scholarly journals SN 2016B a.k.a. ASASSN-16ab: a transitional Type II supernova

2019 ◽  
Vol 486 (2) ◽  
pp. 2850-2872 ◽  
Author(s):  
Raya Dastidar ◽  
Kuntal Misra ◽  
Mridweeka Singh ◽  
D K Sahu ◽  
A Pastorello ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Light Curve ◽  
High Velocity ◽  
Type Ii ◽  
Plateau Phase ◽  
Initial Radius ◽  
Circumstellar Material ◽  
Transitional Type ◽  
Material Interaction

Abstract We present photometry, polarimetry, and spectroscopy of the Type II supernova ASASSN-16ab/SN 2016B in PGC 037392. The photometric and spectroscopic follow-up commenced about 2 weeks after shock breakout and continued until nearly 6 months. The light curve of SN 2016B exhibits intermediate properties between those of Type IIP and IIL. The early decline is steep (1.68 ± 0.10 mag 100 d−1), followed by a shallower plateau phase (0.47 ± 0.24 mag 100 d−1). The optically thick phase lasts for 118 d, similar to Type IIP. The 56Ni mass estimated from the radioactive tail of the bolometric light curve is 0.082 ± 0.019 M⊙. High-velocity component contributing to the absorption trough of H α and H β in the photospheric spectra are identified from the spectral modelling from about 57–97 d after the outburst, suggesting a possible SN ejecta and circumstellar material interaction. Such high-velocity features are common in the spectra of Type IIL supernovae. By modelling the true bolometric light curve of SN 2016B, we estimated a total ejected mass of ∼15 M⊙, kinetic energy of ∼1.4 foe, and an initial radius of ∼400 R⊙.

scholarly journals SN 2015an: a normal luminosity type II supernova with low expansion velocity at early phases

2019 ◽  
Vol 490 (2) ◽  
pp. 1605-1619
Author(s):  
Raya Dastidar ◽  
Kuntal Misra ◽  
Stefano Valenti ◽  
Jamison Burke ◽  
Griffin Hosseinzadeh ◽  
...  
Keyword(s):  
Light Curve ◽  
High Velocity ◽  
Expansion Velocity ◽  
Type Ii ◽  
Mass Yield ◽  
Circumstellar Material ◽  
V Band ◽  
Material Interaction ◽  
Early Phases ◽  
The Continuum

ABSTRACT We present the photometry and spectroscopy of SN 2015an, a type II Supernova (SN) in IC 2367. The recombination phase of the SN lasts up to 120 d, with a decline rate of 1.24 mag/100d, higher than the typical SNe IIP. The SN exhibits bluer colours than most SNe II, indicating higher ejecta temperatures. The absolute V-band magnitude of SN 2015an at 50 d is −16.83 ± 0.04 mag, pretty typical for SNe II. However, the 56Ni mass yield, estimated from the tail V-band light curve to be 0.021 ± 0.010 M⊙, is comparatively low. The spectral properties of SN 2015an are atypical, with low H α expansion velocity and presence of high-velocity component of H α at early phases. Moreover, the continuum exhibits excess blue flux up to 50 d, which is interpreted as a progenitor metallicity effect. The high-velocity feature indicates ejecta-circumstellar material interaction at early phases. The semi-analytical modelling of the bolometric light curve yields a total ejected mass of 12 M⊙, a pre-SN radius of 388 R⊙ and explosion energy of 1.8 foe.

Early Blue Excess from the Type Ia Supernova 2017cbv

2017 ◽  
Vol 14 (S339) ◽  
pp. 47-49
Author(s):  
G. Hosseinzadeh
Keyword(s):  
Light Curve ◽  
Standard Type ◽  
Circumstellar Material ◽  
Type Ia Supernova ◽  
Unusual Distribution ◽  
Photometric Observations ◽  
Type Ia ◽  
Optical Light Curve ◽  
Ia Supernovae

AbstractThis paper presented very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light-curve is unique in that during the first five days of observations it has a blue bump in the U, B, and g bands which is clearly resolved by virtue of our photometric cadence of 5.7 hr during that time span. We modelled the light-curve as the combination of an early shock of the supernova ejecta against a non-degenerate companion star plus a standard Type Ia supernova component. Our best-fit model suggested the presence of a subgiant star 56 R⊙ from the exploding white dwarf, although that number is highly model-dependent. While the model matches the optical light-curve well, it over-predicts the flux expected in the ultraviolet bands. That may indicate that the shock is not a blackbody, perhaps because of line blanketing in the UV. Alternatively, it could point to another physical explanation for the optical blue bump, such as interaction with circumstellar material or an unusual distribution of the element Ni. Early optical spectra of SN 2017cbv show strong carbon absorption as far as day –13 with respect to maximum light, suggesting that the progenitor system contained a significant amount of unburnt material. These results for SN 2017cbv illustrate the power of early discovery and intense follow-up of nearby supernovæ for resolving standing questions about the progenitor systems and explosion mechanisms of Type Ia supernovæ.

scholarly journals SN 2017ivv: two years of evolution of a transitional Type II supernova

2020 ◽  
Vol 499 (1) ◽  
pp. 974-992
Author(s):  
C P Gutiérrez ◽  
A Pastorello ◽  
A Jerkstrand ◽  
L Galbany ◽  
M Sullivan ◽  
...  
Keyword(s):  
Light Curve ◽  
Main Sequence ◽  
Rapid Decline ◽  
Type Ii ◽  
Additional Energy ◽  
V Band ◽  
Weak Phase ◽  
Faint Galaxy ◽  
Transitional Type ◽  
Fast Rise

ABSTRACT We present the photometric and spectroscopic evolution of the Type II supernova (SN II) SN 2017ivv (also known as ASASSN-17qp). Located in an extremely faint galaxy (Mr = −10.3 mag), SN 2017ivv shows an unprecedented evolution during the 2 yr of observations. At early times, the light curve shows a fast rise (∼6−8 d) to a peak of ${\it M}^{\rm max}_{g}= -17.84$ mag, followed by a very rapid decline of 7.94 ± 0.48 mag per 100 d in the V band. The extensive photometric coverage at late phases shows that the radioactive tail has two slopes, one steeper than that expected from the decay of 56Co (between 100 and 350 d), and another slower (after 450 d), probably produced by an additional energy source. From the bolometric light curve, we estimated that the amount of ejected 56Ni is ∼0.059 ± 0.003 M⊙. The nebular spectra of SN 2017ivv show a remarkable transformation that allows the evolution to be split into three phases: (1) Hα strong phase (<200 d); (2) Hα weak phase (between 200 and 350 d); and (3) Hα broad phase (>500 d). We find that the nebular analysis favours a binary progenitor and an asymmetric explosion. Finally, comparing the nebular spectra of SN 2017ivv to models suggests a progenitor with a zero-age main-sequence mass of 15–17 M⊙.

scholarly journals SN 2016gsd: an unusually luminous and linear Type II supernova with high velocities

2020 ◽  
Vol 493 (2) ◽  
pp. 1761-1781 ◽  
Author(s):  
T M Reynolds ◽  
M Fraser ◽  
S Mattila ◽  
M Ergon ◽  
L Dessart ◽  
...  
Keyword(s):  
Light Curve ◽  
Massive Star ◽  
Absolute Magnitude ◽  
Host Galaxy ◽  
Type Ii ◽  
High Luminosity ◽  
Linear Type ◽  
Circumstellar Material ◽  
Low Metallicity ◽  
Edge Tracing

ABSTRACT We present observations of the unusually luminous Type II supernova (SN) 2016gsd. With a peak absolute magnitude of V = −19.95 ± 0.08, this object is one of the brightest Type II SNe, and lies in the gap of magnitudes between the majority of Type II SNe and the superluminous SNe. Its light curve shows little evidence of the expected drop from the optically thick phase to the radioactively powered tail. The velocities derived from the absorption in H α are also unusually high with the blue edge tracing the fastest moving gas initially at 20 000 km s−1, and then declining approximately linearly to 15 000 km s−1 over ∼100 d. The dwarf host galaxy of the SN indicates a low-metallicity progenitor which may also contribute to the weakness of the metal lines in its spectra. We examine SN 2016gsd with reference to similarly luminous, linear Type II SNe such as SNe 1979C and 1998S, and discuss the interpretation of its observational characteristics. We compare the observations with a model produced by the jekyll code and find that a massive star with a depleted and inflated hydrogen envelope struggles to reproduce the high luminosity and extreme linearity of SN 2016gsd. Instead, we suggest that the influence of interaction between the SN ejecta and circumstellar material can explain the majority of the observed properties of the SN. The high velocities and strong H α absorption present throughout the evolution of the SN may imply a circumstellar medium configured in an asymmetric geometry.

scholarly journals The Luminous Type Ibc Supernova 2010as

2011 ◽  
Vol 7 (S279) ◽  
pp. 331-332
Author(s):  
Gastón Folatelli
Keyword(s):  
Light Curve ◽  
Bolometric Luminosity ◽  
Large Yield ◽  
Preliminary Model ◽  
Transitional Type

AbstractWe present photometric and spectroscopic follow-up observations of SN 2010as carried out by the MCSS and CSP. The SN appears to be of the transitional type Ibc (SN Ibc) and is spectroscopically similar to the peculiar SN 2005bf. Based on distance and extinction estimates, a bolometric luminosity light curve is constructed showing that this was a relatively luminous SN Ibc. He i line expansion velocities are remarkably low and remain nearly constant with time, similarly to SN~2005bf. A preliminary model is presented with a progenitor ZAMS mass of 15 M⊙ and a large yield of 0.35 M⊙ of 56Ni.

scholarly journals Final Moments. I. Precursor Emission, Envelope Inflation, and Enhanced Mass Loss Preceding the Luminous Type II Supernova 2020tlf

2022 ◽  
Vol 924 (1) ◽  
pp. 15
Author(s):  
W. V. Jacobson-Galán ◽  
L. Dessart ◽  
D. O. Jones ◽  
R. Margutti ◽  
D. L. Coppejans ◽  
...  
Keyword(s):  
Light Curve ◽  
Mass Loss ◽  
Loss Rate ◽  
Main Sequence ◽  
Mass Loss Rate ◽  
Type Ii ◽  
Stellar Envelope ◽  
Circumstellar Material ◽  
Associated Mass ◽  
Flash Spectroscopy

Abstract We present panchromatic observations and modeling of supernova (SN) 2020tlf, the first normal Type II-P/L SN with confirmed precursor emission, as detected by the Young Supernova Experiment transient survey. Pre-SN activity was detected in riz-bands at −130 days and persisted at relatively constant flux until first light. Soon after discovery, “flash” spectroscopy of SN 2020tlf revealed narrow, symmetric emission lines that resulted from the photoionization of circumstellar material (CSM) shed in progenitor mass-loss episodes before explosion. Surprisingly, this novel display of pre-SN emission and associated mass loss occurred in a red supergiant (RSG) progenitor with zero-age main-sequence mass of only 10–12 M ⊙, as inferred from nebular spectra. Modeling of the light curve and multi-epoch spectra with the non-LTE radiative-transfer code CMFGEN and radiation-hydrodynamical code HERACLES suggests a dense CSM limited to r ≈ 1015 cm, and mass-loss rate of 10−2 M ⊙ yr−1. The luminous light-curve plateau and persistent blue excess indicates an extended progenitor, compatible with an RSG model with R ⋆ = 1100 R ⊙. Limits on the shock-powered X-ray and radio luminosity are consistent with model conclusions and suggest a CSM density of ρ < 2 × 10−16 g cm−3 for distances from the progenitor star of r ≈ 5 × 1015 cm, as well as a mass-loss rate of M ̇ < 1.3 × 10 − 5 M ☉ yr − 1 at larger distances. A promising power source for the observed precursor emission is the ejection of stellar material following energy disposition into the stellar envelope as a result of gravity waves emitted during either neon/oxygen burning or a nuclear flash from silicon combustion.

scholarly journals Two stripped envelope supernovae with circumstellar interaction

2020 ◽  
Vol 643 ◽  
pp. A79
Author(s):  
J. Sollerman ◽  
C. Fransson ◽  
C. Barbarino ◽  
C. Fremling ◽  
A. Horesh ◽  
...  
Keyword(s):  
Light Curve ◽  
Light Curves ◽  
X Rays ◽  
Strong Emission ◽  
Circumstellar Material ◽  
High Ionization ◽  
New Period ◽  
Rich Material ◽  
Narrow Emission

Context. We present observations of SN 2019tsf (ZTF19ackjszs) and SN 2019oys (ZTF19abucwzt). These two stripped envelope (SE) Type Ib supernovae (SNe) suddenly showed a (re-)brightening in their late light curves. We investigate this in the context of circumstellar material (CSM) interaction with previously ejected material, a phenomenon that is unusual among SE SNe. Aims. We use our follow-up photometry and spectroscopy for these supernovae to demonstrate the presence of CSM interaction, estimate the properties of the CSM, and discuss why the signals are so different for the two objects. Methods. We present and analyze observational data, consisting of optical light curves and spectra. For SN 2019oys, we also have detections in radio as well as limits from UV and X-rays. Results. Both light curves show spectacular re-brightening after about 100 days. In the case of SN 2019tsf, the re-brightening is followed by a new period of decline, and the spectra never show signs of narrow emission lines that would indicate CSM interaction. On the contrary, SN 2019oys made a spectral makeover from a Type Ib to a spectrum clearly dominated by CSM interaction at the light curve brightening phase. Deep Keck spectra reveal a plethora of narrow high-ionization lines, including coronal lines, and the radio observations show strong emission. Conclusions. The rather similar light curve behavior – with a late linear re-brightening – of these two Type Ib SE SNe indicate CSM interaction as the powering source. For SN 2019oys the evidence for a phase where the ejecta hit H-rich material, likely ejected from the progenitor star, is conspicuous. We observe strong narrow lines of H and He, but also a plethora of high-ionization lines, including coronal lines, revealing shock interaction. Spectral simulations of SN 2019oys show two distinct density components, one with density ≳109 cm−3, dominated by somewhat broader, low-ionization lines of H I, He I, Na I, and Ca II, and one with narrow, high-ionization lines at a density ∼106 cm−3. The former is strongly affected by electron scattering, while the latter is unaffected. The evidence for CSM interaction in SN 2019oys is corroborated by detections in radio. On the contrary, for SN 2019tsf, we find little evidence in the spectra for any CSM interaction.

Image-guided translumbar type II endoleak repair: A novel approach

2020 ◽  
Vol 4 ◽  
pp. 9
Author(s):  
Salman Mirza ◽  
Shahnawaz Ansari
Keyword(s):  
Mesenteric Artery ◽  
Inferior Mesenteric Artery ◽  
Endovascular Aneurysm Repair ◽  
Type Ii ◽  
Type Ii Endoleak ◽  
Image Guided ◽  
Novel Approach ◽  
Abdominal Aortic ◽  
Aneurysm Repair

We present a case of a 72-year-old male with an abdominal aortic aneurysm status post-endovascular aneurysm repair (EVAR). Follow-up imaging demonstrated an enlarging type II endoleak and attempts at transarterial coil embolization of the inferior mesenteric artery were unsuccessful. The patient underwent image-guided percutaneous translumbar type II endoleak repair using XperGuide (Philips, Andover, MA USA).

scholarly journals Collaural fistula (Work Type II first branchial cleft anomaly) with prolonged morbidity: A case report

2021 ◽  
Vol 9 ◽  
pp. 2050313X2110145
Author(s):  
Dorji Penjor ◽  
Morimasa Kitamura
Keyword(s):  
External Auditory Canal ◽  
Fistulous Tract ◽  
Type Ii ◽  
Complete Excision ◽  
Incision And Drainage ◽  
Branchial Cleft ◽  
Repeated Infections ◽  
Branchial Anomalies ◽  
Work Type

Collaural fistula is a very rare Work Type II first branchial cleft anomaly in which there is a complete fistulous tract between external auditory canal and the neck. Misdiagnosis and mismanagement can lead to prolonged morbidity and complications due to repeated infections. We present a case of an 18-year-old lady with a recurrent discharging sinus on her neck for 4 years. She has been treated with repeated incision and drainage and multiple antibiotics in the past. Otoscopic examination revealed an opening on the floor of the left external auditory canal. A diagnosis of an infected collaural fistula was made. Complete excision of the fistulous tract was done after treatment of the active infection. On follow-up, there was no further recurrence at 1 year. Sound knowledge of embryology of branchial anomalies with good history and examination is important to make correct and early diagnosis to prevent morbidity.

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