Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Late time multi wavelength observations of Swift J1644+5734: A luminous
  optical/IR bump and quiescent X-ray emission   We present late-time multi-wavelength observations of Swift J1644+57,
suggested to be a relativistic tidal disruption flare (TDF). Our observations
extend to >4 years from discovery, and show that 1.4 years after outburst the
relativistic jet switched-off on a timescale less than tens of days,
corresponding to a power-law decay faster than $t^{-70}$. Beyond this point
weak X-rays continue to be detected at an approximately constant luminosity of
$L_X \sim 5 \times 10^{42}$ erg s$^{-1}$, and are marginally inconsistent with
a continuing decay of $t^{-5/3}$, similar to that seen prior to the switch-off.
Host photometry enables us to infer a black hole mass of $M_{BH}=3 \times 10^6$
M$_{\odot}$, consistent with the late time X-ray luminosity arising from
sub-Eddington accretion onto the black hole in the form of either an unusually
optically faint AGN or a slowly varying phase of the transient. Optical/IR
observations show a clear bump in the light curve at timescales of 30-50 days,
with a peak magnitude (corrected for host galaxy extinction) of $M_R \sim
-22-23$. The luminosity of the bump is significantly higher than seen in other,
non-relativistic TDFs and does not match any re-brightening seen at X-ray or
radio wavelengths. Its luminosity, light curve shape and spectrum are broadly
similar to those seen in superluminous SNe, although subject to large
uncertainties in the correction of the significant host extinction. We discuss
these observations in the context of both TDF and massive star origins for
Swift J1644+5734 and other candidate relativistic tidal flares.

23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol