NOAO >   Observing Info >   Approved Programs >   2010A-0263

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Proposal Information for 2010A-0263


PI: Ann Zabludoff, University of Arizona, azabludoff@as.arizona.edu
Address: Steward Observatory, 933 N Cherry Ave, Tucson, AZ 85721, USA

CoI: Yujin Yang, Max-Planck Institut fur Astronomie
CoI: Daniel Eisenstein, University of Arizona
CoI: Romeel Dave', University of Arizona

Title: Resolving the Nature of Newly Discovered Lyman-(alpha) Blobs in the NOAO Bootes Field

Abstract: \lya nebulae (aka "blobs"), extended sources at z ~ 2-5 with typical sizes of 100 kpc and line luminosities of L_\rmLy(alpha)~10^44 \unitcgslum, are among the most mysterious of astronomical objects. There are many theories for the source of their emission, including collisionally ionized gas in galactic superwinds or gas photoionized by young stellar populations and active galactic nuclei. Another possibility is that smooth gas accretion, which is likely to play an important role in the formation of galaxies and which should channel some of its gravitational cooling radiation into atomic emission lines such as \lya, is responsible. Because \lya is a resonant line and typically optically thick in the surrounding intergalactic medium, observational attempts to discriminate among these models using \lya kinematics have disagreed. To resolve the debate about the nature of blobs requires - at the very least - that we discriminate between between outflowing and inflowing models. Thus we have devised a new strategy for determining their gas kinematics unambiguously: using the optically thin H(alpha) line as a reference point in comparison to the center of the optically thick \lya line. \bf We have now made the first detections of the H(alpha) line profiles in such blobs with VLT/SINFONI. Neither of the blobs for which we can compare the H(alpha) and \lya profiles have the strong gas outflows thought to be characteristic of AGN or SNe feedback. \bf Here we propose to use Gemini/GMOS to extend this exciting work to a larger sample in order to constrain the diversity of blob kinematics. This program has just received NSF and NASA/ADP support.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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