Author
Cristina Barbarino
Bio: Cristina Barbarino is an academic researcher from Stockholm University. The author has contributed to research in topics: Supernova & Light curve. The author has an hindex of 17, co-authored 48 publications receiving 2263 citations.
Topics: Supernova, Light curve, Physics, Type (model theory), Population
Papers
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University of Washington1, California Institute of Technology2, Stockholm University3, University of Maryland, College Park4, Humboldt University of Berlin5, Goddard Space Flight Center6, National Central University7, Weizmann Institute of Science8, Macau University of Science and Technology9, Tel Aviv University10, University of California, Santa Barbara11, University of Michigan12, Northwestern University13, Adler Planetarium14, University of California, Berkeley15, Lawrence Berkeley National Laboratory16, Soka University of America17, Centre national de la recherche scientifique18, Radboud University Nijmegen19, University of Wisconsin–Milwaukee20, Los Alamos National Laboratory21
TL;DR: The Zwicky Transient Facility (ZTF) as mentioned in this paper is a new optical time-domain survey that uses the Palomar 48 inch Schmidt telescope, which provides a 47 deg^2 field of view and 8 s readout time, yielding more than an order of magnitude improvement in survey speed relative to its predecessor survey.
Abstract: 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 a 47 deg^2 field of view and 8 s readout time, yielding more than an order of magnitude improvement in survey speed relative to its predecessor survey, the Palomar Transient Factory. We describe the design and implementation of the camera and observing system. The ZTF data system at the Infrared Processing and Analysis Center provides near-real-time reduction to identify moving and varying objects. We outline the analysis pipelines, data products, and associated archive. Finally, we present on-sky performance analysis and first scientific results from commissioning and the early survey. ZTF's public alert stream will serve as a useful precursor for that of the Large Synoptic Survey Telescope.
1,009 citations
Queen's University Belfast1, Max Planck Society2, California Institute of Technology3, University College Dublin4, University of Southampton5, University of Hawaii6, University of Copenhagen7, Weizmann Institute of Science8, University of Warwick9, University of Edinburgh10, Millennium Institute11, Andrés Bello National University12, European Southern Observatory13, Liverpool John Moores University14, Stockholm University15, Pontifical Catholic University of Chile16, Space Science Institute17, University of Padua18, INAF19, Radboud University Nijmegen20, Netherlands Institute for Space Research21, Spanish National Research Council22, Centre national de la recherche scientifique23, University of Chile24, University of Portsmouth25, University of Pittsburgh26, Instituto Superior Técnico27, University of Warsaw28, University of Turku29, University of Iceland30, Valparaiso University31, University of Cambridge32, Lancaster University33, Humboldt University of Berlin34, Heidelberg University35, Heidelberg Institute for Theoretical Studies36, Institut d'Astrophysique de Paris37, University of Oxford38, University of Catania39, Space Telescope Science Institute40, Johns Hopkins University41, Inter-University Centre for Astronomy and Astrophysics42, University of New South Wales43, Australian National University44, Harvard University45, University of the Free State46, Northwestern University47, University of Minnesota48
TL;DR: Observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817, indicate that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.
Abstract: Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.
695 citations
TL;DR: The Zwicky Transient Facility (ZTF) as discussed by the authors is a new time domain survey employing a dedicated camera on the Palomar 48-inch Schmidt telescope with a 47 deg$^2$ field of view and 8 second readout time.
Abstract: The Zwicky Transient Facility (ZTF), a public-private enterprise, is a new time domain survey employing a dedicated camera on the Palomar 48-inch Schmidt telescope with a 47 deg$^2$ field of view and 8 second readout time. It is well positioned in the development of time domain astronomy, offering operations at 10% of the scale and style of the Large Synoptic Survey Telescope (LSST) with a single 1-m class survey telescope. The public surveys will cover the observable northern sky every three nights in g and r filters and the visible Galactic plane every night in g and r. Alerts generated by these surveys are sent in real time to brokers. A consortium of universities which provided funding ("partnership") are undertaking several boutique surveys. The combination of these surveys producing one million alerts per night allows for exploration of transient and variable astrophysical phenomena brighter than r $\sim$ 20.5 on timescales of minutes to years. We describe the primary science objectives driving ZTF including the physics of supernovae and relativistic explosions, multi-messenger astrophysics, supernova cosmology, active galactic nuclei and tidal disruption events, stellar variability, and Solar System objects.
501 citations
California Institute of Technology1, University of Washington2, Stockholm University3, University of Maryland, College Park4, Auburn University5, University of Wisconsin–Milwaukee6, Goddard Space Flight Center7, National Central University8, University of California, Santa Barbara9, University of Michigan10, Adler Planetarium11, Northwestern University12, University of California, Berkeley13, Lawrence Berkeley National Laboratory14, Weizmann Institute of Science15, Radboud University Nijmegen16, Humboldt University of Berlin17, Macau University of Science and Technology18, Tel Aviv University19, Soka University of America20, Centre national de la recherche scientifique21, Los Alamos National Laboratory22
TL;DR: The Zwicky Transient Facility (ZTF) as mentioned in this paper is a new time-domain survey employing a dedicated camera on the Palomar 48-inch Schmidt telescope with a 47 deg^2 field of view and an 8 second readout time.
Abstract: The Zwicky Transient Facility (ZTF), a public–private enterprise, is a new time-domain survey employing a dedicated camera on the Palomar 48-inch Schmidt telescope with a 47 deg^2 field of view and an 8 second readout time. It is well positioned in the development of time-domain astronomy, offering operations at 10% of the scale and style of the Large Synoptic Survey Telescope (LSST) with a single 1-m class survey telescope. The public surveys will cover the observable northern sky every three nights in g and r filters and the visible Galactic plane every night in g and r. Alerts generated by these surveys are sent in real time to brokers. A consortium of universities that provided funding ("partnership") are undertaking several boutique surveys. The combination of these surveys producing one million alerts per night allows for exploration of transient and variable astrophysical phenomena brighter than r ~ 20.5 on timescales of minutes to years. We describe the primary science objectives driving ZTF, including the physics of supernovae and relativistic explosions, multi-messenger astrophysics, supernova cosmology, active galactic nuclei, and tidal disruption events, stellar variability, and solar system objects.
280 citations
Queen's University Belfast1, Liverpool John Moores University2, Florida State University3, Max Planck Society4, University of Sheffield5, Stockholm University6, Spanish National Research Council7, University College Dublin8, University of Pittsburgh9, Weizmann Institute of Science10, University of Turku11, University of California, Santa Barbara12, Las Cumbres Observatory Global Telescope Network13, Harvard University14, University of Southampton15, University of Leicester16, Institute for the Physics and Mathematics of the Universe17, Andrés Bello National University18, Millennium Institute19, University of North Carolina at Chapel Hill20, Space Telescope Science Institute21, Johns Hopkins University22, Katholieke Universiteit Leuven23, University of California, Davis24, Janssen Pharmaceutica25, Lancaster University26
TL;DR: In this article, the peak luminosity and characteristic time-scales of the bolometric light curves are calculated, and the light curves modelled to derive 56Ni and ejecta masses (MNi and Mej).
Abstract: We present observations and analysis of 18 stripped-envelope supernovae observed during 2013–2018. This sample consists of five H/He-rich SNe, six H-poor/He-rich SNe, three narrow lined SNe Ic, and four broad lined SNe Ic. The peak luminosity and characteristic time-scales of the bolometric light curves are calculated, and the light curves modelled to derive 56Ni and ejecta masses (MNi and Mej). Additionally, the temperature evolution and spectral line velocity curves of each SN are examined. Analysis of the [O I] line in the nebular phase of eight SNe suggests their progenitors had initial masses = 2.8 ± 1.5 M⊙ which further strengthens the evidence that SE–SNe arise from low-mass progenitors which are typically and lack of clear bimodality in the distribution implies <30 M⊙ progenitors and that envelope stripping via binary interaction is the dominant evolutionary pathway of these SNe.
111 citations
Cited by
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University of Geneva1, Ioffe Institute2, University of California, Santa Cruz3, University of Mississippi4, Curtin University5, Las Cumbres Observatory Global Telescope Network6, University of California, Santa Barbara7, University of Warwick8, Spanish National Research Council9, University of Colorado Boulder10, University of Hawaii11, Aoyama Gakuin University12, Queen's University Belfast13, Max Planck Society14, Nagoya University15, University of Warsaw16
TL;DR: A binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors.
Abstract: On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient's position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.
2,746 citations
1,288 citations
01 Aug 2006
TL;DR: In this article, distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS) were presented.
Abstract: We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multiband photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: {Omega}{sub M} = 0.263 {+-} 0.042 (stat) {+-} 0.032 (sys) for a flat {Lambda}CDM model; and w = -1.023 {+-} 0.090 (stat) {+-} 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations.
840 citations
01 Dec 2006
TL;DR: In this article, NAFU SA and other role players expressed some criticism about government programmes. The criticism was not so much about the objectives and content of these programmes, but rather about their accessibility, or lack thereof, to emerging farmers.
Abstract: Recently NAFU SA and other role players expressed some criticism about government programmes. The criticism was not so much about the objectives and content of these programmes, but rather about their accessibility, or lack thereof, to emerging farmers.
819 citations
TL;DR: In this article, the authors present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves.
Abstract: We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– 20 deg2 requires at least three detectors of sensitivity within a factor of ∼2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.
804 citations