- ID:
- ivo://CDS.VizieR/J/ApJ/835/58
- Title:
- PTF 12dam & iPTF 13dcc follow-up
- Short Name:
- J/ApJ/835/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the light curves of the hydrogen-poor superluminous supernovae (SLSNe I) PTF 12dam and iPTF 13dcc, discovered by the (intermediate) Palomar Transient Factory. Both show excess emission at early times and a slowly declining light curve at late times. The early bump in PTF 12dam is very similar in duration (~10days) and brightness relative to the main peak (2-3mag fainter) compared to that observed in other SLSNe I. In contrast, the long-duration (>30days) early excess emission in iPTF 13dcc, whose brightness competes with that of the main peak, appears to be of a different nature. We construct bolometric light curves for both targets, and fit a variety of light-curve models to both the early bump and main peak in an attempt to understand the nature of these explosions. Even though the slope of the late-time decline in the light curves of both SLSNe is suggestively close to that expected from the radioactive decay of ^56^Ni and ^56^Co, the amount of nickel required to power the full light curves is too large considering the estimated ejecta mass. The magnetar model including an increasing escape fraction provides a reasonable description of the PTF 12dam observations. However, neither the basic nor the double-peaked magnetar model is capable of reproducing the light curve of iPTF 13dcc. A model combining a shock breakout in an extended envelope with late-time magnetar energy injection provides a reasonable fit to the iPTF 13dcc observations. Finally, we find that the light curves of both PTF 12dam and iPTF 13dcc can be adequately fit with the model involving interaction with the circumstellar medium.
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- ID:
- ivo://CDS.VizieR/J/A+A/609/A106
- Title:
- PTF11mnb Bgri light curves
- Short Name:
- J/A+A/609/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study PTF11mnb, a He-poor supernova (SN) whose light curves resemble those of SN 2005bf, a peculiar double-peaked stripped-envelope (SE) SN, until the declining phase after the main peak. We investigate the mechanism powering its light curve and the nature of its progenitor star. Optical photometry and spectroscopy of PTF11mnb are presented. We compared light curves, colors and spectral properties to those of SN 2005bf and normal SE SNe. We built a bolometric light curve and modeled this light curve with the SuperNova Explosion Code (SNEC) hydrodynamical code explosion of a MESA progenitor star and semi-analytic models.
- ID:
- ivo://CDS.VizieR/J/ApJ/824/6
- Title:
- PTF obs. of a precursor to SNHunt 275 2015 May event
- Short Name:
- J/ApJ/824/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The progenitors of some supernovae (SNe) exhibit outbursts with super-Eddington luminosities prior to their final explosions. This behavior is common among SNe IIn, but the driving mechanisms of these precursors are not yet well-understood. SNHunt 275 was announced as a possible new SN during 2015 May. Here we report on pre-explosion observations of the location of this event by the Palomar Transient Factory (PTF) and report the detection of a precursor about 500 days prior to the 2015 May activity (PTF 13efv). The observed velocities in the 2015 transient and its 2013 precursor absorption spectra are low (1000-2000km/s), so it is not clear yet if the recent activity indeed marks the final disruption of the progenitor. Regardless of the nature of this event, we use the PTF photometric and spectral observations, as well as Swift-UVOT observations, to constrain the efficiency of the radiated energy relative to the total kinetic energy of the precursor. We find that, using an order-of-magnitude estimate and under the assumption of spherical symmetry, the ratio of the radiated energy to the kinetic energy is in the range of 4x10^-2^ to 3.4x10^3^.
- ID:
- ivo://CDS.VizieR/J/A+A/593/A68
- Title:
- PTF12os and iPTF13bvn spectra and light curves
- Short Name:
- J/A+A/593/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by the (i)PTF. We classify PTF12os as a Type IIb SN based on our spectral sequence; iPTF13bvn has previously been classified as Type Ib. Our main objective is to constrain the explosion parameters of iPTF12os and iPTF13bvn, and to put constraints on the SN progenitors, using our comprehensive photometric and spectroscopic datasets.
- ID:
- ivo://CDS.VizieR/J/ApJ/870/1
- Title:
- PUSH CCSN to explosions in spherical symmetry. II.
- Short Name:
- J/ApJ/870/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a previously presented proof-of-principle study, we established a parameterized spherically symmetric explosion method (PUSH) that can reproduce many features of core-collapse supernovae (CCSN). The present paper goes beyond a specific application that is able to reproduce observational properties of SN1987A and performs a systematic study of an extensive set of nonrotating, solar metallicity stellar progenitor models in the mass range from 10.8 to 120M_{sun}_. This includes the transition from neutron stars to black holes as the final result of the collapse of massive stars, and the relation of the latter to supernovae, possibly faint supernovae, and failed supernovae. We discuss the explosion properties of all models and predict remnant mass distributions within this approach. The present paper provides the basis for extended nucleosynthesis predictions in a forthcoming paper to be employed in galactic evolution models.
- ID:
- ivo://CDS.VizieR/J/ApJ/870/2
- Title:
- PUSH CCSN to explosions in spherical symmetry. III.
- Short Name:
- J/ApJ/870/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a previously presented proof-of-principle study, we established a parameterized spherically symmetric explosion method (PUSH) that can reproduce many features of core-collapse supernovae (CCSNe) for a wide range of pre-explosion models. The method is based on the neutrino-driven mechanism and follows collapse, bounce, and explosion. There are two crucial aspects of our model for nucleosynthesis predictions. First, the mass cut and explosion energy emerge simultaneously from the simulation (determining, for each stellar model, the amount of Fe-group ejecta). Second, the interactions between neutrinos and matter are included consistently (setting the electron fraction of the innermost ejecta). In the present paper, we use the successful explosion models from Paper II (Ebinger+, 2019, J/ApJ/870/1) that include two sets of pre-explosion models at solar metallicity, with combined masses between 10.8 and 120M_{sun}_. We perform systematic nucleosynthesis studies and predict detailed isotopic yields. The resulting ^56^Ni ejecta are in overall agreement with observationally derived values from normal CCSNe. The Fe-group yields are also in agreement with derived abundances for metal-poor star HD84937. We also present a comparison of our results with observational trends in alpha element to iron ratios.
- ID:
- ivo://CDS.VizieR/J/ApJ/573/306
- Title:
- Radio emission from supernovae
- Short Name:
- J/ApJ/573/306
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report Very Large Array radio observations of 29 supernovae (SNe) with ages ranging from 10 days to about 90yr past explosion. These observations significantly contribute to the existing data pool on such objects. Included are detections of known radio SNe 1950B, 1957D, 1970G, and 1983N, the suspected radio SN 1923A, and the possible radio SN 1961V. None of the remaining 23 observations resulted in detections, providing further evidence to support the observed trend that most SNe are not detectable radio emitters. To investigate the apparent lack of radio emission from the SNe reported here, we have followed standard practice and used Chevalier's "standard model" to derive (upper limits to) the mass-loss rates for the supernova progenitors. These upper limits to the fluxes are consistent with a lack of circumstellar material needed to provide detectable radio emission for SNe at these ages and distances. Comparison of the radio luminosities of these supernovae as a function of age past explosion to other well-observed radio SNe indicates that the Type II SNe upper limits are more consistent with the extrapolated light curves of SN 1980K than of SN 1979C, suggesting that SN 1980K may be a more typical radio emitter than SN 1979C. For completeness, we have included an appendix where the results of analyses of the non-SN radio sources are presented. Where possible, we make (tentative) identifications of these sources using various methods.
- ID:
- ivo://CDS.VizieR/J/other/Nat/463.513
- Title:
- Radio observations of SN 2009bb
- Short Name:
- J/other/Nat/463.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Long duration gamma-ray bursts (GRBs) mark the explosive death of some massive stars and are a rare sub-class of type Ibc supernovae. They are distinguished by the production of an energetic and collimated relativistic outflow powered by a central engine (an accreting black hole or neutron star). Observationally, this outflow is manifested in the pulse of gamma-rays and a long-lived radio afterglow. Until now, central-engine-driven supernovae have been discovered exclusively through their gamma-ray emission, yet it is expected that a larger population goes undetected because of limited satellite sensitivity or beaming of the collimated emission away from our line of sight. In this framework, the recovery of undetected GRBs may be possible through radio searches for type Ibc supernovae with relativistic outflows. Here we report the discovery of luminous radio emission from the seemingly ordinary type Ibc SN 2009bb, which requires a substantial relativistic outflow powered by a central engine. A comparison with our radio survey of type Ibc supernovae reveals that the fraction harbouring central engines is low, about one per cent, measured independently from, but consistent with, the inferred rate of nearby GRBs. Independently, a second mildly relativistic supernova has been reported.
- ID:
- ivo://CDS.VizieR/J/ApJ/903/132
- Title:
- Radio & optical observations of supernova SN2020oi
- Short Name:
- J/ApJ/903/132
- Date:
- 15 Mar 2022
- Publisher:
- CDS
- Description:
- We report the discovery and panchromatic follow-up observations of the young Type Ic supernova (SNIc) SN2020oi in M100, a grand-design spiral galaxy at a mere distance of 14Mpc. We followed up with observations at radio, X-ray, and optical wavelengths from only a few days to several months after explosion. The optical behavior of the supernova is similar to those of other normal SNeIc. The event was not detected in the X-ray band but our radio observations revealed a bright mJy source (L_{nu}_~1.2x10^27^erg/s/Hz). Given the relatively small number of stripped envelope SNe for which radio emission is detectable, we used this opportunity to perform a detailed analysis of the comprehensive radio data set we obtained. The radio-emitting electrons initially experience a phase of inverse Compton cooling, which leads to steepening of the spectral index of the radio emission. Our analysis of the cooling frequency points to a large deviation from equipartition at the level of {epsilon}_e_/{epsilon}_B_>~200, similar to a few other cases of stripped envelope SNe. Our modeling of the radio data suggests that the shock wave driven by the SN ejecta into the circumstellar matter (CSM) is moving at ~3x10^4^km/s. Assuming a constant mass loss from the stellar progenitor, we find that the mass-loss rate is M~1.4x10^-4^M{sun}/yr for an assumed wind velocity of 1000km/s. The temporal evolution of the radio emission suggests a radial CSM density structure steeper than the standard r-2.
- ID:
- ivo://CDS.VizieR/J/ApJ/820/33
- Title:
- R-band light curves of type II supernovae
- Short Name:
- J/ApJ/820/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- During the first few days after explosion, Type II supernovae (SNe) are dominated by relatively simple physics. Theoretical predictions regarding early-time SN light curves in the ultraviolet (UV) and optical bands are thus quite robust. We present, for the first time, a sample of 57 R-band SN II light curves that are well-monitored during their rise, with >5 detections during the first 10 days after discovery, and a well-constrained time of explosion to within 1-3 days. We show that the energy per unit mass (E/M) can be deduced to roughly a factor of five by comparing early-time optical data to the 2011 model of Rabinak & Waxman, while the progenitor radius cannot be determined based on R-band data alone. We find that SN II explosion energies span a range of E/M=(0.2-20)x10^51^erg/(10M_{sun}), and have a mean energy per unit mass of <E/M>=0.85x10^51^erg/(10M_{sun}), corrected for Malmquist bias. Assuming a small spread in progenitor masses, this indicates a large intrinsic diversity in explosion energy. Moreover, E/M is positively correlated with the amount of ^56^Ni produced in the explosion, as predicted by some recent models of core-collapse SNe. We further present several empirical correlations. The peak magnitude is correlated with the decline rate ({Delta}m_15_), the decline rate is weakly correlated with the rise time, and the rise time is not significantly correlated with the peak magnitude. Faster declining SNe are more luminous and have longer rise times. This limits the possible power sources for such events.
