  Sgr A*, the supermassive black hole (SMBH) at the center of our Milky Way
Galaxy, is known to be a variable source of X-ray, near-infrared (NIR), and
submillimeter (submm) radiation and therefore a prime candidate to study the
electromagnetic radiation generated by mass accretion flow onto a black hole
and/or a related jet. Disentangling the power source and emission mechanisms of
this variability is a central challenge to our understanding of accretion flows
around SMBHs. Simultaneous multiwavelength observations of the flux variations
and their time correlations can play an important role in obtaining a better
understanding of possible emission mechanisms and their origin. This paper
presents observations of two flares that both apparently violate the previously
established patterns in the relative timing of submm/NIR/X-ray flares from Sgr
A*. One of these events provides the first evidence of coeval structure between
NIR and submm flux increases, while the second event is the first example of
the sequence of submm/X-ray/NIR flux increases all occurring within ~1 hr. Each
of these two events appears to upend assumptions that have been the basis of
some analytic models of flaring in Sgr A*. However, it cannot be ruled out that
these events, even though unusual, were just coincidental. These observations
demonstrate that we do not fully understand the origin of the multiwavelength
variability of Sgr A*, and show that there is a continued and important need
for long-term, coordinated, and precise multiwavelength observations of Sgr A*
to characterize the full range of variability behavior.
