Identification of Gamma-Ray Point Sources in Fermi-LAT Data with Minimum Spanning Tree Algorithm

Document Type : Research Paper

Authors

1 Department of Physics, K.N. Toosi University of Technology, Tehran, Iran

2 Department of Physics, K.N Toosi University of Technology, 4 P.O. Box 15875-4416, Tehran, Iran

Abstract

Gamma rays are the most energetic photons in the electromagnetic spectrum, detected with ground-based and space-based detectors in different energy ranges from sources in our galaxy and beyond. Gamma-ray point sources can be identified by special clustering of these photons. The minimum spanning tree (MST) algorithm is a graph-based method in order to find clusters. In this paper, we use the MST algorithm for finding point sources in Fermi gamma-ray space telescope data which is sensitive to photons with energies of 20 MeV up to more than 300 GeV. To this end, we selected eight completely random (10°×10°) fields of Fermi gamma-ray sky and tested the algorithm on the 12-year Fermi-LAT sky (Pass 8) at energy ranges above 3 GeV and above 6 GeV and with different cluster selection criteria. The calculation of Precision and Recall for both fields shows that MST is a useful algorithm in order to identify the point.

Keywords


[1] De Angelis, A., & Mallamaci, M. 2018, EPJ Plus, 133.
[2] Albert, A., & et al. 2020, ApJ, 903, L14.
[3] Atwood, W. B., Abdo, A. A., Ackermann, M., & et al. 2009, ApJ, 697, 1071.
[4] Abdollahi, S., Acero, F., Baldini, L., & et al. 2022, ApJS, 260, 53.
[5] Campana, R., Bernieri, E., Massaro, E., & et al. 2013, Astrophys Space Sci., 347, 169.
[6] Campana, R., Massaro, E., Gasparrini, D., & et al. 2008, MNRAS, 383, 3.
[7] Campana, R., Massaro, E., Bocchino, F., Miceli, M., & et al. 2022, MNRAS, 515, 1676.
[8] Campana, R., & Massaro, E. 2021, A&A, 652, A6.
[9] Campana, R., Massaro, E., & Bernieri, E. 2018, A&A, 619, A23.
[10] Fränti, P., & Mariescu-Istodor, R. 2023, Pattern Recogn. Lett., 167, 115.