The Astronomical Journal, 154:211 (34pp), 2017 November https://doi.org/10.3847/1538-3881/aa8df0 © 2017. The American Astronomical Society. All rights reserved. The Carnegie Supernova Project. I. Third Photometry Data Release of Low-redshift Type Ia Supernovae and Other White Dwarf Explosions Kevin Krisciunas1 , Carlos Contreras2,3, Christopher R. Burns4 , M. M. Phillips2 , Maximilian D. Stritzinger2,3 , Nidia Morrell2 , Mario Hamuy5, Jorge Anais2, Luis Boldt2, Luis Busta2 , Abdo Campillay2, Sergio Castellón2, Gastón Folatelli2,6, Wendy L. Freedman4,7, Consuelo González2, Eric Y. Hsiao2,3,8 , Wojtek Krzeminski2,17, Sven Eric Persson4 , Miguel Roth2,9, Francisco Salgado2,10 , Jacqueline Serón2,11, Nicholas B. Suntzeff1, Simón Torres2,12, Alexei V. Filippenko13,14 , Weidong Li13,17, Barry F. Madore4,15 , D. L. DePoy1, Jennifer L. Marshall1 , Jean-Philippe Rheault1, and Steven Villanueva1,16 1 George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843, USA; [email protected] 2 Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena, Chile 3 Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark 4 Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA 5 Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile 6 Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Instituto de Astrofísica de La Plata (IALP), CONICET, Paseo del Bosque S/N, B1900FWA La Plata, Argentina 7 Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA 8 Department of Physics, Florida State University, Tallahassee, FL 32306, USA 9 GMTO Corporation, Avenida Presidente Riesco 5335, Suite 501, Las Condes, Santiago, Chile 10 Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden, The Netherlands 11 Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile 12 SOAR Telescope, Casilla 603, La Serena, Chile 13 Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA 14 Miller Senior Fellow, Miller Institute for Basic Research in Science, University of California, Berkeley, CA 94720, USA 15 Infrared Processing and Analysis Center, Caltech/Jet Propulsion Laboratory, Pasadena, CA 91125, USA 16 Department of Astronomy, Ohio State University, Columbus, OH 43210, USA Received 2017 July 20; revised 2017 September 12; accepted 2017 September 12; published 2017 November 6 Abstract We present final natural-system optical (ugriBV ) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004–2009 as part of the first stage of the Carnegie Supernova Project (CSP-I). The sample consists of 123 TypeIa SNe, 5 TypeIax SNe, 2 super-Chandrasekhar SN candidates, 2 TypeIa SNe interacting with circumstellar matter, and 2 SN2006bt-like events. The redshifts of the objects range from z = 0.0037 to 0.0835; the median redshift is 0.0241. For 120 (90%) of these SNe, near-infrared photometry was obtained. Average optical extinction coefficients and color terms are derived and demonstrated to be stable during the five CSP-I observing campaigns. Measurements of the CSP-I near-infrared bandpasses are also described, and near-infrared color terms are estimated through synthetic photometry of stellar atmosphere models. Optical and near-infrared magnitudes of local sequences of tertiary standard stars for each supernova are given, and a new calibration of Y-band magnitudes of the Persson et al. standards in the CSP-I natural system is presented. Key words: instrumentation: photometers – supernovae: general – surveys – techniques: photometric Supporting material: figure sets, machine-readable tables 1. Introduction “double-degenerate,” where the system consists of two white dwarfs. Within this scheme, several triggering mechanisms TypeIa supernovae (SNe) are generally agreed to be the have been proposed. The thermonuclear explosion can be result of a carbon–oxygen white dwarf that undergoes a triggered by the heat created during the dynamical merger of thermonuclear runaway (Hoyle & Fowler 1960) owing to mass ( ) two white dwarfs after expelling angular momentum via accretion in a binary system Wheeler & Hansen 1971 . The gravitational radiation (e.g., Iben & Tutukov 1984; Webbink mechanism for the ignition of the degenerate material is 1984). The explosion can also be triggered by compressional thought to be tied to the interplay between the exploding white heating as the white dwarf accretes material from a degenerate dwarf and its companion star. Potential progenitor systems are or nondegenerate companion to close to the Chandrasekhar broadly categorized as “single-degenerate,” where the compa- limit (e.g., Whelan & Iben 1973). A third mechanism involves nion star is a main sequence, red giant, or helium star, or the explosion of a sub-Chandrasekhar-mass white dwarf triggered by detonating a thin surface helium layer, which, in ( ) 17 Deceased. turn, triggers a central detonation front e.g., Nomoto 1982 .A fourth mechanism might be a collision of two C–O white dwarfs in a triple-star system (Kushnir et al. 2013). Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further Currently, it is unclear whether the observed SN Ia distribution of this work must maintain attribution to the author(s) and the title population results from a combination of these explosion of the work, journal citation and DOI. mechanisms or is largely dominated by one. The power-law 1 The Astronomical Journal, 154:211 (34pp), 2017 November Krisciunas et al. dependence of the delay time between the birth of the progenitor should be noted that the CSP-I also obtained observations of system and the explosion as an SN Ia (the “delay-time more than 100 low-redshift core-collapse SNe. distribution”;Maozetal.2010) and the unsuccessful search for Contreras et al. (2010, hereafter Paper I) presented CSP-I evidence of the companions to normal TypeIa SNe (see, e.g., Li photometry of 35 low-redshift SNeIa, 25 of which were et al. 2011; Schaefer & Pagnotta 2012; Olling et al. 2015) would observed in the NIR. Analysis of the photometry of these objects seem to favor the double-degenerate model, but some events, such is given by Folatelli et al. (2010). Stritzinger et al. (2011, as SN2012cg (Marion et al. 2016) and SN2017cbv (Hosseinzadeh hereafter Paper II) presented CSP-I photometry of 50 more low- et al. 2017) show a blue excess in their early-time light curves, redshift SNeIa, 45 of which were observed in the NIR. This indicative of nondegenerate companions. The rare SNeIa that sample included two super-Chandrasekhar candidates (Howell interact with circumstellar matter (CSM), such as SNe 2002ic et al. 2006) and two SN2006bt-like objects (Foley et al. 2010). (Hamuy et al. 2003) and PTF11kx (Dilday et al. 2012),alsofavor The high-redshift objects observed by the CSP-I in the rest- a single-degenerate system. frame i band are discussed by Freedman et al. (2009). TypeIa SNe are important for their role in the chemical In this paper, we present optical and NIR photometry of the enrichment of the universe (e.g., Nomoto et al. 2013, and final 49 SNe in the CSP-I low-redshift sample, including five references therein). They also play a fundamental role in members of the SN2002cx-like subclass, also referred to as observational cosmology as luminous standardizable candles in TypeIax SNe (see Foley et al. 2013), and two examples of the ( ) the optical bands (e.g., Phillips 1993; Hamuy et al. 1996; Riess Type Ia-CSM subtype Silverman et al. 2013 . We provide et al. 1996; Phillips et al. 1999) and as (essentially) standard updated optical and NIR photometry of the 85 previously candles at maximum light in the near-infrared (NIR; Krisciunas published low-redshift SNe in the CSP-I sample since, in et al. 2004; Krisciunas 2012; Phillips 2012, and references several cases, we have eliminated bad data points, improved the therein). The most precise current estimates for the value of the photometric calibrations, and obtained better host-galaxy ( reference images. This combined data set represents the Hubble constant are based on SNe Ia Riess et al. 2016, and fi references therein); moreover, Riess et al. (1998) and de nitive version of the CSP-I photometry for low-redshift Perlmutter et al. (1999) used them to find that the universe is white dwarf SNe and supersedes the light curves published in PapersI andII, as well as those published for a few individual currently expanding at an accelerating rate. ( ) ( ) In this age of precision cosmology, observations of SNeIa objects by Prieto et al. 2007 , Phillips et al. 2007 , Schweizer ( ) et al. (2008), Stritzinger et al. (2010), Taddia et al. (2012), continue to play a crucial role see, e.g., Sullivan et al. 2011 . ( ) ( ) Ironically, we are still faced with the situation that many more Stritzinger et al. 2014 , and Gall et al. 2017 . Other useful optical and near-IR observations of Type Ia SNe include the events have well-observed light curves at high redshifts (z > 0.1) photometry obtained by the Center for Astrophysics group than at low redshifts (Betoule et al. 2014). Since the SNIa results (Hicken et al. 2009, 2012; Friedman et al. 2015). are derived from a comparison of the peak magnitudes of distant and nearby events, the relatively heterogeneous quality of the low- redshift data directly affects the precision with which we are able 2. Supernova Sample to determine the nature of dark energy. Moreover, there are still legitimate concerns about systematic errors arising from the In Figure 1 we present finder charts for the 134SNeIa conversion of instrumental magnitudes into a uniform photometric composing the low-redshift CSP-I white dwarf SN sample, system, calibration errors, the treatment of host-galaxy dust indicating the positions of the SN and the local sequence of reddening corrections, and evolutionary effects caused by tertiary standard stars in each field (see Section 5.2).