Ninth International Fermi Symposium

Session

Exploring Data Analysis

17 Apr 2021, 15:00

Conveners

Exploring Data Analysis: Parallel-13

• Benoit Lott (Centre d'Etudes Nucleaires de Bordeaux Gradignan (CENBG))

115. Point source location and classification at GeV energies using image segmentation and classification neural networks

Boris Panes, Christopher Eckner, Gabrijela Zaharijas, Gudlaugur Johannesson, Klaas Dijkstra, Luc Hendriks, Roberto Ruiz de Austri, Sascha Caron

17/04/2021, 15:00

Analysis Techniques

Contributed

At GeV energies, the sky is dominated by the interstellar emission from the Galaxy. With limited statistics and spatial resolution, accurate separation of point sources is therefore challenging. In this presentation I will describe the first application of deep learning based algorithms to detect and classify point sources from raw gamma-ray data. To detect point sources we utilise U-shaped...

116. A comprehensive power spectral density analysis of astronomical time series: the gamma-ray light curves of selected Fermi blazars

Natalia Zywucka

17/04/2021, 15:15

Analysis Techniques

Contributed

We present results of Fermi-Large Area Telescope (LAT) light curve (LC) modelling
of selected Fermi blazars. All objects possess densely sampled and long-term LCs. For
each blazar we generated three LCs with 7, 10, and 14 days binning, using the latest
4FGL catalogue and binned analysis provided within the fermipy package.
The LCs were modelled with several tools: the Fourier...

117. Eliminating single-band dominance in dual-band pulsar light curve fitting

Albertus Seyffert

17/04/2021, 15:30

Analysis Techniques

Contributed

The wealth of multiwavelength pulsar data has stimulated the development of emission models that predict light curves (LCs) over multiple wavebands, most notably radio and gamma-ray. Using established statistical methods to fit these model LCs to data can prove ineffectual if the data from one waveband are substantially more precise. This waveband—typically radio—dominates the fit and biases...

118. Assessment of the data-model agreement in Fermi-LAT data analysis

Philippe Bruel

17/04/2021, 15:45

Analysis Techniques

Contributed

An important step of a Fermi-LAT data analysis of a Region of Interest consists in performing a binned likelihood fit to find the sky model that, after convolution with the instrument response, best predicts the number of observed counts. The data and model counts are binned in a 3d grid, with two spatial and one spectral dimensions. Checking the goodness-of-fit is not straightforward because...

119. An observational determination of the extragalactic background light from the HST/CANDELS survey in the Fermi and CTA era

Alberto Saldana-Lopez

17/04/2021, 16:00

Analysis Techniques

Contributed

The diffuse extragalactic background light (EBL) is formed by ultraviolet (UV), optical, and infrared (IR) photons mainly produced by star formation processes over the history of the Universe, and contains essential information about galaxy evolution and cosmology. In this talk, we present a new determination of the evolving EBL spectral energy distribution using a novel approach purely based...

120. What Racing Distant Fermi GRB Photons Can Tell Us About our Universe

Robert Nemiroff

17/04/2021, 16:15

Analysis Techniques

Contributed

Do photons of different energies disperse as they race across the universe? Potential reasons for dispersion include violations of Lorentz invariance, violations of the weak equivalence principle, and electromagnetic interactions with the intervening matter. Which parameters make GRBs the most sensitive to these potential differences: their great distance, being seen over such a wide range of...