Ultradeep Near-Infrared ISAAC Observations of the Hubble Deep Field South: Selecting High-Redshift Galaxies in the Rest-Frame Optical

Author(s):  
Ivo Labbé ◽  
Marijn Franx ◽  
Gregory Rudnick ◽  
Alan Moorwood ◽  
Natascha Förster Schreiber ◽  
...  
2003 ◽  
Author(s):  
Ivo Labbe ◽  
Marijn Franx ◽  
Gregory Rudnick ◽  
Alan F. M. Moorwood ◽  
Natascha Foerster Schreiber ◽  
...  

2018 ◽  
Vol 616 ◽  
pp. A30 ◽  
Author(s):  
J. Chisholm ◽  
S. Gazagnes ◽  
D. Schaerer ◽  
A. Verhamme ◽  
J. R. Rigby ◽  
...  

The fraction of ionizing photons that escape high-redshift galaxies sensitively determines whether galaxies reionized the early Universe. However, this escape fraction cannot be measured from high-redshift galaxies because the opacity of the intergalactic medium is large at high redshifts. Without methods to measure the escape fraction of high-redshift galaxies indirectly, it is unlikely that we will know what reionized the Universe. Here, we analyze the far-ultraviolet (UV) H I (Lyman series) and low-ionization metal absorption lines of nine low-redshift, confirmed Lyman continuum emitting galaxies. We use the H I covering fractions, column densities, and dust attenuations measured in a companion paper to predict the escape fraction of ionizing photons. We find good agreement between the predicted and observed Lyman continuum escape fractions (within 1.4σ) using both the H I and ISM absorption lines. The ionizing photons escape through holes in the H I, but we show that dust attenuation reduces the fraction of photons that escape galaxies. This means that the average high-redshift galaxy likely emits more ionizing photons than low-redshift galaxies. Two other indirect methods accurately predict the escape fractions: the Lyα escape fraction and the optical [O III]/[O II] flux ratio. We use these indirect methods to predict the escape fraction of a sample of 21 galaxies with rest-frame UV spectra but without Lyman continuum observations. Many of these galaxies have low escape fractions (fesc ≤ 1%), but 11 have escape fractions >1%. Future studies will use these methods to measure the escape fractions of high-redshift galaxies, enabling upcoming telescopes to determine whether star-forming galaxies reionized the early Universe.


2009 ◽  
Vol 5 (S262) ◽  
pp. 283-286 ◽  
Author(s):  
Anne Pellerin ◽  
Steven L. Finkelstein

AbstractWith the coming generation of instruments and telescopes capable of spectroscopy of high redshift galaxies, the spectral synthesis technique in the rest-frame UV and Far-UV range will become one of a few number of tools remaining to study their young stellar populations in detail. The rest-frame UV lines and continuum of high redshift galaxies, observed with visible and infrared telescopes on Earth, can be used for accurate line profile fitting such as Pvλλ1118, 1128, Ciiiλ1176, and Civλ1550. These lines are very precise diagnostic tools to estimate ages, metallicities, and masses of stellar populations.Here we discuss the potential for spectral synthesis of rest-frame UV spectra obtained at the Keck telescope. As an example, we study the 8 o'clock arc, a lensed galaxy at z=2.7322. We show that the poor spectral type coverage of the actual UV empirical spectral libraries limits the age and metallicity diagnostic. In order to improve our knowledge of high redshift galaxies using spectral synthesis, UV stellar libraries need to be extended to obtain accurate age, metallicity, and mass estimates likely to be occuring in young stellar populations observed in the early universe.


1998 ◽  
Vol 298 (4) ◽  
pp. 1133-1144 ◽  
Author(s):  
L. Pozzetti ◽  
P. Madau ◽  
G. Zamorani ◽  
H. C. Ferguson ◽  
G. Bruzual A.

2009 ◽  
Vol 706 (2) ◽  
pp. 1020-1035 ◽  
Author(s):  
Erin Mentuch ◽  
Roberto G. Abraham ◽  
Karl Glazebrook ◽  
Patrick J. McCarthy ◽  
Haojing Yan ◽  
...  

1996 ◽  
Vol 283 (4) ◽  
pp. 1388-1404 ◽  
Author(s):  
P. Madau ◽  
H. C. Ferguson ◽  
M. E. Dickinson ◽  
M. Giavalisco ◽  
C. C. Steidel ◽  
...  

2001 ◽  
Vol 205 ◽  
pp. 455-456 ◽  
Author(s):  
R.I. Davies ◽  
M. Lehnert ◽  
A.J. Baker ◽  
S. Rabien

The major cornerstone of future ground-based astronomy is imaging and spectroscopy at the diffraction limit using adaptive optics. To exploit the potential of current AO systems, we have begun a survey around bright stars to study intermediate redshift galaxies at high resolution. Using ALFA to reach the diffraction limit of the 3.5-m telescope at Calar Alto allows us to study the structure of distant galaxies in the near-infrared at scales of 100-150 pc for z=0.05 and at scales 1.0-1.5 kpc at z=1. In this contribution we present the initial results of this project, which hint at the exciting prospects possible with the resolution and sensitivity available using an AO camera on the 8-m class VLT.


2003 ◽  
Vol 587 (2) ◽  
pp. L79-L82 ◽  
Author(s):  
Marijn Franx ◽  
Ivo Labb ◽  
Gregory Rudnick ◽  
Pieter G. van Dokkum ◽  
Emanuele Daddi ◽  
...  

1998 ◽  
Vol 298 (4) ◽  
pp. 1133-1144 ◽  
Author(s):  
Lucia Pozzetti ◽  
Piero Madau ◽  
Gianni Zamorani ◽  
Henry C. Ferguson ◽  
Gustavo Bruzual A.

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