Search

Your search keyword '"Ryan, R E"' showing total 36 results
Start Over Author "Ryan, R E" Database OAIster
36 results on '"Ryan, R E"'

1. JWST Photometric Time-delay and Magnification Measurements for the Triply Imaged Type Ia “SN H0pe” at z = 1.78

Author

Pierel, J. D. R., Frye, B. L., Pascale, M., Caminha, G. B., Chen, W., Dhawan, S., Gilman, D., Grayling, M., Huber, S., Kelly, P., Thorp, S., Arendse, N., Birrer, S., Bronikowski, M., Cañameras, R., Coe, D., Cohen, S. H., Conselice, C. J., Driver, S. P., Dśilva, J. C. J., Engesser, M., Foo, N., Gall, C., Garuda, N., Grillo, C., Grogin, N. A., Henderson, J., Hjorth, J., Jansen, R. A., Johansson, J., Kamieneski, P. S., Koekemoer, A. M., Larison, C., Marshall, M. A., Moustakas, L. A., Nonino, M., Ortiz, R., Petrushevska, T., Pirzkal, N., Robotham, A., Ryan, R. E., Schuldt, S., Strolger, L. G., Summers, J., Suyu, S. H., Treu, T., Willmer, C. N. A., Windhorst, R. A., Yan, H., Zitrin, A., Acebron, A., Chakrabarti, S., Coulter, D. A., Fox, O. D., Huang, X., Jha, S. W., Li, G., Mazzali, P. A., Meena, A. K., Pérez-fournon, I., Poidevin, F., Rest, A., Riess, A. G., Pierel, J. D. R., Frye, B. L., Pascale, M., Caminha, G. B., Chen, W., Dhawan, S., Gilman, D., Grayling, M., Huber, S., Kelly, P., Thorp, S., Arendse, N., Birrer, S., Bronikowski, M., Cañameras, R., Coe, D., Cohen, S. H., Conselice, C. J., Driver, S. P., Dśilva, J. C. J., Engesser, M., Foo, N., Gall, C., Garuda, N., Grillo, C., Grogin, N. A., Henderson, J., Hjorth, J., Jansen, R. A., Johansson, J., Kamieneski, P. S., Koekemoer, A. M., Larison, C., Marshall, M. A., Moustakas, L. A., Nonino, M., Ortiz, R., Petrushevska, T., Pirzkal, N., Robotham, A., Ryan, R. E., Schuldt, S., Strolger, L. G., Summers, J., Suyu, S. H., Treu, T., Willmer, C. N. A., Windhorst, R. A., Yan, H., Zitrin, A., Acebron, A., Chakrabarti, S., Coulter, D. A., Fox, O. D., Huang, X., Jha, S. W., Li, G., Mazzali, P. A., Meena, A. K., Pérez-fournon, I., Poidevin, F., Rest, A., and Riess, A. G.

Published
2024

2. JWST Photometric Time-delay and Magnification Measurements for the Triply Imaged Type Ia “SN H0pe” at z = 1.78

Author

Pierel, J. D. R., Frye, B. L., Pascale, M., Caminha, G. B., Chen, W., Dhawan, S., Gilman, D., Grayling, M., Huber, S., Kelly, P., Thorp, S., Arendse, N., Birrer, S., Bronikowski, M., Cañameras, R., Coe, D., Cohen, S. H., Conselice, C. J., Driver, S. P., Dśilva, J. C. J., Engesser, M., Foo, N., Gall, C., Garuda, N., Grillo, C., Grogin, N. A., Henderson, J., Hjorth, J., Jansen, R. A., Johansson, J., Kamieneski, P. S., Koekemoer, A. M., Larison, C., Marshall, M. A., Moustakas, L. A., Nonino, M., Ortiz, R., Petrushevska, T., Pirzkal, N., Robotham, A., Ryan, R. E., Schuldt, S., Strolger, L. G., Summers, J., Suyu, S. H., Treu, T., Willmer, C. N. A., Windhorst, R. A., Yan, H., Zitrin, A., Acebron, A., Chakrabarti, S., Coulter, D. A., Fox, O. D., Huang, X., Jha, S. W., Li, G., Mazzali, P. A., Meena, A. K., Pérez-fournon, I., Poidevin, F., Rest, A., Riess, A. G., Pierel, J. D. R., Frye, B. L., Pascale, M., Caminha, G. B., Chen, W., Dhawan, S., Gilman, D., Grayling, M., Huber, S., Kelly, P., Thorp, S., Arendse, N., Birrer, S., Bronikowski, M., Cañameras, R., Coe, D., Cohen, S. H., Conselice, C. J., Driver, S. P., Dśilva, J. C. J., Engesser, M., Foo, N., Gall, C., Garuda, N., Grillo, C., Grogin, N. A., Henderson, J., Hjorth, J., Jansen, R. A., Johansson, J., Kamieneski, P. S., Koekemoer, A. M., Larison, C., Marshall, M. A., Moustakas, L. A., Nonino, M., Ortiz, R., Petrushevska, T., Pirzkal, N., Robotham, A., Ryan, R. E., Schuldt, S., Strolger, L. G., Summers, J., Suyu, S. H., Treu, T., Willmer, C. N. A., Windhorst, R. A., Yan, H., Zitrin, A., Acebron, A., Chakrabarti, S., Coulter, D. A., Fox, O. D., Huang, X., Jha, S. W., Li, G., Mazzali, P. A., Meena, A. K., Pérez-fournon, I., Poidevin, F., Rest, A., and Riess, A. G.

Published
2024

3. JWST’s PEARLS:A new lens model for ACT-CL J0102−4915, “El Gordo,” and the first red supergiant star at cosmological distances discovered by JWST

Author

Diego, J. M., Meena, A. K., Adams, N. J., Broadhurst, T., Dai, L., Coe, D., Frye, B., Kelly, P., Koekemoer, A. M., Pascale, M., Willner, S. P., Zackrisson, E., Zitrin, A., Windhorst, R. A., Cohen, S. H., Jansen, R. A., Summers, J., Tompkins, S., Conselice, C. J., Driver, S. P., Yan, H., Grogin, N., Marshall, M. A., Pirzkal, N., Robotham, A., Ryan, R. E., Willmer, C. N. A., Bradley, L. D., Caminha, G., Caputi, K., Carleton, T., Kamieneski, P., Diego, J. M., Meena, A. K., Adams, N. J., Broadhurst, T., Dai, L., Coe, D., Frye, B., Kelly, P., Koekemoer, A. M., Pascale, M., Willner, S. P., Zackrisson, E., Zitrin, A., Windhorst, R. A., Cohen, S. H., Jansen, R. A., Summers, J., Tompkins, S., Conselice, C. J., Driver, S. P., Yan, H., Grogin, N., Marshall, M. A., Pirzkal, N., Robotham, A., Ryan, R. E., Willmer, C. N. A., Bradley, L. D., Caminha, G., Caputi, K., Carleton, T., and Kamieneski, P.

Published
2023

4. What global biogeochemical consequences will marine animal–sediment interactions have during climate change?

Author

Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., Stanley, Ryan R. E., Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., and Stanley, Ryan R. E.

Abstract

Benthic animals profoundly influence the cycling and storage of carbon and other elements in marine systems, particularly in coastal sediments. Recent climate change has altered the distribution and abundance of many seafloor taxa and modified the vertical exchange of materials between ocean and sediment layers. Here, we examine how climate change could alter animal-mediated biogeochemical cycling in ocean sediments. The fossil record shows repeated major responses from the benthos during mass extinctions and global carbon perturbations, including reduced diversity, dominance of simple trace fossils, decreased burrow size and bioturbation intensity, and nonrandom extinction of trophic groups. The broad dispersal capacity of many extant benthic species facilitates poleward shifts corresponding to their environmental niche as overlying water warms. Evidence suggests that locally persistent populations will likely respond to environmental shifts through either failure to respond or genetic adaptation rather than via phenotypic plasticity. Regional and global ocean models insufficiently integrate changes in benthic biological activity and their feedbacks on sedimentary biogeochemical processes. The emergence of bioturbation, ventilation, and seafloor-habitat maps and progress in our mechanistic understanding of organism–sediment interactions enable incorporation of potential effects of climate change on benthic macrofaunal mediation of elemental cycles into regional and global ocean biogeochemical models.

Published
2021

5. What global biogeochemical consequences will marine animal–sediment interactions have during climate change?

Author

Geochemistry, Bio-, hydro-, and environmental geochemistry, Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., Stanley, Ryan R. E., Geochemistry, Bio-, hydro-, and environmental geochemistry, Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., and Stanley, Ryan R. E.

Published
2021

6. What global biogeochemical consequences will marine animal–sediment interactions have during climate change?

Author

Geochemistry, Bio-, hydro-, and environmental geochemistry, Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., Stanley, Ryan R. E., Geochemistry, Bio-, hydro-, and environmental geochemistry, Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., and Stanley, Ryan R. E.

Published
2021

7. What global biogeochemical consequences will marine animal–sediment interactions have during climate change?

Author

Geochemistry, Bio-, hydro-, and environmental geochemistry, Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., Stanley, Ryan R. E., Geochemistry, Bio-, hydro-, and environmental geochemistry, Bianchi, Thomas S., Aller, Robert C., Atwood, Trisha B., Brown, Craig J., Buatois, Luis A., Levin, Lisa A., Levinton, Jeffrey S., Middelburg, Jack J., Morrison, Elise S., Regnier, Pierre, Shields, Michael R., Snelgrove, Paul V. R., Sotka, Erik E., and Stanley, Ryan R. E.

Published
2021

8. The Size and Pervasiveness of Ly$\alpha$-UV Spatial Offsets in Star-Forming Galaxies at $z\sim6$

Author

Lemaux, B. C., Fuller, S., Bradač, M., Pentericci, L., Hoag, A., Strait, V., Treu, T., Alvarez, C., Bolan, P., Gandhi, P. J., Jones, T., Mason, C., Pelliccia, D., Ribeiro, B., Ryan, R. E., Schmidt, K. B., Vanzella, E., Khusanova, Y., Fèvre, O. Le, Guaita, L., Hathi, N. P., Koekemoer, A., Pforr, J., Lemaux, B. C., Fuller, S., Bradač, M., Pentericci, L., Hoag, A., Strait, V., Treu, T., Alvarez, C., Bolan, P., Gandhi, P. J., Jones, T., Mason, C., Pelliccia, D., Ribeiro, B., Ryan, R. E., Schmidt, K. B., Vanzella, E., Khusanova, Y., Fèvre, O. Le, Guaita, L., Hathi, N. P., Koekemoer, A., and Pforr, J.

Abstract

We study the projected spatial offset between the ultraviolet continuum and Ly$\alpha$ emission for 65 lensed and unlensed galaxies in the Epoch of Reionization ($5\leq z\leq7$), the first such study at these redshifts, in order to understand the potential for these offsets to confuse estimates of the Ly$\alpha$ properties of galaxies observed in slit spectroscopy. While we find that ~40% of galaxies in our sample show significant projected spatial offsets ($|\Delta_{Ly\alpha-UV}|$), we find a modest average offset of 0.61$\pm$0.08 kpc. A small fraction of our sample, ~10%, exhibits offsets of 2-4 kpc, sizes that are larger than the effective radii of typical galaxies at these redshifts. An internal comparison and a comparison to studies at lower redshift yielded no significant evidence of evolution of $|\Delta_{Ly\alpha-UV}|$ with redshift. In our own sample, UV-bright galaxies showed offsets a factor of three greater than their fainter counterparts, 0.89$\pm$0.18 vs. 0.27$\pm$0.05 kpc, respectively. We argue that offsets are likely not the result of merging processes, but are rather due to internal anisotropic processes resulting from stellar feedback facilitates Ly$\alpha$ fluorescence and/or backscattering from nearby or outflowing gas. The reduction in the Ly$\alpha$ flux due to offset effects for various observational setups was quantified through mock observations of simple simulations. It was found that the loss of Ly$\alpha$ photons for galaxies with average offsets is not, if corrected for, a limiting factor for all but the narrowest slit widths (<0.4''). However, for the largest offsets, if such offsets are mostly perpendicular to the slit major axis, slit losses were found to be extremely severe in cases where slit widths of $\leq$1'' were employed, such as those planned for James Webb Space Telescope/NIRSpec observations. (abridged), Comment: 21 pages, 7 figures, 2 tables. Updated with the accepted MNRAS version that includes minor changes to the text and two tables

Published
2020
Full Text
View/download PDF

9. The Size and Pervasiveness of Ly$\alpha$-UV Spatial Offsets in Star-Forming Galaxies at $z\sim6$

Author

Lemaux, B. C., Fuller, S., Bradač, M., Pentericci, L., Hoag, A., Strait, V., Treu, T., Alvarez, C., Bolan, P., Gandhi, P. J., Jones, T., Mason, C., Pelliccia, D., Ribeiro, B., Ryan, R. E., Schmidt, K. B., Vanzella, E., Khusanova, Y., Fèvre, O. Le, Guaita, L., Hathi, N. P., Koekemoer, A., Pforr, J., Lemaux, B. C., Fuller, S., Bradač, M., Pentericci, L., Hoag, A., Strait, V., Treu, T., Alvarez, C., Bolan, P., Gandhi, P. J., Jones, T., Mason, C., Pelliccia, D., Ribeiro, B., Ryan, R. E., Schmidt, K. B., Vanzella, E., Khusanova, Y., Fèvre, O. Le, Guaita, L., Hathi, N. P., Koekemoer, A., and Pforr, J.

Abstract

We study the projected spatial offset between the ultraviolet continuum and Ly$\alpha$ emission for 65 lensed and unlensed galaxies in the Epoch of Reionization ($5\leq z\leq7$), the first such study at these redshifts, in order to understand the potential for these offsets to confuse estimates of the Ly$\alpha$ properties of galaxies observed in slit spectroscopy. While we find that ~40% of galaxies in our sample show significant projected spatial offsets ($|\Delta_{Ly\alpha-UV}|$), we find a modest average offset of 0.61$\pm$0.08 kpc. A small fraction of our sample, ~10%, exhibits offsets of 2-4 kpc, sizes that are larger than the effective radii of typical galaxies at these redshifts. An internal comparison and a comparison to studies at lower redshift yielded no significant evidence of evolution of $|\Delta_{Ly\alpha-UV}|$ with redshift. In our own sample, UV-bright galaxies showed offsets a factor of three greater than their fainter counterparts, 0.89$\pm$0.18 vs. 0.27$\pm$0.05 kpc, respectively. We argue that offsets are likely not the result of merging processes, but are rather due to internal anisotropic processes resulting from stellar feedback facilitates Ly$\alpha$ fluorescence and/or backscattering from nearby or outflowing gas. The reduction in the Ly$\alpha$ flux due to offset effects for various observational setups was quantified through mock observations of simple simulations. It was found that the loss of Ly$\alpha$ photons for galaxies with average offsets is not, if corrected for, a limiting factor for all but the narrowest slit widths (<0.4''). However, for the largest offsets, if such offsets are mostly perpendicular to the slit major axis, slit losses were found to be extremely severe in cases where slit widths of $\leq$1'' were employed, such as those planned for James Webb Space Telescope/NIRSpec observations. (abridged), Comment: 21 pages, 7 figures, 2 tables. Updated with the accepted MNRAS version that includes minor changes to the text and two tables

Published
2020
Full Text
View/download PDF

10. Spatially Extended Low Ionization Emission Regions (LIERs) at $z\sim0.9$

Author

Hviding, R. E., Brammer, G. B., Momcheva, I. G., Lundgren, B. F., Marchesini, D., Pirzkal, N., Ryan, R. E., Vang, A., Wake, D. A., Bourque, M., Martlin, C., Nedkova, K. V., Hviding, R. E., Brammer, G. B., Momcheva, I. G., Lundgren, B. F., Marchesini, D., Pirzkal, N., Ryan, R. E., Vang, A., Wake, D. A., Bourque, M., Martlin, C., and Nedkova, K. V.

Abstract

We present spatially resolved emission diagnostics for eight $z\sim0.9$ galaxies that demonstrate extended low ionization emission-line regions (LIERs) over kpc scales. Eight candidates are selected based on their spatial extent and emission line fluxes from slitless spectroscopic observations with the HST/WFC3 G141 and G800L grisms in the well-studied GOODS survey fields. Five of the candidates (62.5%) are matched to X-ray counterparts in the \textit{Chandra X-Ray Observatory} Deep Fields. We modify the traditional Baldwin-Philips-Terlevich (BPT) emission line diagnostic diagram to use [SII]/(H$\alpha$+[NII]) instead of [NII]/H$\alpha$ to overcome the blending of [NII] and H$\alpha$+[NII] in the low resolution slitless grism spectra. We construct emission line ratio maps and place the individual pixels in the modified BPT. The extended LINER-like emission present in all of our candidates, coupled with X-Ray properties consistent with star-forming galaxies and weak [OIII]$\lambda$5007\AA\ detections, is inconsistent with purely nuclear sources (LINERs) driven by active galactic nuclei. While recent ground-based integral field unit spectroscopic surveys have revealed significant evidence for diffuse LINER-like emission in galaxies within the local universe $(z\sim0.04)$, this work provides the first evidence for the non-AGN origin of LINER-like emission out to high redshifts., Comment: 11 pages, 1 table, 6 figures, accepted for publication in the Astrophysics Journal (ApJ)

Published
2018
Full Text
View/download PDF

11. Spatially Extended Low Ionization Emission Regions (LIERs) at $z\sim0.9$

Author

Hviding, R. E., Brammer, G. B., Momcheva, I. G., Lundgren, B. F., Marchesini, D., Pirzkal, N., Ryan, R. E., Vang, A., Wake, D. A., Bourque, M., Martlin, C., Nedkova, K. V., Hviding, R. E., Brammer, G. B., Momcheva, I. G., Lundgren, B. F., Marchesini, D., Pirzkal, N., Ryan, R. E., Vang, A., Wake, D. A., Bourque, M., Martlin, C., and Nedkova, K. V.

Abstract

We present spatially resolved emission diagnostics for eight $z\sim0.9$ galaxies that demonstrate extended low ionization emission-line regions (LIERs) over kpc scales. Eight candidates are selected based on their spatial extent and emission line fluxes from slitless spectroscopic observations with the HST/WFC3 G141 and G800L grisms in the well-studied GOODS survey fields. Five of the candidates (62.5%) are matched to X-ray counterparts in the \textit{Chandra X-Ray Observatory} Deep Fields. We modify the traditional Baldwin-Philips-Terlevich (BPT) emission line diagnostic diagram to use [SII]/(H$\alpha$+[NII]) instead of [NII]/H$\alpha$ to overcome the blending of [NII] and H$\alpha$+[NII] in the low resolution slitless grism spectra. We construct emission line ratio maps and place the individual pixels in the modified BPT. The extended LINER-like emission present in all of our candidates, coupled with X-Ray properties consistent with star-forming galaxies and weak [OIII]$\lambda$5007\AA\ detections, is inconsistent with purely nuclear sources (LINERs) driven by active galactic nuclei. While recent ground-based integral field unit spectroscopic surveys have revealed significant evidence for diffuse LINER-like emission in galaxies within the local universe $(z\sim0.04)$, this work provides the first evidence for the non-AGN origin of LINER-like emission out to high redshifts., Comment: 11 pages, 1 table, 6 figures, accepted for publication in the Astrophysics Journal (ApJ)

Published
2018
Full Text
View/download PDF

12. The Environment of the Binary Neutron Star Merger GW170817

Author

Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schrøder, S. L., Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., de Ugarte Postigo, A., Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Palazzi, E., Pian, E., Perley, D. A., Rosswog, Stephan, Ryan, R. E., Schulze, S., Sutton, P., Thöne, C. C., Watson, D. J., Wijers, R. A. M. J., Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schrøder, S. L., Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., de Ugarte Postigo, A., Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Palazzi, E., Pian, E., Perley, D. A., Rosswog, Stephan, Ryan, R. E., Schulze, S., Sutton, P., Thöne, C. C., Watson, D. J., and Wijers, R. A. M. J.

Abstract

We present Hubble Space Telescope (HST) and Chandra imaging, combined with Very Large Telescope MUSE integral field spectroscopy of the counterpart and host galaxy of the first binary neutron star merger detected via gravitational-wave emission by LIGO and Virgo, GW170817. The host galaxy, NGC 4993, is an S0 galaxy at z - 0.009783. There is evidence for large, face-on spiral shells in continuum imaging, and edge-on spiral features visible in nebular emission lines. This suggests that NGC 4993 has undergone a relatively recent (less than or similar to 1 Gyr) dry merger. This merger may provide the fuel for a weak active nucleus seen in Chandra imaging. At the location of the counterpart, HST imaging implies there is no globular or young stellar cluster, with a limit of a few thousand solar masses for any young system. The population in the vicinity is predominantly old with less than or similar to 1% of any light arising from a population with ages <500 Myr. Both the host galaxy properties and those of the transient location are consistent with the distributions seen for short-duration gamma-ray bursts, although the source position lies well within the effective radius (r(e) similar to 3 kpc), providing an r(e)-normalized offset that is closer than similar to 90% of short GRBs. For the long delay time implied by the stellar population, this suggests that the kick velocity was significantly less than the galaxy escape velocity. We do not see any narrow host galaxy interstellar medium features within the counterpart spectrum, implying low extinction, and that the binary may lie in front of the bulk of the host galaxy.

Published
2017
Full Text
View/download PDF

13. Lyman continuum escape fraction of faint galaxies at z similar to 3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC

Author

Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, Michael J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., Yan, H., Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, Michael J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., and Yan, H.

Abstract

Context. The reionization of the Universe is one of the most important topics of present-day astrophysical research. The most plausible candidates for the reionization process are star-forming galaxies, which according to the predictions of the majority of the theoretical and semi-analytical models should dominate the H I ionizing background at z greater than or similar to 3. Aims. We measure the Lyman continuum escape fraction, which is one of the key parameters used to compute the contribution of star-forming galaxies to the UV background. It provides the ratio between the photons produced at lambda <= 912 angstrom rest-frame and those that are able to reach the inter-galactic medium, i.e. that are not absorbed by the neutral hydrogen or by the dust of the galaxy's inter-stellar medium. Methods. We used ultra-deep U-band imaging (U = 30.2 mag at 1 sigma) from Large Binocular Camera at the Large Binocular Telescope (LBC/LBT) in the CANDELS/GOODS-North field and deep imaging in the COSMOS and EGS fields in order to estimate the Lyman continuum escape fraction of 69 star-forming galaxies with secure spectroscopic redshifts at 3.27 <= z <= 3.40 to faint magnitude limits (L = 0.2L*, or equivalently M-1500 similar to -19). The narrow redshift range implies that the LBC U-band filter exclusively samples the lambda <= 912 angstrom rest-frame wavelengths. Results. We measured through stacks a stringent upper limit (<1.7% at 1 sigma) for the relative escape fraction of H I ionizing photons from bright galaxies (L > L*), while for the faint population (L = 0.2L*) the limit to the escape fraction is less than or similar to 10%. We computed the contribution of star-forming galaxies to the observed UV background at z similar to 3 and find that it is not sufficient to keep the Universe ionized at these redshifts unless their escape fraction increases significantly (>= 10%) at low luminosities (M-1500 >= -19). Conclusions. We compare our results on the Lym

Published
2017
Full Text
View/download PDF

14. The environment of the binary neutron star merger GW170817

Author

Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schrøder, S. L, Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., Postigo, A de Ugarte, Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Plazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thöne, C. C., Watson, D. J., Wijers, R. A. M. J., Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schrøder, S. L, Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., Postigo, A de Ugarte, Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Plazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thöne, C. C., Watson, D. J., and Wijers, R. A. M. J.

Abstract

We present Hubble Space Telescope and Chandra imaging, combined with Very Large Telescope MUSE integral field spectroscopy of the counterpart and host galaxy of the first binary neutron star merger detected via gravitational wave emission by LIGO & Virgo, GW170817. The host galaxy, NGC 4993, is an S0 galaxy at z=0.009783. There is evidence for large, face-on spiral shells in continuum imaging, and edge-on spiral features visible in nebular emission lines. This suggests that NGC 4993 has undergone a relatively recent (<1 Gyr) ``dry'' merger. This merger may provide the fuel for a weak active nucleus seen in Chandra imaging. At the location of the counterpart, HST imaging implies there is no globular or young stellar cluster, with a limit of a few thousand solar masses for any young system. The population in the vicinity is predominantly old with <1% of any light arising from a population with ages <500 Myr. Both the host galaxy properties and those of the transient location are consistent with the distributions seen for short-duration gamma-ray bursts, although the source position lies well within the effective radius (r_e ~ 3 kpc), providing an r_e-normalized offset that is closer than ~90% of short GRBs. For the long delay time implied by the stellar population, this suggests that the kick velocity was significantly less than the galaxy escape velocity. We do not see any narrow host galaxy interstellar medium features within the counterpart spectrum, implying low extinction, and that the binary may lie in front of the bulk of the host galaxy., Comment: ApJL in press, 13 pages

Published
2017
Full Text
View/download PDF

15. The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC

Author

Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, M. J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., Yan, H., Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, M. J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., and Yan, H.

Abstract

The reionization of the Universe is one of the most important topics of present day astrophysical research. The most plausible candidates for the reionization process are star-forming galaxies, which according to the predictions of the majority of the theoretical and semi-analytical models should dominate the HI ionizing background at z~3. We aim at measuring the Lyman continuum escape fraction, which is one of the key parameters to compute the contribution of star-forming galaxies to the UV background. We have used ultra-deep U-band imaging (U=30.2mag at 1sigma) by LBC/LBT in the CANDELS/GOODS-North field, as well as deep imaging in COSMOS and EGS fields, in order to estimate the Lyman continuum escape fraction of 69 star-forming galaxies with secure spectroscopic redshifts at 3.27L*), while for the faint population (L=0.2L*) the limit to the escape fraction is ~10%. We have computed the contribution of star-forming galaxies to the observed UV background at z~3 and we have found that it is not enough to keep the Universe ionized at these redshifts, unless their escape fraction increases significantly (>10%) at low luminosities (M1500>-19). We compare our results on the Lyman continuum escape fraction of high-z galaxies with recent estimates in the literature and discuss future prospects to shed light on the end of the Dark Ages. In the future, strong gravitational lensing will be fundamental to measure the Lyman continuum escape fraction down to faint magnitudes (M1500~-16) which are inaccessible with the present instrumentation on blank fields., Comment: Accepted for publication in A&A, 16 pages, 6 figures

Published
2017
Full Text
View/download PDF

16. The environment of the binary neutron star merger GW170817

Author

Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schrøder, S. L, Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., Postigo, A de Ugarte, Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Plazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thöne, C. C., Watson, D. J., Wijers, R. A. M. J., Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schrøder, S. L, Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., Postigo, A de Ugarte, Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Plazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thöne, C. C., Watson, D. J., and Wijers, R. A. M. J.

Abstract

We present Hubble Space Telescope and Chandra imaging, combined with Very Large Telescope MUSE integral field spectroscopy of the counterpart and host galaxy of the first binary neutron star merger detected via gravitational wave emission by LIGO & Virgo, GW170817. The host galaxy, NGC 4993, is an S0 galaxy at z=0.009783. There is evidence for large, face-on spiral shells in continuum imaging, and edge-on spiral features visible in nebular emission lines. This suggests that NGC 4993 has undergone a relatively recent (<1 Gyr) ``dry'' merger. This merger may provide the fuel for a weak active nucleus seen in Chandra imaging. At the location of the counterpart, HST imaging implies there is no globular or young stellar cluster, with a limit of a few thousand solar masses for any young system. The population in the vicinity is predominantly old with <1% of any light arising from a population with ages <500 Myr. Both the host galaxy properties and those of the transient location are consistent with the distributions seen for short-duration gamma-ray bursts, although the source position lies well within the effective radius (r_e ~ 3 kpc), providing an r_e-normalized offset that is closer than ~90% of short GRBs. For the long delay time implied by the stellar population, this suggests that the kick velocity was significantly less than the galaxy escape velocity. We do not see any narrow host galaxy interstellar medium features within the counterpart spectrum, implying low extinction, and that the binary may lie in front of the bulk of the host galaxy., Comment: ApJL in press, 13 pages

Published
2017
Full Text
View/download PDF

17. The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC

Author

Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, M. J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., Yan, H., Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, M. J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., and Yan, H.

Abstract

The reionization of the Universe is one of the most important topics of present day astrophysical research. The most plausible candidates for the reionization process are star-forming galaxies, which according to the predictions of the majority of the theoretical and semi-analytical models should dominate the HI ionizing background at z~3. We aim at measuring the Lyman continuum escape fraction, which is one of the key parameters to compute the contribution of star-forming galaxies to the UV background. We have used ultra-deep U-band imaging (U=30.2mag at 1sigma) by LBC/LBT in the CANDELS/GOODS-North field, as well as deep imaging in COSMOS and EGS fields, in order to estimate the Lyman continuum escape fraction of 69 star-forming galaxies with secure spectroscopic redshifts at 3.27L*), while for the faint population (L=0.2L*) the limit to the escape fraction is ~10%. We have computed the contribution of star-forming galaxies to the observed UV background at z~3 and we have found that it is not enough to keep the Universe ionized at these redshifts, unless their escape fraction increases significantly (>10%) at low luminosities (M1500>-19). We compare our results on the Lyman continuum escape fraction of high-z galaxies with recent estimates in the literature and discuss future prospects to shed light on the end of the Dark Ages. In the future, strong gravitational lensing will be fundamental to measure the Lyman continuum escape fraction down to faint magnitudes (M1500~-16) which are inaccessible with the present instrumentation on blank fields., Comment: Accepted for publication in A&A, 16 pages, 6 figures

Published
2017
Full Text
View/download PDF

18. The Environment of the Binary Neutron Star Merger GW170817

Author

Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schroder, S. L., Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., de Ugarte Postigo, A., Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Palazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thone, C. C., Watson, D. J., Wijers, R. A. M. J., Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schroder, S. L., Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., de Ugarte Postigo, A., Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Palazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thone, C. C., Watson, D. J., and Wijers, R. A. M. J.

Published
2017

19. The Environment of the Binary Neutron Star Merger GW170817

Author

Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schroder, S. L., Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., de Ugarte Postigo, A., Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Palazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thone, C. C., Watson, D. J., Wijers, R. A. M. J., Levan, A. J., Lyman, J. D., Tanvir, N. R., Hjorth, J., Mandel, I., Stanway, E. R., Steeghs, D., Fruchter, A. S., Troja, E., Schroder, S. L., Wiersema, K., Bruun, S. H., Cano, Z., Cenko, S. B., de Ugarte Postigo, A., Evans, P., Fairhurst, S., Fox, O. D., Fynbo, J. P. U., Gompertz, B., Greiner, J., Im, M., Izzo, L., Jakobsson, P., Kangas, T., Khandrika, H. G., Lien, A. Y., Malesani, D., O'Brien, P., Osborne, J. P., Palazzi, E., Pian, E., Perley, D. A., Rosswog, S., Ryan, R. E., Schulze, S., Sutton, P., Thone, C. C., Watson, D. J., and Wijers, R. A. M. J.

Published
2017

20. SPITZER ULTRA FAINT SURVEY PROGRAM (SURFS UP). II. IRAC-DETECTED LYMAN-BREAK GALAXIES AT 6 less than or similar to z less than or similar to 10 BEHIND STRONG-LENSING CLUSTERS

Author

Huang, Kuang-Han, Bradac, Marusa, Lemaux, Brian C., Ryan, R. E., Jr., Hoag, Austin, Castellano, Marco, Amorin, Ricardo, Fontana, Adriano, Brammer, Gabriel B., Cain, Benjamin, Lubin, L. M., Merlin, Emiliano, Schmidt, kasper B., Schrabback, Tim, Treu, Tommaso, Gonzalez, Anthony H., Von Der Linden, Anja, Knight, Robert I., Huang, Kuang-Han, Bradac, Marusa, Lemaux, Brian C., Ryan, R. E., Jr., Hoag, Austin, Castellano, Marco, Amorin, Ricardo, Fontana, Adriano, Brammer, Gabriel B., Cain, Benjamin, Lubin, L. M., Merlin, Emiliano, Schmidt, kasper B., Schrabback, Tim, Treu, Tommaso, Gonzalez, Anthony H., Von Der Linden, Anja, and Knight, Robert I.

Published
2016

21. RCS2 J232727.6-020437:AN EFFICIENT COSMIC TELESCOPE AT z=0.6986

Author

Hoag, A., Bradac, M., Huang, K. H., Ryan, R. E., Jr., Sharon, K., Schrabback, T., Schmidt, K. B., Cain, B., Gonzalez, A. H., Hildebrandt, H., Hinz, J., Lemaux, B. C., von der Linden, A., Lubin, L. M., Treu, T., Zaritsky, D., Hoag, A., Bradac, M., Huang, K. H., Ryan, R. E., Jr., Sharon, K., Schrabback, T., Schmidt, K. B., Cain, B., Gonzalez, A. H., Hildebrandt, H., Hinz, J., Lemaux, B. C., von der Linden, A., Lubin, L. M., Treu, T., and Zaritsky, D.

Published
2015

22. The role of major mergers in the size growth of intermediate-mass spheroids

Author

Kaviraj, S., Huertas-Company, M., Cohen, S., Peirani, S., Windhorst, R. A., O'Connell, R. W., Silk, J., Dopita, M. A., Hathi, N. P., Koekemoer, A. M., Mei, S., Rutkowski, M., Ryan, R. E., Shankar, F., Kaviraj, S., Huertas-Company, M., Cohen, S., Peirani, S., Windhorst, R. A., O'Connell, R. W., Silk, J., Dopita, M. A., Hathi, N. P., Koekemoer, A. M., Mei, S., Rutkowski, M., Ryan, R. E., and Shankar, F.

Abstract

We study of the role of major mergers (mass ratios >1:4) in driving size growth in high-redshift (1 10^10.7 MSun SGs at z<1, then major mergers are also likely to play an important role in the size growth of at least some massive SGs in this mass range., Comment: MNRAS in press

Published
2014
Full Text
View/download PDF

23. The role of major mergers in the size growth of intermediate-mass spheroids

Author

Kaviraj, S., Huertas-Company, M., Cohen, S., Peirani, S., Windhorst, R. A., O'Connell, R. W., Silk, J., Dopita, M. A., Hathi, N. P., Koekemoer, A. M., Mei, S., Rutkowski, M., Ryan, R. E., Shankar, F., Kaviraj, S., Huertas-Company, M., Cohen, S., Peirani, S., Windhorst, R. A., O'Connell, R. W., Silk, J., Dopita, M. A., Hathi, N. P., Koekemoer, A. M., Mei, S., Rutkowski, M., Ryan, R. E., and Shankar, F.

Abstract

We study of the role of major mergers (mass ratios >1:4) in driving size growth in high-redshift (1 10^10.7 MSun SGs at z<1, then major mergers are also likely to play an important role in the size growth of at least some massive SGs in this mass range., Comment: MNRAS in press

Published
2014
Full Text
View/download PDF

24. Measuring the Stellar Masses of z ~ 7 Galaxies with the Spitzer UltRaFaint SUrvey Program (SURFS UP)

Author

Ryan, R. E., Jr., Gonzalez, A. H., Lemaux, B. C., Bradac, M., Casertano, S., Allen, S., Cain, B., Gladders, M., Hildebradt, H., Hinz, J., Huang, K. -H., Lubin, L., Hall, N., Schrabback, T., Stiavelli, M., Treu, T., von der Linden, A., Zaritsky, D., Ryan, R. E., Jr., Gonzalez, A. H., Lemaux, B. C., Bradac, M., Casertano, S., Allen, S., Cain, B., Gladders, M., Hildebradt, H., Hinz, J., Huang, K. -H., Lubin, L., Hall, N., Schrabback, T., Stiavelli, M., Treu, T., von der Linden, A., and Zaritsky, D.

Published
2014

25. Measuring the Stellar Masses of z ~ 7 Galaxies with the Spitzer UltRaFaint SUrvey Program (SURFS UP)

Author

Ryan, R. E., Jr., Gonzalez, A. H., Lemaux, B. C., Bradac, M., Casertano, S., Allen, S., Cain, B., Gladders, M., Hildebradt, H., Hinz, J., Huang, K. -H., Lubin, L., Hall, N., Schrabback, T., Stiavelli, M., Treu, T., von der Linden, A., Zaritsky, D., Ryan, R. E., Jr., Gonzalez, A. H., Lemaux, B. C., Bradac, M., Casertano, S., Allen, S., Cain, B., Gladders, M., Hildebradt, H., Hinz, J., Huang, K. -H., Lubin, L., Hall, N., Schrabback, T., Stiavelli, M., Treu, T., von der Linden, A., and Zaritsky, D.

Published
2014

26. Constraining The Assembly Of Normal And Compact Passively Evolving Galaxies From Redshift z=3 To The Present With CANDELS

Author

Cassata, P., Giavalisco, M., Williams, C. C., Guo, Yicheng, Lee, Bomee, Renzini, A., Ferguson, H., Faber, S. F., Barro, G., McIntosh, D. H., Lu, Yu, Bell, E. F., Koo, D. C., Papovich, C. J., Ryan, R. E., Conselice, C. J., Grogin, N., Koekemoer, A., Hathi, N. P., Cassata, P., Giavalisco, M., Williams, C. C., Guo, Yicheng, Lee, Bomee, Renzini, A., Ferguson, H., Faber, S. F., Barro, G., McIntosh, D. H., Lu, Yu, Bell, E. F., Koo, D. C., Papovich, C. J., Ryan, R. E., Conselice, C. J., Grogin, N., Koekemoer, A., and Hathi, N. P.

Abstract

We study the evolution of the number density, as a function of the size, of passive early-type galaxies with a wide range of stellar masses 10^1010^10 M_sun), passive (SSFR<10^-2 Gyr^-1) and morphologically spheroidal galaxies at 1.22 are all compact or ultra-compact, while normal sized ETGs (meaning ETGs with sizes comparable to those of local counterparts of the same mass) are the most common ETGs only at z<1. The increase of the average size of ETGs at 0

Published
2013
Full Text
View/download PDF

27. Newborn spheroids at high redshift: When and how did the dominant, old stars in today's massive galaxies form?

Author

Kaviraj, S, Cohen, S. H., Ellis, Richard S, Peirani, S, Windhorst, Rogier A, O’Connell, R. W., Silk, Joe, Whitmore, Bradley, Hathi, Nimish P, Ryan, R E, Dopita, Michael, Frogel, Jay A., Dekel, A, Kaviraj, S, Cohen, S. H., Ellis, Richard S, Peirani, S, Windhorst, Rogier A, O’Connell, R. W., Silk, Joe, Whitmore, Bradley, Hathi, Nimish P, Ryan, R E, Dopita, Michael, Frogel, Jay A., and Dekel, A

Abstract

We study ~330 massive (M* > 109.5M⊙), newborn spheroidal galaxies (SGs) around the epoch of peak star formation (1 < z < 3) to explore the high-redshift origin of SGs and gain insight into when and how the old stellar populations that dominate today's U

Published
2013

28. Stellar populations of lyman break galaxies at Z 1-3 in the hst/wfc3 early release science observations

Author

Hathi, Nimish P, Cohen, S. H., Ryan, R E, Finkelstein, S L, McCarthy, P J, Windhorst, Rogier A, Yan, H, Koekemoer, Anton, Rutkowski, M J, O’Connell, R. W., Straughn, Amber, Dopita, Michael, Balick, Bruce, Bond, Howard, E., Kimble, Randy A, Walker, Alistair R, Whitmore, Bradley, Hathi, Nimish P, Cohen, S. H., Ryan, R E, Finkelstein, S L, McCarthy, P J, Windhorst, Rogier A, Yan, H, Koekemoer, Anton, Rutkowski, M J, O’Connell, R. W., Straughn, Amber, Dopita, Michael, Balick, Bruce, Bond, Howard, E., Kimble, Randy A, Walker, Alistair R, and Whitmore, Bradley

Abstract

We analyze the spectral energy distributions (SEDs) of Lyman break galaxies (LBGs) at z ≃ 1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST/WFC3 observations cover about 50 arcmin2 in the GOOD

Published
2013

29. Constraining The Assembly Of Normal And Compact Passively Evolving Galaxies From Redshift z=3 To The Present With CANDELS

Author

Cassata, P., Giavalisco, M., Williams, C. C., Guo, Yicheng, Lee, Bomee, Renzini, A., Ferguson, H., Faber, S. F., Barro, G., McIntosh, D. H., Lu, Yu, Bell, E. F., Koo, D. C., Papovich, C. J., Ryan, R. E., Conselice, C. J., Grogin, N., Koekemoer, A., Hathi, N. P., Cassata, P., Giavalisco, M., Williams, C. C., Guo, Yicheng, Lee, Bomee, Renzini, A., Ferguson, H., Faber, S. F., Barro, G., McIntosh, D. H., Lu, Yu, Bell, E. F., Koo, D. C., Papovich, C. J., Ryan, R. E., Conselice, C. J., Grogin, N., Koekemoer, A., and Hathi, N. P.

Abstract

We study the evolution of the number density, as a function of the size, of passive early-type galaxies with a wide range of stellar masses 10^1010^10 M_sun), passive (SSFR<10^-2 Gyr^-1) and morphologically spheroidal galaxies at 1.22 are all compact or ultra-compact, while normal sized ETGs (meaning ETGs with sizes comparable to those of local counterparts of the same mass) are the most common ETGs only at z<1. The increase of the average size of ETGs at 0

Published
2013
Full Text
View/download PDF

30. Constraining stellar assembly and active galactic nucleus feedback at the peak epoch of star formation

Author

Kimm, Taysun, Kaviraj, S, Devriendt, Julien E G, Cohen, S. H., Windhorst, Rogier A, Dubois, Yohan, Slyz, Adrianne, Hathi, Nimish P, Ryan, R E, O'Connell, Robert W, Dopita, Michael, Silk, J, Kimm, Taysun, Kaviraj, S, Devriendt, Julien E G, Cohen, S. H., Windhorst, Rogier A, Dubois, Yohan, Slyz, Adrianne, Hathi, Nimish P, Ryan, R E, O'Connell, Robert W, Dopita, Michael, and Silk, J

Abstract

We study stellar assembly and feedback from active galactic nuclei (AGN) around the epoch of peak star formation (1 ≲ z ≲ 2), by comparing hydrodynamic simulations to rest-frame UV-optical galaxy colours from the Wide Field Camera 3 (WFC3) Early Relea

Published
2012

31. The size evolution of passive galaxies: Observations from the wide-field camera 3 early release science program

Author

Ryan, R E, McCarthy, P J, Cohen, S. H., Yan, H, Hathi, Nimish P, Koekemoer, Anton, Rutkowski, M J, Mechtley, M. R., Windhorst, Rogier A, O’Connell, R. W., Dopita, Michael, Bond, Howard, E., Frogel, Jay, MacKenty, John, Mutchler, Max, Walker, Alistair R, Ryan, R E, McCarthy, P J, Cohen, S. H., Yan, H, Hathi, Nimish P, Koekemoer, Anton, Rutkowski, M J, Mechtley, M. R., Windhorst, Rogier A, O’Connell, R. W., Dopita, Michael, Bond, Howard, E., Frogel, Jay, MacKenty, John, Mutchler, Max, and Walker, Alistair R

Abstract

We present the size evolution of passively evolving galaxies at z 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates

Published
2012

32. Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies

Author

Ryan, R. E., Cohen, S. H., Windhorst, R. A., Silk, J., Ryan, R. E., Cohen, S. H., Windhorst, R. A., and Silk, J.

Abstract

We present a measurement of the galaxy merger fraction and number density from observations in the Hubble Ultra Deep Field for 0.510^10 M_sol. When correcting for mass incompleteness, the major merger fraction is not simply proportional to (1+z)^m, but appears to peak at z_frac~=1.3+-0.4. From this merger fraction, we infer that ~42% of massive galaxies have undergone a major merger since z~1. We show that the major merger number density peaks at z_dens~1.2, which marks the epoch where major merging of massive galaxies is most prevalent. This critical redshift is comparable to the peak of the cosmic star formation rate density, and occurs roughly 2.6 Gyr earlier in cosmic time than the peak in the number density of X-ray selected active galactic nuclei. These observations support an indirect evolutionary link between merging, starburst, and active galaxies., Comment: Accepted to ApJ. 7 pages, 6 figures, 1 table. Uses and includes emulateapj.cls. In the initial submission, Figures 1 and 2 where switched

Published
2007
Full Text
View/download PDF

33. Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies

Author

Ryan, R. E., Cohen, S. H., Windhorst, R. A., Silk, J., Ryan, R. E., Cohen, S. H., Windhorst, R. A., and Silk, J.

Abstract

We present a measurement of the galaxy merger fraction and number density from observations in the Hubble Ultra Deep Field for 0.510^10 M_sol. When correcting for mass incompleteness, the major merger fraction is not simply proportional to (1+z)^m, but appears to peak at z_frac~=1.3+-0.4. From this merger fraction, we infer that ~42% of massive galaxies have undergone a major merger since z~1. We show that the major merger number density peaks at z_dens~1.2, which marks the epoch where major merging of massive galaxies is most prevalent. This critical redshift is comparable to the peak of the cosmic star formation rate density, and occurs roughly 2.6 Gyr earlier in cosmic time than the peak in the number density of X-ray selected active galactic nuclei. These observations support an indirect evolutionary link between merging, starburst, and active galaxies., Comment: Accepted to ApJ. 7 pages, 6 figures, 1 table. Uses and includes emulateapj.cls. In the initial submission, Figures 1 and 2 where switched

Published
2007
Full Text
View/download PDF

34. Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies

Author

Ryan, R. E., Cohen, S. H., Windhorst, R. A., Silk, J., Ryan, R. E., Cohen, S. H., Windhorst, R. A., and Silk, J.

Abstract

We present a measurement of the galaxy merger fraction and number density from observations in the Hubble Ultra Deep Field for 0.510^10 M_sol. When correcting for mass incompleteness, the major merger fraction is not simply proportional to (1+z)^m, but appears to peak at z_frac~=1.3+-0.4. From this merger fraction, we infer that ~42% of massive galaxies have undergone a major merger since z~1. We show that the major merger number density peaks at z_dens~1.2, which marks the epoch where major merging of massive galaxies is most prevalent. This critical redshift is comparable to the peak of the cosmic star formation rate density, and occurs roughly 2.6 Gyr earlier in cosmic time than the peak in the number density of X-ray selected active galactic nuclei. These observations support an indirect evolutionary link between merging, starburst, and active galaxies., Comment: Accepted to ApJ. 7 pages, 6 figures, 1 table. Uses and includes emulateapj.cls. In the initial submission, Figures 1 and 2 where switched

Published
2007
Full Text
View/download PDF

35. The Stardust – a successful encounter with the remarkable comet Wild 2

Author

Brownlee, D. E., Anderson, J. D, Atkins, K., Bhaskaran, S., Cheuvront, A. R., Clark, B. C., Duxbury, T. C., Economou, T., Hanner, M. S., Hörz, F., Kissel, J., McDonnell, J. A. M., Green, S., Newburn, R. L., Perkins, D. E., Price, S., Ryan, R. E., Sandford, S., Sekanina, Z., Tsou, P., Tuzzolino, A. J., Villinga, J. M., Williams, K. E., Zolensky, M. E., Brownlee, D. E., Anderson, J. D, Atkins, K., Bhaskaran, S., Cheuvront, A. R., Clark, B. C., Duxbury, T. C., Economou, T., Hanner, M. S., Hörz, F., Kissel, J., McDonnell, J. A. M., Green, S., Newburn, R. L., Perkins, D. E., Price, S., Ryan, R. E., Sandford, S., Sekanina, Z., Tsou, P., Tuzzolino, A. J., Villinga, J. M., Williams, K. E., and Zolensky, M. E.

Abstract

On January 2, 2004 the Stardust spacecraft completed a close flyby of comet Wild2 (P81). Flying at a relative speed of 6.1 km/s within 237km of the 5 km nucleus, the spacecraft took 72 close-in images, measured the flux of impacting particles and did TOF mass spectrometry.

36. The Stardust – a successful encounter with the remarkable comet Wild 2

Author

Brownlee, D. E., Anderson, J. D, Atkins, K., Bhaskaran, S., Cheuvront, A. R., Clark, B. C., Duxbury, T. C., Economou, T., Hanner, M. S., Hörz, F., Kissel, J., McDonnell, J. A. M., Green, S., Newburn, R. L., Perkins, D. E., Price, S., Ryan, R. E., Sandford, S., Sekanina, Z., Tsou, P., Tuzzolino, A. J., Villinga, J. M., Williams, K. E., Zolensky, M. E., Brownlee, D. E., Anderson, J. D, Atkins, K., Bhaskaran, S., Cheuvront, A. R., Clark, B. C., Duxbury, T. C., Economou, T., Hanner, M. S., Hörz, F., Kissel, J., McDonnell, J. A. M., Green, S., Newburn, R. L., Perkins, D. E., Price, S., Ryan, R. E., Sandford, S., Sekanina, Z., Tsou, P., Tuzzolino, A. J., Villinga, J. M., Williams, K. E., and Zolensky, M. E.

Abstract

On January 2, 2004 the Stardust spacecraft completed a close flyby of comet Wild2 (P81). Flying at a relative speed of 6.1 km/s within 237km of the 5 km nucleus, the spacecraft took 72 close-in images, measured the flux of impacting particles and did TOF mass spectrometry.

Catalog

Books, media, physical & digital resources
See catalog results