%0 Generic %1 law2012velocity %A Law, David R. %A Shapley, Alice E. %A Steidel, Charles C. %A Reddy, Naveen A. %A Christensen, Charlotte R. %A Erb, Dawn K. %D 2012 %K dispersion spiral structure velocity %T High Velocity Dispersion in A Rare Grand Design Spiral Galaxy at Redshift z=2.18 %U http://arxiv.org/abs/1207.4196 %X Although relatively common in the local Universe, only one grand-design spiral galaxy has been spectroscopically confirmed to lie at z>2 (HDFX 28; z=2.011), and may prove to be a major merger that simply resembles a spiral in projection. The rarity of spirals has been explained as a result of disks being dynamically 'hot' at z>2 which may instead favor the formation of commonly-observed clumpy structures. Alternatively, current instrumentation may simply not be sensitive enough to detect spiral structures comparable to those in the modern Universe. At redshifts <2, the velocity dispersion of disks decreases, and spiral galaxies are more numerous by z~1. Here we report observations of the grand design spiral galaxy Q2343-BX442 at z=2.18. Spectroscopy of ionized gas shows that the disk is dynamically hot, implying an uncertain origin for the spiral structure. The kinematics of the galaxy are consistent with a thick disk undergoing a minor merger, which can drive the formation of short-lived spiral structure. A duty cycle of < 100 Myr for such tidally-induced spiral structure in a hot massive disk is consistent with their rarity.

@misc{law2012velocity, abstract = {Although relatively common in the local Universe, only one grand-design spiral galaxy has been spectroscopically confirmed to lie at z>2 (HDFX 28; z=2.011), and may prove to be a major merger that simply resembles a spiral in projection. The rarity of spirals has been explained as a result of disks being dynamically 'hot' at z>2 which may instead favor the formation of commonly-observed clumpy structures. Alternatively, current instrumentation may simply not be sensitive enough to detect spiral structures comparable to those in the modern Universe. At redshifts <2, the velocity dispersion of disks decreases, and spiral galaxies are more numerous by z~1. Here we report observations of the grand design spiral galaxy Q2343-BX442 at z=2.18. Spectroscopy of ionized gas shows that the disk is dynamically hot, implying an uncertain origin for the spiral structure. The kinematics of the galaxy are consistent with a thick disk undergoing a minor merger, which can drive the formation of short-lived spiral structure. A duty cycle of < 100 Myr for such tidally-induced spiral structure in a hot massive disk is consistent with their rarity.}, added-at = {2012-07-19T08:07:18.000+0200}, author = {Law, David R. and Shapley, Alice E. and Steidel, Charles C. and Reddy, Naveen A. and Christensen, Charlotte R. and Erb, Dawn K.}, biburl = {https://www.bibsonomy.org/bibtex/291a459d629eb5361b26ca2e539302cff/miki}, description = {[1207.4196] High Velocity Dispersion in A Rare Grand Design Spiral Galaxy at Redshift z=2.18}, interhash = {ea0208408857207259db5b5a54c948f2}, intrahash = {91a459d629eb5361b26ca2e539302cff}, keywords = {dispersion spiral structure velocity}, note = {cite arxiv:1207.4196Comment: Accepted for publication in Nature (July 19 2012). Includes 15-page supplement}, timestamp = {2012-07-19T08:07:18.000+0200}, title = {High Velocity Dispersion in A Rare Grand Design Spiral Galaxy at Redshift z=2.18}, url = {http://arxiv.org/abs/1207.4196}, year = 2012 }