Browsing by Author "Thomas, D."

Now showing 1 - 5 of 5
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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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    [O II] emitters in MultiDark-Galaxies and DEEP2
    (2020) Favole, G.; Gonzalez Perez, V.; Stoppacher, D.; Orsi, A.; Comparat, J.; Cora, S. A.; Vega Martinez, C. A.; Stevens, A. R. H.; Maraston, C.; Padilla, Nelson; Croton, D.; Knebe, A.; Benson, A. J.; Montero Dorta, A. D.; Prada, F.; Thomas, D.
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    SDSS-IV MaNGA: spatially resolved star formation histories in galaxies as a function of galaxy mass and type
    (OXFORD UNIV PRESS, 2017) Goddard, D.; Thomas, D.; Maraston, C.; Westfall, K.; Etherington, J.; Riffel, R.; Mallmann, N. D.; Zheng, Z.; Argudo Fernandez, M.; Lian, J.; Bershady, M.; Bundy, K.; Drory, N.; Law, D.; Yan, R.; Wake, D.; Weijmans, A.; Bizyaev, D.; Brownstein, J.; Lane, R. R.; Maiolino, R.; Masters, K.; Merrifield, M.; Nitschelm, C.; Pan, K.; Roman Lopes, A.; Storchi Bergmann, T.; Schneider, D. P.
    We study the internal gradients of stellar population propertieswithin 1.5 R-e for a representative sample of 721 galaxies, with stellar masses ranging between 10(9)M circle dot and 10(11.5)M circle dot from the SDSS-IV MaNGA Integral-Field-Unit survey. Through the use of our full spectral fitting code FIREFLY, we derive light-and mass-weighted stellar population properties and their radial gradients, as well as full star formation and metal enrichment histories. We also quantify the impact that different stellar population models and full spectral fitting routines have on the derived stellar population properties and the radial gradient measurements. In our analysis, we find that age gradients tend to be shallow for both early-type and late-type galaxies. Mass-weighted age gradients of early-types arepositive (similar to 0.09 dex/Re) pointing to ` outsidein' progression of star formation, while late-type galaxies have negative light-weighted age gradients (similar to-0.11 dex/R-e), suggesting an ` inside-out' formation of discs. We detect negative metallicity gradients in both early-and late-type galaxies, but these are significantly steeper in late-types, suggesting that the radial dependence of chemical enrichment processes and the effect of gas inflow and metal transport are far more pronounced in discs. Metallicity gradients of both morphological classes correlate with galaxy mass, with negative metallicity gradients becoming steeper with increasing galaxy mass. The correlation with mass is stronger for late-type galaxies, with a slope of d(del[Z/H])/d(logM) similar to -0.2 +/- 0.05, compared to d(del[Z/H])/d(logM) similar to -0.05 +/- 0.05 for early-types. This result suggests that the merger history plays a relatively small role in shaping metallicity gradients of galaxies.
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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.
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    The Atacama Cosmology Telescope: A Catalog of >4000 Sunyaev-Zel'dovich Galaxy Clusters
    (2021) Hilton, M.; Sifon, C.; Naess, S.; Madhavacheril, M.; Oguri, M.; Rozo, E.; Rykoff, E.; Abbott, T. M. C.; Adhikari, S.; Aguena, M.; Aiola, S.; Allam, S.; Amodeo, S.; Amon, A.; Annis, J.; Ansarinejad, B.; Aros-Bunster, C.; Austermann, J. E.; Avila, S.; Bacon, D.; Battaglia, N.; Beall, J. A.; Becker, D. T.; Bernstein, G. M.; Bertin, E.; Bhandarkar, T.; Bhargava, S.; Bond, J. R.; Brooks, D.; Burke, D. L.; Calabrese, E.; Carrasco Kind, M.; Carretero, J.; Choi, S. K.; Choi, A.; Conselice, C.; Costa, L. N. da; Costanzi, M.; Crichton, D.; Crowley, K. T.; Dunner, R.; Denison, E. V.; Devlin, M. J.; Dicker, S. R.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Duff, S. M.; Duivenvoorden, A. J.; Dunkley, J.; Everett, S.; Ferraro, S.; Ferrero, I.; Ferte, A.; Flaugher, B.; Frieman, J.; Gallardo, P. A.; Garcia-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Giles, P.; Golec, J. E.; Gralla, M. B.; Grandis, S.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Han, D.; Hartley, W. G.; Hasselfield, M.; Hill, J. C.; Hilton, G. C.; Hincks, A. D.; Hinton, S. R.; Ho, S-P. P.; Honscheid, K.; Hoyle, B.; Hubmayr, J.; Huffenberger, K. M.; Hughes, J. P.; Jaelani, A. T.; Jain, B.; James, D. J.; Jeltema, T.; Kent, S.; Knowles, K.; Koopman, B. J.; Kuehn, K.; Lahav, O.; Lima, M.; Lin, Y-T.; Lokken, M.; Loubser, S. I.; MacCrann, N.; Maia, M. A. G.; Marriage, T. A.; Martin, J.; McMahon, J.; Melchior, P.; Menanteau, F.; Miquel, R.; Miyatake, H.; Moodley, K.; Morgan, R.; Mroczkowski, T.; Nati, F.; Newburgh, L. B.; Niemack, M. D.; Nishizawa, A. J.; Ogando, R. L. C.; Orlowski-Scherer, J.; Page, L. A.; Palmese, A.; Partridge, B.; Paz-Chinchon, F.; Phakathi, P.; Plazas, A. A.; Robertson, N. C.; Romer, A. K.; Rosell, A. Carnero; Salatino, M.; Sanchez, E.; Schaan, E.; Schillaci, A.; Sehgal, N.; Serrano, S.; Shin, T.; Simon, S. M.; Smith, M.; Soares-Santos, M.; Spergel, D. N.; Staggs, S. T.; Storer, E. R.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; To, C.; Trac, H.; Ullom, J. N.; Vale, L. R.; Lanen, J. Van; Vavagiakis, E. M.; Vicente, J. De; Wilkinson, R. D.; Wollack, E. J.; Xu, Z.; Zhang, Y.
    We present a catalog of 4195 optically confirmed Sunyaev-Zel'dovich (SZ) selected galaxy clusters detected with signal-to-noise ratio >4 in 13,211 deg(2) of sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were selected by applying a multifrequency matched filter to 98 and 150 GHz maps constructed from ACT observations obtained from 2008 to 2018 and confirmed using deep, wide-area optical surveys. The clusters span the redshift range 0.04 < z < 1.91 (median z = 0.52). The catalog contains 222 z > 1 clusters, and a total of 868 systems are new discoveries. Assuming an SZ signal versus mass-scaling relation calibrated from X-ray observations, the sample has a 90% completeness mass limit of M-500c > 3.8 x 10(14) M, evaluated at z = 0.5, for clusters detected at signal-to-noise ratio >5 in maps filtered at an angular scale of 24. The survey has a large overlap with deep optical weak-lensing surveys that are being used to calibrate the SZ signal mass-scaling relation, such as the Dark Energy Survey (4566 deg(2)), the Hyper Suprime-Cam Subaru Strategic Program (469 deg(2)), and the Kilo Degree Survey (825 deg(2)). We highlight some noteworthy objects in the sample, including potentially projected systems, clusters with strong lensing features, clusters with active central galaxies or star formation, and systems of multiple clusters that may be physically associated. The cluster catalog will be a useful resource for future cosmological analyses and studying the evolution of the intracluster medium and galaxies in massive clusters over the past 10 Gyr.