Multi-wavelength observations provide a complementary view of the formation of young directly-imaged planet-mass companions .
We report the ALMA 1.3 mm and Magellan adaptive optics ( MagAO ) H \alpha , i ^ { \prime } , z ^ { \prime } , and Y _ { S } observations of the GQ Lup system , a classical T Tauri star with a 10–40 M _ { \text { Jup } } substellar companion at \sim 110 AU projected separation .
We estimate the accretion rates for both components from the observed H \alpha fluxes .
In our \sim 0 \farcs 05 resolution ALMA map , we resolve GQ Lup A ’ s disk in dust continuum , but no signal is found from the companion .
The disk is compact , with a radius of \sim 22 AU , a dust mass of \sim 6 M _ { \earth } , an inclination angle of \sim 56° , and a very flat surface density profile indicative of a radial variation in dust grain sizes .
No gaps or inner cavity are found in the disk , so there is unlikely a massive inner companion to scatter GQ Lup B outward .
Thus , GQ Lup B might have formed in situ via disk fragmentation or prestellar core collapse .
We also show that GQ Lup A ’ s disk is misaligned with its spin axis , and possibly with GQ Lup B ’ s orbit .
Our analysis on the tidal truncation radius of GQ Lup A ’ s disk suggests that GQ Lup B ’ s orbit might have a low eccentricity .