2012MNRAS.427.3055C -
Mon. Not. R. Astron. Soc., 427, 3055-3070 (2012/December-3)
No evidence for Lyman α emission in spectroscopy of z > 7 candidate galaxies.
CARUANA J., BUNKER A.J., WILKINS S.M., STANWAY E.R., LACY M., JARVIS M.J., LORENZONI S. and HICKEY S.
Abstract (from CDS):
We present Gemini/Gemini Near Infrared Spectrograph (GNIRS) spectroscopic observations of four
z-band (
z ≈ 7) dropout galaxies and Very Large Telescope (VLT)/XSHOOTER observations of one
z-band dropout and three
Y-band (
z ≈ 8–9) dropout galaxies in the
Hubble Ultra Deep Field, which were selected with Wide Field Camera 3 imaging on the
Hubble Space Telescope. We find no evidence of Lyman α emission with a typical 5σ sensitivity of 5 x 10
–18erg/cm2/s, and use the upper limits on Lyman α flux and the broad-band magnitudes to constrain the rest-frame equivalent widths for this line emission. Accounting for incomplete spectral coverage, we survey 3.0
z-band dropouts and 2.9
Y-band dropouts to a Lyman α rest-frame equivalent width limit >120 Å (for an unresolved emission line); for an equivalent width limit of 50 Å the effective numbers of drop-outs surveyed fall to 1.2
z-band drop-outs and 1.5
Y-band drop-outs. A simple model where the fraction of high rest-frame equivalent width emitters follows the trend seen at
z = 3–6.5 is inconsistent with our non-detections at
z = 7–9 at the ≈ 1σ level for spectrally unresolved lines, which may indicate that a significant neutral HI fraction in the intergalactic medium suppresses the Lyman α line in
z-drop and
Y-drop galaxies at
z > 7.
Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile, as part of programme 086.A-0968(B).
Abstract Copyright:
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Journal keyword(s):
galaxies: evolution - galaxies: formation - galaxies: high-redshift - galaxies: starburst - ultraviolet: galaxies
Simbad objects:
12
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2012MNRAS.427.3055C and select 'bookmark this link' or equivalent in the popup menu