The galaxy correlation function in the CNOC2 redshift survey: Dependence on color, luminosity, and redshift

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dc.contributor.authorShepherd, CW
dc.contributor.authorCarlberg, RG
dc.contributor.authorYee, HKC
dc.contributor.authorMorris, SL
dc.contributor.authorLin, H
dc.contributor.authorSawicki, M
dc.contributor.authorHall, PB
dc.contributor.authorPatton, DR
dc.date.accessioned2025-01-21T01:30:40Z
dc.date.available2025-01-21T01:30:40Z
dc.date.issued2001
dc.description.abstractWe examine how the spatial correlation function of galaxies from the Canadian Network for Observational Cosmology Field Galaxy Redshift Survey (CNOC2) depends on galaxy color, luminosity, and redshift. The projected correlation w(p) function is determined for volume-limited samples of objects with 0.12 less than or equal to z < 0.51 and evolution-compensated R-C-band absolute magnitudes M-R(O) < -20, over the co-moving projected separation range 0.04 h(-1) Mpc < r(p) <10 h(-1) Mpc. Our sample consists of 2937 galaxies that are classified as being either early- or late-type objects according to their spectral energy distribution (SED), as determined from UBVRCIC photometry. For the sake of simplicity, galaxy SEDs are classified independently of redshift : Our classification scheme therefore does not take into account the color evolution of galaxies. Objects with SEDs corresponding to early-type galaxies are found to be more strongly clustered by a factor of <similar to>3 and to have a steeper correlation function than those with late-type SEDs. Modeling the spatial correlation function, as a function of comoving separation r, as xi (r) = (r/r(o))(-gamma), we find r(o) = 5.45 +/- 0.28 h(-1) Mpc and gamma = 1.91 +/- 0.06 for early-type objects, and r(o) = 3.95 +/- 0.12 h(-1) Mpc and gamma = 1.59 +/- 0.08 for late-type objects (for Omega (M) = 0.2 Omega (Lambda) = 0). While changing the cutoff between early- and late-type SEDs does affect the correlation amplitudes of the two samples, the ratio of the amplitudes remains constant to within 10%. The redshift dependence of the correlation function also depends on SED type. Modeling the redshift dependence of the comoving correlation amplitude r(o)(gamma) r(o)(gamma)(z) proportional to (1 + z)(gamma -3-epsilon), we find that early-type objects have epsilon = -3.9 +/- 1.0, and late-type objects have epsilon = -7.7 +/- 1.3. Both classes of objects therefore have clustering amplitudes, measured in comoving coordinates, which appear to decrease rapidly with cosmic time. The excess clustering of galaxies with early-type SEDs, relative to late-type objects, is present at all redshifts in our sample. In contrast to the early- and late-type SED samples, the combined sample undergoes little apparent evolution, with epsilon = -2.1 +/- 1.3, which is consistent with earlier results. The apparent increase with redshift of the clustering amplitude in the early- and late-type samples is almost certainly caused by evolution of the galaxies themselves rather than by evolution of the correlation function. If galaxy SEDs have evolved significantly since z similar to 0.5, then our method of classifying SEDs may cause us to overestimate the true evolution of the clustering amplitude for the unevolved counterparts to our early- and late-type samples. However, if color evolution is to explain the apparent clustering evolution, the color evolution experienced by a galaxy must be correlated with the galaxy correlation function. We also investigate the luminosity dependence of the correlation function for volume-limited samples with 0.12 less than or equal to z < 0.40 and M-R(o) < -19.25.
dc.description.abstractWe detect a weak luminosity dependence of the correlation amplitude for galaxies with early-type SEDs, d log <xi>/dM(R)(o) = -0.35 +/- 0.17, but no significant dependence for late-type objects, d log xi /dM(R)(o) = 0.02 +/- 0.16.
dc.fuente.origenWOS
dc.identifier.eissn1538-4357
dc.identifier.issn0004-637X
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/96849
dc.identifier.wosidWOS:000171587300007
dc.issue.numero1
dc.language.isoen
dc.pagina.final85
dc.pagina.inicio72
dc.revistaAstrophysical journal
dc.rightsacceso restringido
dc.subjectgalaxies : clusters : general
dc.subjectgalaxies : evolution
dc.subjectlarge-scale structure of universe
dc.titleThe galaxy correlation function in the CNOC2 redshift survey: Dependence on color, luminosity, and redshift
dc.typeartículo
dc.volumen560
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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