Journal article
Flat Rotation Curves Found in Merging Dusty Starbursts at z = 2.3 through Tilted-ring Modeling
Astrophysical journal. Letters, Vol.864(1), p.L11
08/29/2018
DOI: 10.3847/2041-8213/aad9a9
Abstract
The brightest 500 m source in the XMM-LSS field, HXMM01, is a rare merger of luminous starburst galaxies at z = 2.3 with a dust-obscured star formation rate of 2000 M yr−1. Here we present high-resolution spectroscopic observations of HXMM01 with the Atacama Large Millimeter/submillimeter Array (ALMA). We detect line emission from CO J = 7 → 6, [C i] 3P2 → 3P1, and p-H2O 211 → 202 and continuum emission at 230 GHz. At a spatial resolution of 0 2 and a spectral resolution of 40 km s−1, the source is resolved into three distinct components, which are spatially and dynamically associated within a projected radius of 20 kpc and a radial velocity range of 2000 km s−1. For two major components, our Bayesian-based tilted-ring modeling of the ALMA spectral cubes shows almost flat rotation curves peaking at ∼500 km s−1 at galactocentric distances between 2 and 5 kpc. Each of them has a dynamical mass of ∼1011 M . The combination of the dynamical masses and the archival CO J = 1 → 0 data places strong upper limits on the CO → H2 conversion factor of CO 1.4-2.0 M (K km s−1 pc2)−1. These limits are significantly below the Galactic inner disk CO value of 4.3 M (K km s−1 pc2)−1 but are consistent with those of local starbursts. Therefore, the previously estimated short gas depletion timescale of ∼200 Myr remains unchanged.
Details
- Title: Subtitle
- Flat Rotation Curves Found in Merging Dusty Starbursts at z = 2.3 through Tilted-ring Modeling
- Creators
- Rui Xue - University of IowaHai Fu - University of IowaJacob Isbell - University of IowaR. J Ivison - University of EdinburghAsantha Cooray - University of California, IrvineIván Oteo - University of Edinburgh
- Resource Type
- Journal article
- Publication Details
- Astrophysical journal. Letters, Vol.864(1), p.L11
- DOI
- 10.3847/2041-8213/aad9a9
- ISSN
- 2041-8205
- eISSN
- 2041-8213
- Publisher
- The American Astronomical Society
- Number of pages
- 9
- Language
- English
- Date published
- 08/29/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199843402771
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