SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES
We present spatially resolved imaging obtained with the Australia Telescope Compact Array (ATCA) of three CO lines in two high-redshift gravitationally lensed dusty star-forming galaxies, discovered by the South Pole Telescope. Strong lensing allows us to probe the structure and dynamics of the mole...
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ftcdlib:oai:escholarship.org:ark:/13030/qt5h82q68s 2023-06-18T03:43:05+02:00 SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES Spilker, JS Aravena, M Marrone, DP Béthermin, M Bothwell, MS Carlstrom, JE Chapman, SC Collier, JD de Breuck, C Fassnacht, CD Galvin, T Gonzalez, AH González-López, J Grieve, K Hezaveh, Y Ma, J Malkan, M O’Brien, A Rotermund, KM Strandet, M Vieira, JD Weiss, A Wong, GF 124 2015-10-01 application/pdf https://escholarship.org/uc/item/5h82q68s unknown eScholarship, University of California qt5h82q68s https://escholarship.org/uc/item/5h82q68s public The Astrophysical Journal, vol 811, iss 2 galaxies: high-redshift galaxies: ISM galaxies: star formation ISM: molecules astro-ph.GA Astronomical and Space Sciences Atomic Molecular Nuclear Particle and Plasma Physics Physical Chemistry (incl. Structural) Astronomy & Astrophysics article 2015 ftcdlib 2023-06-05T18:01:44Z We present spatially resolved imaging obtained with the Australia Telescope Compact Array (ATCA) of three CO lines in two high-redshift gravitationally lensed dusty star-forming galaxies, discovered by the South Pole Telescope. Strong lensing allows us to probe the structure and dynamics of the molecular gas in these two objects, at z = 2.78 and z = 5.66, with effective source-plane resolution of less than 1 kpc. We model the lensed emission from multiple CO transitions and the dust continuum in a consistent manner, finding that the cold molecular gas as traced by low-J CO always has a larger half-light radius than the 870 μm dust continuum emission. This size difference leads to up to 50% differences in the magnification factor for the cold gas compared to dust. In the z = 2.78 galaxy, these CO observations confirm that the background source is undergoing a major merger, while the velocity field of the other source is more complex. We use the ATCA CO observations and comparable resolution Atacama Large Millimeter/submillimeter Array dust continuum imaging of the same objects to constrain the CO-H2 conversion factor with three different procedures, finding good agreement between the methods and values consistent with those found for rapidly star-forming systems. We discuss these galaxies in the context of the star formation - gas mass surface density relation, noting that the change in emitting area with observed CO transition must be accounted for when comparing high-redshift galaxies to their lower redshift counterparts. Article in Journal/Newspaper South pole University of California: eScholarship South Pole |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
galaxies: high-redshift galaxies: ISM galaxies: star formation ISM: molecules astro-ph.GA Astronomical and Space Sciences Atomic Molecular Nuclear Particle and Plasma Physics Physical Chemistry (incl. Structural) Astronomy & Astrophysics |
spellingShingle |
galaxies: high-redshift galaxies: ISM galaxies: star formation ISM: molecules astro-ph.GA Astronomical and Space Sciences Atomic Molecular Nuclear Particle and Plasma Physics Physical Chemistry (incl. Structural) Astronomy & Astrophysics Spilker, JS Aravena, M Marrone, DP Béthermin, M Bothwell, MS Carlstrom, JE Chapman, SC Collier, JD de Breuck, C Fassnacht, CD Galvin, T Gonzalez, AH González-López, J Grieve, K Hezaveh, Y Ma, J Malkan, M O’Brien, A Rotermund, KM Strandet, M Vieira, JD Weiss, A Wong, GF SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES |
topic_facet |
galaxies: high-redshift galaxies: ISM galaxies: star formation ISM: molecules astro-ph.GA Astronomical and Space Sciences Atomic Molecular Nuclear Particle and Plasma Physics Physical Chemistry (incl. Structural) Astronomy & Astrophysics |
description |
We present spatially resolved imaging obtained with the Australia Telescope Compact Array (ATCA) of three CO lines in two high-redshift gravitationally lensed dusty star-forming galaxies, discovered by the South Pole Telescope. Strong lensing allows us to probe the structure and dynamics of the molecular gas in these two objects, at z = 2.78 and z = 5.66, with effective source-plane resolution of less than 1 kpc. We model the lensed emission from multiple CO transitions and the dust continuum in a consistent manner, finding that the cold molecular gas as traced by low-J CO always has a larger half-light radius than the 870 μm dust continuum emission. This size difference leads to up to 50% differences in the magnification factor for the cold gas compared to dust. In the z = 2.78 galaxy, these CO observations confirm that the background source is undergoing a major merger, while the velocity field of the other source is more complex. We use the ATCA CO observations and comparable resolution Atacama Large Millimeter/submillimeter Array dust continuum imaging of the same objects to constrain the CO-H2 conversion factor with three different procedures, finding good agreement between the methods and values consistent with those found for rapidly star-forming systems. We discuss these galaxies in the context of the star formation - gas mass surface density relation, noting that the change in emitting area with observed CO transition must be accounted for when comparing high-redshift galaxies to their lower redshift counterparts. |
format |
Article in Journal/Newspaper |
author |
Spilker, JS Aravena, M Marrone, DP Béthermin, M Bothwell, MS Carlstrom, JE Chapman, SC Collier, JD de Breuck, C Fassnacht, CD Galvin, T Gonzalez, AH González-López, J Grieve, K Hezaveh, Y Ma, J Malkan, M O’Brien, A Rotermund, KM Strandet, M Vieira, JD Weiss, A Wong, GF |
author_facet |
Spilker, JS Aravena, M Marrone, DP Béthermin, M Bothwell, MS Carlstrom, JE Chapman, SC Collier, JD de Breuck, C Fassnacht, CD Galvin, T Gonzalez, AH González-López, J Grieve, K Hezaveh, Y Ma, J Malkan, M O’Brien, A Rotermund, KM Strandet, M Vieira, JD Weiss, A Wong, GF |
author_sort |
Spilker, JS |
title |
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES |
title_short |
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES |
title_full |
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES |
title_fullStr |
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES |
title_full_unstemmed |
SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES |
title_sort |
sub-kiloparsec imaging of cool molecular gas in two strongly lensed dusty, star-forming galaxies |
publisher |
eScholarship, University of California |
publishDate |
2015 |
url |
https://escholarship.org/uc/item/5h82q68s |
op_coverage |
124 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
The Astrophysical Journal, vol 811, iss 2 |
op_relation |
qt5h82q68s https://escholarship.org/uc/item/5h82q68s |
op_rights |
public |
_version_ |
1769009344240680960 |