J. L. Prieto
A5086015383- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Nuclear Physics and Applications
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Nuclear reactor physics and engineering
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Crystal Structures and Properties
- Advanced X-ray and CT Imaging
- Neutrino Physics Research
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Catalysis and Oxidation Reactions
- Particle Detector Development and Performance
- Geological and Geophysical Studies
Millennium Institute of Astrophysics
2015-2024
Diego Portales University
2015-2024
Princeton University
2011-2022
University of Cuenca
2022
California Institute of Behavioral Neurosciences and Psychology (United States)
2022
Loyola Medicine
2022
MacNeal Hospital
2022
Hospital de Especialidades José Carrasco Arteaga
2022
Universidad de Santiago de Chile
2022
Universidad del Azuay
2022
Aims. We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The dataset includes several low-redshift samples (z< 0.1), all three seasons (0.05 <z< 0.4), years (0.2 1), it totals 740 spectroscopically confirmed supernovae with high-quality light curves.
After the All-Sky Automated Survey for SuperNovae (ASAS-SN) discovered a significant brightening of inner region NGC 2617, we began ~70 day photometric and spectroscopic monitoring campaign from X-ray through near-infrared (NIR) wavelengths. We report that 2617 went dramatic outburst, during which its flux increased by over an order magnitude followed increase optical/ultraviolet (UV) continuum almost magnitude. classified as Seyfert 1.8 galaxy in 2003, is now 1 due to appearance broad...
The All-Sky Automated Survey for Supernovae (ASAS-SN) is working toward imaging the entire visible sky every night to a depth of mag. present data covers and spans ∼2–5 years with ∼100–400 epochs observation. should contain some ∼1 million variable sources, ultimate goal have database these observations publicly accessible. We describe here first step, simple but unprecedented web interface https://asas-sn.osu.edu/ that provides an up date aperture photometry light curve any user-selected...
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...
On 2017 August 17, gravitational waves were detected from a binary neutron star merger, GW170817, along with coincident short gamma-ray burst, GRB170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, and infrared light curves SSS17a extending 10.9 hours to 18 days post-merger. constrain radioactively-powered resulting ejection neutron-rich material. The fast rise curves, subsequent...
We present measurements of the Hubble diagram for 103 Type Ia supernovae (SNe) with redshifts 0.04 < z 0.42, discovered during first season (Fall 2005) Sloan Digital Sky Survey-II (SDSS-II) Supernova Survey. These data fill in redshift "desert" between low- and high-redshift SN surveys. combine SDSS-II new distance estimates published from ESSENCE survey, Legacy Survey, Space Telescope, a compilation nearby measurements. Combining Baryon Acoustic Oscillations SDSS Luminous Red Galaxy sample...
The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. survey region is stripe 2.5° wide centered the celestial equator in Southern Galactic Cap that been imaged numerous times earlier years, enabling construction deep reference image discovery new objects. Supernova observations are being...
We present ∼47,000 periodic variables found during the analysis of 5.4 million variable star candidates within a 20,000 deg2 region covered by Catalina Surveys Data Release-1 (CSDR1). Combining these with type ab RR Lyrae from our previous work, we produce an online catalog containing periods, amplitudes, and classifications for ∼61,000 variables. By cross-matching those prior surveys, find that >90% ∼8000 known in survey are recovered. For sources, excellent agreement between values...
The All-Sky Automated Survey for Supernovae (ASAS-SN) is the first optical survey to routinely monitor whole sky with a cadence of $\sim2-3$ days down V$\lesssim17$ mag. ASAS-SN has monitored since 2014, collecting $\sim100-500$ epochs observations per field. V-band light curves candidate variables identified during search supernovae are classified using random forest classifier and visually verified. We present catalog 66,179 bright, new variable stars discovered our supernovae, including...
We compare the chemical abundances at sites of 12 nearby (z < 0.14) Type Ic supernovae (SN Ic) that showed broad lines, but had no observed gamma-ray burst (GRB), with in five 0.25) galaxies GRBs where broad-lined SN were seen after fireball faded. It has previously been noted GRB hosts are low luminosity and their metal abundances. If metallicity is sufficient to force evolution massive stars end lives as an accompanying Ic, then we would expect higher for have detected GRBs. This what...
We present ground-based and Swift photometric spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at center PGC 043234 ($d\simeq90$ Mpc) by All-Sky Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity $L\simeq10^{44}$ ergs s$^{-1}$ total integrated energy $E\simeq7\times10^{50}$ radiated over $\sim6$ months presented. UV/optical emission is well-fit blackbody with roughly constant temperature $T\sim35,000$ K, while...
On 2017 August 17, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of binary neutron star gravitational wave event GW170817. We report time-series spectroscopy SSS17a from 11.75 hours until 8.5 days after merger. Over first hour observations ejecta rapidly expanded and cooled. Applying blackbody fits to spectra, we measure photosphere cooling $11,000^{+3400}_{-900}$ K $9300^{+300}_{-300}$ K, determine a photospheric velocity roughly 30% speed light. The...
ASASSN-14ae is a candidate tidal disruption event (TDE) found at the center of SDSS J110840.11+340552.2 ($d\simeq200$~Mpc) by All-Sky Automated Survey for Supernovae (ASAS-SN). We present ground-based and Swift follow-up photometric spectroscopic observations source, finding that transient had peak luminosity $L\simeq8\times10^{43}$~erg~s$^{-1}$ total integrated energy $E\simeq1.7\times10^{50}$ ergs radiated over $\sim5$ months presented. The blackbody temperature remains roughly constant...
We present analysis of 12,227 type-ab RR Lyraes (RRLs) found among the 200 million public light curves in Catalina Surveys Data Release 1. These stars span largest volume Milky Way ever surveyed with RRLs, covering ∼20,000 deg2 sky (0° < α 360°, −22° δ 65°) to heliocentric distances up 60 kpc. Each RRLs is observed between and 419 times over a six-year period. Using period finding Fourier fitting techniques we determine periods apparent magnitudes for each source. find that are generally...
Chemistry plays a key role in many astrophysical situations regulating the cooling and thermal properties of gas, which are relevant during gravitational collapse, evolution disks fragmentation process. In order to simplify usage chemical networks large numerical simulations, we present chemistry package KROME, consisting Python pre-processor generates subroutine for solution can be embedded any code. For rate equations, make use high-order solver DLSODES, was shown both accurate efficient...
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 Legacy ExtraGalactic UV Survey (LEGUS) is a Cycle 21 Treasury program on the Hubble Space Telescope aimed at investigation of star formation and its relation with galactic environment in nearby galaxies, from scales individual stars to those ∼kiloparsec-size clustered structures. Five-band imaging near-ultraviolet I band Wide-Field Camera 3 (WFC3), plus parallel optical Advanced for Surveys (ACS), being collected selected pointings 50 galaxies within local 12 Mpc. filters used...
We present the ATLAS discovery and initial analysis of first 18 days unusual transient event, ATLAS18qqn/AT2018cow. It is characterized by a high peak luminosity ($\sim$1.7 $\times$ 10$^{44}$ erg s$^{-1}$), rapidly evolving light curves ($>$5 mag rise to in $\sim$3.5 days), hot blackbody spectra, peaking at $\sim$27000 K that are relatively featureless unchanging over two weeks. The bolometric curve cannot be powered radioactive decay under realistic assumptions. detection high-energy...
The variable stars in the VSX catalog are derived from a multitude of inhomogeneous data sources and classification tools. This inhomogeneity complicates our understanding star types, statistics, properties, it directly affects attempts to build training sets for current (and next) generation all-sky, time-domain surveys. We homogeneously analyze ASAS-SN V-band light curves ${\sim}412,000$ variables catalog. classified using an updated random forest classifier with $F_1$ score 99.4\%...
Extragalactic transient searches have historically been limited to looking for the appearance of new sources such as supernovae. It is now possible carry out a kind survey that will do opposite, is, search disappearance massive stars. This entail systematic observation galaxies within distance 10 Mpc in order watch ~106 supergiants. Reaching this critical number ensures something occur yearly, since these stars must end their lives with core collapse yr. Using deep imaging and image...
Spectra and light curves of SN 2006gz show the strongest signature unburned carbon one slowest fading ever seen in a Type Ia event [Δm15(B) = 0.69 ± 0.04]. The early-time Si II velocity is low, implying it was slowed by an envelope material. Our best estimate luminosity implies MV -19.74 production ~1.2 M☉ 56Ni. This suggests super-Chandrasekhar mass progenitor. A double degenerate merger consistent with these observations.
We identify a "supernova rate problem": the measured cosmic core-collapse supernova is factor of ~ 2 smaller (with significance sigma) than that predicted from massive-star formation rate. The comparison critical for topics galaxy evolution and enrichment to abundance neutron stars black holes. systematically explore possible resolutions. accuracy precision star data conversion are well supported, proposed changes would have far-reaching consequences. dominant effect likely many supernovae...
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...
The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in 300 deg2 region along the celestial equator during its first two seasons three-season campaign. Multi-band (ugriz) light curves were measured for most sources, which include solar system objects, galactic variable stars, active nuclei, supernovae (SNe), and other astronomical transients. imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure...