Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simultaneous Monitoring of X-ray and Radio Variability in Sagittarius A*   Monitoring of Sagittarius A* from X-ray to radio wavelengths has revealed
structured variability --- including X-ray flares --- but it is challenging to
establish correlations between them. Most studies have focused on variability
in the X-ray and infrared, where variations are often simultaneous, and because
long time series at sub-millimeter and radio wavelengths are limited. Previous
work on sub-mm and radio variability hints at a lag between X-ray flares and
their candidate sub-millimeter or radio counterparts, with the long wavelength
data lagging the X-ray. However, there is only one published time lag between
an X-ray flare and a possible radio counterpart. Here we report 9
contemporaneous X-ray and radio observations of Sgr A*. We detect significant
radio variability peaking $\gtrsim$176 minutes after the brightest X-ray flare
ever detected from Sgr A*. We also report other potentially associated X-ray
and radio variability, with the radio peaks appearing $\lesssim$80 minutes
after these weaker X-ray flares. Taken at face value, these results suggest
that stronger X-ray flares lead to longer time lags in the radio. However, we
also test the possibility that the variability at X-ray and radio wavelengths
is not temporally correlated. We cross-correlate data from mismatched X-ray and
radio epochs and obtain comparable correlations to the matched data. Hence, we
find no overall statistical evidence that X-ray flares and radio variability
are correlated, underscoring a need for more simultaneous, long duration
X-ray--radio monitoring of Sgr A*.

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The categories of this paper are: hep-lat
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: nlin
2
The categories of this paper are: math
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The categories of this paper are: cond-mat
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The categories of this paper are: atom-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: hep-ex
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: dg-ga