Gamma-ray catalogs produced with data of the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope typically integrate years of exposure. Since Active Galactic Nuclei (AGNs) are characterized by strong and fast variability, their emission is diluted by long-time data integration. Transient sources can be more easily detected over short time scales. In order to search for...
We report the results of cross-match between the hard X-ray and GeV gamma-ray catalogs, by making use of the latest 105-month Swift/BAT and 10-yr Fermi/LAT catalogs, respectively. We found 181 matched sources in total, which include 36 of false-match, unidentified, and ambiguous sources. The firmly matched sources consist of blazars (> 60%), pulsars and pulsar wind nebulae (∼10%), radio...
The Fermi Large Area Telescope (LAT) has been detecting hundreds of Galactic sources, most of which are pulsars. Many Galactic sources are still undetected or unresolved due to their low flux, below the Fermi LAT sensitivity, or because of foreground and source confusion. Moreover, among the many unassociated sources, which are one third of the detected sources, a large amount may have...
TeV DM candidates are gradually earning more and more attention within the community. Among others, extra-dimensional brane-world models may produce thermal DM candidates with masses up to 100 TeV, which could be detected with the next generation of very-high-energy gamma-ray observatories such as the Cherenkov Telescope Array (CTA).
In this work, we study the sensitivity of CTA to branon DM...
The release of the Fermi-LAT 4FGL catalog includes over 1,000 unidentified Fermi-LAT sources (roughly 25% of sources). One of the most successful ways to uncover their counterparts are through X-ray observations. Over their ~20 year lifetimes XMM-Newton and Chandra have observed a large number of Galactic fields, many of which contain unidentified Galactic Fermi-LAT sources. Often these fields...
Gamma-ray probes have historically been a gold-standard in indirect dark matter detection due to their smaller set of complicating factors and generally lower backgrounds. However, they are most optimally sensitive to the traditional supersymmetric WIMP annihilation channels and leptophilic channels (particularly for larger masses) are much harder to probe effectively in this manner. However,...
The Fermi LAT Fourth Source Catalog (4FGL) contains over 5000 gamma-ray sources detected using 8 years of LAT data. Among these sources, over 3000 are associated with known blazars, 239 are associated with pulsars, and over 1300 are classified as 'unassociated' sources, meaning they have no known plausible counterpart at any other wavelength. Following on our previous work on the 3FGL Catalog...
Recent studies of the effects on the Earth’s atmosphere by astrophysical sources, such as nearby gamma-ray bursts or supernovae, have shown that these events could lead to severe changes in atmospheric composition. Depletion of ozone, the most notable of these changes, is extremely dangerous to living organisms as any decrease in ozone levels leads to an increase in the irradiance of harmful...
