High statistics search for ultrahigh energy {gamma}-ray emission from Cygnus X-3 and Hercules X-1

Journal Article · Sat Feb 01 00:00:00 EST 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.55.1714· OSTI ID:467464

Borione, A; Chantell, M C; Covault, C E; Cronin, J W; Fick, B E; Fowler, J W; Fortson, L F; Gibbs, K G; Green, K D; Newport, B J; Ong, R A; Oser, S; Rosenberg, L J ^[1]; Catanese, M A; Glasmacher, M A; Matthews, J; Nitz, D F; Sinclair, D; van der Velde, J C ^[2]; Kieda, D B ^[3]

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1. The Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637 (United States)
2. Department of Physics, The University of Michigan, Ann Arbor, Michigan 48109 (United States)
3. Department of Physics, The University of Utah, Salt Lake City, Utah 84112 (United States)

We have carried out a high statistics (2{times}10{sup 9} events) search for ultrahigh energy {gamma}-ray emission from the x-ray binary sources Cygnus X-3 and Hercules X-1. Using data taken with the CASA-MIA detector over a five year period (1990{endash}1995), we find no evidence for steady emission from either source. The derived 90{percent} C.L. upper limit to the steady integral flux of {gamma} rays from Cygnus X-3 is {Phi}(E{gt}115TeV){lt}6.3{times}10{sup {minus}15} photons cm{sup {minus}2}sec{sup {minus}1}, and from Hercules X-1 it is {Phi}(E{gt}115TeV){lt}8.5{times}10{sup {minus}15} photonscm{sup {minus}2}sec{sup {minus}1}. These limits are more than two orders of magnitude lower than earlier claimed detections and are better than recent experiments operating in the same energy range. We have also searched for transient emission on time periods of one day and 0.5 h and find no evidence for such emission from either source. The typical daily limit on the integral {gamma}-ray flux from Cygnus X-3 or Hercules X-1 is {Phi}{sub daily}(E{gt}115TeV){lt}2.0{times}10{sup {minus}13} photons cm{sup {minus}2}sec{sup {minus}1}. For Cygnus X-3, we see no evidence for emission correlated with the 4.8 h x-ray periodicity or with the occurrence of large radio flares. Unless one postulates that these sources were very active earlier and are now dormant, the limits presented here put into question the earlier results, and highlight the difficulties that possible future experiments will have in detecting {gamma}-ray signals at ultrahigh energies. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 467464
• Journal Information: Physical Review, D, Vol. 55, Issue 4; Other Information: PBD: Feb 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COSMIC X-RAY SOURCES
GAMMA RADIATION
STELLAR RADIATION
VARIABLE STARS
NEUTRON STARS
EMISSION
SIGNALS
DETECTION
GALAXIES
BINARY STARS