2016ApJ...827...57O -
Astrophys. J., 827, 57-57 (2016/August-2)
Spatially resolved spectroscopy of submillimeter galaxies at z ~= 2.
OLIVARES V., TREISTER E., PRIVON G.C., ALAGHBAND-ZADEH S., CASEY C.M., SCHAWINSKI K., KURCZYNSKI P., GAWISER E., NAGAR N., CHAPMAN S., BAUER F.E. and SANDERS D.
Abstract (from CDS):
We present near-infrared integral-field spectroscopic observations targeting Hα in eight submillimeter galaxies (SMGs) at z=1.3-2.5 using the Very Large Telescope/Spectrograph for Integral Field Observations in the Near Infrared, obtaining significant detections for six of them. The star formation rates derived from the Hα emission are ∼100 M_☉ yr^-1, which account for only ∼20%-30% of the infrared-derived values, thus suggesting that these systems are very dusty. Two of these systems present [N ii]/Hα ratios indicative of the presence of an active galactic nucleus. We mapped the spatial distribution and kinematics of the star-forming regions in these galaxies on kiloparsec scales. In general, the Hα morphologies tend to be highly irregular and/or clumpy, showing spatial extents of ∼3-11 kpc. We find evidence for significant spatial offsets, of ∼0.''1-0.''4 or 1.2-3.4 kpc, between the Hα and the continuum emission in three of the sources. Performing a kinemetry analysis, we conclude that the majority of the sample is not consistent with disk-like rotation-dominated kinematics. Instead, they tend to show irregular and/or clumpy and turbulent velocity and velocity dispersion fields. This can be interpreted as evidence for a scenario in which these extreme star formation episodes are triggered by galaxy-galaxy interactions and major mergers. In contrast to recent results for SMGs, these sources appear to follow the same relations between gas and star-forming rate densities as less luminous and/or normal star-forming galaxies.
Abstract Copyright:
© 2016. The American Astronomical Society. All rights reserved.
Journal keyword(s):
galaxies: high-redshift - galaxies: starburst - submillimeter: galaxies - submillimeter: galaxies
Simbad objects:
13
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