G. Pignata
A5003056520- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Advancements in Semiconductor Devices and Circuit Design
- Particle accelerators and beam dynamics
- Neutrino Physics Research
- Calibration and Measurement Techniques
- Electrical Fault Detection and Protection
- Non-Destructive Testing Techniques
- Astrophysics and Star Formation Studies
- Radiation Detection and Scintillator Technologies
- Advanced Optical Sensing Technologies
- Particle Detector Development and Performance
- solar cell performance optimization
- Spectroscopy and Laser Applications
- Advanced Research in Systems and Signal Processing
University of Tarapacá
2023-2024
South African Radio Astronomy Observatory
2024
Astronomical Observatory
2024
Cerro Tololo Inter-American Observatory
2024
Universidad Andrés Bello
2014-2023
Millennium Institute of Astrophysics
2014-2023
Osservatorio Astrofisico di Catania
2018-2022
National Institute for Astrophysics
2005-2022
Astronomical Observatory of Rome
2018-2022
Osservatorio Astronomico di Padova
2004-2022
We present constraints on the dark energy equation-of-state parameter, w=P/(rho c^2), using 60 Type Ia supernovae (SNe Ia) from ESSENCE supernova survey. derive a set of nature assuming flat Universe. By including (Omega_M, w) baryon acoustic oscillations, we obtain value for static parameter w=-1.05^{+0.13}_{-0.12} (stat; 1 sigma) +- 0.11 (sys) and Omega_M=0.274^{+0.033}_{-0.020} with best-fit chi^2/DoF 0.96. These results are consistent those reported by SuperNova Legacy Survey in similar...
The first cosmological results from the ESSENCE supernova survey (Wood-Vasey and coworkers) are extended to a wider range of models including dynamical dark energy nonstandard models. We fold in greater number external data sets such as recent Higher-z release high-redshift supernovae (Riess coworkers), well several complementary probes. Model comparison statistics Bayesian Akaike information criteria applied gauge worth These favor that give good fit with fewer parameters. Based on this...
We describe observed properties of the Type Iax class supernovae (SNe Iax), consisting SNe observationally similar to its prototypical member, SN 2002cx. The currently has 25 members, and we present optical photometry and/or spectroscopy for most them. are spectroscopically Ia, but have lower maximum-light velocities (2000 ≲ |v| 8000 km s−1), typically peak magnitudes (−14.2 ⩾ MV, ≳ −18.9 mag), hot photospheres. Relative low luminosities their light-curve shape. There is a correlation...
Context. The ESO public survey VISTA variables in the Vía Láctea (VVV) started 2010. VVV targets 562 sq. deg Galactic bulge and an adjacent plane region is expected to run for about five years.
High-dispersion observations of the Na i D λλ5890, 5896 and K λλ7665, 7699 interstellar lines, diffuse band at 5780 Å in spectra 32 Type Ia supernovae are used as an independent means probing dust extinction. We show that extinction objects where is detected consistent with visual derived from supernova colors. This strongly suggests producing predominantly located medium host galaxies not circumstellar material associated progenitor system. One quarter display anomalously large column...
We report the results of a three-year-long dedicated monitoring campaign restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and spectroscopically optical near-infrared domains. monitored number erupting episodes past few years, increased density our observations during eruptive episodes. In this paper, we present full historical data set from 2009 to 2012 with multi-wavelength dense coverage two high-luminosity events between August...
We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as most luminous supernova yet found. At redshift z = 0.2326, reached an absolute magnitude M_{u,AB} -23.5+/-0.1 and bolometric luminosity L_bol (2.2+/-0.2)x 10^45 ergs s^-1, is more than twice any previously known supernova. It has several major features characteristic hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources progenitors are currently poorly understood. In contrast to SLSNe-I that reside in...
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...
The photometric and spectroscopic properties of 26 well observed Type Ia Supernovae (SNeIa) were analyzed with the aim to explore SNIa diversity. sample includes (Branch-)normal SNe as extreme events like 1991T 1991bg, while truly peculiar SNIa, SN2000cx SN2002cx are not included in our . A statistical treatment reveals existence three different groups. first group (FAINT) consists faint SNeIa similar SN1991bg, low expansion velocities rapid evolution SiII velocity. second ``normal'' SNeIa,...
We describe the implementation and optimization of ESSENCE supernova survey, which we have undertaken to measure equation state parameter dark energy. present a method for optimizing survey exposure times cadence maximize our sensitivity energy w=P/rho c^2 given fixed amount telescope time. For on CTIO 4m telescope, measuring luminosity distances redshifts supernovae at modest (z~0.5 +- 0.2) is optimal determining w. data analysis pipeline based using reliable robust image subtraction find...
Aims.We present a study of the optical and near-infrared (NIR) properties Type Ia Supernova (SN Ia) 2003du.
We present new data for five under-luminous type II-plateau supernovae (SNe IIP), namely SN 1999gn, 2002gd, 2003Z, 2004eg and 2006ov. This sample of low-luminosity SNe IIP (LL IIP) is analyzed together with similar objects studied in the past. All them show a flat light curve plateau lasting about 100 days, an under luminous late-time exponential tail, intrinsic colours that are unusually red, spectra showing prominent narrow P-Cygni lines. A velocity ejected material below 10^3 km/s...
This is the first release of optical spectroscopic data low-redshift Type Ia supernovae (SNe Ia) by Carnegie Supernova Project including 604 previously unpublished spectra 93 SNe Ia. The observations cover a range phases from 12 days before to over 150 after time B-band maximum light. With addition 228 near-maximum literature, we study diversity among in quantitative manner. For that purpose, parameters are employed such as expansion velocities spectral line blueshifts and pseudo-equivalent...
We present ultraviolet, optical and near-infrared observations of the interacting transient SN 2009ip, covering period from start outburst in 2012 October until end observing season. The reached a peak magnitude MV = −17.7 mag, with total integrated luminosity 1.9 × 1049 erg over August–December. light curve fades rapidly, dropping by 4.5 mag V-band 100 d. spectra are dominated narrow emission lines broad electron scattering wings, signalling dense circumstellar environment, together...
SN 2014J in M82 is the closest detected Type Ia supernova (SN Ia) at least 28 years and perhaps 410 years. Despite its small distance of 3.3 Mpc, surprisingly faint, peaking V = 10.6 mag, assuming a typical luminosity, we infer an observed visual extinction A_V 2.0 +/- 0.1 mag. But this picture, with R_V 1.6 0.2, too simple to account for all observations. We combine 10 epochs (spanning month) HST/STIS ultraviolet through near-infrared spectroscopy HST/WFC3, KAIT, FanCam photometry from...
We investigate the early-time light curves of a large sample 223 Type II supernovae (SNe II) from Sloan Digital Sky Survey and Supernova Legacy Survey. Having cadence few days sufficient non-detections prior to explosion, we constrain rise-times, i.e. durations estimated first maximum light, as function effective wavelength. At rest-frame g′ band (λeff = 4722 Å), find distribution fast rise-times with median (7.5 ± 0.3) d. Comparing these analytical shock models Rabinak & Waxman Nakar Sari,...
We present observations and analysis of 18 stripped-envelope supernovae observed during 2013–2018. This sample consists five H/He-rich SNe, six H-poor/He-rich three narrow lined SNe Ic, four broad Ic. The peak luminosity characteristic time-scales the bolometric light curves are calculated, modelled to derive 56Ni ejecta masses (MNi Mej). Additionally, temperature evolution spectral line velocity each SN examined. Analysis [O i] in nebular phase eight suggests their progenitors had initial...
We present UV through NIR broad-band photometry, and optical spectroscopy of Type Iax supernova 2012Z. The data set consists both early late-time observations, including the first late phase spectrum obtained for a spectroscopically classified SN Iax. Simple model calculations its bolometric light curve suggest 2012Z produced ~0.3 M_sun (56)Ni, ejected about Chandrasekhar mass material, had an explosion energy ~10^51 erg, making it one brightest most energetic yet observed. is found to...
We present extensive datasets for a class of intermediate-luminosity optical transients known as luminous red novae. They show double-peaked light curves, with an initial rapid luminosity rise to blue peak (at −13 −15 mag), which is followed by longer-duration that sometimes attenuated, resembling plateau. The progenitors three them (NGC 4490−2011OT1, M 101−2015OT1, and SNhunt248), likely relatively massive yellow stars, were also observed in pre-eruptive stage when their was slowly...
ABSTRACT We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by All-Sky Automated Survey for Supernovae (ASAS-SN) at distance d ≃ 98 Mpc. observed ASASSN-19dj from −21 to 392 relative peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From ASAS-SN g-band data, we determine that TDE began brighten on 2019 February 6.8 first 16 rise was consistent with flux ∝t2...
Abstract Fast X-ray Transients (FXTs) are extragalactic bursts of soft X-rays first identified ≳10 yr ago. Since then, nearly 40 events have been discovered, although almost all these recovered from archival Chandra and XMM-Newton data. To date, optical sky surveys follow-up searches not revealed any multiwavelength counterparts. The Einstein Probe, launched in 2024 January, has started surveying the regime (0.5–4 keV) will rapidly increase sample FXTs discovered real time. Here we report...
Evidence of high-velocity features (HVFs) such as those seen in the near-maximum spectra some Type Ia supernovae (SNe Ia; e.g., SN 2000cx) has been searched for available observed earlier than 1 week before B maximum. Recent observational efforts have doubled number SNe with very early spectra. Remarkably, all data (seven our Research Training Network sample and 10 from other programs) show signs features, to a greater or lesser degree, Ca II IR also Si λ6355 line. HVFs may be interpreted...