Galactic Cosmic Ray Energy Spectrum for Fe from ~0 Galactic Cosmic Ray Energy Spectrum for Fe from ~0.8 to ~10 GeV/nuc with the SuperTIGER Instrument A.W. Labrador (1*), W.R. Binns (2), R.G. Bose (2), T.J. Brandt (3), P.F. Dowkontt (2), T. Hams (3,6), M.H. Israel (2), J.T. Link (3,6), R.A. Mewaldt (1), J.W. Mitchell (3), R.P. Murphy (2), B.F. Rauch (2), K. Sakai (3,6), M. Sasaki (3,6), E. C. Stone (1), C.J. Waddington (4), J.E. Ward (2), and M. E. Wiedenbeck (5) 1. California Institute of Technology, Pasadena, CA 91125 USA; 2. Washington University, St. Louis, MO 63130 USA; 3. NASA/Goddard Space Flight Center, Greenbelt, MD 20771 USA; 4. The University of Minnesota, Minneapolis, MN 55455, USA: 5. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA 6. Center for Research and Exploration in Space Science and Technology (CRESST), Greenbelt, MD 20771, USA E-mail: labrador@srl.caltech.edu

SuperTIGER “Super” Trans-Iron Galactic Element Recorder A balloon-borne cosmic ray instrument that can measure galactic cosmic ray abundances for Z=~10–60 for energies ~0.8-10 GeV/nuc Primary Goals: Measure Z=30–60 abundances to test OB association models for cosmic ray origins Secondary Goals: Spectra, spectral features A clear picture is emerging of how cosmic rays originate in OB associations, regions of our Galaxy in which there are a number of young, short-lived, massive stars [19,20] that form superbubbles. The cosmic-ray source is understood as a mixture of old interstellar material with the outflow from massive stars (importantly including Wolf-Rayet stars and their precursor phases) and ejecta from core-collapse supernovae (SNII, SNIb,c), which occur mostly in OB associations. This model is supported by the 22Ne/20Ne and 58Fe/56Fe overabundances in the GCRs measured most recently by the CRIS instrument on ACE as well as the element ratio N/O [9,10]. In addition, elements that reside primarily in grains in interstellar space (refractory elements) are preferentially accelerated compared to those that reside primarily as gas (volatile elements), and this enrichment appears to be mass dependent for both refractories and volatiles. The mass-dependent element enrichment is supported by abundances measured by TIGER at GeV/nuc energies [23,24,28], ACE at energies of hundreds of MeV/nuc [21], and CREAM at TeV/nuc energies [2

SuperTIGER Jason Link [CRD139] - SuperTIGER, SuperTIGER 2 Nathan Walsh [CRD047] - SuperTIGER Z=41-56 abundances ICRC 2015 Hams et al.; Sasaki et al. - CR origins Murphy et al. –– Ultraheavy element analysis Labrador et al. –– SuperTIGER Z=10-30 abundances

SuperTIGER

SuperTIGER December 8, 2012 –– February 1, 2013

Line of Sight (LOS) Data SuperTIGER Line of Sight (LOS) Data

Microquasars Heinz & Sunyaev (“Cosmic Rays from Microquasars: A Narrow Component to the CR Spectrum?”, Astron & Astrophys, 390 (2002) 751) Suggested that relativistic jets observed in micro-quasars like GRS 1915+105 and GRO J1655-40 might produce narrow features in some cosmic ray spectra.

Microquasar Hypothetical Signature Fe Beam at 5 GeV/nuc, width 0.5 GeV/nuc Interstellar model: A.Davis et al., JGR, A12, 29,979, 2001 Solar Modulation is spherically symmetric diffusion calculation after Fisk, JGR (1971).

Line of Sight (LOS) Data SuperTIGER Line of Sight (LOS) Data

Analysis — Energy Scaling Aerogels n=1.043/n=1.025 (thresholds ~2.5 GeV/nuc, ~3.3 GeV/nuc) Background signals move the zero Cherenkov signal point knock-ons Scintillation Goretex Cherenkov

Analysis — Energy Scaling Aerogels n=1.043/n=1.025 (thresholds ~2.5 GeV/nuc, ~3.3 GeV/nuc) Background signals move the zero Cherenkov signal point knock-ons Scintillation Goretex Cherenkov

The Analysis Done Energy scaling Energy shifts TO DO (after the Conference) Livetime and instrument efficiency Interaction loss corrections Deconvolution

Fe Scaled Spectrum ACE Data (open triangles) from ACE Science Center (www.srl.caltech.edu/ACE/ASC) for the same dates as the SuperTIGER data. Interstellar model: A.Davis et al., JGR, A12, 29,979, 2001 Solar Modulation to 575 MV.

Fe Scaled Spectrum

Conclusions SuperTIGER spectrum calculations are under way, though final calculations from the first flight will likely wait until after the conference. Even without absolute intensities, we have sufficient statistics with a sample of data to eliminate large, narrow microquasar signatures in Fe (e.g. 5 GeV/nuc beam, 0.5 GeV/nuc width). Additional scaled spectra will be reported in the final version of this paper.