HEASA 2026 (29 Sep - 02 Oct)

Session

Transients 3 / Multi-Messenger

1 Oct 2026, 10:30

Description

Chair: Anna Luashvili

61. Extending the Cosmic Distance Ladder to High Redshifts with Gamma-Ray Bursts

Tamador Aldowma (Johannesburg University, Omdurman Islamic University)

01/10/2026, 10:30

GRBs, FRBs and other Transients

Contributed Talk

Gamma-ray bursts (GRBs) can extend cosmological studies beyond the redshift range of Type Ia supernovae (SNe Ia), but their calibration is affected by the circularity problem. We apply LADDER, a deep-learning reconstruction trained on Pantheon+ SNe Ia, to obtain a model-independent distance-redshift relation. Building a self-contained calibration pipeline applied directly to raw Fermi-GBM...

70. The use of simulated spectra for machine learning methods with the Fermi GBM catalogue

Saeeda Sajjad (Theoretical Research Institute, Pakistan Academy of Sciences (TRIPAS), Pakistan, Centre for Astro-Particle Physics (CAPP), University of Johannesburg, South Africa)

01/10/2026, 10:43

GRBs, FRBs and other Transients

Contributed Talk

Machine learning approaches based on the Fermi GBM catalogue data typically use parameters such as the duration of the bursts, its fluence or flux along with various parameters obtained from spectral fits. These approaches typically ignore the error on the spectral parameters. Yet, these errors also contain information about the GRB. In this work, we use the errors on the spectral parameters...

26. Multiwavelength Study of the Candidate Neutrino Blazar PKS~0215+015 During the IceCube-220225A Epoch

Athira M Bharathan (North-West University, South Africa)

01/10/2026, 10:56

1

Multi-Messenger Astrophysics and Astro-Particle Physics

Contributed Talk

The flat-spectrum radio quasar PKS~0215+015 ($z \simeq 1.715$) was found to be positionally and temporally coincident with the IceCube neutrino event IceCube-220225A, detected on 25~February~2022 with a reconstructed energy of $\sim$154~TeV. The source was the only $\gamma$-ray emitter within the 90\% neutrino localisation region and was independently confirmed to be in an elevated...

53. Multi-frequency views of high-redshift dark matter halos

Geoff Beck

01/10/2026, 11:09

Multi-Messenger Astrophysics and Astro-Particle Physics

Contributed Talk

Indirect dark matter searches have historically concentrated on the nearby universe. In this work we explore whether higher redshift objects $z \gtrsim 0.1$ could be an under-utilised resource in the search for the fundamental nature of dark matter. We do so by exploring MeerKAT observations of higher redshift galaxy clusters and considering current and future gamma-ray experiment...

60. Probing Dark Matter-Photon Interactions with High Energy Gamma-Ray Observations

Khushboo Dixit

01/10/2026, 11:22

Multi-Messenger Astrophysics and Astro-Particle Physics

Contributed Talk

High-energy astrophysical messengers provide a unique probe of possible non-gravitational interactions of dark matter. In particular, gamma rays produced in the vicinity of supermassive black holes may traverse large dark-matter column densities, especially in the presence of dense dark-matter spikes, and can consequently be attenuated through dark matter–photon scattering. In this work, we...