Projects / Programmes
Detectablity of GRBs at the Pierre Auger Observatory
| Code |
Science |
Field |
Subfield |
| 1.02.03 |
Natural sciences and mathematics |
Physics |
Astronomy |
| Code |
Science |
Field |
| P211 |
Natural sciences and mathematics |
High energy interactions, cosmic rays |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
gamma ray bursts, high energy emission, cosmic rays, neutrinos, gamma rays, gravitational waves, multi-messenger
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
36945 |
PhD Lili Yang |
Physics |
Head |
2017 - 2018 |
263 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
1540 |
University of Nova Gorica |
Nova Gorica |
5920884000 |
14,072 |
Abstract
Gamma-Ray Bursts (GRBs) are the most violent explosion across the sky, being proposed as the origin of the ultra high energy cosmic rays (UHECRs) with energies above 1018 eV.
During the explosion, the shock regions are formed, where the cosmic rays are accelerated and high energy gamma rays are produced via synchrotron and Inverse Compton. During the propagation of UHECRs, they interact with ambient material and radiation fields, leading to the generation of neutrinos.
The recently discovered gravitational wave (GW) events by the advanced LIGO interferometers are believed to originate in the mergers of two black holes, which are one of the suspect progenitors of a subclass of GRBs (short GRBs). It is natural to search for GRB events coincident with GW events. It is clear that multi‐messenger observational campaigns are needed to reveal the progenitors and properties GRBs. We live in a privileged time in which we have many highly sensitive observatories simultaneously observing the sky. In this project, we will in particular benefit from the high energy data from the following experiments: Fermi, LIGO, IceCube and the Pierre Auger Observatory (PAO).
In particular, we will search of last 15 years' PAO data for ultra-high energy neutrinos from GRBs, with the selection criteria, which has been well established by PAO. In case of no neutrino candidate found, we will derive the most stringent limits on individual GRB flux and diffuse neutrino flux in the EeV energy range, complementary to IceCube and ANTARES. Also we will simulate GRB neutrino production with the tools of Simulations Of Photo Hadronic Interactions in Astrophysics (SOPHIA) and NeuCosmA and put constraints on existing models, such as the emission radius and the bulk Lorentz factor. In addition to the search for neutrinos, we will apply the novel “single particle technique” to search for coincident GeV photons from GRBs of PAO data. This technique has recently been shown to be promising for transient events by our group and we will apply here for the first time for the GRB search. This method is based on the fact that if the high-energy emission of GRBs is sufficiently intense, the isolated particles at the ground could lead to significant excess when compared with the background fluctuations. On a time scale of one second, one would therefore see an increase of the background rate on all the detectors.
In the next step, we will search for cross-correlations between single GRBs, and the highest-energy cosmic rays collected at PAO during the past 10 years. A coincidence between the arrival directions of an UHECR and GRB can be determined as an event where the angle between the directions of the two events is less than the joint error box or less than 10 degree. When the pairs of UHECR-GRB have been established, Monte Carlo simulation will be run to test the significant statistics.
In addition to PAO data we will also study the sensitivity of the Cherenkov Telescope array (CTA) to the GRB signals. The sensitivity studies needed to optimize the observational strategy of the array are therefore timely, and within this project we will test the sensitivity of CTA to these transients for our future study as well. With the simulated gamma-ray flux for some special GRBs with high energy gamma ray emission, we will see within up to few hundreds seconds if and how CTA can catch these GRBs.
In summary, GRBs are center stage in the new era of multi-messenger astronomy, as their nature is probed via photons, neutrinos, gravitational waves and cosmic rays. With our study in the global network of observatories, we foresee the next few years will find the revolutionary discovery of the first GRB as the crowning achievement for this joint international collaboration.
Significance for science
Gamma-ray bursts (GRBs) as powerful lights of the early Universe and extreme physical laboratories, are one of the hottest topics in astrophysics and in the center stage of multi-messenger era. It’s an exciting time in the GRB field, thanks to various space satellites and ground-based observatories. The discoveries of cosmic rays, neutrinos, photons and gravitational waves from GRBs will permit unprecedented insights in their nature and origin. Moreover, GRBs are a key ingredient for understanding the stellar evolution and early galaxies.
Pierre Auger Observatory (PAO) as the world’s largest ultra high energy cosmic ray (UHECR) detector in the world, has gained a big success in the observation of these energetic particles. In this work, the detectability of GRBs at PAO will be verified through the search of neutrinos and photon burst and cross-correlation with UHECRs. More important, with PAO one indispensable part of the global network of multi-messenger instruments, we will develop observational strategies and perform data analysis to interpret discoveries. We believe with the efforts of joint international collaboration, the first revolutionary detections will be achieved.
Significance for the country
Astrophysics as a basic science probes the properties of nature and advances the fundamental knowledge of society as a whole. The discovery of GRBs these distant transient phenomena will be a spectacular to understand the Universe and basic physical laws in nature. In turn, to achieve more success, the development and diffuse technological innovations will be motivated. The direct impact of the project on the economy and society arises through the possibility of a transfer of knowledge and state-of-the-art techniques, developed for use at International Research Collaborations. This will advance the technological and general development of the society.
Most important scientific results
Interim report,
final report
Most important socioeconomically and culturally relevant results
Interim report,
final report
