Close Pairs of Lyman Break Galaxies at z 3

Berrier, Joel C.; Cooke, J.; Bullock, J.; Barton, E.
Bibliographical reference

American Astronomical Society, AAS Meeting #215, #410.28; Bulletin of the American Astronomical Society, Vol. 42, p.239

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1
2010
Number of authors
4
IAC number of authors
0
Citations
0
Refereed citations
0
Description
We use a well understood N-body simulation combined with an analytic subhalo model to generate statistics for a defined sample of z 3 Lyman break galaxy (LBG) pairs. We select our sample by matching the two-point correlation function in the simulation to the observed correlation function for LBG's. We calculate the mean number of companions (Nc) per galaxy, or the close pair fraction, in the volume of our sample using two techniques. First, a standard cylinder is used to calculate the total close pair fraction that would be observed. Second, mock spectroscopic slits are constructed to mimic existing spectroscopic samples and are "observed" with multiple on-the-sky orientations. The results are used to calculate Nc for a randomly oriented spectroscopic slit geometry and are compared to the results from a sample of observed z 3 LBGs. We use mock spectroscopic slits whose lengths are randomly chosen from a catalog of slit lengths used in our observational sample. We use a maximum velocity separation of +/- 500 km/s to define our close pairs. We find Nc = 4.8% +- 0.2% for the spectroscopic slit, a value which is consistent with the observational results of 6.8% +- 1.2%. This implies a total close pair fraction of 42.2% +/- 1.1% using cylinder radii generated by our random slit lengths for each sample.