Anastasios Tzanidakis
A5059864975- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Neutrino Physics Research
- Optical Systems and Laser Technology
- Galaxies: Formation, Evolution, Phenomena
- Advanced Optical Sensing Technologies
- Nuclear Physics and Applications
- Atmospheric and Environmental Gas Dynamics
- Semiconductor Lasers and Optical Devices
- Solar and Space Plasma Dynamics
- Geological and Geophysical Studies
- Magneto-Optical Properties and Applications
- Planetary Science and Exploration
- Integrated Circuits and Semiconductor Failure Analysis
- Geomagnetism and Paleomagnetism Studies
- solar cell performance optimization
- Atomic and Subatomic Physics Research
- Viral gastroenteritis research and epidemiology
California Institute of Technology
2020-2024
University of Washington
2023-2024
City University of Seattle
2023
Columbia University
2017-2018
Abstract We present a public catalog of transients from the Zwicky Transient Facility (ZTF) Bright Survey, magnitude-limited ( m < 19 mag in either g or r filter) survey for extragalactic ZTF stream. introduce cuts on coverage, sky visibility around peak light, and other properties unconnected to nature transient, show that resulting statistical sample is spectroscopically 97% complete at <18 mag, 93% <18.5 75% <19 mag. summarize fundamental this population, identifying distinct...
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...
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...
Abstract We present observations of SN 2021csp, the second example a newly identified type supernova (SN) hallmarked by strong, narrow, P Cygni carbon features at early times (Type Icn). The appears as fast and luminous blue transient times, reaching peak absolute magnitude −20 within 3 days due to strong interaction between ejecta ( v ≈ 30,000 km s −1 ) massive, dense, fast-moving C/O wind shed WC-like progenitor months before explosion. narrow-line disappear from spectrum 10–20 after...
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...
Abstract Luminous red novae (LRNe) are transients characterized by low luminosities and expansion velocities, they associated with mergers or common-envelope ejections in stellar binaries. Intermediate-luminosity (ILRTs) an observationally similar class unknown origins, but generally believed to be either electron-capture supernovae super-asymptotic giant branch stars outbursts dusty luminous blue variables (LBVs). In this paper, we present a systematic sample of eight LRNe ILRTs detected as...
Abstract We present observations of three core-collapse supernovae (CCSNe) in elliptical hosts, detected by the Zwicky Transient Facility Bright Survey (BTS). SN 2019ape is a Ic that exploded main body typical galaxy. Its properties are consistent with an explosion regular progenitor. A secondary g -band light-curve peak could indicate interaction ejecta circumstellar material (CSM). An H α -emitting source at site suggests residual local star formation origin. 2018fsh and 2020uik SNe II...
Eruptive mass loss of massive stars prior to supernova (SN) explosion is key understanding their evolution and end fate. An observational signature pre-SN the detection an early, short-lived peak radioactive-powered in lightcurve SN. This usually attributed SN shock passing through extended envelope or circumstellar medium (CSM). Such early common for double-peaked Type IIb SNe with Hydrogen but uncommon normal Ibc very compact progenitors. In this paper, we systematically study a sample 14...
(Abridged) Using the Zwicky Transient Facility alert stream, we are conducting a large campaign to spectroscopically classify all transients occurring in galaxies Census of Local Universe (CLU) catalog. The aim experiment is construct complete, volume-limited sample coincident within 100" CLU out 200 Mpc, and depth 20 mag. We describe survey design spectroscopic completeness from first 16 months operations. present results systematic search for Calcium rich gap 22 low luminosity (peak...
Abstract The dividing line between gamma-ray bursts (GRBs) and ordinary stripped-envelope core-collapse supernovae (SNe) is yet to be fully understood. Observationally mapping the variety of ejecta outcomes (ultrarelativistic, mildly relativistic, or nonrelativistic) in SNe Type Ic with broad lines (Ic-BL) can provide a key test stellar explosion models. However, this requires large samples rare SN Ic-BL events follow-up observations radio, where fast probed largely free geometry viewing...
Abstract We present the luminosity function and volumetric rate of a sample Type IIP supernovae (SNe) from Zwicky Transient Facility Census Local Universe survey (CLU). This is largest SNe systematic volume-limited to-date. The final includes 330 36 low-luminosity II (LLIIP) with M r ,peak > −16 mag, which triples literature LLIIP SNe. fraction <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>9</mml:mn>...
Abstract The Monoceros Ring (also known as the Galactic Anticenter Stellar Structure) and A13 are stellar overdensities at estimated heliocentric distances of d ∼ 11 kpc 15 observed low latitudes toward anticenter our Galaxy. While these were initially thought to be remnants a tidally disrupted satellite galaxy, an alternate scenario is that they composed stars from Milky Way (MW) disk kicked out their current location due interactions between galaxy disk. To test this scenario, we study...
We present a systematic search for optical counterparts to 13 gravitational wave (GW) triggers involving at least one neutron star during LIGO/Virgo's third observing run. searched binary (BNS) and black hole (NSBH) merger localizations with the Zwicky Transient Facility (ZTF) undertook follow-up Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration. The GW had median localization 4480 deg^2, distance 267 Mpc false alarm rates ranging from 1.5 1e-25 per yr. ZTF...
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 d < t1/2 12 d, 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 (published...
We present SN 2020jfo, a Type IIP supernova in the nearby galaxy M61. Optical light curves from Zwicky Transient Facility, complemented with data Swift and near-IR photometry are presented. The 350-day duration bolometric curve exhibits relatively short (~ 65 days) plateau. This implies moderate ejecta mass 5 Msun). A series of spectroscopy is presented, including spectropolarimetric observations. nebular spectra dominated by Halpha but also reveal emission lines oxygen calcium. Comparisons...
Stars aligned in thin stream-like features (feathers), with widths of $\delta\sim1-10^{\circ}$ and lengths as large $\Delta l\sim180^{\circ}$, have been observed towards the Anticenter our Galaxy their properties mapped abundances phase-space. We study origin by analysing similar arising an N-body simulation a Galactic disc interacting Sagittarius-like dwarf spheroidal galaxy (Sgr). By following orbits particles identified contributing to feathers backwards time, we trace excitation one...
Abstract Interaction-powered supernovae (SNe) explode within an optically thick circumstellar medium (CSM) that could be ejected during eruptive events. To identify and characterize such pre-explosion outbursts, we produce forced-photometry light curves for 196 interacting SNe, mostly of Type IIn, detected by the Zwicky Transient Facility between early 2018 2020 June. Extensive tests demonstrate only expect a few false detections among 70,000 analyzed images after applying quality cuts bias...
Abstract The fate of stars in the zero-age main-sequence (ZAMS) range ≈8–12 M ⊙ is unclear. They could evolve to form white dwarfs or explode as electron-capture supernovae (SNe) iron core-collapse SNe (CCSNe). Even though initial mass function indicates that this should account for over 40% all CCSN progenitors, few have been observationally confirmed, likely due faintness and rapid evolution some these transients. In paper, we present a sample nine Ca-rich/O-poor Type IIb detected by...
Eruptive mass loss of massive stars prior to supernova (SN) explosion is key understanding their evolution and end fate. An observational signature pre-SN the detection an early, short-lived peak radioactive-powered in lightcurve SN. This usually attributed SN shock passing through extended envelope or circumstellar medium (CSM). Such early common for double-peaked Type IIb SNe with Hydrogen but uncommon normal Ibc very compact progenitors. In this paper, we systematically study a sample 14...
We present the first homogeneous release of several thousand Type Ia supernovae (SNe Ia), all having spectroscopic classification, and redshifts for half sample. This release, named "DR2", contains 3628 nearby (z < 0.3) SNe discovered, followed classified by Zwicky Transient Facility survey between March 2018 December 2020. Of these, 3000 have good-to-excellent sampling 2667 pass standard cosmology light-curve quality cuts. is thus largest SN to date, increasing an order magnitude number...
Abstract We study a magnitude-limited sample of 36 broad-lined type Ic supernovae (SNe Ic-BL) from the Zwicky Transient Facility Bright Survey (detected between 2018 March and 2021 August), which is largest systematic SNe Ic-BL done in literature thus far. present light curves (LCs) for each analyze shape LCs to derive empirical parameters, along with explosion epochs every event. The has an average absolute peak magnitude r band <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract The first binary neutron star merger, GW170817, was accompanied by a radioactivity-powered optical/infrared transient called kilonova. To date, no compelling kilonova has been found in all-sky optical surveys, independently of short gamma-ray burst and gravitational-wave triggers. In this work, we searched the 23 months Zwicky Transient Facility (ZTF) data stream for candidate kilonovae form rapidly evolving transients. We combined ZTF alert queries with forced point-spread-function...
We present the discovery of ZTF 21aaoryiz/SN 2021fcg -- an extremely low-luminosity Type Iax supernova. SN was discovered by Zwicky Transient Facility in star-forming galaxy IC0512 at a distance $\approx$ 27 Mpc. It reached peak absolute magnitude $M_{r} =$ $-12.66\pm0.20$ mag, making it least luminous thermonuclear supernova to date. The E(B-V) contribution from underlying host is unconstrained. However, even if were as large 0.5 would be = -13.78\pm0.20$ mag still consistent with being...