NOAO >   Observing Info >   Approved Programs >   2004B-0368

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Proposal Information for 2004B-0368


PI: William C. Keel, University of Alabama, keel@bildad.astr.ua.edu
Address: Physics Department, Box 870324, Tuscaloosa, AL 35487, USA

CoI: Raymond E. White, III, University of Alabama
CoI: Scott Chapman, Caltech
CoI: Rogier A. Windhorst, Arizona State University

Title: Are the high-redshift Lyman (alpha) blobs enriched?

Abstract: The nature and energy source of the Lyman (alpha) blobs found in abundance at z>2 remains controversial. Our \it Chandra data for three blobs with known central AGN show that the nuclear continua are insufficient to power the emission-line clouds by photoionization. Additional data show [O III] in three of the clouds and C IV in one. Thus these clouds are significantly enriched, which rules out a picture of cooling flows of pristine gas and suggests a deep chemical history for gas around galaxies in the early Universe. We propose a systematic detection survey for C IV emission in the rich SSA22 clustering at z=3.1 as the fastest way to see whether such enrichment is a general property of Ly (alpha) blobs. Possible results could be that the enriched blobs are (1) typical, in which case Ly (alpha) blobs represent material which already belongs to the star/gas cycle; (2) anomalous, in which case we can start to explore the reasons for this; or (3) belong to an enriched subclass, which we can then learn to distinguish and interpret. Any of these outcomes improves our knowledge of the early chemical history of galaxies.


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NOAO >   Observing Info >   Approved Programs >   2004B-0368

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