arXiv subjects

M. Rowan-Robinson

Publications and source records attributed to M. Rowan-Robinson.

182 records · Page 11Linked to original sources

arXiv1996

The nature of the faint galaxies in the Hubble Deep Field

We present a study of the galaxies found in the Hubble Deep Field. A high proportion of HDF galaxies are undergoing a strong episode of star formation, as evidenced by their very blue colours. A wide range of morphological types is found, with a high proportion of peculiar and merger morphologies. Fitting the multiband spectra with redshifted SEDs of galaxy types E to HII, we predict the spectral types and redshifts of galaxies detected in the HDF. We find a median redshift of 1.6, with $68\%$ having $z > 1$ and $31\%$ with $z >2$. The I-band absolute magnitude distributions as a function of galaxy types show a plausible trend of decreasing luminosity towards later types. The derived I-band luminosity function agrees well with that from the Canada-France survey (Lilly et al 1996) for $z < 1$ and shows strong luminosity evolution at $M_I < -21$ for $1 < z < 3$, comparable to the rate seen in quasars and starburst galaxies. We have predicted infrared and submillimetre fluxes assuming most of the galaxies are undergoing a strong starburst. Several planned space-borne and ground-based deep surveys are capable of detecting interesting numbers of HDF galaxies.

astro-ph↗

arXiv1993

Reconstruction Analysis I.: Redshift--space deprojection in the quasi--nonlinear regime

We present a new method for extracting the true 3-d velocity and density fields from the nonlinear redshift--space projected density field. The method is based on the nonlinear, nonlocal transformation of the density field. We assume a curl--free velocity field, although in the formulation presented here this assumption can be dropped. Toy models with special symmetry are used to test the intrinsic accuracy of the method compared to linear theory. Finding significant improvement we then test the method in more detail on N--body simulations, considering the problems associated with sampling the density field using sparse, magnitude--limited galaxy redshift surveys. A method of estimating the magnitude of shot--noise effects on the deprojected velocity field is derived. We find there is a good correlation between the true and deprojected density and velocity fields, even in the mildly nonlinear regime, provided that on large scales galaxies trace the mass. An initial application is made to the IRAS--QDOT all--sky redshift survey.

astro-ph↗