Browsing by Author "Holden, BP"

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    Advanced camera for surveys observations of a strongly lensed arc in a field elliptical galaxy
    (2004) Blakeslee, JP; Zekser, KC; Benítez, N; Franx, M; White, RL; Ford, HC; Bouwens, RJ; Infante, L; Cross, NJ; Hertling, G; Holden, BP; Illingworth, GD; Motta, V; Menanteau, F; Meurer, GR; Postman, M; Rosati, P; Zheng, W
    We report the discovery of a strongly lensed arc system around a field elliptical galaxy in Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) images of a parallel field observed during NICMOS observations of the HST Ultra Deep Field. The ACS parallel data comprise deep imaging in the F435W, F606W, F775W, and F850LP bandpasses. The main arc is at a radius of 1."6 from the galaxy center and subtends about 120degrees. Spectroscopic follow-up at Magellan Observatory yields a redshift z = 0.6174 for the lensing galaxy, and we photometrically estimate z(phot) = 2.4 +/- 0.3 for the arc. We also identify a likely counterarc at a radius of 0."6 that shows structure similar to that seen in the main arc. We model this system and find a good fit to an elliptical isothermal potential of velocity dispersion a sigma approximate to 300 km s(-1), the value expected from the fundamental plane, and some external shear. Several other galaxies in the field have colors similar to the lensing galaxy and likely make up a small group.
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    Advanced camera for surveys photometry of the cluster RDCS 1252.9-2927
    (2003) Blakeslee, JP; Franx, M; Postman, M; Rosati, P; Holden, BP; Illingworth, GD; Ford, HC; Cross, NJG; Gronwall, C; Benítez, N; Bouwens, RJ; Broadhurst, TJ; Clampin, M; Demarco, R; Golimowski, DA; Hartig, GF; Infante, L; Martel, AR; Miley, GK; Menanteau, F; Meurer, GR; Sirianni, M; White, RL
    We investigate the color-magnitude (CM) relation of galaxies in the distant X-ray-selected cluster RDCS 1252.9 - 2927 z = 1.24 at using images obtained with the Advanced Camera for Surveys on the Hubble Space Telescope in the F775W and F850LP bandpasses. We select galaxies based on morphological classifications extending about 3.5 mag down the galaxy luminosity function, augmented by spectroscopic membership information. At the core of the cluster is an extensive early-type galaxy population surrounding a central pair of galaxies that show signs of dynamical interaction. The early-type population defines a tight sequence in the CM diagram, with an intrinsic scatter in observed (i(775)-z(850)) of 0.029 +/- 0.007 mag based on 52 galaxies or 0.024 +/- 0.008 mag for similar to30 elliptical galaxies. Simulations using the latest stellar population models indicate an age scatter for the elliptical galaxies of about 34%, with a mean age tau(L) greater than or similar to 2.6 Gyr (corresponding to z(L) greater than or similar to 2.7), and the last star formation occurring at z(end) greater than or similar to 1.5 Transforming to rest-frame (U-B), we conclude that the slope end and scatter in the CM relation for morphologically selected early-type galaxies show little or no evidence of evolution out to z approximate to 1.2. Thus, elliptical galaxies were already well established in X-ray - luminous clusters when the universe was a third of its present age.
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    Evolution in the cluster early-type galaxy size-surface brightness relation at z ≃ 1
    (2005) Holden, BP; Blakeslee, JP; Postman, M; Illingworth, GD; Demarco, R; Franx, M; Rosati, P; Bouwens, RJ; Martel, AR; Ford, H; Clampin, M; Hartig, GF; Benítez, N; Cross, NJG; Homeier, N; Lidman, C; Menanteau, F; Zirm, A; Ardila, DR; Bartko, F; Bradley, LD; Broadhurst, TJ; Brown, RA; Burrows, CJ; Cheng, ES; Feldman, PD; Golimowski, DA; Goto, T; Gronwall, C; Infante, L; Kimble, RA; Krist, JE; Lesser, MP; Magee, D; Mei, S; Meurer, GR; Miley, GK; Motta, V; Sirianni, M; Sparks, WB; Tran, HD; Tsvetanov, ZI; White, RL; Zheng, W
    We investigate the evolution in the distribution of surface brightness, as a function of size, for elliptical and S0 galaxies in the two clusters RDCS J1252.9 - 2927 ( z = 1: 237) and RX J0152.7 - 1357 ( z = 0: 837). We use multicolor imaging with the Advanced Camera for Surveys on the Hubble Space Telescope to determine these sizes and surface brightnesses. Using three different estimates of the surface brightnesses, we find that we reliably estimate the surface brightness for the galaxies in our sample with a scatter of < 0.2 mag and with systematic shifts of <= 0.05 mag. We construct samples of galaxies with early- type morphologies in both clusters. For each cluster, we use a magnitude limit in a band that closely corresponds to the rest- frame B, to magnitude limit of M-B = - 18: 8 at z = 0, and select only those galaxies within the color- magnitude sequence of the cluster or by using our spectroscopic redshifts. We measure evolution in the rest- frame B surface brightness and find - 1: 41 +/- 0: 14 mag from the Coma Cluster of galaxies for RDCS J1252.9 - 2927 and - 0: 90 +/- 0: 12 mag of evolution for RX J0152.7 - 1357, or an average evolution of ( - 1: 13 +/- 0: 15) z mag. Our statistical errors are dominated by the observed scatter in the size - surface brightness relation, sigma = 0: 42 +/- 0: 05 mag for RX J0152.7 - 1357 and sigma = 0: 76 +/- 0: 10 mag for RDCS J1252.9 - 2927. We find no statistically significant evolution in this scatter, although an increase in the scatter could be expected. Overall, the pace of luminosity evolution we measure agrees with that of the fundamental plane of early- type galaxies, implying that the majority of massive early- type galaxies observed at z similar or equal to 1 formed at high redshifts.
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    Evolution of the color-magnitude relation in high-redshift clusters
    (2006) Mei, S; Blakeslee, JP; Stanford, SA; Holden, BP; Rosati, P; Strazzullo, V; Homeier, N; Postman, M; Franx, M; Rettura, A; Ford, H; Illingworth, GD; Ettori, S; Bouwens, RJ; Demarco, R; Martel, AR; Clampin, M; Hartig, GF; Eisenhardt, P; Ardila, DR; Bartko, F; Benítez, N; Bradley, LD; Broadhurst, TJ; Brown, RA; Burrows, CJ; Cheng, ES; Cross, NJG; Feldman, PD; Golimowski, DA; Goto, T; Gronwall, C; Infante, L; Kimble, RA; Krist, JE; Lesser, MP; Menanteau, F; Meurer, GR; Miley, GK; Motta, V; Sirianni, M; Sparks, WB; Tran, HD; Tsvetanov, ZI; White, RL; Zheng, W
    The color-magnitude relation has been determined for the RDCS J0910+5422 cluster of galaxies at redshift z = 1.106. Cluster members were selected from the Hubble Space Telescope Advanced Camera for Surveys (HST ACS) images, combined with ground-based near-IR imaging and optical spectroscopy. The observed early-type color-magnitude relation (CMR) in i(775) - z(850) versus z(850) shows an intrinsic scatter in color of 0.060 +/- 0.009 mag, within 10 from the cluster X-ray emission center. Both the elliptical and the S0 galaxies show small scatter about the CMR of 0.042 +/- 0.010 and 0.044 +/- 0.020 mag, respectively. From the scatter about the CMR, a mean luminosity weighted age t > 3: 3 Gyr (z(f) approximate to 3) is derived for the elliptical galaxies, assuming a simple stellar population modeling (single-burst solar metallicity). Strikingly, the S0 galaxies in RDCS J0910+5422 are systematically bluer in i(775) - z(850), by 0.07 +/- 0.02 mag, than the ellipticals. The ellipticity distribution as a function of color indicates that the face-on S0s in this particular cluster have likely been classified as elliptical. Thus, if anything, the offset in color between the elliptical and S0 populations may be even more significant. The color offset between S0 and E galaxies corresponds to an age difference of approximate to 1 Gyr for a single-burst solar-metallicity model. A solar-metallicity model with an exponential decay in star formation will reproduce the offset for an age of 3.5 Gyr; i.e., the S0s have evolved gradually from star-forming progenitors. The early-type population in this cluster appears to be still forming. The blue early-type disk galaxies in RDCS J0910+5422 likely represent the direct progenitors of the more evolved S0s that follow the same red sequence as elliptical galaxies in other clusters. Thirteen red galaxy pairs are observed, and the galaxies associated in pairs constitute similar to 40% of the CMR galaxies in this cluster.