Browsing by Author "Siegert, T."

Now showing items 1-10 of 10

    • 26Al kinematics: superbubbles following the spiral arms? : Constraints from the statistics of star clusters and HI supershells 

      Krause, Martin; Diehl, R.; Bagetakos, Y.; Brinks, E.; Burkert, A.; Gerhard, O.; Greiner, J.; Kretschmer, K.; Siegert, T. (2015-06-12)
      High energy resolution spectroscopy of the 1.8 MeV radioactive decay line of 26Al with the SPI instrument on board the INTEGRAL satellite has recently revealed that diffuse 26Al has large velocities in comparison to other ...

    • Correlated optical, X-ray, and $-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni 

      Rodriguez, J.; Cadolle Bel, M.; Alfonso-Garzón, J.; Siegert, T.; Zhang, X.-L.; Grinberg, V.; Savchenko, V.; Tomsick, J.~A.; Chenevez, J.; Clavel, M.; Corbel, S.; Diehl, R.; Domingo, A.; Gouiffès, C.; Greiner, J.; Krause, M.~G.~H.; Laurent, P.; Loh, A.; Markoff, S.; Mas-Hesse, J.~M.; Miller-Jones, J.~C.~A.; Russell, D.~M.; Wilms, J. (2015-09-23)
      After 25 years of quiescence, the microquasar V404 Cyg entered a new period of activity in June 2015. This X-ray source is known to undergo extremely bright and variable outbursts seen at all wavelengths. It is therefore ...

    • Early 56Ni decay gamma rays from SN2014J suggest an unusual explosion 

      Diehl, R.; Siegert, T.; Hillebrandt, W.; Grebenev, S.~A.; Greiner, J.; Krause, M.; Kromer, M.; Maeda, K.; Röpke, F.; Taubenberger, S. (2014-09-05)
      Type Ia supernovae result from binary systems that include a carbon-oxygen white dwarf, and these thermonuclear explosions typically produce 0.5 solar mass of radioactive 56Ni. The 56Ni is commonly believed to be buried ...

    • Gamma-ray spectroscopy of positron annihilation in the Milky Way 

      Siegert, T.; Diehl, R.; Khachatryan, G.; Krause, M.~G.~H.; Guglielmetti, F.; Greiner, J.; Strong, A.~W.; Zhang, X. (2016-02-01)
      Context. The annihilation of positrons in the Galaxy's interstellar medium produces characteristic gamma-rays with a line at 511 keV. This gamma-ray emission has been observed with the spectrometer SPI on ESA's INTEGRAL ...

    • INTEGRAL/SPI γ -ray line spectroscopy : Response and background characteristics 

      Diehl, R.; Siegert, T.; Greiner, J.; Krause, M.; Kretschmer, K.; Lang, M.; Pleintinger, M.; Strong, A.~W.; Weinberger, C.; Zhang, X. (2018-03-20)
      Context. The space based γ-ray observatory INTEGRAL of the European Space Agency (ESA) includes the spectrometer instrument "SPI". This is a coded mask telescope featuring a 19-element Germanium detector array for ...

    • Positron Annihilation in the Galaxy 

      Kierans, C.~A.; Beacom, J.~F.; Boggs, S.; Buckley, M.; Caputo, R.; Crocker, R.; De Becker, M.; Diehl, R.; Fryer, C.~L.; Griffin, S.; Hartmann, D.; Hays, E.; Jean, P.; Krause, M.~G.~H.; Linden, T.; Marcowith, A.; Martin, P.; Moiseev, A.; Oberlack, U.; Orlando, E.; Panther, F.; Prantzos, N.; Rothschild, R.; Seitenzahl, I.; Shrader, C.; Siegert, T.; Strong, A.; Tomsick, J.; Vestrand, W.~T.; Zoglauer, A. (2019-03-13)
      The 511 keV line from positron annihilation in the Galaxy was the first γ-ray line detected to originate from outside our solar system. Going into the fifth decade since the discovery, the source of positrons is still ...

    • Positron annihilation signatures associated with the outburst of the microquasar V404 Cygni 

      Siegert, T.; Diehl, R.; Greiner, J.; Krause, M.~G.~H.; Beloborodov, A.~M.; Bel, M.~C.; Guglielmetti, F.; Rodriguez, J.; Strong, A.~W.; Zhang, X. (2016-03-17)
      Microquasars1, 2, 3, 4 are stellar-mass black holes accreting matter from a companion star5 and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of 106 ...

    • Revisiting INTEGRAL/SPI observations of $^44$Ti from Cassiopeia A 

      Siegert, T.; Diehl, R.; Krause, Martin; Greiner, J. (2015-07-15)
      Context. The 340-yr old supernova remnant Cassiopeia A, located at 3.4 kpc distance, is the best-studied young core-collapse super- nova remnant. Nucleosynthesis yields in radioactive isotopes have been studied with different ...

    • Search for 511 keV Emission in Satellite Galaxies of the Milky Way with INTEGRAL/SPI 

      Siegert, T.; Diehl, R.; Vincent, A.~C.; Guglielmetti, F.; Krause, M.~G.~H.; Boehm, C. (2016-10-24)
      The positron annihilation gamma-ray signal in the Milky Way (MW) shows a puzzling morphology: a very bright bulge and a very low surface-brightness disk. A coherent explanation of the positron origin, propagation through ...

    • SN2014J gamma rays from the $^56$Ni decay chain 

      Diehl, R.; Siegert, T.; Hillebrandt, W.; Krause, M.; Greiner, J.; Maeda, K.; Röpke, F.~K.; Sim, S.~A.; Wang, Wei; Zhang, X. (2015-02-01)
      Context. The detection and measurement of gamma-ray lines from the decay chain of 56Ni provides unique information about the explosion in supernovae. SN2014J at 3.3 Mpc is a sufficiently-nearby supernova of type Ia so that ...