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J/ApJ/789/104         SNe IIn observations and properties          (Ofek+, 2014)

Precursors prior to type IIn supernova explosions are common: precursor rates, properties, and correlations. Ofek E.O., Sullivan M., Shaviv N.J., Steinbok A., Arcavi I., Gal-Yam A., Tal D., Kulkarni S.R., Nugent P.E., Ben-Ami S., Kasliwal M.M., Cenko S.B., Laher R., Surace J., Bloom J.S., Filippenko A.V., Silverman J.M., Yaron O. <Astrophys. J., 789, 104 (2014)> =2014ApJ...789..104O (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry ; Magnitudes Keywords: stars: mass-loss - supernovae: general - supernovae: individual: SN 2010mc - PTF 10bjb - SN 2011ht - PTF 10weh - PTF 12cxj - SN 2009ip Abstract: There is a growing number of Type IIn supernovae (SNe) which present an outburst prior to their presumably final explosion. These precursors may affect the SN display, and are likely related to poorly charted phenomena in the final stages of stellar evolution. By coadding Palomar Transient Factory (PTF) images taken prior to the explosion, here we present a search for precursors in a sample of 16 Type IIn SNe. We find five SNe IIn that likely have at least one possible precursor event (PTF 10bjb, SN 2010mc, PTF 10weh, SN 2011ht, and PTF 12cxj), three of which are reported here for the first time. For each SN we calculate the control time. We find that precursor events among SNe IIn are common: at the one-sided 99% confidence level, >50% of SNe IIn have at least one pre-explosion outburst that is brighter than 3x107 L taking place up to 1/3 yr prior to the SN explosion. The average rate of such precursor events during the year prior to the SN explosion is likely ≳ 1/yr, and fainter precursors are possibly even more common. Ignoring the two weakest precursors in our sample, the precursors rate we find is still on the order of one per year. We also find possible correlations between the integrated luminosity of the precursor and the SN total radiated energy, peak luminosity, and rise time. These correlations are expected if the precursors are mass-ejection events, and the early-time light curve of these SNe is powered by interaction of the SN shock and ejecta with optically thick circumstellar material. Description: We used PTF observations of the SNe in our sample. The PTF data reduction is described by Laher et al. (2014PASP..126..674L), and the photometric calibration is discussed by Ofek et al. (2012PASP..124...62O, 2012PASP..124..854O). Our search is based on image subtraction, and the flux residuals in the individual image subtractions for all the SNe in our sample are listed in Table 2. In order to calculate the rate of SN precursors, we need to estimate the "control time"-that is, for how long each SN location was observed (prior to its explosion) to a given limiting magnitude. Table 5 lists, for each SN, the time bin windows (of 15 days) prior to the SN explosion and the 5σ sensitivity depth at each window for bins with more than five measurements (second channel), or the median 6σ limiting magnitudes at windows with fewer than six measurements (first channel). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 119 21 SN Sample refs.dat 79 25 References table2.dat 74 5834 SN Observations table5.dat 32 226 Control time
See also: B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-) J/other/Nat/494.65 : SN 2010mc outburst before explosion (Ofek+, 2013) J/ApJ/824/6 : PTF obs. of a precursor to SNHunt 275 2015 May event (Ofek+, 2016) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 9 A9 --- SN Supernova identifier 11- 17 A7 --- Type Type according to SN classification 19- 28 F10.6 deg RAdeg Aperture Right Ascension (J2000) 30- 39 A10 deg DEdeg Aperture Declinaison (J2000) 41 A1 --- l_RMagpeak ? Limit flag on RMagpeak 42- 46 F5.1 mag RMagpeak ? Peak absolute R band magnitude 47 A1 --- u_RMagpeak ? Uncertainty flag on RMagpeak 49- 54 F6.4 --- z ? SN redshift 56- 60 F5.2 mag DM ? Distance modulus 62- 66 A5 d trise ? MJD of the estimated start of the SN rise 67 A1 --- u_trise ? Uncertainty flag on trise 69- 73 A5 d tpeak ? MJD of the light-curve peak 74 A1 --- u_tpeak ? Uncertainty flag on tpeak 76- 79 F4.2 --- FAP ?=- False-alarm probability (1) 81- 89 A9 --- Name SN name as in table2 91-119 A29 --- Ref References, in refs.dat file
Note (1): FAP is the false-alarm probability to detect a precursor by coadding images in 15 day bins as estimated using the bootstrap method (see Section 4.2). The values are based on 100 bootstrap simulations and are therefore truncated to two figures after the decimal point. SNe with no data are those in which the precursor is clearly detected in many individual images and thus the bootstrap analysis on the coadded data is ineffective (see Section 4.2).
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Ref Reference number 4- 22 A19 --- BibCode BibCode 24- 40 A17 --- Aut Author's name 41- 79 A39 --- Com Comments
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 9 A9 --- SN Supernova identifier 11 A1 --- Filter [Rg] Filter used in the observation 13- 22 F10.5 d Time Time relative to trise (in table1) 24- 34 F11.5 d MJD Modified Julian Date 36- 41 F6.3 mag mag Observed luptitude in Filter (1) 43- 50 F8.3 mag emag Error in mag 52- 57 F6.3 mag lmag Limiting magnitude 59- 66 F8.1 ct Flux Flux residual 68- 74 F7.1 ct e_Flux Error in Flux
Note (1): Magnitude are calculated in luptitudes, and they have meaning only when smaller than the limiting magnitude. A magnitude measure in which the logarithm is replaced with a hyperbolic sine. Unlike normal magnitudes, luptitudes are defined for negative fluxes (Lupton, Gunn, & Szalay 1999AJ....118.1406L)
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 9 A9 --- SN Supernova identifier 11- 16 F6.1 d Time Time relative to trise (in table1) (1) 18- 22 F5.2 mag Rmag Apparent PTF R band limiting magnitude 24- 29 F6.2 mag RMag Absolute PTF R band limiting magnitude 31- 32 I2 --- Num Number of measurements in time bin (2)
Note (1): within each 15-day bin. Note (2): For bins with Num < 6 we present the median of all 6σ limiting magnitudes in the bin. We mark instances with Num = 1 (even if Num > 1).
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 08-Mar-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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