Direct imaging surveys have discovered wide-orbit planetary-mass companions that challenge existing models of both star and planet formation , but their demographics remain poorly sampled .
We have developed an automated binary companion point spread function ( PSF ) fitting pipeline to take advantage of Spitzer ’ s infrared sensitivity to planetary-mass objects and circum ( sub ) stellar disks , measuring photometry across the four IRAC channels of 3.6 \mu m , 4.5 \mu m , 5.8 \mu m , and 8.0 \mu m. We present PSF-fitting photometry of archival Spitzer /IRAC images for 11 young , low-mass ( M \sim 0.044 –0.88 M _ { \odot } ; M7.5–K3.5 ) members of three nearby star-forming regions ( Chameleon , Taurus , and Upper Scorpius ; d \sim 150 pc ; \tau \sim 1–10 Myr ) that host confirmed or candidate faint companions at \rho = 1 \farcs 68 - 7 \farcs 31 .
We recover all system primaries , six confirmed , and two candidate low-mass companions in our sample .
We also measure non-photospheric [ 3.6 ] - [ 8.0 ] colors for three of the system primaries , four of the confirmed companions , and one candidate companion , signifying the presence of circumstellar or circum ( sub ) stellar disks .
We furthermore report the confirmation of a \rho = 4 \farcs 66 ( 540 au ) companion to [ SCH06 ] J0359+2009 which was previously identified as a candidate via imaging over five years ago , but was not studied further .
Based on its brightness ( M _ { [ 3.6 ] } = 8.53 mag ) , we infer the companion mass to be M = 20 \pm 5 M _ { \mathrm { Jup } } given the primary ’ s model-derived age of 10 Myr .
Our framework is sensitive to companions with masses less than 10 M _ { \mathrm { Jup } } at separations of \rho = 300 AU in nearby star-forming regions , opening up a new regime of parameter space that has yet to be studied in detail , discovering planetary-mass companions in their birth environments and revealing their circum ( sub ) stellar disks .