Bright Lyman-alpha Emitters at z~9: constraints on the luminosity function from HiZELS
Monthly Notices of the Royal Astronomical Society: Letters Blackwell Publishing (2009)
Abstract:
New results are presented, as part of the Hi-z Emission Line Survey (HiZELS), from the largest area survey to date (1.4 sq.deg) for Lyman-alpha emitters (LAEs) at z~9. The survey, which is primarily targeting H-alpha emitters at z<3, uses the Wide Field CAMera on the United Kingdom Infrared Telescope and a custom narrow-band filter in the J band and reaches a Lyman-alpha luminosity limit of ~10^43.8 erg/s over a co-moving volume of 1.12x10^6 Mpc^3 at z=8.96+-0.06. Only 2 candidates were found out of 1517 line emitters and those were rejected as LAEs after follow-up observations. The limit on the space density of bright LAEs is improved by 3 orders of magnitude, consistent with suppression of the bright end of the Lyman-alpha luminosity function beyond z~6. Combined with upper limits from smaller but deeper surveys, this rules out some of the most extreme models for high-redshift LAEs. The potential contamination of future narrow-band Lyman-alpha surveys at z>7 by Galactic brown dwarf stars is also examined, leading to the conclusion that such contamination may well be significant for searches at 7.7Bright Lyα emitters at z ~ 9: Constraints on the LF from HizELS
Monthly Notices of the Royal Astronomical Society: Letters 398:1 (2009)
Abstract:
New results are presented, as part of the Hi-z Emission Line Survey (HizELS), from the largest area survey to date (1.4 deg2) for Lyα emitters (LAEs) at z ~ 9. The survey, which is primarily targeting Hα emitters at z < 3, uses the Wide Field CAMera on the United Kingdom Infrared Telescope and a custom narrow-band filter in the J band and reaches a Lyα luminosity limit of ~1043.8ergs-1 over a co-moving volume of 1.12 × 106 Mpc3 at z = 8.96 ± 0.06. Only two candidates were found out of 1517 line emitters and those were rejected as LAEs after follow-up observations. The limit on the space density of bright LAEs is improved by three orders of magnitude, consistent with suppression of the bright end of the Lyα luminosity function beyond z ~ 6. Combined with upper limits from smaller but deeper surveys, this rules out some of the most extreme models for high-redshift LAEs. The potential contamination of future narrow-band Lyα surveys at z > 7 by Galactic brown dwarf stars is also examined, leading to the conclusion that such contamination may well be significant for searches at 7.7 < z < 8.0, 9.1 < z < 9.5 and 11.7 < z < 12.2. © 2009 The Authors. Journal compilation © 2009 RAS.Radiation-hard/high-speed data transmission using optical links
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment Elsevier 607:1 (2009) 240-243
Stellar populations of early-type galaxies in the ATLAS3D sample
AIP Conference Proceedings 1111 (2009) 111-114
Abstract:
ATLAS3D is a multi-wavelength, volume-limited survey of 263 morphologicallyselected early-type galaxies within a distance of 42 Mpc and complete to MK ≤ -21.5. Here we present the ATLAS3D project and our first results on the stellar populations of galaxies in the ATLAS3Dsample based on SAURON integral-field spectroscopy. We show relations between integrated line-strength indices and stellar velocity dispersion o in the range 55 ≤ Σ(km/s) ≤ 350. We derive simple-stellar-population-equivalent age, metallicity and α/Fe abundance ratio and discuss their relation to stellar velocity dispersion, environment and galaxy internal kinematics. These preliminary results indicate that slow rotators tend to be older and have less variation in age than fast rotators. We also find that galaxies in lower density environments are on average younger than those in denser environments, as found by other authors. © 2009 American Institute of Physics.Bright Lyman-alpha Emitters at z~9: constraints on the luminosity function from HiZELS
(2009)