G. Cannizzaro
A5008387446- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Nuclear Physics and Applications
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Advanced Research in Systems and Signal Processing
- Scientific Research and Discoveries
- Optical Systems and Laser Technology
- Analytical Chemistry and Sensors
- Earthquake Detection and Analysis
- Methane Hydrates and Related Phenomena
- Reservoir Engineering and Simulation Methods
- Photovoltaic System Optimization Techniques
- Advanced X-ray and CT Imaging
- Geological and Geophysical Studies
Radboud University Nijmegen
2018-2022
SRON Netherlands Institute for Space Research
2017-2022
Max Planck Society
2018
Sapienza University of Rome
2016
We report on the discovery of a new member magnetar class, SGR J1935+2154, and its timing spectral properties measured by an extensive observational campaign carried out between 2014 July 2015 March with Chandra XMM–Newton (11 pointings). discovered spin period J1935+2154 through detection coherent pulsations at about 3.24 s. The is slowing down rate |$\dot{P} = 1.43(1)\times 10^{-11}$| s s−1 decreasing trend due to negative |$\ddot{P}$| −3.5(7) × 10−19 s−2. This implies surface dipolar...
We present light curves and spectra of the tidal disruption event (TDE) ASASSN-18pg / AT 2018dyb spanning a period one year. The shows plethora strong emission lines, including Balmer series, He II, I metal lines O III $\lambda$3760 N $\lambda\lambda$ 4100, 4640 (blended with II). latter are consistent originating from Bowen fluorescence mechanism. By analyzing literature past events, we conclude that these common in TDEs. spectral diversity optical TDEs is thus larger than previously...
At 66 Mpc, AT2019qiz is the closest optical tidal disruption event (TDE) to date, with a luminosity intermediate between bulk of population and iPTF16fnl. Its proximity allowed very early detection triggering multiwavelength spectroscopic follow-up well before maximum light. The velocity dispersion host galaxy fits TDE light curve indicate black hole mass $\approx 10^6$ M$_\odot$, disrupting star 1$ M$_\odot$. Comprehensive UV, X-ray data shows that emission dominated by an outflow,...
Spectroscopically, TDEs are characterized by broad ( 10$^{4}$ km/s) emission lines and show large diversity as well different line profiles. After carefully consistently performing a series of data reduction tasks including host galaxy light subtraction, we present here the first detailed, spectroscopic population study 16 optical/UV TDEs. We report time lag between peaks optical light-curves peak luminosity H$\alpha$ spanning 7 - 45 days. If interpreted light-echoes, these lags correspond...
ABSTRACT We present the results of a large multiwavelength follow-up campaign tidal disruption event (TDE) AT 2019dsg, focusing on low to high resolution optical spectroscopy, X-ray, and radio observations. The galaxy hosts super massive black hole mass $\rm (5.4\pm 3.2)\times 10^6\, M_\odot$ careful analysis finds no evidence for presence an active galactic nucleus, instead TDE host shows narrow emission lines that likely arise from star formation activity. transient is luminous in X-rays,...
Aims. The modelling of spectroscopic observations tidal disruption events (TDEs) to date suggests that the newly formed accretion disks are mostly quasi-circular. In this work we study transient event AT 2020zso, hosted by an active galactic nucleus (AGN; as inferred from narrow emission line diagnostics), with aim characterising properties its flow. Methods. We classify 2020zso a TDE based on blackbody evolution UV/optical photometric and spectral content evolution. identify transient,...
Context. The absolute magnitudes of luminous red novae (LRNe) are intermediate between those and supernovae (SNe), show a relatively homogeneous spectro-photometric evolution. Although they were thought to derive from core instabilities in single stars, there is growing support for the idea that triggered by binary interaction possibly ends with merging two stars. Aims. AT 2018hso new transient showing transitional properties LRNe class intermediate-luminosity transients (ILRTs) similar SN...
We present the discovery with Keck of extremely infrared (IR) luminous transient AT 2017gbl, coincident Northern nucleus galaxy (LIRG) IRAS 23436+5257. Our extensive multi-wavelength follow-up spans ~900 days, including photometry and spectroscopy in optical IR, (very long baseline interferometry) radio X-ray observations. Radiative transfer modelling host spectral energy distribution long-term pre-outburst variability mid-IR indicate presence a hitherto undetected dust obscured active...
We present the results from a dense multi-wavelength (optical/UV, near-infrared (IR), and X-ray) follow-up campaign of nuclear transient AT2017gge, covering total 1698 days transient's discovery. The bolometric lightcurve, black body temperature radius, broad H He I $\lambda$5876 emission lines their evolution with time, are all consistent tidal disruption event (TDE) nature. A soft X-ray flare is detected delay $\sim$200 respect to optical/UV peak it rapidly followed by emergence II...
We present the results of our photometric and spectroscopic follow-up intermediate-luminosity optical transient AT 2017jfs. At peak, object reaches an absolute magnitude Mg=-15.46+-0.15 mag a bolometric luminosity 5.5x10^41 erg/s. Its light curve has double-peak shape typical Luminous Red Novae (LRNe), with narrow first peak bright in blue bands, while second is longer lasting more luminous red near-infrared (NIR) bands. During spectrum shows continuum emission lines H Fe II. becomes cooler,...
We present the results from Nordic Optical Telescope and X-shooter follow-up campaigns of tidal disruption event (TDE) iPTF16fnl, covering first $\sim$100 days after transient discovery. followed source photometrically until TDE emission was no longer detected above host galaxy light. The bolometric luminosity evolution is consistent with an exponential decay e-folding constant t$_{0}$=17.6$\pm$0.2 days. early time spectra are dominated by broad He II $\lambda$4686, H$\beta$, H$\alpha$ N III...
We present the spectroscopic and photometric study of five intermediate-luminosity red transients (ILRTs), namely AT 2010dn, 2012jc, 2013la, 2013lb, 2018aes. They share common observational properties belong to a family objects similar prototypical ILRT SN~2008S. These events have rise time that is less than 15 days absolute peak magnitudes between $-11.5$ $-14.5$ mag. Their pseudo-bolometric light curves in range $0.5$ - $9.0 \times10^{40}~\mathrm{erg~s}^{-1}$ their total radiated energies...
We present the results of a multi-wavelength follow up campaign for luminous nuclear transient Gaia16aax, which was first identified in January 2016. The is spatially consistent with nucleus an active galaxy at z=0.25, hosting black hole mass $\rm \sim6\times10^8M_\odot$. brightened by more than 1 magnitude Gaia G-band over timescale less one year, before fading back to its pre-outburst state following three years. optical spectra source show broad Balmer lines similar ones spectrum. During...
Over the past few years, $\sim$30 extragalactic fast X-ray transients (FXRTs) have been discovered, mainly in Chandra and XMM-Newton data. Their nature remains unclear, with proposed origins including a double neutron star merger, tidal disruption event involving an intermediate-mass black hole white dwarf, or supernova shock breakout. A decisive differentiation between these three promising mechanisms for their origin requires understanding of FXRT energetics, environments, and/or host...
ABSTRACT We present a dynamical study of the intermediate polar and dwarf nova cataclysmic variable GK Persei (Nova 1901) based on multisite optical spectroscopy R-band photometry campaign. The radial velocity curve evolved donor star has semi-amplitude $K_2=126.4 \pm 0.9 \, \mathrm{km}\, \mathrm{s}^{-1}$ an orbital period $P=1.996872 0.000009 \mathrm{d}$. refine projected rotational to $v_\mathrm{rot} \sin i = 52 2 that, together with K2, provides white mass ratio q M2/M1 0.38 ± 0.03. also...
CSS100217 was a nuclear, rapid and luminous flare in Narrow-Line Seyfert 1 galaxy, whose initial interpretation as supernova is now debated between variability of the active galactic nucleus (AGN) or tidal disruption event (TDE). In this paper, we present discuss new evidence favour TDE extreme flaring episode scenario. After decay flare, galaxy entered long-term low luminosity state, 0.4 magnitudes lower than pre-outburst emission V band. We attribute to creation cavity accretion disk after...
We present results of our analysis spectra the host galaxies candidate Tidal Disruption Events (TDEs) XMMSL1 J111527.3+180638 and PTF09axc to determine nature these transients. subtract starlight component from galaxy origin nuclear emission lines. Using a Baldwin-Phillips-Terlevich (BPT) diagram we conclude that is classified as Seyfert galaxy, suggesting this transient likely be caused by (extreme) variability in active galactic nucleus. find falls 'star-forming' region BPT-diagram,...
We present results of spectroscopic monitoring observations the Ultra-Luminous Infra Red Galaxy F01004-2237. This galaxy was observed to undergo changes in its optical spectrum, detected by comparing a spectrum from 2015 with one 2000. These were coincident photometric brightening. The main are enhanced He II $\lambda$4686 emission and appearance I $\lambda$3898,$\lambda$5876 lines. favoured interpretation these that tidal disruption event (TDE) happening 2010. However, subsequent work...