A5087020189- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Advanced Power Generation Technologies
- Astronomy and Astrophysical Research
- Pulsars and Gravitational Waves Research
- Nuclear reactor physics and engineering
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- History and Developments in Astronomy
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Evolutionary Game Theory and Cooperation
- Historical Astronomy and Related Studies
- Diverse Scientific and Engineering Research
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Distributed and Parallel Computing Systems
- Advanced Frequency and Time Standards
- Calibration and Measurement Techniques
- Neutrino Physics Research
- Space Science and Extraterrestrial Life
- Scientific Measurement and Uncertainty Evaluation
Stockholm University
2015-2022
AlbaNova
2015-2022
Context. We investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by (intermediate) Palomar Transient Factory [(i)PTF]. These SNe, designated PTF12os/SN 2012P and iPTF13bvn, exploded within ~520 days of one another at a similar distance from host-galaxy center. classify PTF12os as Type IIb SN based on our spectral sequence; iPTF13bvn has previously been classified Ib having likely progenitor with zero age main sequence (ZAMS) mass below ~17 M⊙. Because...
We present a sample of supernovae Type IIn (SNe IIn) from the untargeted, magnitude-limited surveys Palomar Transient Factory (PTF) and its successor, intermediate PTF (iPTF). The SNe found followed by PTF/iPTF were used to select 42 events with useful constraints on rise times as well available post-peak photometry. discovered in 2009-2016 have at least one low-resolution classification spectrum, photometry P48 P60 telescopes Observatory. study light-curve properties these using spline fits...
Left-over, ablated material from a possible non-degenerate companion can reveal itself after about one year in spectra of Type Ia SNe (SNe Ia). We have searched for such SN 2011fe (at 294 days the explosion) and 2014J (315 past explosion). The observations are compared with numerical models simulating expected line emission. spectral lines sought H-alpha, [O I] 6300 [Ca II] 7291,7324, width these is 1000 km/s. No signs be traced any two supernovae. When systematic uncertainties included,...
Context. Some circumstellar-interacting (CSI) supernovae (SNe) are produced by the explosions of massive stars that have lost mass shortly before SN explosion. There is evidence precursors some SNe IIn were luminous blue variable (LBV) stars. For a small number CSI SNe, outbursts been observed Eruptive events named as impostors (SN IMs) and whether they herald forthcoming or not still unclear. The large variety observational properties suggests existence other progenitors, such red...
A Type IIn supernova (SN) is dominated by the interaction of SN ejecta with circumstellar medium (CSM). Some SNe (e.g., 2006jd) have episodes re-brightening ("bumps") in their light curves. We present iPTF13z, a discovered intermediate Palomar Transient Factory (iPTF) and characterised several bumps its curve. analyse this peculiar behaviour trying to infer properties CSM explosion, as well nature progenitor star. obtained multi-band optical photometry for over 1000 days after discovery P48...
In this paper we report the results of first ~four years spectroscopic and photometric monitoring Type IIn supernova SN 2015da (also known as PSN J13522411+3941286, or iPTF16tu). The exploded in nearby spiral galaxy NGC 5337 a relatively highly extinguished environment. transient showed prominent narrow Balmer lines emission at all times slow rise to maximum bands. addition, early observations performed by amateur astronomers give very well-constrained explosion epoch. observables are...
If advanced extraterrestrial civilizations choose to construct vast numbers of Dyson spheres harvest radiation energy, this could affect the characteristics their host galaxies. Potential signatures such astroengineering projects include reduced optical luminosity, boosted infrared luminosity and morphological anomalies. Here, we apply a technique pioneered by Annis (1999) search for Kardashev type III in disk galaxies, based on predicted offset these galaxies from Tully-Fisher relation. By...
We present the results from a high cadence, multi-wavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This dataset complements current literature by adding higher cadence as well extended coverage lightcurve evolution and late-time spectroscopic evolution. Photometric reveals that underwent significant photometric variability followed two luminous events, latter which reached absolute magnitude M$_V\sim$-18.5 mag. is similar to transient SN 2009ip whose...
Context: Research on supernovae (SNe) over the past decade has confirmed that there is a distinct class of events which are much more luminous (by $\sim2$ mag) than canonical core-collapse SNe (CCSNe). These with visual peak magnitudes $\lesssim-21$ called superluminous (SLSNe). Aims: There few intermediate have luminosities between these two classes. Here we study one such object, SN 2012aa. Methods: The optical photometric and spectroscopic follow-up observations event were conducted time...
We present ultra-violet to mid-infrared observations of the long-lasting Type IIn supernova (SN) 2013L obtained by Carnegie Supernova Project II (CSP-II). The spectra SN are dominated H emission features characterized three components attributed different regions. A unique feature this is that blue shifted line profile macroscopic velocity expanding shock wave SN. therefore able trace evolution in dense and partially opaque circumstellar medium (CSM), from $\sim 4800~km~s^{-1}$ at +48 d,...
Several thousand core-collapse supernovae (CCSNe) of different flavors have been discovered so far. However, identifying their progenitors has remained an outstanding open question in astrophysics. Studies SN host galaxies proven to be powerful providing constraints on the progenitor populations. In this paper, we present all CCSNe detected between 2009 and 2017 by Palomar Transient Factory. This sample includes 888 SNe 12 distinct classes out redshift $z\approx1$. We photometric properties...
We study 34 Type Ic supernovae that have broad spectral features (SNe Ic-BL). obtained our photometric data with the Palomar Transient Factory (PTF) and its continuation, intermediate (iPTF). This is first large, homogeneous sample of SNe Ic-BL from an untargeted survey. Furthermore, given high cadence (i)PTF, most these were discovered soon after explosion. present K-corrected $Bgriz$ light curves SNe, through photometry on template-subtracted images. analyzed shape $r$-band curves, finding...
We present the best 265 sampled R-band light curves of spectroscopically identified Type Ia supernovae (SNe) from Palomar Transient Factory (PTF; 2009-2012) survey and intermediate (iPTF; 2013-2017). A model-independent curve template is built our data-set with purpose to investigate average properties diversity in sample. searched for multiple populations using machine learning tools. also utilised long history curves, up 4000 days, exclude any significant pre- or post- supernova flares....
Abstract Active galactic nuclei (AGNs) are extremely powerful cosmic objects, driven by accretion of hot gas upon super-massive black holes. The zoo AGN classes is divided into two major groups, with Type-1 AGNs displaying broad Balmer emission lines and Type-2 narrow ones. For a long time it was believed that viewed through dusty kiloparsec-sized torus, but an emerging body observations suggests more than just the viewing angle matters. Here we report significant differences in supernova...
Context . Pulsars are well studied all over the electromagnetic spectrum, and Crab pulsar may be most object in sky. Nevertheless, a high-quality optical to near-infrared (NIR) spectrum of or any other has not been published date. Aims Obtaining properly flux-calibrated enables us measure spectral index emission, without many caveats from previous studies. This was main aim this project, but addition we could also detect absorption emission features nebula an unprecedentedly wide wavelength...
Hydrogen-poor superluminous supernovae (SLSN-I) are a class of rare and energetic explosions discovered in untargeted transient surveys the past decade. The progenitor stars physical mechanism behind their large radiated energies ($\sim10^{51}$ erg) both debated, with one models primarily requiring rotational energy, while other requires very massive progenitors to either convert kinetic energy into radiation via interaction circumstellar material (CSM), or engender pair-instability...