Conveners
Galactic Sources: I - Chernoff Auditorium
- Lars Mohrmann (Max Planck Institute for Nuclear Physics, Heidelberg)
Galactic Sources: II - Chernoff Auditorium
- Robert B.
Galactic Sources: III - Humphrey Auditorium
- Julian Sitarek
Galactic Sources: IV - Humphrey Auditorium
- Sajan Kumar (University of Maryland, College Park)
Supernova remnants are known to accelerate cosmic rays from the detection of non-thermal emission of radio waves, X-rays, and gamma rays. The presence of cut-offs in the gamma-ray spectra of several young SNRs led to the idea that the highest energies might only be achieved during the very initial stages of a remnant’s evolution. Unfortunately, the gamma-ray luminosity is assumed to peak in...
The origin of the cosmic rays (CRs) is a complex problem that requires a proper understanding of the CR's acceleration, diffusion, and radiation mechanisms. However, observations suggest that these properties of CRs depend highly on the initial supernova explosion conditions and the structure of the ambient material into which a supernova remnant (SNR) expands. Therefore, a source-by-source...
Supernova remnants (SNRs) are known to accelerate particles to relativistic energies, from the detection of nonthermal emission. The particularities of the acceleration mechanism are still debated. Here, we discuss how particle escape modifies the observable spectra as well as morphological features that might be revealed by the observational progress from radio to gamma-ray energies.
We...
More than a decade after their discovery, the mechanism behind the Fermi bubbles features is still elusive. The two main models considered for the advection of cosmic-rays (CRs) are a jet model for leptonic process or wind model for hadronic process. An alternative has been proposed where CRs, produced by pp collisions, are both diffused and advected by a Galactic breeze, ie a subsonic...
Galactic PeVatrons are astrophysical sources accelerating particles up to a few PeV ($\sim$10$^{15}$ eV). The primary identification of both electron and proton PeVatrons is gamma-ray radiation at ultra-high energies (UHE, E$>$100 TeV). Recently, LHAASO detected 14 steady gamma-ray sources with photon energies above 100 TeV and up to 1.4 PeV. Most of these sources contain possible source...
LHAASO J2108+5157 is the first gamma-ray source directly discovered in the Ultra-High-Energy band by the LHAASO collaboration. Two molecular clouds identified in the direction towards LHAASO J2108+5157 make the source a promising galactic PeVatron candidate. In 2021, the Large-Sized Telescope prototype (LST-1) of the Cherenkov Telescope Array (CTA) Observatory performed observations of LHAASO...
The supernova remnant SNR G106.3+2.7 in the proximity of the Boomerang PWN has recently gained a lot of attention due to the emission above 100 TeV detected by HAWC, Tibet ASγ, and LHAASO. This SNR shows a characteristic comet-like morphology in radio observations, with a head and a tail. Due to the limited angular resolution of air shower experiments, it is not clear if the emission comes...
W50/SS433 is a complex and fascinating system that represents an important test bed for many astrophysical processes. Powered by the microquasar SS 433, the W50 nebula — classified as a supernova remnant with an unusual double-lobed morphology reminiscent of a Manatee — has been proposed to be a Galactic PeVatron candidate; a scenario that has been recently revived with the detection of very...
The recent detection of the Geminga PWN by HAWC in the multi-TeV band allows us to infer precious information about the transport of pairs in the immediate surroundings of the pulsar and on the spectrum of pairs contributed by a Geminga-like pulsar to the spectrum of pairs in the cosmic radiation. Moreover, this detection allows us to address the issue of how typical are the so-called TeV...
The VERITAS imaging atmospheric Cherenkov telescope array has been operating regularly since 2007. One of the key science programs for VERITAS throughout its lifetime has been searching for and monitoring gamma-ray binary systems. These systems are comprised of a massive star and a compact object, either black hole or neutron star, with the peak energy output of their emission occuring in the...
TeV halos have become a new class of astrophysical objects which were not predicted before their recent observation. They offer evidence that diffusion around sources (concretely, pulsars) is not compatible with the effective average diffusion that our models predict for the Galaxy. This directly impacts Galaxy formation, our knowledge of the propagation process throughout the Galaxy and our...
LS 5039 is a high mass X-ray binary with an orbital periodicity of 3.9 days located about 1.5 degrees from the galactic plane. Previously, the H.E.S.S. telescope detected very high energy gamma-ray emissions from this source and measured the spectral energy in a broad inferior conjunction phase (0.45<phi<0.9) and a complimentary superior conjunction phase. However, the behavior of the...
The high flux of hadronic cosmic rays and the detection of bright gamma-ray sources suggest a tight connection between them, which implies that Galactic neutrino sources must exist. However, none have been detected. Where are they? We outline constraints on the properties of hadronic PeVatrons based on the existing data. We introduce a new population-based approach, calibrated to the observed...
We investigate the hypothesis that hadrons are accelerated as a result of the reconnection of the White Dwarf magnetic field during the initial dense and fast wind in Nova explosion. Hadrons are expected to interact efficiently with a dense matter of the wind producing neutrinos with TeV energies. We estimate the muon neutrino event rates in the IceCube telescope in the case of a few Novae....
RS Ophiuchi (RS Oph) is a recurrent symbiotic nova. Its latest outburst, on 8th of August 2021, brought to the first detection of this class of sources in very-high-energy (above 100GeV) gamma rays. We present the MAGIC observations of RS Oph during this event, triggered by the Fermi-LAT detection of high energy gamma rays from this source. We characterize the emission from one day after the...
The Cherenkov Telescope Array (CTA) will be the next-generation ground-based gamma-ray observatory, and will achieve unprecedented sensitivity in the energy range between 20 GeV and 300 TeV. The Large-Sized Telescopes (LSTs) provide the best sensitivity in the lowest part of the CTA energy range. The prototype LST (LST-1) for CTA was inaugurated in 2018, on La Palma, the northern site of CTA....
