N. Blagorodnova
A5014535628- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Optical Systems and Laser Technology
- Scientific Research and Discoveries
- Calibration and Measurement Techniques
- Power Systems and Technologies
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Integrated Circuits and Semiconductor Failure Analysis
- Earth Systems and Cosmic Evolution
- Advanced Optical Sensing Technologies
- Methane Hydrates and Related Phenomena
- Neutrino Physics Research
- Atmospheric and Environmental Gas Dynamics
- Geomagnetism and Paleomagnetism Studies
- Semiconductor Lasers and Optical Devices
Radboud University Nijmegen
2019-2023
Universitat de Barcelona
2016-2023
California Institute of Technology
2016-2020
University of Cambridge
2012-2017
Institute of Astronomy
2017
Swinburne University of Technology
2017
The Zwicky Transient Facility (ZTF) is a new optical time-domain survey that uses the Palomar 48 inch Schmidt telescope. A custom-built wide-field camera provides 47 deg2 field of view and 8 s readout time, yielding more than an order magnitude improvement in speed relative to its predecessor survey, Factory. We describe design implementation observing system. ZTF data system at Infrared Processing Analysis Center near-real-time reduction identify moving varying objects. outline analysis...
The Zwicky Transient Facility (ZTF), a public-private enterprise, is new time domain survey employing dedicated camera on the Palomar 48-inch Schmidt telescope with 47 deg$^2$ field of view and 8 second readout time. It well positioned in development astronomy, offering operations at 10% scale style Large Synoptic Survey Telescope (LSST) single 1-m class telescope. public surveys will cover observable northern sky every three nights g r filters visible Galactic plane night r. Alerts...
Merging neutron stars offer an exquisite laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of electromagnetic counterpart EM170817 to gravitational waves (GW170817) detected from merging stars. By synthesizing a panchromatic dataset, we demonstrate that are long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma-rays seen dissimilar classical short gamma-ray bursts with...
The Zwicky Transient Facility (ZTF) is a new robotic time-domain survey currently in progress using the Palomar 48-inch Schmidt Telescope. ZTF uses 47 square degree field with 600 megapixel camera to scan entire northern visible sky at rates of ~3760 degrees/hour median depths g ~ 20.8 and r 20.6 mag (AB, 5sigma 30 sec). We describe Science Data System that housed IPAC, Caltech. This comprises data-processing pipelines, alert production system, data archive, user interfaces for accessing...
The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. We describe the data reduction strategy and products which are publicly available through ESO archive Data Release 1 (SSDR1). PESSTO uses New Technology Telescope with EFOSC2 SOFI to provide optical NIR spectroscopy imaging. target supernovae transients brighter than 20.5mag for classification. Science targets then selected follow-up based on...
Wide-field optical surveys have begun to uncover large samples of fast (trise ≲ 5 d), luminous (Mpeak < −18), blue transients. While commonly attributed the breakout a supernova shock into dense wind, great distances transients this class found so far hampered detailed investigation their properties. We present photometry and spectroscopy from comprehensive worldwide campaign observe AT 2018cow (ATLAS 18qqn), first fast-luminous transient be in real time at low redshift. Our spectra (<2 days...
Abstract Narrow transient emission lines (flash-ionization features) in early supernova (SN) spectra trace the presence of circumstellar material (CSM) around massive progenitor stars core-collapse SNe. The disappear within days after SN explosion, suggesting that this is spatially confined, and originates from enhanced mass loss shortly (months to a few years) prior explosion. We performed systematic survey H-rich (Type II) SNe discovered less than 2 explosion during first phase Zwicky...
We report the discovery by intermediate Palomar Transient Factory (iPTF) of a candidate tidal disruption event (TDE) iPTF16axa at $z=0.108$, and present its broadband photometric spectroscopic evolution from 3 months follow-up observations with ground-based telescopes Swift. The light curve is well fitted $t^{-5/3}$ decay, we constrain rise-time to peak be $<$49 rest-frame days after disruption, which roughly consistent fallback timescale expected for $\sim 5\times$10$^{6}$ $M_\odot$ black...
The mass of the central black hole in a galaxy that hosted tidal disruption event (TDE) is an important parameter understanding its energetics and dynamics.We present first homogeneously measured masses complete sample 12 optically/UV-selected TDE host galaxies (down to g ≤ 22 mag z = 0.37) Northern sky.The estimates are based on velocity dispersion measurements, performed late time optical spectroscopic observations.We find range 3 × 10 5 M BH 2 7 .The dominated by low-mass holes (∼ 6 ), as...
Current time domain facilities are discovering hundreds of new galactic and extra-galactic transients every week. Classifying the ever-increasing number is challenging, yet crucial to further our understanding their nature, discover classes, or ensuring sample purity, for instance, Supernova Ia cosmology. The Zwicky Transient Facility one example such a survey. In addition, it has dedicated very-low resolution spectrograph, SEDMachine, operating on Palomar 60-inch telescope. This...
We present a radio-quiet quasar at z=0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected in nucleus of galaxy with an archival SDSS spectrum weak narrow-line emission characteristic low-ionization line region (LINER). Our follow-up spectra show dramatic appearance broad Balmer lines and power-law continuum luminous (L_bol~10^45 erg/s) type 1 12 years later. photometric monitoring PTF from 2009-2012, serendipitous X-ray...
A key tracer of the elusive progenitor systems Type Ia supernovae (SNe Ia) is detection narrow blueshifted time-varying Na i D absorption lines, interpreted as evidence circumstellar material surrounding system. The origin this controversial, but simplest explanation that it results from previous mass-loss in a system containing white dwarf and non-degenerate companion star. We present new single-epoch intermediate-resolution spectra 17 low-redshift SNe taken with XShooter on European...
The Zwicky Transient Facility is a large optical survey in multiple filters producing hundreds of thousands transient alerts per night. We describe here various machine learning (ML) implementations and plans to make the maximal use data set by taking advantage temporal nature data, further combining it with other sets. start initial steps separating bogus candidates from real ones, stars galaxies, go on classification objects into classes. Besides usual methods (e.g., based features...
We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because light from stellar explosion magnified more than 50 times by curvature space around matter in an intervening galaxy. used high-spatial-resolution observations to resolve four images approximately 0.3 arc seconds center foreground The probe physical scale ~1 kiloparsec, smaller is typical other studies extragalactic...
Early-time observations of Type Ia supernovae (SNe Ia) are essential to constrain their progenitor properties. In this paper, we present high-quality light curves 127 SNe discovered by the Zwicky Transient Facility (ZTF) in 2018. We describe our method perform forced point spread function (PSF) photometry, which can be applied other types extragalactic transients. With a planned cadence six per night ($3g+3r$), all detected both $g$ and $r$ band more than 10\,d (in rest frame) prior epoch...
We present multi-wavelength observations of the tidal disruption event (TDE) iPTF15af, discovered by intermediate Palomar Transient Factory (iPTF) survey at redshift $z=0.07897$. The optical and ultraviolet (UV) light curves transient show a slow decay over five months, in agreement with previous optically TDEs. It also has comparable black-body peak luminosity $L_{\rm{peak}} \approx 1.5 \times 10^{44}$ erg/s. inferred temperature from UV data shows value (3$-$5) $\times 10^4$ K. is not...
Context. Since July 2014, the Gaia mission has been engaged in a high-spatial-resolution, time-resolved, precise, accurate astrometric, and photometric survey of entire sky. Aims. We present Science Alerts project, which operation since 1 June 2016. describe system developed to enable discovery publication transient events as seen by . Methods. outline data handling, timings, performances, we detection algorithms filtering procedures needed manage high false alarm rate. identify two classes...
While tidal disruption events (TDEs) have long been heralded as laboratories for the study of quiescent black holes, small number known TDEs and uncertainties in their emission mechanism hindered progress towards this promise. Here present 17 new that detected recently by Zwicky Transient Facility along with Swift UV X-ray follow-up observations. Our homogeneous analysis optical/UV light curves, including 22 previously from literature, reveals a clean separation curve properties...
The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay $^{56}$Ni to $^{56}$Co at early times, and $^{56}$Fe from ~60 days after explosion. We examine evolution [Co III] 5892 A emission complex during nebular phase for SNe with multiple spectra show that line flux follows square mass as a function time. This result indicates both efficient local energy deposition positrons produced in decay, long-term stability ionization state nebula. compile 77 25 SN literature...
We present ground-based and \textit{Swift} observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6 Mpc. The lightcurve object peaked absolute $M_g=-17.2$ mag. maximum bolometric luminosity (from optical UV) was $L_p~\simeq~(1.0\,\pm\,0.15) \times 10^{43}$ erg/s, an order magnitude fainter than any other TDE so far. in first 60 days is consistent with exponential decay, $L \propto e^{-(t-t_0)/\tau}$, where...
Current time domain facilities are finding several hundreds of transient astronomical events a year. The discovery rate is expected to increase in the future as soon new surveys such Zwicky Transient Facility (ZTF) and Large Synoptic Sky Survey (LSST) come online. Presently, at which transients classified approximately one order or magnitude lower than rate, leading an increasing "follow-up drought". Existing telescopes with moderate aperture can help address this deficit when equipped...
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...
Abstract We report the first maximum-light far-ultraviolet (FUV) to near-infrared (NIR) spectra (1000 Å − 1.62 μ m, rest) of a hydrogen-poor superluminous supernova, Gaia16apd. At z = 0.1018, it is second closest and UV brightest SLSN-I, with 17.4 mag in Swift UVW2 band at −11 days pre-maximum. The coordinated observations HST , Palomar, Keck were taken −2 +25 days. Assuming an exponential (or t 2 ) form, we derived rise time 33 peak bolometric luminosity 3 × 10 44 erg s −1 . maximum,...
Abstract The detonation of a helium shell on white dwarf (WD) has been proposed as possible explosion triggering mechanism for SNe Ia. Here, we report ZTF 18aaqeasu (SN 2018byg/ATLAS 18pqq), peculiar Type I supernova, consistent with being helium-shell double-detonation. With rise time ≈18 days from explosion, the transient reached peak absolute magnitude M R ≈ −18.2 mag, exhibiting light curve akin to sub-luminous SN 1991bg-like Ia, albeit an unusually steep increase in brightness within...
Luminous Red Novae (LRNe) are astrophysical transients associated with the partial ejection of a binary system's common envelope (CE) shortly before its merger. Here we present results our photometric and spectroscopic follow-up campaign AT2018bwo (DLT18x), LRN discovered in NGC45, investigate progenitor system using stellar-evolution models. The transient reached peak magnitude $M_r=-10.97\pm0.11$ maintained this brightness during optical plateau $t_p = 41\pm5$days. During phase, it showed...