A search for neutral hydrogen absorption in the double quasar 0957 + 561

Nature ◽  
1980 ◽  
Vol 283 (5743) ◽  
pp. 175-176
Author(s):  
C. L. Bennett ◽  
C. R. Lawrence ◽  
B. F. Burke
2001 ◽  
Vol 325 (1) ◽  
pp. 151-158 ◽  
Author(s):  
R. J. Beswick ◽  
A. Pedlar ◽  
C. G. Mundell ◽  
J. F. Gallimore

1978 ◽  
Vol 83 ◽  
pp. 1412 ◽  
Author(s):  
P. Silverglate ◽  
Y. Terzian

1978 ◽  
Vol 225 ◽  
pp. 343
Author(s):  
A. D. Haschick ◽  
W. A. Baan ◽  
B. F. Burke

1981 ◽  
Vol 243 ◽  
pp. L143 ◽  
Author(s):  
W. A. Baan ◽  
A. D. Haschick

2019 ◽  
Vol 08 (02) ◽  
pp. 1950004 ◽  
Author(s):  
L. Philip ◽  
Z. Abdurashidova ◽  
H. C. Chiang ◽  
N. Ghazi ◽  
A. Gumba ◽  
...  

We introduce Probing Radio Intensity at high-Z from Marion (PRIZM), a new experiment designed to measure the globally averaged sky brightness, including the expected redshifted 21[Formula: see text]cm neutral hydrogen absorption feature arising from the formation of the first stars. PRIZM consists of two dual-polarization antennas operating at central frequencies of 70 and 100[Formula: see text]MHz, and the experiment is located on Marion Island in the sub-Antarctic. We describe the initial design and configuration of the PRIZM instrument that was installed in 2017, and we present preliminary data that demonstrate that Marion Island offers an exceptionally clean observing environment, with essentially no visible contamination within the FM band.


1995 ◽  
Vol 272 (2) ◽  
pp. 355-362 ◽  
Author(s):  
C. G. Mundell ◽  
A. Pedlar ◽  
S. A. Baum ◽  
C. P. O’Dea ◽  
J. F. Gallimore ◽  
...  

2001 ◽  
Vol 18 (1) ◽  
pp. 64-75 ◽  
Author(s):  
Paul J. Francis ◽  
Greg M. Wilson ◽  
Bruce E. Woodgate

AbstractFrancis & Hewett (1993) identified two 10 Mpc-scale regions of the high-redshift universe that were seemingly very overdense in neutral hydrogen. Subsequent observations showed that at least one of these gas-rich regions enveloped a cluster of galaxies at redshift 2 ·38. We present improved observations of the three background QSOs with sightlines passing within a few Mpc of this cluster of galaxies. All three QSOs show strong neutral hydrogen absorption at the cluster redshift, suggesting that this cluster (and perhaps all high-redshift clusters) may be surrounded by a ~5 Mpc-scale region containing ~10 12 Mʘ of neutral gas. We show that if most high-redshift clusters are surrounded by such regions, the gas must be in the form of many small (<1 kpc), dense (> 0·03 cm ˗3 ) clouds, each of mass <10 6 Mʘ . These clouds are themselves probably gathered into >20 kpc-sized clumps, which may be galaxy halos or protogalaxies. If this gas exists, it will be partially photoionised by the UV background. We predict the diffuse Lyα flux from this photoionisation, and place observational limits on its intensity.


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