Browsing by Author "Bechtol, K."

Now showing 1 - 8 of 8
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    Constraints on the Physical Properties of GW190814 through Simulations Based on DECam Follow-up Observations by the Dark Energy Survey
    (2020) Morgan, R.; Soares Santos, M.; Annis, J.; Herner, K.; Garcia, A.; Palmese, A.; Drlica Wagner, A.; Kessler, R.; Garcia Bellido, J.; Quirola Vásquez, Jonathan Alexander; Bachmann, T. G.; Sherman, N.; Allam, S.; Bechtol, K.; Bom, C. R.; Brout, D.; Butler, R. E.; Butner, M.; Cartier, R.; Chen, H.; Conselice, C.; Cook, E.; Davis, T. M.; Doctor, Z.; Farr, B.; Figueiredo, A. L.; Finley, D. A.; Foley, R. J.; Galarza, J. Y.; Gill, M. S. S.; Gruendl, R. A.; Holz, D. E.; Kuropatkin, N.; Lidman, C.; Lin, H.; Malik, U.; Mann, A. W.; Marriner, J.; Marshall, J. L.; Martinez Vazquez, C. E.; Meza, N.; Neilsen, E.; Nicolaou, C.; Olivares, E. F.; Paz Chinchon, F.; Points, S.; Rodriguez, O.; Sako, M.; Scolnic, D.; Smith, M.; Sobreira, F.; Tucker, D. L.; Vivas, A. K.
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    FERMI-LAT. OBSERVATIONS. OF. HIGH-ENERGY. gamma-RAY. EMISSION. TOWARD. THE. GALACTIC. CENTER
    (2016) Ajello, M.; Albert, A.; Atwood, W.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R.; Gómez Vargas, Germán Arturo; Bloom, E.; Bonino, R.; Bottacini, E.; Brandt, T.; Bregeon, J.; Bruel, P.
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    First cosmology results using Type Ia supernova from the Dark Energy Survey: simulations to correct supernova distance biases
    (2019) Kessler, R.; Brout, D.; D'Andrea, C. B.; Davis, T. M.; Hinton, S. R.; Kim, A. G.; Lasker, J.; Lidman, C.; Macaulay, E.; Moeller, A.; Sako, M.; Scolnic, D.; Smith, M.; Sullivan, M.; Zhang, B.; Andersen, P.; Asorey, J.; Avelino, A.; Calcino, J.; Carollo, D.; Challis, P.; Childress, M.; Clocchiatti, A.; Crawford, S.; Filippenko, A. V.; Foley, R. J.; Glazebrook, K.; Hoormann, J. K.; Kasai, E.; Kirshner, R. P.; Lewis, G. F.; Mandel, K. S.; March, M.; Morganson, E.; Muthukrishna, D.; Nugent, P.; Pan, Y. -C.; Sommer, N. E.; Swann, E.; Thomas, R. C.; Tucker, B. E.; Uddin, S. A.; Abbott, T. M. C.; Allam, S.; Annis, J.; Avila, S.; Banerji, M.; Bechtol, K.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Kind, M. Carrasco; Carretero, J.; Castander, F. J.; Crocce, M.; da Costa, L. N.; Davis, C.; De Vicente, J.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Flaugher, B.; Fosalba, P.; Frieman, J.; Garcia-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Hartley, W. G.; Hollowood, D. L.; Honscheid, K.; James, D. J.; Johnson, M. W. G.; Johnson, M. D.; Krause, E.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Lima, M.; Marshall, J. L.; Martini, P.; Menanteau, F.; Miller, C. J.; Miquel, R.; Nord, B.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Thomas, D.; Walker, A. R.; Zhang, Y.
    We describe catalogue-level simulations of Type Ia supernova (SN Ia) light curves in the Dark Energy Survey Supernova Program (DES-SN) and in low-redshift samples from the Center for Astrophysics (CfA) and the Carnegie Supernova Project (CSP). These simulations are used to model biases from selection effects and light-curve analysis and to determine bias corrections for SN Ia distance moduli that are used to measure cosmological parameters. To generate realistic light curves, the simulation uses a detailed SN Ia model, incorporates information from observations (point spread function, sky noise, zero-point), and uses summary information (e.g. detection efficiency versus signal-to-noise ratio) based on 10 000 fake SN light curves whose fluxes were overlaid on images and processed with our analysis pipelines. The quality of the simulation is illustrated by predicting distributions observed in the data. Averaging within redshift bins, we find distance modulus biases up to 0.05 mag over the redshift ranges of the low-z and DES-SN samples. For individual events, particularly those with extreme red or blue colour, distance biases can reach 0.4 mag. Therefore, accurately determining bias corrections is critical for precision measurements of cosmological parameters. Files used to make these corrections are available at https://des.ncsa.illinois.edu/releases/sn.
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    First Cosmology Results using Type Ia Supernovae from the Dark Energy Survey : Constraints on Cosmological Parameters
    (2019) Abbott, T.M.C.; Allam, S.; Andersen, P.; Angus, C.; Asorey, J.; Avelino, A.; Avila, S.; Bassett, B.A.; Bechtol, K.; Clocchiatti, Alejandro; Bernstein, G.M.
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    Kinematic Sunyaev-Zel'dovich effect with ACT, DES, and BOSS: A novel hybrid estimator
    (2023) Mallaby-Kay, M.; Amodeo, S.; Hill, J. C.; Aguena, M.; Allam, S.; Alves, O.; Annis, J.; Battaglia, N.; Battistelli, E. S.; Baxter, E. J.; Bechtol, K.; Becker, M. R.; Bertin, E.; Bond, J. R.; Brooks, D.; Calabrese, E.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Choi, A.; Crocce, M.; da Costa, L. N.; Pereira, M. E. S.; De Vicente, J.; Desai, S.; Dietrich, J. P.; Doel, P.; Doux, C.; Drlica-Wagner, A.; Dunkley, J.; Elvin-Poole, J.; Everett, S.; Ferraro, S.; Ferrero, I.; Frieman, J.; Gallardo, P. A.; Garcia-Bellido, J.; Giannini, G.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Hinton, S. R.; Hollowood, D. L.; James, D. J.; Kosowsky, A.; Kuehn, K.; Lokken, M.; Louis, T.; Marshall, J. L.; McMahon, J.; Mena-Fernandez, J.; Menanteau, F.; Miquel, R.; Moodley, K.; Mroczkowski, T.; Naess, S.; Niemack, M. D.; Ogando, R. L. C.; Page, L.; Pandey, S.; Pieres, A.; Malagon, A. A. Plazas; Raveri, M.; Rodriguez-Monroy, M.; Rykoff, E. S.; Samuroff, S.; Sanchez, E.; Schaan, E.; Sevilla-Noarbe, I.; Sheldon, E.; Sifon, C.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; To, C.; Vargas, C.; Vavagiakis, E. M.; Weaverdyck, N.; Weller, J.; Wiseman, P.; Yanny, B.
    The kinematic and thermal Sunyaev-Zel'dovich (kSZ and tSZ) effects probe the abundance and thermodynamics of ionized gas in galaxies and clusters. We present a new hybrid estimator to measure the kSZ effect by combining cosmic microwave background temperature anisotropy maps with photometric and spectroscopic optical survey data. The method interpolates a velocity reconstruction from a spectroscopic catalog at the positions of objects in a photometric catalog, which makes it possible to leverage the high number density of the photometric catalog and the precision of the spectroscopic survey. Combining this hybrid kSZ estimator with a measurement of the tSZ effect simultaneously constrains the density and temperature of free electrons in the photometrically selected galaxies. Using the 1000 deg2 of overlap between the Atacama Cosmology Telescope (ACT) Data Release 5, the first three years of data from the Dark Energy Survey (DES), and the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we detect the kSZ signal at 4.8 & sigma; and reject the null (no-kSZ) hypothesis at 5.1 & sigma;. This corresponds to 2.0 & sigma; per 100,000 photometric objects with a velocity field based on a spectroscopic survey with 1=5th the density of the photometric catalog. For comparison, a recent ACT analysis using exclusively spectroscopic data from BOSS measured the kSZ signal at 2.1 & sigma; per 100,000 objects. Our derived constraints on the thermodynamic properties of the galaxy halos are consistent with previous measure-ments. With future surveys, such as the Dark Energy Spectroscopic Instrument and the Rubin Observatory Legacy Survey of Space and Time, we expect that this hybrid estimator could result in measurements with significantly better signal-to-noise than those that rely on spectroscopic data alone.
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    Search for extended gamma-ray emission from the Virgo galaxy cluster with Fermi-LAT
    (2015) Ackermann, M.; Ajello, Albert A.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Gómez Vargas, Germán Arturo
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    Searching for dark matter annihilation from Milky Way dwarf spheroidal galaxies with six years of Fermi Large Area Telescope data
    (2015) Ackermann, M.; Albert, A.; Anderson, B.; Atwood, W. B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Gómez Vargas, Germán Arturo
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    SOAR/Goodman Spectroscopic Assessment of Candidate Counterparts of the LIGO/Virgo Event GW190814*
    (2022) Tucker, D. L.; Wiesner, M. P.; Allam, S. S.; Soares-Santos, M.; Bom, C. R.; Butner, M.; Garcia, A.; Morgan, R.; Olivares E, F.; Palmese, A.; Santana-Silva, L.; Shrivastava, A.; Annis, J.; Garcia-Bellido, J.; Gill, M. S. S.; Herner, K.; Kilpatrick, C. D.; Makler, M.; Sherman, N.; Amara, A.; Lin, H.; Smith, M.; Swann, E.; Arcavi, I; Bachmann, T. G.; Bechtol, K.; Berlfein, F.; Briceno, C.; Brout, D.; Butler, R. E.; Cartier, R.; Casares, J.; Chen, H-Y; Conselice, C.; Contreras, C.; Cook, E.; Cooke, J.; Dage, K.; D'Andrea, C.; Davis, T. M.; de Carvalho, R.; Diehl, H. T.; Dietrich, J. P.; Doctor, Z.; Drlica-Wagner, A.; Drout, M.; Farr, B.; Finley, D. A.; Fishbach, M.; Foley, R. J.; Forster-Buron, F.; Fosalba, P.; Friedel, D.; Frieman, J.; Frohmaier, C.; Gruendl, R. A.; Hartley, W. G.; Hiramatsu, D.; Holz, D. E.; Howell, D. A.; Kawash, A.; Kessler, R.; Kuropatkin, N.; Lahav, O.; Lundgren, A.; Lundquist, M.; Malik, U.; Mann, A. W.; Marriner, J.; Marshall, J. L.; Martinez-Vazquez, C. E.; McCully, C.; Menanteau, F.; Meza, N.; Narayan, G.; Neilsen, E.; Nicolaou, C.; Nichol, R.; Paz-Chinchon, F.; Pereira, M. E. S.; Pineda, J.; Points, S.; Quirola-Vasquez, J.; Rembold, S.; Rest, A.; Rodriguez, O.; Romer, A. K.; Sako, M.; Salim, S.; Scolnic, D.; Smith, J. A.; Strader, J.; Sullivan, M.; Swanson, M. E. C.; Thomas, D.; Valenti, S.; Varga, T. N.; Walker, A. R.; Weller, J.; Wood, M. L.; Yanny, B.; Zenteno, A.; Aguena, M.; Andrade-Oliveira, F.; Bertin, E.; Brooks, D.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Costanzi, M.; da Costa, L. N.; De Vicente, J.; Desai, S.; Everett, S.; Ferrero, I; Flaugher, B.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gschwend, J.; Gutierrez, G.; Hinton, S. R.; Hollowood, D. L.; Honscheid, K.; James, D. J.; Kuehn, K.; Lima, M.; Maia, M. A. G.; Miquel, R.; Ogando, R. L. C.; Pieres, A.; Malagon, A. A. Plazas; Rodriguez-Monroy, M.; Sanchez, E.; Scarpine, V; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, I; Suchyta, E.; Tarle, G.; To, C.; Zhang, Y.
    On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star-black hole merger (NSBH), the first ever identified. An extensive search for an optical counterpart of this event, designated GW190814, was undertaken using the Dark Energy Camera on the 4 m Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory. Target of Opportunity interrupts were issued on eight separate nights to observe 11 candidates using the 4.1 m Southern Astrophysical Research (SOAR) telescope's Goodman High Throughput Spectrograph in order to assess whether any of these transients was likely to be an optical counterpart of the possible NSBH merger. Here, we describe the process of observing with SOAR, the analysis of our spectra, our spectroscopic typing methodology, and our resultant conclusion that none of the candidates corresponded to the gravitational wave merger event but were all instead other transients. Finally, we describe the lessons learned from this effort. Application of these lessons will be critical for a successful community spectroscopic follow-up program for LVC observing run 4 (O4) and beyond.