Publication details for Prof David AlexanderLehmer, B.D., Brandt, W.N., Alexander, D.M., Bauer, F.E., Conselice, C.J., Dickinson, M.E., Giavalisco, M., Grogin, N.A., Koekemoer, A.M., Lee, K.-S., Moustakas, L.A. & Schneider, D.P. (2005). X-Ray Properties of Lyman Break Galaxies in the Great Observatories Origins Deep Survey. Astronomical Journal 129(1): 1-8.
- Publication type: Journal Article
- ISSN/ISBN: 0004-6256, 1538-3881
- DOI: 10.1086/426335
- Keywords: Cosmology: Observations, Surveys, X-Rays: Galaxies, X-Rays: General
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
AbstractWe constrain the X-ray emission properties of Lyman break galaxies (LBGs) at z~3-6 using the ~2 Ms Chandra Deep Field North and ~1 Ms Chandra Deep Field South. Large samples of LBGs were discovered using the Hubble Space Telescope as part of the Great Observatories Origins Deep Survey (GOODS). Deep optical and X-ray imaging over the GOODS fields have allowed us to place the most significant constraints on the X-ray properties of LBGs to date. Mean X-ray properties of 449, 1734, 629, and 247 LBGs with z~3, 4, 5, and 6, respectively, were determined using stacking techniques. When stacked, we detect X-ray emission from LBGs at z~3 (~7 sigma) and from an optically bright subset (brightest 25%) of LBGs at z~4 (~3 sigma) the latter is the highest redshift detection yet for ``normal'' galaxies in the X-ray band. The effective exposure times for these stacked observations are ~0.7 and 0.5 Gs, respectively. The derived average rest-frame 2.0-8.0 keV luminosities are 1.5×1041 and 1.4×1041 ergs s-1, respectively. X-ray emission from these LBGs is likely due to high-mass X-ray binaries and Type II supernovae; the corresponding star formation rates are ~10-30 Msolar yr-1. The X-ray-to-B-band mean luminosity ratio (LX/LB) at z~3 is somewhat elevated with respect to that measured for starburst galaxies in the local universe (significance ~3 sigma). When stacking full samples of LBGs at z~4, 5, and 6, we do not obtain significant detections (<3 sigma) and derive rest-frame 2.0-8.0 keV luminosity upper limits (3 sigma) of 0.9, 2.8, and 7.1 × 1041 ergs s-1, respectively. These upper limits constrain any widespread active galactic nucleus (AGN) activity in these objects to be modest at best. Furthermore, we find that ~0.5% of our LBGs from z~3 to z~6 are detected individually in the X-ray band. These LBGs have spectral shapes and luminosities characteristic of moderate-power AGNs (e.g., Seyfert galaxies and quasars).
Lead the scientific data analyses and conclusions and wrote resulting publication.