PASSAGES: The Wide-ranging, Extreme Intrinsic Properties of Planck-selected, Lensed Dusty Star-forming Galaxies

Abstract

The PASSAGES (Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts) collaboration has recently defined a sample of 30 gravitationally lensed dusty star-forming galaxies (DSFGs). These rare, submillimeter-selected objects enable high-resolution views of the most extreme sites of star formation in galaxies at cosmic noon. Here, we present the first major compilation of strong lensing analyses using lenstool for PASSAGES, including 15 objects spanning z = 1.1–3.3, using complementary information from 0.″6-resolution 1.1 mm Atacama Large Millimeter/submillimeter Array and 0.″4 5 cm Jansky Very Large Array continuum imaging, in tandem with 1.6 μ m Hubble and optical imaging with Gemini-S. Magnifications range from μ = 2 to 28 (median μ = 7), yielding intrinsic infrared luminosities of L _IR = 0.2–5.9 × 10 ^13 L _⊙ (median 1.4 × 10 ^13 L _⊙ ) and inferred star formation rates of 170–6300 M _⊙ yr ^−1 (median 1500 M _⊙ yr ^−1 ). These results suggest that the PASSAGES objects comprise some of the most extreme known starbursts, rivaling the luminosities of even the brightest unlensed objects, further amplified by lensing. The intrinsic sizes of far-infrared continuum regions are large ( R _e = 1.7–4.3 kpc; median 3.0 kpc) but consistent with L _IR – R _e scaling relations for z > 1 DSFGs, suggesting a widespread spatial distribution of star formation. With modestly high angular resolution, we explore if these objects might be maximal starbursts. Instead of approaching Eddington-limited surface densities, above which radiation pressure will disrupt further star formation, they are safely sub-Eddington—at least on global, galaxy-integrated scales.

Keywords

• Gravitational lensing
• Ultraluminous infrared galaxies
• Starburst galaxies