QSO Candidates in the HDF

Conti, A., Kennefick, J., Martini, P., and Osmer, P. 1996, BAAS, 189, 3901

The Hubble Deep Field gives us an unprecendented view of our universe and an opportunity to study a wide range of questions in galaxy evolution and cosmology. Here, we will focus on the search for faint quasars and AGN in the crude combined images using a multicolor imaging analysis that has proven very successful in recent years. To produce a catalog of objects in the field, we used the FOCAS package for object detection with particular care to the set of input parameters used to minimize spurious detections. For each detected source we measured aperture magnitudes in several different apertures using the IRAF PHOT routine. For object classification we have chosen not to use the built-in FOCAS routines, instead we have developed classification schemes that closely resemble those of Flynn et al. (1996) to distinguish resolved from unresolved objects in the Hubble Deep Field. We generated synthetic quasar spectra in the range 2.0 < z < 5.5 including the effects of intrinsic emission lines and absorption by Ly\alpha forest and Lyman-limit systems and computed expected quasar colors. These colors are used to identify areas of the multicolor space where quasars might be expected. A quasar candidate list is being formed. Routines were developed to determine the commpleteness of our data to point sources in the observeed bands. The data are 50% complete at 27.0, 28.9, 29.1, and 28.2 in the F300W (U), F450W (B), F606W (V), and F814W (I) filters, respectively. These completeness limits closely approximate the 3\sigma detection limit. We will present a list of quasars candidates and compare the results to expectations from previous surveys and extrapolations from current models. Our initial extrapolations, based on the luminosity function of Boyle (1991), and Warren et al. (1994), suggest that the Hubble Deep Field may contain of order 10 quasars.

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