Early science with the Large Millimeter Telescope: observations of extremely luminous high-z sources identified by Planck

• Published in: Monthly notices of the Royal Astronomical Society Vol. 458; no. 4; pp. 4383 - 4399
• Main Authors: Harrington, K. C., Yun, Min S., Cybulski, R., Wilson, G. W., Aretxaga, I., Chavez, M., De la Luz, V., Erickson, N., Ferrusca, D., Gallup, A. D., Hughes, D. H., Montaña, A., Narayanan, G., Sánchez-Argüelles, D., Schloerb, F. P., Souccar, K., Terlevich, E., Terlevich, R., Zeballos, M., Zavala, J. A.
• Format: Journal Article
• Language: English
• Published: London Oxford University Press 01-06-2016
• Subjects: Continuums; Galaxies; Imaging; Luminosity; Photometry; Receivers & amplifiers; Red shift; Searching; Space telescopes; Spectrum analysis; Star & galaxy formation; galaxies: starburst; infrared: galaxies; submillimetre: galaxies; galaxies: ISM; galaxies: high-redshift; gravitational lensing: strong
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stw614

We present 8.5 arcsec resolution 1.1-mm continuum imaging and CO spectroscopic redshift measurements of eight extremely bright submillimetre galaxies identified from the Planck and Herschel surveys, taken with the Large Millimeter Telescope's AzTEC and Redshift Search Receiver instruments. We compiled a candidate list of high-redshift galaxies by cross-correlating the Planck Surveyor mission's highest frequency channel (857 GHz, full width at half-maximum = 4.5 arcmin) with the archival Herschel Spectral and Photometric Imaging Receiver imaging data, and requiring the presence of a unique, single Herschel counterpart within the 150-arcsec search radius of the Planck source positions with 350-μm flux density larger than 100 mJy, excluding known blazars and foreground galaxies. All eight candidate objects observed are detected in 1.1 mm continuum by AzTEC bolometer camera, and at least one CO line is detected in all cases with a spectroscopic redshift between 1.3 < z
CO < 3.3. Their infrared (IR) spectral energy distributions (SEDs) mapped using the Herschel and AzTEC photometry are consistent with cold dust emission with characteristic temperature between T
d = 43 and 84 K. With apparent IR luminosity of up to L
IR = 3 × 1014μ−1 L⊙, they are some of the most luminous galaxies ever found (with yet unknown gravitational magnification factor μ). The analysis of their SEDs suggests that star formation is powering the bulk of their extremely large IR luminosities. Derived molecular gas masses of
$M_{\rm {H_2}}=(0.6{\rm -}7.8)\times 10^{11} \,\mathrm{M}_{\odot }$
(for μ ≈ 10) also make them some of the most gas-rich high-redshift galaxies ever detected.