Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: GRBs as Probes of the Early Universe with TSO   Long gamma-ray bursts (GRBs) are the most luminous known electromagnetic
radiation sources in the Universe for the 3 to 300 sec of their prompt flashes
(isotropic X/ gamma-ray luminosities up to 10^53 ergs/sec). Their afterglows
have first day rest-frame UV/optical absolute magnitudes AB = -30 to -23. This
luminous continuum nUV-nIR back-light provides the ultimate probe of the SFR(z)
back to the first Pop III to II.5 stars, expected to be massive and GRB
progenitors. GRB afterglow spectra in the first 1 to 3 hours will directly
measure their host galaxy ionization fraction x_i vs. z in the Epoch of
Reionization (EOR), tracing the growth of structure. Only 28% of Swift GRBs
have measured redshifts due to limited followup at R, J >21. Some ~25% of GRBs
are optically dark due to dust absorption in their host galaxies, but those
with low NH in their X-ray spectra are likely at z >7. Current 8-10m telescopes
and coming ELTs cannot pursue optically dark GRBs promptly, nor can JWST or
WFIRST slew within 0.5 to 1 days of a GRB. The Time-domain Spectroscopic
Observatory (TSO) is a proposed Probe-class 1.3m telescope at L2, with imaging
and spectroscopy (R = 200, 1800) in 4 bands (0.3 to 5um) and rapid slew
capability to 90% of sky. TSO would finally utilize z > 6 to 12 GRBs as the
most direct probe of the SFR(z), EOR(z), and possibly the first direct
detection of the core collapse of the very first (Pop III) stars.

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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: comp-gas