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The Tilepy Platform: Multi-Messenger Astrophysics at your fingertips

Tilepy creates optimized observation schedules for gravitational waves, gamma-ray bursts and neutrino alerts, making coordinated follow-up faster and easier.

Tilepy is a cutting-edge platform designed to optimize and facilitate the scheduling of follow-up observations of multi-messenger events. Developed over the last eight years by a dedicated team of researchers at IRFU, led by myself, the team includes former PhD students Monica Seglar-Arroyo and Halim Ashkar, who began their contributions during their doctoral studies, as well as postdoc Mathieu de Bony de Lavergne. Tilepy, now publicly accessible, offers innovative and easy to use solutions for scheduling follow-up observations of events like gravitational waves (GW), gamma-ray bursts (GRB), and high-energy neutrinos. Tilepy has already been adopted by the international H.E.S.S. and CTA/LST-1 observatories as the default scheduling tool for multi-messenger studies.

​Multiwavelength observations scheduled across multiple, very different observatories searching for the electromagnetic counterpart of (a simulated) gravitational wave event.

Key Features:

  1. Optimized Observation Scheduling: Tilepy automatically derives optimal follow-up observation plans, taking into account telescope visibility and observability constraints. This ensures that the most probable regions to host the astrophysical event are prioritized.
  2. Versatile Application: Initially developed for GW follow-up during LIGO-Virgo Collaboration’s Observing Run O2, Tilepy’s current version supports various poorly localized transient events with uncertainty regions provided by HEALPix maps.
  3. Integration with Astro-COLIBRI: The Tilepy API is seamlessly integrated into the Astro-COLIBRI platform, providing a user-friendly interface for scheduling observations via web and smartphone apps. Scheduling complex follow-up observations are now as simple as the click of a button.
  4. Easy-to-use but Flexible and Customizable: Tilepy can be employed either automatically or manually, tailored to specific collaboration and individual requirements. While most observation plans are easily accessible via a public API, users can fine-tune and configure detailed observability constraints, adapt all intrinsic parameters like the required resolution, and choose between different algorithms to suit their scientific objectives using the Tilepy code and its extensive examples and tutorials.

Scheduling complex follow-up observations of multi-messenger events has never been easier thanks to the integration of Tilepy into the Astro-COLIBRI interfaces. ​

**​Supporting Multi-Messenger Astronomy
**Tilepy’s capabilities are showcased through its application in various multi-observatory, multi-wavelength campaigns. It is currently the default scheduling tool for searches of high-energy gamma-ray emission with the H.E.S.S. and CTA/LST-1 observatories [2]. Tilepy played a pivotal role in the H.E.S.S. multi-messenger campaign of GW170817, the first detected neutron star merger, scheduling observations that allowed H.E.S.S. to be the first ground-based instrument to observe the merger location and this several hours before the discovery of the optical counterpart [3]. Tilepy has since been extended and can now be used to efficiently schedule observations across the full electromagnetic spectrum from radio waves to the highest energy gamma-rays.

**Open Source and Community-Driven
**As an open-source project, Tilepy invites contributions from the global research community. The code is available on GitHub, and we welcome feedback and collaboration to continuously improve its functionalities.

**Recent Publication
**Tilepy has been detailed in a recently published article in the Astrophysical Journal Supplement Series (ApJS 274 (2024) 1). This publication provides an in-depth look at the algorithms and performance of Tilepy, further establishing its significance in the field of multi-messenger astrophysics.

For more information and to access the Tilepy code, visit our GitHub repository (https://github.com/astro-transients/Tilepy) and the official Tilepy website (https://Tilepy.com). In addition, the Astro-COLIBRI platform (https://astro-colibri.science) is providing an integrated experience to Tilepy’s scheduling capabilities.

**Contact and Support
**For questions, support, and further discussions, visit the Astro-COLIBRI forum (https://forum.astro-colibri.science/c/instrumentation-and-tools/Tilepy) or reach out to the Tilepy team at [email protected]. 

References:
[1] M. Seglar-Arroyo et al., “Cross-Observatory Coordination with tilepy: A Novel Tool for Observations of Multi-Messenger Transient Events”, ApJS 274 (2024) 1
[2] H. Ashkar et al., “The H.E.S.S. gravitational wave rapid follow-up program”, JCAP 03 (2021) 045 
[3] Abdalla H. et al. (H.E.S.S. Collaboration), “TeV gamma-ray observations of the binary neutron star merger GW170817 with H.E.S.S.”, Astrophys. J. Lett. 850 L22