| 1. |
- Chen, Ping, et al.
(författare)
-
A 12.4-day periodicity in a close binary system after a supernova
- 2024
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625:7994, s. 253-258
-
Tidskriftsartikel (refereegranskat)abstract
- Neutron stars and stellar-mass black holes are the remnants of massive star explosions1. Most massive stars reside in close binary systems2, and the interplay between the companion star and the newly formed compact object has been theoretically explored3, but signatures for binarity or evidence for the formation of a compact object during a supernova explosion are still lacking. Here we report a stripped-envelope supernova, SN 2022jli, which shows 12.4-day periodic undulations during the declining light curve. Narrow Hα emission is detected in late-time spectra with concordant periodic velocity shifts, probably arising from hydrogen gas stripped from a companion and accreted onto the compact remnant. A new Fermi-LAT γ-ray source is temporally and positionally consistent with SN 2022jli. The observed properties of SN 2022jli, including periodic undulations in the optical light curve, coherent Hα emission shifting and evidence for association with a γ-ray source, point to the explosion of a massive star in a binary system leaving behind a bound compact remnant. Mass accretion from the companion star onto the compact object powers the light curve of the supernova and generates the γ-ray emission.
|
|
| 2. |
- Soumagnac, Maayane T., et al.
(författare)
-
SN 2018fif : The Explosion of a Large Red Supergiant Discovered in Its Infancy by the Zwicky Transient Facility
- 2020
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 902:1
-
Tidskriftsartikel (refereegranskat)abstract
- High-cadence transient surveys are able to capture supernovae closer to their first light than ever before. Applying analytical models to such early emission, we can constrain the progenitor stars' properties. In this paper, we present observations of SN 2018fif (ZTF 18abokyfk). The supernova was discovered close to first light and monitored by the Zwicky Transient Facility (ZTF) and the Neil Gehrels Swift Observatory. Early spectroscopic observations suggest that the progenitor of SN 2018fif was surrounded by relatively small amounts of circumstellar material compared to all previous cases. This particularity, coupled with the high-cadence multiple-band coverage, makes it a good candidate to investigate using shock-cooling models. We employ the SOPRANOS code, an implementation of the model by Sapir & Waxman and its extension to early times by Morag et al. Compared with previous implementations, SOPRANOS has the advantage of including a careful account of the limited temporal validity domain of the shock-cooling model as well as allowing usage of the entirety of the early UV data. We find that the progenitor of SN 2018fif was a large red supergiant with a radius of R = 744.0(-128.0)(+183.0) R-circle dot and an ejected mass of M-ej = 9.3(-5.8)(+0.4) M-circle dot. Our model also gives information on the explosion epoch, the progenitor's inner structure, the shock velocity, and the extinction. The distribution of radii is double-peaked, with smaller radii corresponding to lower values of the extinction, earlier recombination times, and a better match to the early UV data. If these correlations persist in future objects, denser spectroscopic monitoring constraining the time of recombination, as well as accurate UV observations (e.g., with ULTRASAT), will help break the extinction/radius degeneracy and independently determine both.
|
|
| 3. |
- Strotjohann, Nora L., et al.
(författare)
-
Search for Supernova Progenitor Stars with ZTF and LSST
- 2024
-
Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 960:1
-
Tidskriftsartikel (refereegranskat)abstract
- The direct detection of core-collapse supernova (SN) progenitor stars is a powerful way of probing the last stages of stellar evolution. However, detections in archival Hubble Space Telescope images are limited to about one detection per year. Here, we explore whether we can increase the detection rate by using data from ground-based wide-field surveys. Due to crowding and atmospheric blurring, progenitor stars can typically not be identified in preexplosion images alone. Instead, we combine many pre-SN and late-time images to search for the disappearance of the progenitor star. As a proof of concept, we implement our search of ZTF data. For a few hundred images, we achieve limiting magnitudes of ∼23 mag in the g and r bands. However, no progenitor stars or long-lived outbursts are detected for 29 SNe within z ≤ 0.01, and the ZTF limits are typically several magnitudes less constraining than detected progenitors in the literature. Next, we estimate progenitor detection rates for the Legacy Survey of Space and Time (LSST) with the Vera C. Rubin telescope by simulating a population of nearby SNe. The background from bright host galaxies reduces the nominal LSST sensitivity by, on average, 0.4 mag. Over the 10 yr survey, we expect the detection of ∼50 red supergiant progenitors and several yellow and blue supergiants. The progenitors of Type Ib and Ic SNe will be detectable if they are brighter than −4.7 or −4.0 mag in the LSST i band, respectively. In addition, we expect the detection of hundreds of pre-SN outbursts depending on their brightness and duration.
|
|
