imager (GPI) AO WFS data. This gives insight into how the effective wind speed can affect the wind-driven halo seen in the AO image point spread function. In this paper, we will present results from simulated and GPI WFS data. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16441v1

    1 phút
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Giới Thiệu

Daily Astro papers on the arXiv in astro-ph.IM.

Thông Tin

  • Kênh
    Astro arXiv
  • Nhà sáng tạo
    Corentin Cadiou
  • Năm hoạt động
    2 N
  • Tập
    116
  • Xếp hạng
    Sạch
  • Bản quyền
    © Copyright (c) 2022 Corentin Cadiou and University College London
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