Publications (25)
A New Component from the Quiet Sun: Synchrotron Radiation from Galactic Cosmic-Ray Electrons
Elena Orlando, Vahe' Petrosian, Andrew Strong
The quiet Sun, i.e. in its non-flaring state or non-flaring regions, emits thermal radiation from radio to ultraviolet. The quiet Sun produces also non-thermal radiation observed i…
Discovery of GeV Emission from the Circinus galaxy with the Fermi-LAT
Masaaki Hayashida, Lukasz Stawarz, Chi C. Cheung +7
We report the discovery of gamma-ray emission from the Circinus galaxy using the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. Circinus is a nearby (~4 Mp…
Transport of Cosmic ray electrons from 1 AU to the Sun
Vahe' Petrosian, Elena Orlando, Andrew Strong
Gamma rays are produced by cosmic ray (CR) protons interacting with the particles at solar photosphere and by cosmic ray electrons and positrons (CRes) via inverse Compton scatteri…
A magnetised Galactic halo from inner Galaxy outflows
He-Shou Zhang, Gabriele Ponti, Ettore Carretti +12
Magnetic halos of galaxies are crucial for understanding galaxy evolution, galactic-scale outflows, and feedback from star formation activity. Identifying the magnetised halo of th…
Gamma-Ray Burst Detection with INTEGRAL/SPI
Andreas von Kienlin, Nikolas Arend, Giselher Lichti +2
The spectrometer SPI, one of the two main instruments of the INTEGRAL spacecraft, has strong capabilities in the field of Gamma-Ray Burst (GRB) detections. In its 16 deg field of v…
Cosmic Rays and Interstellar Medium with Gamma-Ray Observations at MeV Energies
Elena Orlando, Isabelle Grenier, Vincent Tatischeff +10
Latest precise cosmic-ray (CR) measurements and present gamma-ray observations have started challenging our understanding of CR transport and interaction in the Galaxy. Moreover, b…
Galactic synchrotron emission with cosmic ray propagation models
Elena Orlando, Andrew Strong
Cosmic-ray (CR) leptons produce radio synchrotron radiation by gyrating in interstellar magnetic fields (B-field). Details of B-fields, CR electron distributions and propagation ar…
eROSITA X-ray Analysis of the PeVatron Candidate Westerlund 1
Konstantin Haubner, Manami Sasaki, Alison Mitchell +7
It is unclear which fraction of cosmic rays above an energy of 1 PeV is accelerated by the observed Galactic PeVatron population. These sources' gamma-ray data is typically degener…
Gamma-Ray Burst Detection with INTEGRAL/SPI
Andreas von Kienlin, Nikolas Arend, Giselher G. Lichti +2
The spectrometer SPI, one of the two main instruments of the INTEGRAL spacecraft, has strong capabilities in the Field of Gamma-Ray Burst (GRB) detections. In its 16 degree Field o…
Exploring the MeV Sky with a Combined Coded Mask and Compton Telescope: The Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO)
Elena Orlando, Eugenio Bottacini, Alexander Moiseev +33
The sky at MeV energies is currently poorly explored. Here we present an innovative mission concept that builds on and improves past and currently proposed missions at such energie…
eROSITA narrowband maps at the energies of soft X-ray emission lines
Xueying Zheng, Gabriele Ponti, Nicola Locatelli +10
[abridged] Hot plasma plays a crucial role in regulating the baryon cycle within the Milky Way, flowing from the energetic sources in the Galactic center and disc, to the corona an…
Extended solar emission - an analysis of the EGRET data
Elena Orlando, Dirk Petry, Andrew Strong
The Sun was recently predicted to be an extended source of gamma-ray emission, produced by inverse-Compton scattering of cosmic-ray electrons with the solar radiation. The emission…
Morphological Evidence for the eROSITA Bubbles Being Giant and Distant Structures
Teng Liu, Andrea Merloni, Jeremy Sanders +13
There are two contradictory views of the eROSITA bubbles: either a 10 kpc-scale pair of giant bubbles blown by the Galactic center (GC), or a 100 pc-scale local structure coinciden…
COMPTEL Reloaded: a heritage project in MeV astronomy
Andrew Strong, Werner Collmar
COMPTEL was the Compton telescope on NASA's Compton Gamma Ray Observatory CGRO launched in April 1991 and which was re-entered in June 2000. COMPTEL covered the energy range 0.75 t…
eROSITA studies of the Carina Nebula
Manami Sasaki, Jan Robrade, Martin G. H. Krause +4
During the first four all-sky surveys eRASS:4 carried out from December 2019 to 2021, the extended Roentgen Survey with an Imaging Telescope Array (eROSITA) on board Spektrum-Roent…
The origin of Galactic cosmic rays: challenges to the standard paradigm
Stefano Gabici, Carmelo Evoli, Daniele Gaggero +5
A critical review of the standard paradigm for the origin of Galactic cosmic rays is presented. Recent measurements of local and far-away cosmic rays reveal unexpected behaviours,…
A study of super-luminous stars with the Fermi Large Area Telescope
Raniere de Menezes, Elena Orlando, Mattia Di Mauro +1
The -ray emission from stars is induced by the interaction of cosmic rays with stellar atmospheres and photon fields. This emission is expected to come in two components: a ste…
StellarICS: Inverse Compton Emission from the Quiet Sun and Stars from keV to TeV
Elena Orlando, Andrew Strong
The study of the quiet Sun in gamma rays started over a decade ago, and rapidly gained a wide interest. Gamma rays from the quiet Sun are produced by Cosmic Rays (CRs) interacting…
Imaging the Gamma-Ray Sky with SPI aboard INTEGRAL
Jürgen Knödlseder, Georg Weidenspointner, Pierre Jean +6
The spectrometer SPI on INTEGRAL allows for the first time simultaneous imaging of diffuse and point-like emission in the hard X-ray and soft gamma-ray regime. To fully exploit the…
Gamma-rays from halos around stars and the Sun
Elena Orlando, Andrew Strong
Inverse Compton scattering by relativistic electrons produces a major component of the diffuse emission from the Galaxy. The photon fields involved are the cosmic microwave backgro…
Solar gamma rays and modulation of cosmic rays in the inner heliosphere
Elena Orlando, Nicola Giglietto, Igor Moskalenko +2
The first evidence of the gamma-ray emission from the quiescent Sun was found in the archival EGRET data that was later confirmed by Fermi-LAT observations with high significance.…
Detailed Investigation of the Gamma-Ray Emission in the Vicinity of SNR W28 with FERMI-LAT
Yoshitaka Hanabata, Hideaki Katagiri, John W. Hewitt +9
We present a detailed investigation of the -ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.40.1) observed by the Large Area Telescope (LAT) onboard the…
StellarICs: Stellar and solar Inverse Compton emission package
Elena Orlando, Andrew Strong
StellarICs is software to compute gamma-ray emission from inverse-Compton scattering by cosmic-ray leptons in the heliosphere and in the photospheres of stars. It includes a set of…
GALPROP cosmic-ray propagation code: recent results and updates
Elena Orlando, Gudlaugur Johannesson, Igor V. Moskalenko +2
Information on cosmic-ray (CR) composition comes from direct CR measurements while their distribution in the Galaxy is evaluated from observations of their associated diffuse emiss…
Reevaluation of the cosmic antideuteron flux from cosmic-ray interactions and from exotic sources
Laura Å erkÅ¡nytÄ, Stephan Königstorfer, Philip von Doetinchem +8
Cosmic-ray antideuterons could be a key for the discovery of exotic phenomena in our Galaxy, such as dark-matter annihilations or primordial black hole evaporation. Unfortunately t…