6,271 research outputs found

    The Orbifold-String Theories of Permutation-Type: I. One Twisted BRST per Cycle per Sector

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    We resume our discussion of the new orbifold-string theories of permutation-type, focusing in the present series on the algebraic formulation of the general bosonic prototype and especially the target space-times of the theories. In this first paper of the series, we construct one twisted BRST system for each cycle jj in each twisted sector σ\sigma of the general case, verifying in particular the previously-conjectured algebra [Qi(σ),Qj(σ)]+=0[Q_{i}(\sigma),Q_{j}(\sigma)]_{+} =0 of the BRST charges. The BRST systems then imply a set of extended physical-state conditions for the matter of each cycle at cycle central charge c^j(σ)=26fj(σ)\hat{c}_{j}(\sigma)=26f_{j}(\sigma) where fj(σ)f_{j}(\sigma) is the length of cycle jj.Comment: 31 page

    X-ray Observations and Infrared Identification of the Transient 7.8 s X-ray Binary Pulsar XTE J1829-098

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    XMM-Newton and Chandra observations of the transient 7.8 s pulsar XTE J1829-098 are used to characterize its pulse shape and spectrum, and to facilitate a search for an optical or infrared counterpart. In outburst, the absorbed, hard X-ray spectrum with Gamma = 0.76+/-0.13 and N_H = (6.0+/-0.6) x 10^{22} cm^{-2} is typical of X-ray binary pulsars. The precise Chandra localization in a faint state leads to the identification of a probable infrared counterpart at R.A. = 18h29m43.98s, decl. = -09o51'23.0" (J2000.0) with magnitudes K=12.7, H=13.9, I>21.9, and R>23.2. If this is a highly reddened O or B star, we estimate a distance of 10 kpc, at which the maximum observed X-ray luminosity is 2x10^{36} ergs s^{-1}, typical of Be X-ray transients or wind-fed systems. The minimum observed luminosity is 3x10^{32}(d/10 kpc)^2 ergs s^{-1}. We cannot rule out the possibility that the companion is a red giant. The two known X-ray outbursts of XTE J1829-098 are separated by ~1.3 yr, which may be the orbital period or a multiple of it, with the neutron star in an eccentric orbit. We also studied a late M-giant long-period variable that we found only 9" from the X-ray position. It has a pulsation period of ~1.5 yr, but is not the companion of the X-ray source.Comment: 6 pages, 7 figures. To appear in The Astrophysical Journa
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