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High velocity dispersion in a rare grand-design spiral galaxy at redshift z = 2.18

Law, David R. and Shapley, Alice E. and Steidel, Charles C. and Reddy, Naveen A. and Christensen, Charlotte R. and Erb, Dawn K. (2012) High velocity dispersion in a rare grand-design spiral galaxy at redshift z = 2.18. Nature, 487 (7407). pp. 338-340. ISSN 0028-0836. doi:10.1038/nature11256.

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Although grand-design spiral galaxies are relatively common in the local Universe, only one has been spectroscopically confirmed to lie at redshift z > 2 (HDFX 28; z = 2.011); and it 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 (refs 2-5), which may instead favour 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 z < 2, the velocity dispersion of disks decreases, and spiral galaxies are more numerous by z ≈ 1 (refs 7, 13-15). 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 its rarity.

Item Type:Article
Related URLs:
URLURL TypeDescription ReadCube access
Law, David R.0000-0002-9402-186X
Shapley, Alice E.0000-0003-3509-4855
Steidel, Charles C.0000-0002-4834-7260
Reddy, Naveen A.0000-0001-9687-4973
Erb, Dawn K.0000-0001-9714-2758
Additional Information:© 2012 Macmillan Publishers Limited. Received 02 January 2012. Accepted 22 May 2012. Published online 18 July 2012. D.R.L and C.C.S have been supported by grant GO-11694 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. A.E.S acknowledges support from the David and Lucile Packard Foundation. C.R.C acknowledges support from the US National Science Foundation through grant AST-1009452. D.R.L appreciates discussions with J. Taylor, R. Abraham, J. Dubinski, F. Governato and A. Brooks, and thanks M. Peeples for help in obtaining the Keck/OSIRIS data. Author Contributions: D.R.L. performed the morphological analysis of the Hubble Space Telescope data and wrote the main manuscript text. The Keck/OSIRIS data were obtained by D.R.L. and A.E.S., and analysed by D.R.L. with extensive input from A.E.S. and C.C.S.. N.A.R. provided the Keck/LRIS spectra, Spitzer/MIPS photometry and stellar population modelling code, C.R.C. contributed the hydrodynamic galaxy simulations, and D.K.E. provided the Keck/NIRSPEC spectra. All authors reviewed, discussed and commented on the manuscript. The authors declare no competing financial interests.
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NASANAS 5-26555
David and Lucile Packard FoundationUNSPECIFIED
Issue or Number:7407
Record Number:CaltechAUTHORS:20120810-145208297
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Official Citation:High velocity dispersion in a rare grand-design spiral galaxy at redshift z = 2.18 David R. Law, Alice E. Shapley, Charles C. Steidel, Naveen A. Reddy, Charlotte R. Christensen & Dawn K. Erb Nature 487, 338–340 (19 July 2012) doi:10.1038/nature11256
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:33106
Deposited By: Ruth Sustaita
Deposited On:10 Aug 2012 22:49
Last Modified:09 Nov 2021 21:32

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