The Unique Type Ia Supernova 2000cx in NGC 524

By Weidong Li, A. Filippenko, E. Gates, Ryan Chornock, A. Gal-yam, Eran Ofek, D. Leonard, Maryam Modjaz, R. Rich, A. Riess and 2 more. 2001

159 citations recorded by the source corpus.

We present extensive photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2000cx in the S0 galaxy NGC 524, which reveal it to be peculiar. Photometrically, SN 2000cx is different from all known SNe Ia, and its light curves cannot be fitted well by the fitting techniques currently available. There is an apparent asymmetry in the B‐band peak, in which the premaximum brightening is relatively fast (similar to that of the normal SN 1994D), but the postmaximum decline is relatively slow (similar to that of the overluminous SN 1991T). The color evolution of SN 2000cx is also peculiar: the (B−V)0 color has a unique plateau phase and the (V−R)0 and (V−I)0 colors are very blue. Although the premaximum spectra of SN 2000cx are similar to those of SN 1991T–like objects (with weak Si ii lines), its overall spectral evolution is quite different. The Si ii lines that emerged near maximum B‐band brightness stay strong in SN 2000cx until about 3 weeks past maximum. The change in the excitation stages of iron‐peak elements is slow. Both the iron‐peak and the intermediate‐mass elements are found to be moving at very high expansion velocities in the ejecta of SN 2000cx. We discuss theoretical models for SN 2000cx. SN 2000cx may be an overluminous object like SN 1991T, but with a larger yield of 56Ni and a higher kinetic energy in the ejecta. We also briefly discuss the implications of our observations for the luminosity versus light‐curve width relation.

Subfields: Astronomy and Astrophysics, Instrumentation, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/3a2129293d29276619be50a1962707378b79c96e

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In Astronomy and Astrophysics

1. A. Filippenko
2. K. Luhman
3. N. Smith
4. E. Berger
5. Ryan Chornock
6. S. Smartt
7. Weidong Li
8. R. Kirshner

In Instrumentation

1. N. Smith
2. K. Luhman
3. A. Filippenko
4. J. Silverman
5. Michael C. Liu
6. Weidong Li
7. Luis C. Ho
8. A. Riess

In Nuclear and High Energy Physics

1. N. Smith
2. E. Berger
3. A. Filippenko
4. Ryan Chornock
5. B. Leibundgut
6. Weidong Li
7. R. Kirshner
8. S. Jha

Citations in the corpus

• Nearby Supernova Rates from the Lick Observatory Supernova Search. II. The Observed Luminosity Functions and Fractions of Supernovae in a Complete Sample (2010, background): “Li et al. (2001b) studied the rate of peculiar SNe Ia with a sample of 45 SNe Ia discovered by LOSS during the period between 1997 and 1999, and found a fraction of 64% normal, 16% SN 1991bg-like, and 20% SN 1991T-like.”
• Supernova 2002bo: inadequacy of the single parameter description (2003, background): “A minority of SNe Ia are obviously peculiar (Leibundgut et al. (1993); Turatto et al. (1996); Turatto et al. (1998); Li et al. (2001)), although their significance for the overall picture is not clear.”
• TYPE Iax SUPERNOVAE: A NEW CLASS OF STELLAR EXPLOSION (2012, background): “…et al. 1992b; Phillips et al. 1992) and SN 1991bg (Filippenko et al. 1992a; Leibundgut et al. 1993), respectively, as well as the unique SN 2000cx (Li et al. 2001a), SNe similar to SN 2006bt (Foley et al. 2010b), SN 2010X (Kasliwal et al. 2010), and ultraluminous SNe I (e.g., Pastorello et al.…”
• FROM SHOCK BREAKOUT TO PEAK AND BEYOND: EXTENSIVE PANCHROMATIC OBSERVATIONS OF THE TYPE Ib SUPERNOVA 2008D ASSOCIATED WITH SWIFT X-RAY TRANSIENT 080109 (2008, methodology): “To convert the KAIT instrumental magnitudes into the standard Johnson BV and Cousins RI system, the color terms for the KAIT filters as determined from many photometric calibrations are used in the conversion (as detailed by Modjaz et al. 2001 and Li et al. 2001).”
• RESULTS OF THE LICK OBSERVATORY SUPERNOVA SEARCH FOLLOW-UP PHOTOMETRY PROGRAM: BVRI LIGHT CURVES OF 165 TYPE Ia SUPERNOVAE (2010, unknown): “We try not to discriminate between SN Ia subclasses; however, our final sample of 165 most certainly suffers from observational bias and does not reflect the true demographics of SNe Ia (e.g., Li et al. 2001a, 2001b).”
• Optical and Near-Infrared Observations of the Highly Reddened, Rapidly Expanding Type Ia Supernova SN 2006X in M100 (2007, methodology): “The Fe II and Fe III lines are sometimes used to measure the expansion velocities of the inner ejecta of Fe, providing additional clues to the nature of SN Ia explosions (e.g., Li et al. 2001).”
• The ESSENCE Supernova Survey: Survey Optimization, Observations, and Supernova Photometry (2007, methodology): “In brief, we assume the SN Ia luminosity function used by Li et al. (2001a) modeled as three distinct luminosity classes representing ‘‘normal,’’ overluminous (SN 1991TY like; e.g., Filippenko et al. 1992b), and subluminous (SN 1991bgYlike; e.g., Filippenko et al. 1992a) SNe Ia, each following a…”
• THE SPECTROSCOPIC DIVERSITY OF TYPE Ia SUPERNOVAE (2000, unknown): “…al. 2004a 1999ac Garavini et al. 2005a, Phillips et al. 2006 1999aw Strolger et al. 2002 1999ee Hamuy et al. 2002a 2000E Valentini et al. 2003a 2000cx Li et al. 2001a 2001ay Krisciunas et al. 2011b 2001el Wang et al. 2003a, Mattila et al. 2005 2002bo Benetti et al. 2004a 2002dj Pignata et al.…”
• Observational and Physical Classification of Supernovae (2016, unknown): “The prototype of this class of unusual events was pointed out by Filippenko et al. (1992a) as an unusual SN with a distinctive pre-peak spectrum dominated by Fe III lines (Ruiz-Lapuente et al. 1992; Mazzali et al. 1995) that later evolves to resemble normal SNe Ia, as well as being more luminous (by”
• Twenty-Three High-Redshift Supernovae from the Institute for Astronomy Deep Survey: Doubling the Supernova Sample at z > 0.7 (2004, background): “…of SNe Ia in the first 15 days after B-band maximum light correlates with luminosity and that the latetime color curves of all unreddened SNe Ia are uniform, regardless of decline rate (Lira 1995; however, the peculiar SN Ia 2002cx [Li et al. 2001] does not follow the standard Lira relation).”
• Comparative Direct Analysis of Type Ia Supernova Spectra. I. SN 1994D (2005, background): “The observed multicomponent absorption of the IR3 has been discussed by Li et al. (2001), Wang et al. (2003), Kasen et al. (2003), and Thomas et al. (2004), and is known to have involved asymmetrical structures at high velocity.”
• Determining the Type, Redshift, and Age of a Supernova Spectrum (2006, background): “Such is the case of SNe 2000cx (Li et al. 2001a), 2002cx (Li et al. 2003) and 2005hk (Phillips et al. 2007).”
• Improved Distances to Type Ia Supernovae with Multicolor Light-Curve Shapes: MLCS2k2 (2006, background): “First, we have excluded from the fit the very peculiar SN 2000cx (Li et al. 2001), which is a clear outlier in the histogram and whose light curve (but not peak luminosity) is significantly unlike other SNe Ia (Li et al. 2001; Jha et al. 2006).”
• Optical and Infrared Spectroscopy of SN 1999ee and SN 1999ex (2002, methodology): “5 of Li et al. 2001b), SN 1991T was a much more extreme event, in the sense that the premaximum spectrum did not display the Ca ii H and K 3934, 3968 blend shown by Branch-normal SNe and also because it remained spectroscopically distinct several days after maximum (Phillips et al. 1992).”
• SUPERNOVA CONSTRAINTS AND SYSTEMATIC UNCERTAINTIES FROM THE FIRST THREE YEARS OF THE SUPERNOVA LEGACY SURVEY (2011, unknown): “In any case, we remove the known spectroscopically peculiar SNe 2000cx (Li et al. 2001), 2001ay (Krisciunas et al., 2011, in preparation), 2002cx (Li et al. 2003), 2005hk (Phillips et al. 2007), 2005gj (Aldering et al. 2006), 03D3bb (Howell et al. 2006), 05D1by (which is spectroscopically similar…”
• SN 2002cx: The Most Peculiar Known Type Ia Supernova (2003, methodology): “SN 1999aa–like objects (Li et al. 2001a) are similar to the SN 1991T–like ones, but with significant Caii H and K absorption lines in their premaximum spectra.”
• UBVRI Light Curves of 44 Type Ia Supernovae (2005, methodology): “…a meaningful fit limits the application of this method to 22 of 7The four objects include SN 1998D and SN 1999cw, for which thefirst observation was well after maximum light; SN 1998co, for which the data are quite sparse; and SN 2000cx, whose light curve is unique among all SN Ia (Li et al. 2001).”