Multi-messenger astrophysics

The paper examines the "Matthew Effect" in science, where more well-known scientists or institutions tend to receive a disproportionate amount of credit for discoveries, even in collaborative efforts. This effect extends to large research collaborations, as demonstrated by the case of the LIGO, Virgo, and KAGRA collaborations. While LIGO, Virgo, and KAGRA have been working together since 2007 and co-author all their gravitational-wave observation papers, the wider scientific community often overlooks the contributions of Virgo and KAGRA, attributing most of the credit to LIGO. The paper identifies three main types of issues: Attributing the first gravitational wave detection, GW150914, solely to LIGO, even though the discovery was a collaborative effort. Downplaying the crucial role of Virgo in the discovery of GW170817, the first confirmed merger of compact stars. While the signal was detected only by LIGO, Virgo's data enabled precise sky localization, crucial for multimessenger observations. Attributing overall science results and future projections in the field to LIGO alone. The authors' efforts resulted in about half of the problematic papers being corrected. However, the study found no significant difference in the citation impact of corrected versus uncorrected papers. This suggests that more work is needed to understand the social dynamics of this cognitive bias and to promote a more equitable recognition of scientific contributions in large collaborations. Publication: P. Barneo et al., "Addressing the problem of the LIGO-Virgo-KAGRA visibility in the scientific literature", The European Physical Journal H, (2024) 49:2 (arXiv:2402.03359) Acknowledgements: Image credit ICRR, Univ. of Tokyo/LIGO Lab/Caltech/MIT/Virgo Collaboration. The podcast was created with Google/NotebookLM.

Ultra-high-energy cosmic rays (UHECRs) are a mystery. Scientists still don’t know where or how they are created. A new study combines three kinds of data measured at the Auger Observatory: the energy spectrum, shower maximum depth distributions, and arrival directions of UHECRs. Publication: A.A. Halim et al., "Constraining models for the origin of ultra-high-energy cosmic rays with a novel combined analysis of arrival directions, spectrum, and composition data measured at the Pierre Auger Observatory", JCAP 01 (2024) 022 Acknowledgements: Image credits Pierre Auger Observatory. The podcast was created with Google/NotebookLM

GRB 201216C, a long GRB, was observed by numerous instruments, including Swift-BAT, Fermi-GBM, and the MAGIC telescopes. MAGIC detected GRB 201216C at a redshift of z = 1.1, making it the farthest known source detected at VHE gamma rays. Modeling of GRB 201216C's multiwavelength data, including the MAGIC observations, favors a scenario where the GRB jet is expanding into a wind-like medium shaped by the progenitor star. This is consistent with the observed light curves and SEDs. Publication: H. Abe et al., "MAGIC detection of GRB 201216C at z = 1.1", MNRAS 527, 3 (2024), 5856–5867 Acknowledgement: Illustration credits Gabriel Pérez Díaz (IAC). The podcast was produced by Google/NotebookLM

This episode explores the search for Galactic PeVatrons, powerful cosmic accelerators that boost cosmic rays to PeV energies (1 PeV = 10^15 eV). The study, conducted by researchers using the HAWC gamma-ray observatory and the IceCube Neutrino Observatory, focuses on identifying neutrino emission from known gamma-ray sources. The study focused on 22 gamma-ray sources detected by HAWC. The researchers first used HAWC data to create a detailed spatial and spectral model for each gamma-ray source. They then combined this information with IceCube neutrino data, looking for evidence of neutrino emission from the same locations. The researchers did not find any significant evidence of neutrino emission from any of the 22 gamma-ray sources. Publication: R. Alfaro et al., "Search for joint multimessenger signals from potential Galactic PeVatrons with HAWC and IceCube", arXiv:2405.03817 Acknowledgements: Illustration credits WIPAC, Department of Physics, UW–Madison. Podcast created with Google/NotebookLM.

Millisecond pulsars (MSPs) are incredibly stable rotators and can be used as extremely precise clocks. Pulsar Timing Arrays (PTAs) monitor a collection of these pulsars to detect gravitational waves (GWs). GWs affect the arrival times of pulses from these pulsars, causing tiny, correlated fluctuations. There are four main PTAs: The European Pulsar Timing Array (EPTA) combines data from five major European radio telescopes and the synthesized Large European Array for Pulsars (LEAP). The Indian Pulsar Timing Array (InPTA), focusing on low-frequency observations, uses data from the upgraded Giant Metrewave Radio Telescope (GMRT). The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) utilizes data from the Arecibo Observatory, Green Bank Telescope, Very Large Array, and the Canadian Hydrogen Intensity Mapping Experiment (CHIME). The Parkes Pulsar Timing Array (PPTA) in Australia employs the Parkes radio telescope The most recent PTA data sets have yielded promising results. They have all detected CRN and the PPTA, NANOGrav, EPTA, and InPTA have found evidence of quadrupolar correlations in this noise, suggesting the presence of a GW background. This is a major step towards a definitive GW detection and opens up exciting possibilities for understanding the universe through GWs in the nanohertz frequency range. Publication: J. Verbiest et al., "Status Report on Global Pulsar-Timing-Array Efforts to Detect Gravitational Waves", arXiv:2404.19529 Acknowledgements: Image credit: David J. Champion. Podcast created by Google/NotebookLM

This paper proposes that binary neutron star mergers are the source of ultrahigh energy cosmic rays (UHECRs). The authors argue that these mergers produce jets with nearly universal maximum rigidities, explaining the observed narrow range of rigidities in UHECRs. The paper also explains how the rate of these mergers, the power of their jets, and the production of heavy nuclei like tellurium during the merger process all contribute to the observed properties of UHECRs. The authors also predict that neutrinos should be detected alongside gravitational waves from these mergers, providing a testable prediction of their theory. Publication: G. Farrar, "Binary neutron star mergers as the source of the highest energy cosmic rays", arXiv:2405.12004 Acknowledgements: Illustration credtis: NASA/Goddard Space Flight Center. Podcast created by Google/NotebookLM

SN 2023ixf provided the earliest ever detection of shock breakout from a supernova. The red supergiant progenitor star had a radius of about 440 solar radii. Early observations revealed that the light curves evolved very rapidly (timescales of 1-2 hours), appearing fainter and redder than models predicted. The study authors attribute this to an optically thick dust shell surrounding the star that was destroyed as the shockwave passed through. Based on the best fit models, the study authors conclude that the shock breakout, and possibly the dust shell itself, were not spherically symmetric. Publications: Li et al., "A Shock Flash Breaking Out of a Dusty Red Supergiant", Nature 627, pages 754-758 (2024) Kilpatrick et al. (2023) "SN 2023ixf in Messier 101: A Variable Red Supergiant as the Progenitor Candidate to a Type II Supernova", 2023 ApJL 952 L23 Grefenstette et al., "Early Hard X-rays from the Nearby Core-Collapse Supernova SN2023ixf", 2023 ApJL 952 L3 Acknowledgements: Illustration from A. Singh et al. (arXiv:2405.20989). Podcast created with Google/NotebookLM.

Description: Tilepy is an open-source platform revolutionizing multi-messenger astrophysics by optimizing the scheduling of follow-up observations for events with large sky localization uncertainties, such as gravitational waves, gamma-ray bursts, and high-energy neutrinos. Main Points ● What is Tilepy? Tilepy is a Python package designed to efficiently schedule observations by correlating galaxy distributions with 3D localization information and optimizing observation strategies across the electromagnetic spectrum. ● How does it work? Tilepy employs sophisticated algorithms that take into account telescope visibility and observability constraints to create observation plans that prioritize the most probable regions of an event. ● Key features: ○ Automatic generation of optimized observation plans. ○ Versatility for various transient events. ○ Integration with Astro-COLIBRI for user-friendly scheduling via web and smartphone apps. ○ Customization options for individual needs and research objectives. ● Real-world impact: Tilepy is the default scheduling tool for high-energy gamma-ray observatories like H.E.S.S. and CTA/LST-1. It was instrumental in the rapid follow-up of GW170817, allowing H.E.S.S. to be the first ground-based instrument to observe the merger location. ● Accessibility: Tilepy is an open-source project available on GitHub, encouraging community contributions and collaboration. Pronunciation: "Tile-pie" ;-) Main Papers: ● M. Seglar-Arroyo et al., “Cross-Observatory Coordination with tilepy: A Novel Tool for Observations of Multi-Messenger Transient Events”, ApJS 274 1 (2024) ● H. Ashkar et al., "The H.E.S.S. gravitational wave rapid follow-up program", JCAP 03 (2021) 045 Additional Resources ● Tilepy GitHub repository: https://github.com/astro-transients/Tilepy ● Tilepy website: https://tilepy.com ● Astro-COLIBRI platform: https://astro-colibri.science Illustration from tilepy.com. Podcast created with Google/NotebookLM.

Episode Title: Unveiling the Secrets of the BOAT (GRB 221009A) Description: Explore the awe-inspiring power and scientific significance of GRB 221009A, the brightest gamma-ray burst ever recorded. Join us as we unpack the observations from multiple telescopes, including Fermi-LAT, LHAASO, and H.E.S.S., to understand the mechanisms behind this extraordinary event. Key Talking Points: Unprecedented Brightness: We'll discuss how GRB 221009A's brightness caused a Bad Time Interval (BTI) for the Fermi-LAT instrument due to the intense flux of X-rays and soft gamma rays. Multiwavelength Observations: Discover how observations from the Fermi Large Area Telescope (LAT), the Large High Altitude Air Shower Observatory (LHAASO), and the High Energy Stereoscopic System (H.E.S.S.) provided crucial insights into the burst's behavior across a wide energy range. Challenging Existing Models: Learn how the high-energy emissions observed challenge traditional synchrotron models and point towards the possibility of synchrotron self-Compton (SSC) radiation as a key contributor. Record-Breaking Photon: We'll examine the detection of a remarkable 400 GeV photon by Fermi-LAT and a record-breaking 18 TeV photon by LHAASO, pushing the boundaries of our understanding of GRB physics. Links to Papers: Fermi-LAT Collaboration Paper: https://arxiv.org/abs/2409.04580v1 H.E.S.S. Collaboration Paper: https://iopscience.iop.org/article/10.3847/2041-8213/acc405/pdf LHAASO Collaboration Papers: https://www.science.org/doi/10.1126/science.adg9328 https://www.science.org/doi/10.1126/sciadv.adj2778 Acknowledgements: Illustration from NASA/Swift/Cruz deWilde. Podcast created by Google/NotebookLM.

Shownotes for a Podcast Episode: Unprecedented Energy in Gamma-Ray Bursts Topic: A New Era of Gamma-Ray Burst Astronomy Introduction: Gamma-ray bursts (GRBs) are brief, intense flashes of gamma-ray radiation originating from distant galaxies. They are the most powerful explosions known in the universe. These bursts occur in two distinct phases: the prompt emission, a short, bright burst of gamma rays, and the afterglow, a longer-lasting emission spanning various wavelengths. While GRB afterglows are typically observed in wavelengths like radio waves and X-rays, recent observations have revealed an unexpected phenomenon – the presence of very-high-energy (VHE) gamma rays, specifically at teraelectronvolt (TeV) energies. Unveiling the Unexpected: This episode explores three groundbreaking studies that detail the first-ever observations of TeV emission from GRB afterglows. The three GRBs in focus are GRB 180720B, GRB 190114C, and GRB 190829A. These discoveries were made possible by sophisticated ground-based gamma-ray telescopes like the High Energy Stereoscopic System (H.E.S.S.) and the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes. These telescopes employ the ingenious method of imaging atmospheric Cherenkov telescopes, which capture the extremely faint, short flashes of Cherenkov radiation produced when VHE gamma rays collide with particles in Earth's atmosphere. Implications and the Future of GRB Astronomy: These observations have revolutionized our understanding of GRBs. They have unearthed a previously unknown emission component in GRB afterglows, challenging existing models and pushing the boundaries of our knowledge regarding particle acceleration in these extreme environments. As we enter a new age of GRB astronomy, it is essential to continue studying these powerful events. New and more powerful observatories, like the Cherenkov Telescope Array Observatory (CTAO), will be critical in further refining our understanding. References: "A very-high-energy component deep in the γ-ray burst afterglow" - https://www.nature.com/articles/s41586-019-1743-9 "Teraelectronvolt emission from the γ-ray burst GRB 190114C" - https://www.nature.com/articles/s41586-019-1750-x "Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow" - https://www.science.org/doi/10.1126/science.abe8560 Acknowledgements: Illustration from Desy-Zeuthen/Science Communication Lab. Podcast produced with Google/NotebookLM

Astro-COLIBRI is a platform designed for real-time exploration of extreme astronomical events, facilitating multi-messenger astrophysics research. The platform offers a user-friendly interface and state-of-the-art architecture, enabling astronomers worldwide to identify and observe events across various timescales. Astro-COLIBRI has been used in several research projects and has been featured in various publications, including articles by the SETI Institute and CNET. The platform also hosts workshops and events related to multi-messenger astrophysics. Created with the help of Google/NotebookLM.