%0 Generic %1 prescott2014spatially %A Prescott, Moire K. M. %A Martin, Crystal L. %A Dey, Arjun %D 2014 %K blobs gas kinematics lya resolved %T Spatially Resolved Gas Kinematics within a Ly$\alpha$ Nebula: Evidence for Large-scale Rotation %U http://arxiv.org/abs/1411.2589 %X We use spatially extended measurements of Ly$\alpha$ as well as less optically thick emission lines from an $\approx$80 kpc Ly$\alpha$ nebula at $z\approx1.67$ to assess the role of resonant scattering and to disentangle kinematic signatures from Ly$\alpha$ radiative transfer effects. We find that the Ly$\alpha$, CIV, HeII, and CIII emission lines all tell a similar story in this system, and that the kinematics are broadly consistent with large-scale rotation. First, the observed surface brightness profiles are similar in extent in all four lines, strongly favoring a picture in which the Ly$\alpha$ photons are produced in situ instead of being resonantly scattered from a central source. Second, we see low kinematic offsets between Ly$\alpha$ and the less optically thick HeII line ($\sim$100-200 km s$^-1$), providing further support for the argument that the Ly$\alpha$ and other emission lines are all being produced within the spatially extended gas. Finally, the full velocity field of the system shows coherent velocity shear in all emission lines: $\approx$500 km s$^-1$ over the central $\approx$50 kpc of the nebula. The kinematic profiles are broadly consistent with large-scale rotation in a gas disk that is at least partially stable against collapse. These observations suggest that the Ly$\alpha$ nebula represents accreting material that is illuminated by an offset, hidden AGN or distributed star formation, and that is undergoing rotation in a clumpy and turbulent gas disk. With an implied mass of M(<R=20 kpc)$\sim3\times10^11$ $M_ødot$, this system may represent the early formation of a large Milky Way mass galaxy or galaxy group.

@misc{prescott2014spatially, abstract = {We use spatially extended measurements of Ly$\alpha$ as well as less optically thick emission lines from an $\approx$80 kpc Ly$\alpha$ nebula at $z\approx1.67$ to assess the role of resonant scattering and to disentangle kinematic signatures from Ly$\alpha$ radiative transfer effects. We find that the Ly$\alpha$, CIV, HeII, and CIII] emission lines all tell a similar story in this system, and that the kinematics are broadly consistent with large-scale rotation. First, the observed surface brightness profiles are similar in extent in all four lines, strongly favoring a picture in which the Ly$\alpha$ photons are produced in situ instead of being resonantly scattered from a central source. Second, we see low kinematic offsets between Ly$\alpha$ and the less optically thick HeII line ($\sim$100-200 km s$^{-1}$), providing further support for the argument that the Ly$\alpha$ and other emission lines are all being produced within the spatially extended gas. Finally, the full velocity field of the system shows coherent velocity shear in all emission lines: $\approx$500 km s$^{-1}$ over the central $\approx$50 kpc of the nebula. The kinematic profiles are broadly consistent with large-scale rotation in a gas disk that is at least partially stable against collapse. These observations suggest that the Ly$\alpha$ nebula represents accreting material that is illuminated by an offset, hidden AGN or distributed star formation, and that is undergoing rotation in a clumpy and turbulent gas disk. With an implied mass of M(<R=20 kpc)$\sim3\times10^{11}$ $M_{\odot}$, this system may represent the early formation of a large Milky Way mass galaxy or galaxy group.}, added-at = {2014-11-12T10:00:30.000+0100}, author = {Prescott, Moire K. M. and Martin, Crystal L. and Dey, Arjun}, biburl = {https://www.bibsonomy.org/bibtex/2dfdce0bef11a1aec1d817042b67778fe/miki}, description = {[1411.2589] Spatially Resolved Gas Kinematics within a Ly$\alpha$ Nebula: Evidence for Large-scale Rotation}, interhash = {c30919009f282e72e49192ed0f7a0937}, intrahash = {dfdce0bef11a1aec1d817042b67778fe}, keywords = {blobs gas kinematics lya resolved}, note = {cite arxiv:1411.2589Comment: Accepted to ApJ; 25 pages in emulateapj format; 15 figures, 4 tables}, timestamp = {2014-11-12T10:00:30.000+0100}, title = {Spatially Resolved Gas Kinematics within a Ly$\alpha$ Nebula: Evidence for Large-scale Rotation}, url = {http://arxiv.org/abs/1411.2589}, year = 2014 }