Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Transition to the Soft State in GRS 1758-258   Near the end of 2001 February, the black-hole candidate (BHC) GRS 1758-258
made an abrupt transition from a standard hard (low) state to a soft state.
Unlike Cyg X-1 and other BHCs, whose luminosity increases during this
transition, GRS 1758-258 was dimmer after the transition. We present
observations with the Proportional Counter Array on the Rossi X-ray Timing
Explorer and interpret the phenomenon in the context of a ``dynamical'' soft
state model. Using this model we predicted that mass transfer from the
companion had ceased, and that the luminosity should decay on a timescale of a
few weeks. The most recent data support this prediction, being consistent with
a decay time of 34 dy. The current state is consistent with the ``off'' state
of GRS 1758-258 reported by GRANAT/Sigma in 1991-1992.

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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con