PASSAGES: The Large Millimeter Telescope and ALMA Observations of Extremely Luminous High Redshift Galaxies Identified by the Planck

TL;DR

This study identifies and characterizes some of the most luminous high-redshift dusty star-forming galaxies using Planck, WISE, LMT, and ALMA data, revealing their extreme luminosities, lensing effects, and obscured AGN activity.

Contribution

It reports the discovery and detailed analysis of 22 extremely luminous, high-redshift DSFGs, demonstrating their lensing nature and providing insights into their luminosity, morphology, and AGN activity.

Findings

Identified 22 high-redshift luminous DSFGs with IR luminosities up to 3.1×10^14 L_sun.

ALMA imaging shows ring or arc morphologies indicative of strong lensing.

Spectral analysis suggests minimal detectable AGN activity despite high luminosity.

Abstract

The Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts (PASSAGES) project aims to identify a population of extremely luminous galaxies using the Planck All-Sky Survey and to explore the nature of their gas fuelling, induced starburst, and the resulting feedback that shape their evolution. Here, we report the identification of 22 high redshift luminous dusty star forming galaxies (DSFGs) at $z=1.1-3.3$ drawn from a candidate list constructed using the Planck Catalog of Compact Sources (PCCS) and WISE All-Sky Survey. They are confirmed through follow-up dust continuum imaging and CO spectroscopy using AzTEC and the Redshift Search Receiver (RSR) on the Large Millimeter Telescope Alfonso Serrano (LMT). Their apparent IR luminosities span $(0.1-3.1)\times 10^{14} L_\odot$ (median of $1.2\times10^{14}L_\odot$), making them some of the most luminous galaxies found so far. They are also some of the rarest objects in the sky with a source density of $\lesssim0.01$ deg$^{-2}$. Our Atacama Large Millimeter/submillimeter Array (ALMA) 1.1 mm continuum observations with $\theta$ $\approx$ 0.4" resolution show clear ring or arc morphologies characteristic of strong lensing. Their lensing-corrected luminosity of $L_{\rm IR}\gtrsim 10^{13}L_\odot$ ($SFR\gtrsim10^3 M_\odot$ yr$^{-1}$) indicates that they are the magnified versions of the most intrinsically luminous DSFGs found at these redshifts. Our spectral energy distribution (SED) analysis finds little detectable AGN activity despite their enormous luminosity, and any AGN activity present must be extremely heavily obscured.