high-energy gamma-ray and neutrino emission from the microquasar lsi +61 303
DESCRIPTION
High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303. Gustavo E. Romero, Instituto Argentino de Radioastronomía (IAR) Department of Astronomy and Geophysics, University of La Plata, Argentina Mariana Orellana Instituto Argentino de Radioastronomía (IAR) - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/1.jpg)
High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303
Gustavo E. Romero, Instituto Argentino de Radioastronomía (IAR)
Department of Astronomy and Geophysics, University of La Plata, Argentina
Mariana OrellanaInstituto Argentino de Radioastronomía (IAR)
Department of Astronomy and Geophysics, University of La Plata, Argentina
![Page 2: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/2.jpg)
LSI +61 303
Primary star B0VCompact object ? Distance 2 kpcPorb 26.5 d e 0.72 ± 0.15
β apar ≥ 0.4Phase of periastron 0.23
Paredes, J.M. [astroph:0501576]
3EG J0241+6103 ?
Orbital parameters: Casares et al. 2005
fro
m M
ass
i et
al.
20
03
Massi et al. 2004
![Page 3: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/3.jpg)
MAGIC detection of LSI +61 303
![Page 4: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/4.jpg)
MAGIC detection of LSI +61 303
Albert et al. 2006
![Page 5: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/5.jpg)
MAGIC detection of LSI +61 303
![Page 6: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/6.jpg)
Up-dated SED
Sidoli et al. 2006
![Page 7: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/7.jpg)
Gamma-ray emission from MQs:Models Leptonic (Aharonian & Atoyan 1999; Bosch-Ramon et al. 2005, 2006; Dermer & Boettcher 2006, Bednarek 2006) Hadronic (Romero et al. 2003, 2005; Aharonian et al. 2006)In microquasars with high-mass stars, the stellar wind can provide a matter
field for interactions with relativistic protons from the jet
Pure leptonic channels also result from the decay of secondary particles
Secondary leptons
![Page 8: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/8.jpg)
Model: interactions between relativistic protons from the jet and cold protons form the wind
Romero, G.E. et al 2003, A&A, 410, L1
Spherically symmetric wind
Circular orbit
![Page 9: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/9.jpg)
Orbital phases for LS I +61 303
Massi 2004
![Page 10: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/10.jpg)
Evolution of some parameters with the orbital phase
with n=3.2 (Gregory & Neish 2002).
![Page 11: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/11.jpg)
Accretion rate onto the compact object
The model is dependent on the accretion rate and hence instrinsically time dependent
![Page 12: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/12.jpg)
Some assumptions
• Magnetic field is determined from equipartition with the kinetic energy of the jet, hence it is phase dependent.
• Protons are accelerated by shocks in the inner jet to a power law of index p. Radiative losses are negligible so size constraints impose the upper limit on the proton energy.
• There is a phenomenological “mixing factor” which accounts for the fraction of relativistic protons that interact with cold protons (typically fm~0.1).
![Page 13: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/13.jpg)
Main parameters for the model
![Page 14: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/14.jpg)
Photon-photon absorption due to the star
Dubus 2006
![Page 15: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/15.jpg)
Photon-photon absorption
![Page 16: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/16.jpg)
Total photon-photon absorption
![Page 17: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/17.jpg)
Light curve @ 200 GeV
![Page 18: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/18.jpg)
Spectral energy distribution at different phases
![Page 19: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/19.jpg)
Cascades close to the periastron passage
qj=1
![Page 20: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/20.jpg)
Synchroton emission from secondary pairs
![Page 21: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/21.jpg)
Neutrino emission
The estimated neutrino flux from LS I +61 303 on Earth is 4-5 muon-type neutrinos per km-squared per year (Christinasen, Orellana & Romero 2006). It could be detectable by IceCube .
1400 m
2400 m
Ice top
Southern Hemisphere ICECUBE
![Page 22: High-energy gamma-ray and neutrino emission from the microquasar LSI +61 303](https://reader034.vdocuments.us/reader034/viewer/2022051623/56815a9d550346895dc821cb/html5/thumbnails/22.jpg)
Conclusions
Jet models where the jet power depends on a variable accretion rate will produce variable gamma-ray emission.
In the case of LS I +61 303, opacity effects due to the radiation fields of the primary star and the circumstellar disk result in a maximum at ~0.5. This is independent of the gamma-ray production mechanism.
A hadronic model for the gamma-ray emission at high-energies cannot be ruled out by the current observations.
Future neutrino observations of LSI +61 303 could be crucial to establish the nature of the radiative mechanism in the source.