- ID:
- ivo://CDS.VizieR/J/ApJ/769/99
- Title:
- Nucleosynthetic yields for stars >12M{sun}
- Short Name:
- J/ApJ/769/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore the sensitivity of nucleosynthesis in massive stars to the truncation of supernova explosions above a certain mass. It is assumed that stars of all masses contribute to nucleosynthesis by their pre-explosive winds, but above a certain limiting main sequence mass, M_BH_, the presupernova star becomes a black hole and ejects nothing more. The solar abundances from oxygen to atomic mass 90 are fit quite well assuming no cutoff at all, i.e., by assuming all stars up to 120M_{sun}_ make successful supernovae. Little degradation in the fit occurs if M_BH_ is reduced to 25M_{sun}_. If this limit is reduced further however, the nucleosynthesis of the s-process declines precipitously and the production of species made in the winds, e.g., carbon, becomes unacceptably large compared with elements made in the explosion, e.g., silicon and oxygen. By varying uncertain physics, especially the mass loss rate for massive stars and the rate for the ^22^Ne({alpha},n)^25^Mg reaction rate, acceptable nucleosynthesis might still be achieved with a cutoff as low as 18M_{sun}_. This would require, however, a supernova frequency three times greater than the fiducial value obtained when all stars explode in order to produce the required ^16^O. The effects of varying M_BH_ on the nucleosynthesis of ^60^Fe and ^26^Al, the production of helium as measured by {Delta}Y/{Delta}Z, and the average masses of compact remnants are also examined.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/873/L3
- Title:
- NUV to NIR photometry of type IIP ASASSN-16at
- Short Name:
- J/ApJ/873/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report distinctly double-peaked H{alpha} and H{beta} emission lines in the late-time, nebular-phase spectra (>~200 days) of the otherwise normal at early phases (<~100 days) type IIP supernova ASASSN-16at (SN2016X). Such distinctly double-peaked nebular Balmer lines have never been observed for a type II SN. The nebular-phase Balmer emission is driven by the radioactive ^56^Co decay, so the observed line profile bifurcation suggests a strong bipolarity in the ^56^Ni distribution or in the line-forming region of the inner ejecta. The strongly bifurcated blueshifted and redshifted peaks are separated by ~3x10^3^km/s and are roughly symmetrically positioned with respect to the host-galaxy rest frame, implying that the inner ejecta are composed of two almost-detached blobs. The red peak progressively weakens relative to the blue peak, and disappears in the 740 days spectrum. One possible reason for the line-ratio evolution is increasing differential extinction from continuous formation of dust within the envelope, which is also supported by the near-infrared flux excess that develops after ~100 days.
- ID:
- ivo://CDS.VizieR/J/PAZh/30/37
- Title:
- Observations of supernovae in 1997-1999
- Short Name:
- J/PAZh/30/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric observations of 15 supernovae discovered in the period 1997-1999 are presented.
- ID:
- ivo://CDS.VizieR/J/AcA/63/1
- Title:
- OGLE-IV Magellanic Bridge Data supernovae
- Short Name:
- J/AcA/63/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze two years (mid-2010 to mid-2012) of OGLE-IV data covering ~65deg^2^ of the Magellanic Bridge (the area between the Magellanic Clouds) and find 130 transient events including 126 supernovae (SNe), two foreground dwarf novae and another two SNe-like transients that turned out to be active galactic nuclei (AGNs). We show our SNe detection efficiency as a function of SN peak magnitude based on available SNe rate estimates. It is 100% for SNe peak magnitudes I<18.8mag and drops to 50% at I~19.7mag. With our current observing area between and around the Magellanic Clouds (~600deg^2^), we expect to find 24 SNe peaking above I<18mag, 100 above I<19mag, and 340 above I<20mag, annually. We briefly introduce our on-line near-real-time detection system for SNe and other transients, the OGLE Transient Detection System.
- ID:
- ivo://CDS.VizieR/J/AcA/64/197
- Title:
- OGLE-IV 2012-2014 transients
- Short Name:
- J/AcA/64/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the design and first results of a real-time search for transients within the 650 sq. deg. area around the Magellanic Clouds, conducted as part of the OGLE-IV project and aimed at detecting supernovae, novae and other events. The average sampling of about four days from September to May, yielded a detection of 238 transients in 2012/2013 and 2013/2014 seasons. The superb photometric and astrometric quality of the OGLE data allows for numerous applications of the discovered transients. We use this sample to prepare and train a Machine Learning-based automated classifier for early light curves, which distinguishes major classes of transients with more than 80% of correct answers. Spectroscopically classified 49 supernovae Type Ia are used to construct a Hubble Diagram with statistical scatter of about 0.3mag and fill the least populated region of the redshifts range in the Union sample. We investigate the influence of host galaxy environments on supernovae statistics and find the mean host extinction of A_I_=0.19+/-0.10mag and A_V_=0.39+/-0.21mag based on a subsample of supernovae Type Ia. We show that the positional accuracy of the survey is of the order of 0.5pixels (0.13") and that the OGLE-IV Transient Detection System is capable of detecting transients within the nuclei of galaxies. We present a few interesting cases of nuclear transients of unknown type. All data on the OGLE transients are made publicly available to the astronomical community via the OGLE website.
- ID:
- ivo://CDS.VizieR/J/ApJS/213/19
- Title:
- Optical and near-IR light curves of 64 SNe
- Short Name:
- J/ApJS/213/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a densely sampled, homogeneous set of light curves of 64 low-redshift (z<~0.05) stripped-envelope supernovae (SNe of Type IIb, Ib, Ic, and Ic-BL). These data were obtained between 2001 and 2009 at the Fred L. Whipple Observatory (FLWO) on Mount Hopkins in Arizona, with the optical FLWO 1.2m and the near-infrared (NIR) Peters Automated Infrared 1.3m telescopes. Our data set consists of 4543 optical photometric measurements on 61 SNe, including a combination of UBVRI, UBVr'i', and u'BVr'i', and 1919 JHK_s_ NIR measurements on 25 SNe. This sample constitutes the most extensive multi-color data set of stripped-envelope SNe to date. Our photometry is based on template-subtracted images to eliminate any potential host-galaxy light contamination. This work presents these photometric data, compares them with data in the literature, and estimates basic statistical quantities: date of maximum, color, and photometric properties. We identify promising color trends that may permit the identification of stripped-envelope SN subtypes from their photometry alone. Many of these SNe were observed spectroscopically by the Harvard-Smithsonian Center for Astrophysics (CfA) SN group, and the spectra are presented in a companion paper. A thorough exploration that combines the CfA photometry and spectroscopy of stripped-envelope core-collapse SNe will be presented in a follow-up paper.
- ID:
- ivo://CDS.VizieR/J/ApJ/863/90
- Title:
- Optical and NIR LCs of the nearby SN 2017cbv
- Short Name:
- J/ApJ/863/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On 2017 March 11, the DLT40 Transient Discovery Survey discovered SN2017cbv in NGC 5643, a Type 2 Seyfert Galaxy in the Lupus Constellation. SN 2017cbv went on to become a bright Type Ia supernova, with a Vmax of 11.51+/-0.05mag. We present early time optical and infrared photometry of SN 2017cbv covering the rise and fall of over 68 days. We find that SN 2017cbv has a broad light curve {Delta}m_15_(B)=0.88+/-0.07, a B-band maximum at 2457840.97+/-0.43, a negligible host galaxy reddening where E(B-V)_host_~0, and a distance modulus of 30.49+/-0.32 to the SN, corresponding to a distance of 12.58_-1.71_^+1.98^Mpc. We also present the results of two different numerical models we used for analysis in this paper: SALT2, an empirical model for Type Ia supernova optical light curves that accounts for variability components; and SNooPy, the CSP-II light-curve model that covers both optical and near-infrared wavelengths and is used for distance estimates.
- ID:
- ivo://CDS.VizieR/J/ApJ/904/14
- Title:
- Optical and NIR observation of SN (Ia) 2017cbv
- Short Name:
- J/ApJ/904/14
- Date:
- 24 Mar 2022 06:19:55
- Publisher:
- CDS
- Description:
- Supernova (SN) 2017cbv in NGC5643 is one of a handful of Type Ia supernovae (SNeIa) reported to have excess blue emission at early times. This paper presents extensive BVRIYJHKs-band light curves of SN2017cbv, covering the phase from -16 to +125days relative to B-band maximum light. The SN2017cbv reached a B-band maximum of 11.710{+/-}0.006mag, with a postmaximum magnitude decline of {Delta}m15(B)=0.990{+/-}0.013mag. The SN suffered no host reddening based on Phillips intrinsic color, the Lira-Phillips relation, and the CMAGIC diagram. By employing the CMAGIC distance modulus {mu}=30.58{+/-}0.05mag and assuming H0=72km/s/Mpc, we found that 0.73M{sun} 56Ni was synthesized during the explosion of SN2017cbv, which is consistent with estimates using reddening- and distance-free methods via the phases of the secondary maximum of the near-IR- (NIR-) band light curves. We also present 14 NIR spectra from -18 to +49 days relative to the B-band maximum light, providing constraints on the amount of swept-up hydrogen from the companion star in the context of the single degenerate progenitor scenario. No Pa{beta} emission feature was detected from our postmaximum NIR spectra, placing a hydrogen mass upper limit of 0.1M{sun}. The overall optical/NIR photometric and NIR spectral evolution of SN2017cbv is similar to that of a normal SN Ia, even though its early evolution is marked by a flux excess not seen in most other well-observed normal SNe Ia. We also compare the exquisite light curves of SN2017cbv with some Mch delayed detonation models and sub-Mch double detonation models.
- ID:
- ivo://CDS.VizieR/J/ApJ/895/118
- Title:
- Optical and NIR photometry of 2 Ia type supernovae
- Short Name:
- J/ApJ/895/118
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- We present photometric and spectroscopic observations of SN2013aa and SN2017cbv, two nearly identical type Ia supernovae (SNeIa) in the host galaxy NGC5643. The optical photometry has been obtained using the same telescope and instruments used by the Carnegie Supernova Project. This eliminates most instrumental systematics and provides light curves in a stable and well-understood photometric system. Having the same host galaxy also eliminates systematics due to distance and peculiar velocity, providing an opportunity to directly test the relative precision of SNeIa as standard candles. The two SNe have nearly identical decline rates, negligible reddenings, and remarkably similar spectra, and, at a distance of ~20Mpc, they are ideal potential calibrators for the absolute distance using primary indicators such as Cepheid variables. We discuss to what extent these two SNe can be considered twins and compare them with other supernova "siblings" in the literature and their likely progenitor scenarios. Using 12 galaxies that hosted two or more SNe Ia, we find that when using SNeIa, and after accounting for all sources of observational error, one gets consistency in distance to 3%.
- ID:
- ivo://CDS.VizieR/J/ApJ/853/62
- Title:
- Optical and NIR spectra and LCs of SN2016ija
- Short Name:
- J/ApJ/853/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our analysis of the Type II supernova DLT16am (SN2016ija). The object was discovered during the ongoing D<40Mpc (DLT40) one-day cadence supernova search at r~20.1mag in the "edge-on" nearby (D=20.0+/-4.0Mpc) galaxy NGC1532. The subsequent prompt and high-cadenced spectroscopic and photometric follow-up revealed a highly extinguished transient, with E(B-V)=1.95+/-0.15mag, consistent with a standard extinction law with R_V_=3.1 and a bright (M_V_=-18.48+/-0.77mag) absolute peak magnitude. A comparison of the photometric features with those of large samples of SNe II reveals a fast rise for the derived luminosity and a relatively short plateau phase, with a slope of S_50V_=0.84+/-0.04mag/50days, consistent with the photometric properties typical of those of fast-declining SNeII. Despite the large uncertainties on the distance and the extinction in the direction of DLT16am, the measured photospheric expansion velocity and the derived absolute V-band magnitude at ~50days after the explosion match the existing luminosity-velocity relation for SNeII.
