High redshift galaxies in the HUDF

In summary, the conversation discusses designing a survey targeting 100 galaxies with a redshift of z=7 and minimizing exposure time by taking single band imaging of the rest frame UV. The Hubble Ultra Deep Field contains almost 10,000 galaxies, some with redshifts higher than 6. To compute the number of galaxies with a redshift of z=7, the source density at that redshift must be considered. This is given by the equation \Sigma( > SFR ) = 10 ( SFR )^{-2.1} . The relation between star formation rate and rest frame UV luminosity is SFR = 1.4 10^{-28} L_{UV} , and the relation between luminosity
  • #1
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In the Hubble Ultra Deep Field ( http://en.wikipedia.org/wiki/Hubble_Ultra-Deep_Field ) there are almost 10.000 galaxies and some of them with redshift Z>6 . Making some approximations i need to compute the number of galaxies with redshift z = 7.

If the source density ( number / arcmin^2 ) at z=7 is given by,

[tex] \Sigma( > SFR ) = 10 ( SFR )^{-2.1} [/tex]

and the relation between star formation rate and the rest frame UV luminosity is given by,

[tex] SFR = 1.4 10^{-28} L_{UV}[/tex]

The relation between luminosity and flux density is,

[tex] f_v =\frac{L_v (1+z)}{4 \pi d_l^2} [/tex]

and finally the minimum luminosity observed for an exposure time for a given filter is given

[tex] f = f_1 t_{exp}^{-1/2} [/tex]

Given that information how can i design a survey that is targeting 100 galaxies with redshift z=7 and how could i minimize the exposure time , by taking single band imaging of the rest frame UV. Any ideas ?
 
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1. What is the HUDF and why is it important for studying high redshift galaxies?

The HUDF, or Hubble Ultra Deep Field, is an image taken by the Hubble Space Telescope that captures a small region of the sky with extreme depth and clarity. This makes it an ideal tool for studying distant objects, such as high redshift galaxies, which are too faint to be seen by other telescopes. The HUDF allows scientists to study the formation and evolution of galaxies in the early universe.

2. How are high redshift galaxies identified in the HUDF?

High redshift galaxies can be identified in the HUDF through a process called spectroscopy. This involves measuring the wavelengths of light emitted by the galaxies and using that information to determine their distance from Earth. The farther away a galaxy is, the more its light will be shifted towards the red end of the spectrum. By analyzing the spectra of objects in the HUDF, scientists can identify which ones are high redshift galaxies.

3. What have we learned about high redshift galaxies from the HUDF?

The HUDF has provided a wealth of information about high redshift galaxies. Through its images and spectroscopic data, we have learned that these galaxies are much smaller and more irregular in shape compared to galaxies in the present-day universe. We have also observed that they are forming stars at a much faster rate and contain a higher proportion of gas compared to galaxies in the nearby universe. These findings have helped us understand the processes involved in the formation and evolution of galaxies.

4. How has our understanding of high redshift galaxies changed with advancements in technology and the study of the HUDF?

Advancements in technology, such as the Hubble Space Telescope and other ground-based telescopes, have allowed us to study high redshift galaxies in more detail and with greater accuracy. As a result, our understanding of these galaxies has evolved significantly. We now know that high redshift galaxies played a crucial role in the formation and growth of galaxies in the early universe, and they continue to play a vital role in shaping the universe as we know it.

5. What future research is planned for studying high redshift galaxies in the HUDF?

Scientists are planning to use the upcoming James Webb Space Telescope (JWST) to study high redshift galaxies in the HUDF. The JWST is equipped with advanced instruments that will provide even more detailed and precise data on these galaxies, allowing us to study them in even greater depth. This research will help us gain a deeper understanding of the formation and evolution of galaxies in the early universe and shed light on the mysteries of our cosmic origins.

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