Igor Andreoni
A5069620740- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Optical Systems and Laser Technology
- Geophysics and Gravity Measurements
- Particle accelerators and beam dynamics
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Radio Astronomy Observations and Technology
- Superconducting Materials and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Galaxies: Formation, Evolution, Phenomena
- Smart Grid Security and Resilience
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Neutrino Physics Research
- Calibration and Measurement Techniques
- Particle physics theoretical and experimental studies
Joint Space Science Institute
2022-2025
University of Maryland, College Park
2022-2025
Goddard Space Flight Center
2022-2025
Deleted Institution
2022-2025
ARC Centre of Excellence for Gravitational Wave Discovery
2017-2025
University of North Carolina at Chapel Hill
2025
California Institute of Technology
2018-2023
Swinburne University of Technology
2016-2019
Australian Astronomical Observatory
2017-2019
ARC Centre of Excellence for All-sky Astrophysics
2017
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in new era multi-messenger astronomy. In this paper, we present event GW170817 and its SSS17a/DLT17ck (IAU label AT2017gfo) 14 Australian telescopes partner observatories as part Australian-based Australian-led research programs. We report early- late-time multi-wavelength observations, including optical imaging spectroscopy,...
We report the discovery of four Fast Radio Bursts (FRBs) in ongoing SUrvey for Pulsars and Extragalactic at Parkes Telescope: FRBs 150610, 151206, 151230 160102. Our real-time discoveries have enabled us to conduct extensive, rapid multimessenger follow-up 12 major facilities sensitive radio, optical, X-ray, gamma-ray photons neutrinos on time-scales ranging from an hour a few months post-burst. No counterparts were found we provide upper limits afterglow luminosities. None seen repeat....
Tidal disruption events (TDEs) offer a unique way to study dormant black holes. While the number of observed TDEs has grown thanks emergence wide-field surveys in past few decades, questions regarding nature optical, UV, and X-ray emission remain. We present uniformly selected sample 30 spectroscopically classified from Zwicky Transient Facility Phase I survey operations with follow-up \textit{Swift} UV observations. Through our investigation into correlations between light curve properties,...
Long-duration gamma-ray bursts (GRBs) are powerful cosmic explosions, signaling the death of massive stars. Among them, GRB 221009A is by far brightest burst ever observed. Because its enormous energy (Eiso ≈ 1055 erg) and proximity (z 0.15), an exceptionally rare event that pushes limits our theories. We present multiwavelength observations covering first 3 months afterglow evolution. The x-ray brightness decays as a power law with slope ≈t-1.66, which not consistent standard predictions...
Abstract We present a search for extragalactic fast blue optical transients (FBOTs) during Phase I of the Zwicky Transient Facility (ZTF). identify 38 candidates with durations above half-maximum light 1 day < t 1/2 12 days, which 28 have ( g − r ≲ −0.2 mag) colors at peak light. Of (28 FBOTs), 19 (13) can be spectroscopically classified as core-collapse supernovae (SNe): 11 (8) H- or He-rich (Type II/IIb/Ib) SNe, 6 (4) interacting IIn/Ibn) and 2 (1) H&He-poor Ic/Ic-BL) SNe. Two FBOTs...
Abstract Classical gamma-ray bursts (GRBs) have two distinct emission episodes: prompt from ultrarelativistic ejecta and afterglow shocked circumstellar material. While both components are extremely luminous in known GRBs, a variety of scenarios predict the existence with little or no associated high-energy emission. We present AT 2019pim, first spectroscopically confirmed observed to be identified. Serendipitously discovered during follow-up observations gravitational-wave trigger located...
We present the spectroscopic evolution of AT 2017gfo, optical counterpart first binary neutron star (BNS) merger detected by LIGO and Virgo, GW170817. While models have long predicted that a BNS could produce kilonova (KN), we not been able to definitively test these until now. From one day four days after merger, took five spectra 2017gfo before it faded away, which was possible because at distance only 39.5 Mpc in galaxy NGC 4993. The evolve from blue ($\sim6400$K) red ($\sim3500$K) over...
Abstract The Zwicky Transient Facility (ZTF) is performing a three-day cadence survey of the visible northern sky (∼3 π ) with newly found transient candidates announced via public alerts. ZTF Bright Survey (BTS) large spectroscopic campaign to complement photometric survey. BTS endeavors spectroscopically classify all extragalactic transients m peak ≤ 18.5 mag in either g or r filters, and publicly announce said classifications. discoveries are predominantly supernovae (SNe), making this...
On 2019 August 14, the Advanced LIGO and Virgo interferometers detected high-significance gravitational wave (GW) signal S190814bv. The GW data indicated that event resulted from a neutron star--black hole (NSBH) merger, or potentially low-mass binary black merger. Due to low false alarm rate precise localization (23 deg$^2$ at 90\%), S190814bv presented community with best opportunity yet directly observe an optical/near-infrared counterpart NSBH To search for potential counterparts, GROWTH...
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...
Detecting gravitationally lensed supernovae is among the biggest challenges in astronomy. It involves a combination of two very rare phenomena: catching transient signal stellar explosion distant galaxy and observing it through nearly perfectly aligned foreground that deflects light towards observer. Here we describe how high-cadence optical observations with Zwicky Transient Facility, its unparalleled large field view, led to detection multiply imaged type Ia supernova, SN Zwicky, also...
Abstract During the Zwicky Transient Facility (ZTF) Phase I operations, 78 hydrogen-poor superluminous supernovae (SLSNe-I) were discovered in less than 3 yr, constituting largest sample from a single survey. This paper (Paper I) presents data, including optical/UV light curves and classification spectra, while Paper II this series will focus on detailed analysis of modeling. Our photometry is primarily taken by ZTF g , r i bands, with additional data other ground-based facilities Swift. The...
Abstract One of the open questions following discovery GW170817 is whether neutron star (NS) mergers are only astrophysical sites capable producing r -process elements. Simulations have shown that 0.01–0.1 M ⊙ material could be generated in outflows originating from accretion disk surrounding rapidly rotating black hole forms as a remnant to both NS and collapsing massive stars associated with long-duration gamma-ray bursts (collapsars). The hallmark signature nucleosynthesis binary merger...
Magnetars are slowly rotating neutron stars that possess the strongest magnetic fields known in cosmos (10 14 − 10 15 G). They display a range of transient high-energy electromagnetic activity. The brightest and most energetic these events gamma-ray bursts (GRBs) as magnetar giant flares (MGFs), with isotropic energies E iso ≈ 44 46 erg. Only seven MGF detections have been made to date: three unambiguous occurred our Galaxy Magellanic Clouds, other four candidates associated nearby...
Abstract We present the results of our multiwavelength (X-ray to radio) follow-up campaign Einstein Probe transient EP240408a. The initial 10 s trigger displayed bright soft X-ray (0.5–4 keV) radiation with peak luminosity L X ≳ 49 (10 50 ) erg −1 for an assumed redshift z 0.5 (2.0). Neil Gehrels Swift Observatory and Neutron star Interior Composition ExploreR discovered a fading counterpart lasting ∼5 days (observer frame), which showed long-lived (∼4 days) plateau-like emission ( t −0.5...
Abstract Fast X-ray transients (FXTs) are a new observational class of phenomena with no clear physical origin. This is at least partially consequence limited multiwavelength follow-up this in real time. Here we present deep optical ( g - and i -band) photometry Keck, prompt radio observations the Very Large Array FXT 210423 obtained δ t ≈ 14–36 days since trigger. We use these multiband observations, combined publicly available data sets, to constrain presence properties on-axis off-axis...
We report on the discovery of a new fast radio burst, FRB 150215, with Parkes telescope 2015 February 15. The burst was detected in real time dispersion measure (DM) 1105.6$\pm$0.8 pc cm^{-3}, pulse duration 2.8^{+1.2}_{-0.5} ms, and measured peak flux density assuming at beam center 0.7^{+0.2}_{-0.1} Jy. originated Galactic longitude latitude 24.66^{\circ}, 5.28^{\circ}, 25 degrees away from Center. found to be 43$\pm$5% linearly polarized rotation (RM) range -9 < RM 12 rad m^{-2} (95%...