A test of the foreground proximity effect at z=1.2

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Hst Proposal Id #9877 Quasar Absorption Lines And Igm

Scientific paper

The diffuse UV background flux J is a crucial component for cosmological evolution models, though few determinations have been made. The prox- imity effect, the thinning out of the Lyman alpha forest near a sight- line's background quasar and explained at least partly by the enhanced ionization from the quasar, is a key method to measure J. A foreground proximity effect {FPE} should exist from quasars close on the sky but at different z; it can constrain J and test the enhanced ionization model. Galaxy clustering around the quasar may modify the effect, but knowing the galaxy density around the Lya forest should allow for corrections. We propose to measure the FPE at z=1.2, which is advantageous because 1} the diffuse UV flux is lower, and thus contrast with the UV flux of neighboring quasars is higher, and 2} galaxies are easier to identify at z=1.2. We have good knowledge of the physical volume we wish to study through surveys for quasars, MgII absorbers and galaxies, to constrain the redshift-dependent galaxy density along the line of sight. We will analyze the results based on pixel opacities, which is more sensitive to fluctuations in J than traditional line counting, and will compare our results with cosmological simulations to derive estimates of the UV background in the context of available physical models.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A test of the foreground proximity effect at z=1.2 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A test of the foreground proximity effect at z=1.2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A test of the foreground proximity effect at z=1.2 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1133638

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.