Search Results - "Richards, G T"

The 2dF-SDSS LRG and QSO survey: QSO clustering and the L-z degeneracy by DaÂngela, J., Shanks, T., Croom, S. M., Weilbacher, P., Brunner, R. J., Couch, W. J., Miller, L., Myers, A. D., Nichol, R. C., Pimbblet, K. A., De Propris, R., Richards, G. T., Ross, N. P., Schneider, D. P., Wake, D.

“…We combine the quasi-stellar object (QSO) samples from the 2dF QSO Redshift Survey (2QZ) and the 2dF-Sloan Digital Sky Survey luminous red galaxy (LRG) and QSO…”
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The X-Ray Spectral Properties and Variability of Luminous High-Redshift Active Galactic Nuclei by Shemmer, O, Brandt, W. N, Vignali, C, Schneider, D. P, Fan, X, Richards, G. T, Strauss, Michael A

“…We perform a detailed investigation of moderate- to high-quality X-ray spectra of 10 of the most luminous active galactic nuclei (AGNs) known at z > 4 (up to z…”
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A Full Year's Chandra Exposure on Sloan Digital Sky Survey Quasars from the Chandra Multiwavelength Project by Green, Paul J, Aldcroft, T. L, Richards, G. T, Barkhouse, W. A, Constantin, A, Haggard, D, Karovska, M, Kim, D.-W, Kim, M, Vikhlinin, A, Anderson, S. F, Mossman, A, Kashyap, V, Myers, A. C, Silverman, J. D, Wilkes, B. J, Tananbaum, H

“…We study the spectral energy distributions and evolution of a large sample of optically selected quasars from the Sloan Digital Sky Survey that were observed…”
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Active galactic nuclei: what’s in a name? by Padovani, P., Alexander, D. M., Assef, R. J., De Marco, B., Giommi, P., Hickox, R. C., Richards, G. T., Smolčić, V., Hatziminaoglou, E., Mainieri, V., Salvato, M.

“…Active galactic nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique…”
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An Investigation into the Effects of Luminosity on the Mid-Infrared Spectral Energy Distributions of Radio-quiet Quasars by Gallagher, S. C, Richards, G. T, Lacy, M, Hines, D. C, Elitzur, M, Storrie-Lombardi, L. J

“…We present an analysis of the effects of luminosity on the shape of the mid-infrared spectral energy distributions (SEDs) of 234 radio-quiet quasars originally…”
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X-RAY INSIGHTS INTO THE NATURE OF PHL 1811 ANALOGS AND WEAK EMISSION-LINE QUASARS: UNIFICATION WITH A GEOMETRICALLY THICK ACCRETION DISK? by Luo, B., Brandt, W. N., Hall, P. B., Wu, Jianfeng, Anderson, S. F., Garmire, G. P., Gibson, R. R., Plotkin, R. M., Richards, G. T., Schneider, D. P., Shemmer, O., Shen, Yue

“…ABSTRACT We present an X-ray and multiwavelength study of 33 weak emission-line quasars (WLQs) and 18 quasars that are analogs of the extreme WLQ, PHL 1811, at…”
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SDSS data management and photometric quality assessment by Ivezić, Ž., Lupton, R. H., Schlegel, D., Boroski, B., Adelman-McCarthy, J., Yanny, B., Kent, S., Stoughton, C., Finkbeiner, D., Padmanabhan, N., Rockosi, C. M., Gunn, J. E., Knapp, G. R., Strauss, M. A., Richards, G. T., Eisenstein, D., Nicinski, T., Kleinman, S. J., Krzesinski, J., Newman, P. R., Snedden, S., Thakar, A. R., Szalay, A., Munn, J. A., Smith, J. A., Tucker, D., Lee, B. C.

“…We summarize the Sloan Digital Sky Survey data acquisition and processing steps, and describe runQA, a pipeline designed for automated data quality assessment…”
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Clustering on very small scales from a large sample of confirmed quasar pairs: does quasar clustering track from Mpc to kpc scales? by Eftekharzadeh, S., Myers, A. D., Hennawi, J. F., Djorgovski, S. G., Richards, G. T., Mahabal, A. A., Graham, M. J.

“…Abstract We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes…”
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THE OBSCURED FRACTION OF ACTIVE GALACTIC NUCLEI IN THE XMM -COSMOS SURVEY: A SPECTRAL ENERGY DISTRIBUTION PERSPECTIVE by LUSSO, E, Hennawi, J F, Comastri, A, Zamorani, G, Richards, G T, Vignali, C, Treister, E, Schawinski, K, Salvato, M, Gilli, R

“…The fraction of active galactic nucleus (AGN) luminosity obscured by dust and re-emitted in the mid-IR is critical for understanding AGN evolution,…”
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Evidence for Proton Acceleration up to TeV Energies Based on VERITAS and Fermi-LAT Observations of the Cas A SNR by Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Buckley, J. H., Chromey, A. J., Cui, W., Daniel, M. K., Das, S., Dwarkadas, V. V., Falcone, A., Feng, Q., Finley, J. P., Fortson, L., Gent, A., Gillanders, G. H., Giuri, C., Gueta, O., Hanna, D., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Kumar, S., Lang, M. J., Maier, G., Moriarty, P., Mukherjee, R., Nievas-Rosillo, M., O'Brien, S., Ong, R. A., Park, N., Petrashyk, A., Pfrang, K., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Sushch, I., Weinstein, A., Wilcox, P., Wilhelm, A., Williams, D. A., Williamson, T. J, Zitzer, B., Ghiotto, A.

“…We present a study of γ-ray emission from the core-collapse supernova remnant Cas A in the energy range from 0.1 GeV to 10 TeV. We used 65 hr of the Very…”
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Insights into quasar UV spectra using unsupervised clustering analysis by Tammour, A., Gallagher, S. C., Daley, M., Richards, G. T.

“…Machine learning techniques can provide powerful tools to detect patterns in multidimensional parameter space. We use K-means – a simple yet powerful…”
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Active galactic nuclei: what’s in a name? by Padovani, P., Alexander, D. M., Assef, R. J., De Marco, B., Giommi, P., Hickox, R. C., Richards, G. T., Smolčić, V., Hatziminaoglou, E., Mainieri, V., Salvato, M.

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A Strong Limit on the Very-high-energy Emission from GRB 150323A by Abeysekara, A. U., Archer, A., Benbow, W., Bird, R., Brose, R., Buchovecky, M., Bugaev, V., Connolly, M. P., Cui, W., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Flinders, A., Fortson, L., Furniss, A., Gillanders, G. H., Hütten, M., Hanna, D., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Krennrich, F., Lang, M. J., Lin, T. T. Y., Maier, G., McArthur, S., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Park, N., Perkins, J. S., Petrashyk, A., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rulten, C., Sadeh, I., Santander, M., Sembroski, G. H., Shahinyan, K., Tyler, J., Wakely, S. P., Weiner, O. M., Weinstein, A., Wells, R. M., Wilcox, P., Wilhelm, A., Williams, D. A., Zitzer, B., Vurm, Indrek, Beloborodov, Andrei

“…On 2015 March 23, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) responded to a Swift-Burst Alert Telescope (BAT) detection of a…”
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The environments of z ∼ 1 active galactic nuclei at 3.6 μm by Falder, J. T., Stevens, J. A., Jarvis, Matt J., Hardcastle, M. J., Lacy, M., McLure, R. J., Hatziminaoglou, E., Page, M. J., Richards, G. T.

“…We present an analysis of a large sample of active galactic nuclei (AGN) environments at z∼ 1 using stacked Spitzer data at 3.6 μm. The sample contains type 1…”
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The environments of z similar to 1 active galactic nuclei at 3.6 mu m by Falder, J T, Stevens, JA, Jarvis, Matt J, Hardcastle, MJ, Lacy, M, McLure, R J, Hatziminaoglou, E, Page, MJ, Richards, G T

“…We present an analysis of a large sample of active galactic nuclei (AGN) environments at z similar to 1 using stacked Spitzer data at 3.6 mu m. The sample…”
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VERY HIGH ENERGY OBSERVATIONS OF THE BINARIES V 404 CYG AND 4U 0115+634 DURING GIANT X-RAY OUTBURSTS by Archer, A., Benbow, W., Bird, R., Bourbeau, E., Buchovecky, M., Buckley, J. H., Bugaev, V., Byrum, K., Cerruti, M., Connolly, M. P., Cui, W., Errando, M., Falcone, A., Feng, Q., Fernandez-Alonso, M., Finley, J. P., Fleischhack, H., Flinders, A., Fortson, L., Furniss, A., Griffin, S., Grube, J., Hütten, M., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Johnson, C. A., Kaaret, P., Kar, P., Kelley-Hoskins, N., Kertzman, M., Kieda, D., Krause, M., Kumar, S., Lang, M. J., Lin, T. T. Y., Maier, G., Moriarty, P., Mukherjee, R., Nieto, D., O'Brien, S., Ong, R. A., Park, N., Pohl, M., Popkow, A., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Richards, G. T., Roache, E., Rousselle, J., Rovero, A. C., Sadeh, I., Schlenstedt, S., Sembroski, G. H., Shahinyan, K., Staszak, D., Telezhinsky, I., Tyler, J., Wakely, S. P., Wilcox, P., Wilhelm, A., Williams, D. A.

“…ABSTRACT Transient X-ray binaries produce major outbursts in which the X-ray flux can increase over the quiescent level by factors as large as 107. The…”
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Detection of Cosmic Magnification with the Sloan Digital Sky Survey by Scranton, Ryan, Ménard, Brice, Richards, Gordon T, Nichol, Robert C, Myers, Adam D, Jain, Bhuvnesh, Gray, Alex, Bartelmann, Matthias, Brunner, Robert J, Connolly, Andrew J, Gunn, James E, Sheth, Ravi K, Bahcall, Neta A, Brinkman, John, Loveday, Jon, Schneider, Donald P, Thakar, Aniruddha, York, Donald G

“…We present an 8 s detection of cosmic magnification measured by the variation of quasar density due to gravitational lensing by foreground large-scale…”
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First Measurement of the Clustering Evolution of Photometrically Classified Quasars by Myers, Adam D, Brunner, Robert J, Richards, Gordon T, Nichol, Robert C, Schneider, Donald P, Vanden Berk, Daniel E, Scranton, Ryan, Gray, Alexander G, Brinkmann, Jon

“…We present new measurements of the quasar angular autocorrelation function from a sample of 680,000 photometrically classified quasars taken from the First…”
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Spectral Variability of Quasars in the Sloan Digital Sky Survey. I. Wavelength Dependence by Wilhite, Brian C, Vanden Berk, Daniel E, Kron, Richard G, Schneider, Donald P, Pereyra, Nicholas, Brunner, Robert J, Richards, Gordon T, Brinkmann, Jonathan V

“…SDSS repeat spectroscopic observations have resulted in multiepoch spectroscopy for 62500 quasars observed more than 50 days apart. From this sample,…”
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X-rays from the first massive black holes by Brandt, W.N., Vignali, C., Schneider, D.P., Alexander, D.M., Anderson, S.F., Bauer, F.E., Fan, X., Garmire, G.P., Kaspi, S., Richards, G.T.

“…X-ray studies of high-redshift ( z > 4) active galaxies have advanced substantially over the past few years, largely due to results from the new generation of…”
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