Examinando por Autor "Hsiao, E.Y."
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Ítem Defining photometric peculiar type Ia supernovae(Institute of Physics Publishing, 2014) González-Gaitán, S.; Hsiao, E.Y.; Pignata, G.; Förster, F.; Gutiérrez, C.; Bufano, F.; Galbany, L.; Folatelli, G.; Phillips, M.M.; Hamuy, M.; Anderson, J.P.; De Jaeger, T.Ítem Extensive HST ultraviolet spectra and multiwavelength observations of SN 2014J in M82 indicate reddening and circumstellar scattering by typical dust(Oxford University Press, 2014) Foley, Ryan J.; Fox, O.D.; McCully, C.; Phillips, M.M.; Sand, D.J.; Zheng, W.; Challis, P.; Filippenko, A.V.; Folatelli, G.; Hillebrandt, W.; Hsiao, E.Y.; Jha, S.W.; Kirshner, R.P.; Kromer, M.; Marion, G.H.; Nelso, M.; Pakmor, R.; Pignata, G.; R̈opke, F.K.; Seitenzahl, I.R.; Silverman, J.M.; Skrutskie, M.; Stritzinger, M.D.SN 2014J in M82 is the closest detected Type Ia supernova (SN Ia) in at least 28 yr and perhaps in 410 yr. Despite its small distance of 3.3 Mpc, SN 2014J is surprisingly faint, peaking at V = 10.6 mag, and assuming a typical SN Ia luminosity, we infer an observed visual extinction of AV = 2.0 ± 0.1 mag. But this picture, with RV = 1.6 ± 0.2, is too simple to account for all observations. We combine 10 epochs (spanning a month) of HST/Space Telescope Imaging Spectrograph (STIS) ultraviolet through near-infrared spectroscopy with HST/Wide Field Camera 3 (WFC3), Katzman Automatic Imaging Telescope, and FanCam photometry from the optical to the infrared and nine epochs of high-resolution TRES (Tillinghast Reflection Echelle Spectrograph) spectroscopy to investigate the sources of extinction and reddening for SN 2014J. We argue that the wide range of observed properties for SN 2014J is caused by a combination of dust reddening, likely originating in the interstellar medium of M82, and scattering off circumstellar material. For this model, roughly half of the extinction is caused by reddening from typical dust (E(B − V) = 0.45 mag and RV = 2.6) and roughly half by scattering off Large Magellanic Cloud-like dust in the circumstellar environment of SN 2014J.Ítem PESSTO: Survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects(EDP Sciences, 2015-07) Smartt, S.J.; Valenti, S.; Fraser, M.; Inserra, C.; Young, D.R.; Sullivan, M.; Pastorello, A.; Benetti, S.; Gal-Yam, A.; Knapic, C.; Molinaro, M.; Smareglia, R.; Smith, K.W.; Taubenberger, S.; Yaron, O.; Anderson, J.P.; Ashall, C.; Balland, C.; Baltay, C.; Barbarino, C.; Bauer, F.E.; Baumont, S.; Bersier, D.; Blagorodnova, N.; Bongard, S.; Botticella, M.T.; Bufano, F.; Bulla, M.; Cappellaro, E.; Campbell, H.; Cellier-Holzem, F.; Chen, T.-W.; Childress, M.J.; Clocchiatti, A.; Contreras, C.; Dall'Ora, M.; Danziger, J.; De Jaeger, T.; De Cia, A.; Della Valle, M.; Dennefeld, M.; Elias-Rosa, N.; Elman, N.; Feindt, U.; Fleury, M.; Gall, E.; Gonzalez-Gaitan, S.; Galbany, L.; Morales Garoffolo, A.; Greggio, L.; Guillou, L.L.; Hachinger, S.; Hadjiyska, E.; Hage, P.E.; Hillebrandt, W.; Hodgkin, S.; Hsiao, E.Y.; James, P.A.; Jerkstrand, A.; Kangas, T.; Kankare, E.; Kotak, R.; Kromer, M.; Kuncarayakti, H.; Leloudas, G.; Lundqvist, P.; Lyman, J.D.; Hook, I.M.; Maguire, K.; Manulis, I.; Margheim, S.J.; Mattila, S.; Maund, J.R.; Mazzali, P.A.; McCrum, M.; McKinnon, R.; Moreno-Raya, M.E.; Nicholl, M.; Nugent, P.; Pain, R.; Pignata, G.; Phillips, M.M.; Polshaw, J.; Pumo, M.; Rabinowitz, D.; Reilly, E.; Romero-Cañizales, C.; Scalzo, R.; Schmidt, B.; Schulze, S.; Sim, S.; Sollerman, J.; Taddia, F.; Tartaglia, L.; Terreran, G.; Tomasella, L.; Turatto, M.; Walker, E.; Walton, N.A.; Wyrzykowski, L.; Yuan, F.; Zampieri, L.Context. The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. PESSTO classifies transients from publicly available sources and wide-field surveys, and selects science targets for detailed spectroscopic and photometric follow-up. PESSTO runs for nine months of the year, January - April and August - December inclusive, and typically has allocations of 10 nights per month. Aims. We describe the data reduction strategy and data products that are publicly available through the ESO archive as the Spectroscopic Survey data release 1 (SSDR1). Methods. PESSTO uses the New Technology Telescope with the instruments EFOSC2 and SOFI to provide optical and NIR spectroscopy and imaging. We target supernovae and optical transients brighter than 20.5m for classification. Science targets are selected for follow-up based on the PESSTO science goal of extending knowledge of the extremes of the supernova population. We use standard EFOSC2 set-ups providing spectra with resolutions of 13-18 Å between 3345-9995 Å. A subset of the brighter science targets are selected for SOFI spectroscopy with the blue and red grisms (0.935-2.53 μm and resolutions 23-33 Å) and imaging with broadband JHKs filters. Results. This first data release (SSDR1) contains flux calibrated spectra from the first year (April 2012-2013). A total of 221 confirmed supernovae were classified, and we released calibrated optical spectra and classifications publicly within 24 h of the data being taken (via WISeREP). The data in SSDR1 replace those released spectra. They have more reliable and quantifiable flux calibrations, correction for telluric absorption, and are made available in standard ESO Phase 3 formats. We estimate the absolute accuracy of the flux calibrations for EFOSC2 across the whole survey in SSDR1 to be typically ∼15%, although a number of spectra will have less reliable absolute flux calibration because of weather and slit losses. Acquisition images for each spectrum are available which, in principle, can allow the user to refine the absolute flux calibration. The standard NIR reduction process does not produce high accuracy absolute spectrophotometry but synthetic photometry with accompanying JHKs imaging can improve this. Whenever possible, reduced SOFI images are provided to allow this. Conclusions. Future data releases will focus on improving the automated flux calibration of the data products. The rapid turnaround between discovery and classification and access to reliable pipeline processed data products has allowed early science papers in the first few months of the survey. © ESO, 2015.Ítem SN 2020wnt: a slow-evolving carbon-rich superluminous supernova with no O II lines and a bumpy light curve(Oxford University Press, 2022-09) Gutiérrez, C.P.; Pastorello, A.; Bersten, M.; Benetti, S.; Orellana, M.; Fiore, A.; Karamehmetoglu, E.; Kravtsov, T.; Reguitti, A.; Reynolds, T.M.; Valerin, G.; Mazzali, P.; Sullivan, M.; Cai, Y.-Z.; Elias-Rosa, N.; Fraser, M.; Hsiao, E.Y.; Kankare, E.; Kotak, R.; Kuncarayakti, H.; Li, Z.; Mattila, S.; Mo, J.; Moran, S; Ochner, P.; Shahbandeh, M.; Tomasella, L.; Wang, X.; Yan, S.; Zhang, J.; Zhang, T.; Stritzinger, M. D.We present the analysis of SN 2020wnt, an unusual hydrogen-poor superluminous supernova (SLSN-I), at a redshift of 0.032. The light curves of SN 2020wnt are characterized by an early bump lasting ∼5 d, followed by a bright main peak. The SN reaches a peak absolute magnitude of Mmax r = −20.52 ± 0.03 mag at ∼77.5 d from explosion. This magnitude is at the lower end of the luminosity distribution of SLSNe-I, but the rise-time is one of the longest reported to date. Unlike other SLSNe-I, the spectra of SN 2020wnt do not show O II, but strong lines of C II and Si II are detected. Spectroscopically, SN 2020wnt resembles the Type Ic SN 2007gr, but its evolution is significantly slower. Comparing the bolometric light curve to hydrodynamical models, we find that SN 2020wnt luminosity can be explained by radioactive powering. The progenitor of SN 2020wnt is likely a massive and extended star with a pre-SN mass of 80 M and a pre-SN radius of 15 R that experiences a very energetic explosion of 45 × 1051 erg, producing 4 M of 56Ni. In this framework, the first peak results from a post-shock cooling phase for an extended progenitor, and the luminous main peak is due to a large nickel production. These characteristics are compatible with the pair-instability SN scenario. We note, however, that a significant contribution of interaction with circumstellar material cannot be ruled out.Ítem SN 2021fxy: mid-ultraviolet flux suppression is a common feature of Type Ia supernovae(Oxford University Press, 2023-07-01) DerKacy, J.M.; Paugh, S.; Baron, E.; Brown, P.J.; Ashall, C.; Burns, C.R.; Hsiao, E.Y.; Kumar, S.; Lu, J.; Morrell, N.; Phillips, M.M.; Shahbandeh, M.; Shappee, B.J.; Stritzinger, M.D.; Tucker, M.A.; Yarbrough, Z.; Boutsia, K.; Hoeflich, P.; Wang, L.; Galbany, L.; Karamehmetoglu, E.; Krisciunas, K.; Mazzali, P.; Piro, A.L.; Suntzeff, N.B.; Fiore, A.; Gutiérrez, C.P.; Lundqvist, P.; Reguitti, A.We present ultraviolet (UV) to near-infrared (NIR) observations and analysis of the nearby Type Ia supernova SN 2021fxy. Our observations include UV photometry from Swift/UVOT, UV spectroscopy from HST/STIS, and high-cadence optical photometry with the Swope 1-m telescope capturing intranight rises during the early light curve. Early B − V colours show SN 2021fxy is the first 'shallow-silicon' (SS) SN Ia to follow a red-to-blue evolution, compared to other SS objects which show blue colours from the earliest observations. Comparisons to other spectroscopically normal SNe Ia with HST UV spectra reveal SN 2021fxy is one of several SNe Ia with flux suppression in the mid-UV. These SNe also show blueshifted mid-UV spectral features and strong high-velocity Ca II features. One possible origin of this mid-UV suppression is the increased effective opacity in the UV due to increased line blanketing from high velocity material, but differences in the explosion mechanism cannot be ruled out. Among SNe Ia with mid-UV suppression, SNe 2021fxy and 2017erp show substantial similarities in their optical properties despite belonging to different Branch subgroups, and UV flux differences of the same order as those found between SNe 2011fe and 2011by. Differential comparisons to multiple sets of synthetic SN Ia UV spectra reveal this UV flux difference likely originates from a luminosity difference between SNe 2021fxy and 2017erp, and not differing progenitor metallicities as suggested for SNe 2011by and 2011fe. These comparisons illustrate the complicated nature of UV spectral formation, and the need for more UV spectra to determine the physical source of SNe Ia UV diversity. © 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.Ítem The Early Detection and Follow-up of the Highly Obscured Type II Supernova 2016ija/DLT16am(Institute of Physics Publishing, 2018-01) Tartaglia, L.; Sand, D.J.; Valenti, S.; Wyatt, S.; Anderson, J.P.; Arcavi, I.; Ashall, C.; Botticella, M.T.; Cartier, R.; Chen, T.-W.; Cikota, A.; Coulter, D.; Valle, M.D.; Foley, R.J.; Gal-Yam, A.; Galbany, L.; Gall, C.; Haislip, J.B.; Harmanen, J.; Hosseinzadeh, G.; Howell, D.A.; Hsiao, E.Y.; Inserra, C.; Jha, S.W.; Kankare, E.; Kilpatrick, C.D.; Kouprianov, V.V.; Kuncarayakti, H.; Maccarone, T.J.; Maguire, K.; Mattila, S.; Mazzali, P.A.; McCully, C.; Melandri, A.; Morrell, N.; Phillips, M.M.; Pignata, G.; Piro, A.L.; Prentice, S.; Reichart, D.E.; Rojas-Bravo, C.; Smartt, S.J.; Smith, K.W.; Sollerman, J.; Stritzinger, M.D.; Sullivan, M.; Taddia, F.; Young, D.R.We present our analysis of the Type II supernova DLT16am (SN 2016ija). The object was discovered during theongoing D < 40 Mpc (DLT40) one-day cadence supernova search at r ∼ 20.1 mag in the edge-on nearby(D = 20.0 ± 4.0 Mpc) galaxy NGC 1532. The subsequent prompt and high-cadenced spectroscopic andphotometric follow-up revealed a highly extinguished transient, with E(B - V) = 1.95 ±0.15 mag, consistentwith a standard extinction law with RV=3.1 and a bright (MV = -18.48 ±0.77 mag) absolute peak magnitude. Acomparison of the photometric features with those of large samples of SNe II reveals a fast rise for the derivedluminosity and a relatively short plateau phase, with a slope of S50V = 0.84 ±0.04 mag 50 days, consistent withthe photometric properties typical of those of fast-declining SNe II. Despite the large uncertainties on the distance andthe extinction in the direction of DLT16am, the measured photospheric expansion velocity and the derived absoluteV-band magnitude at ~50 days after the explosion match the existing luminosity-velocity relation for SNe II.Ítem The type IIP supernova 2012aw in m95: Hydrodynamical modeling of the photospheric phase from accurate spectrophotometric monitoring(Institute of Physics Publishing, 2014-06) Dall'Ora, M.; Botticella, M.T.; Pumo, M.L.; Zampieri, L.; Tomasella, L.; Pignata, G.; Bayless, A.J.; Pritchard, T.A.; Taubenberger, S.; Kotak, R.; Inserra, C.; Della Valle, M.; Cappellaro, E.; Benetti, S.; Benitez, S.; Bufano, F.; Elias-Rosa, N.; Fraser, M.; Haislip, J.B.; Harutyunyan, A.; Howell, D.A.; Hsiao, E.Y.; Iijima, T.; Kankare, E.; Kuin, P.; Maund, J.R.; Morales-Garoffolo, A.; Morrell, N.; Munari, U.; Ochner, P.; Pastorello, A.; Patat, F.; Phillips, M.M.; Reichart, D.; Roming, P.W.A.; Siviero, A.; Smartt, S.J.; Sollerman, J.; Taddia, F.; Valenti, S.; Wright, D.We present an extensive optical and near-infrared photometric and spectroscopic campaign of the Type IIP supernova SN 2012aw. The data set densely covers the evolution of SN 2012aw shortly after the explosion through the end of the photospheric phase, with two additional photometric observations collected during the nebular phase, to fit the radioactive tail and estimate the 56Ni mass. Also included in our analysis is the previously published Swift UV data, therefore providing a complete view of the ultraviolet-optical-infrared evolution of the photospheric phase. On the basis of our data set, we estimate all the relevant physical parameters of SN 2012aw with our radiation-hydrodynamics code: envelope mass Menv ∼ 20 M , progenitor radius R ∼ 3 × 1013 cm (∼430 R ), explosion energy E ∼ 1.5 foe, and initial 56Ni mass ∼0.06 M . These mass and radius values are reasonably well supported by independent evolutionary models of the progenitor, and may suggest a progenitor mass higher than the observational limit of 16.5 ± 1.5 M of the Type IIP events.Ítem Two transitional type Ia supernovae located in the Fornax cluster member NGC 1404: SN 2007on and SN 2011iv(EDP Sciences, 2018-03) Gall, C.; Stritzinger, M.D.; Ashall, C.; Baron, E.; Burns, C.R.; Hoeflich, P.; Hsiao, E.Y.; Mazzali, P.A.; Phillips, M.M.; Filippenko, A.V.; Anderson, J.P.; Benetti, S.; Brown, P.J.; Campillay, A.; Challis, P.; Contreras, C.; Elias De La Rosa, N.; Folatelli, G.; Foley, R.J.; Fraser, M.; Holmbo, S.; Marion, G.H.; Morrell, N.; Pan, Y.-C.; Pignata, G.; Suntzeff, N.B.; Taddia, F.; Robledo, S.T.; Valenti, S.We present an analysis of ultraviolet (UV) to near-infrared observations of the fast-declining Type Ia supernovae (SNe Ia) 2007on and 2011iv, hosted by the Fornax cluster member NGC 1404. The B-band light curves of SN 2007on and SN 2011iv are characterised by Δm 15 (B) decline-rate values of 1.96 mag and 1.77 mag, respectively. Although they have similar decline rates, their peak B- and H-band magnitudes differ by ~ 0.60 mag and ~0.35 mag, respectively. After correcting for the luminosity vs. decline rate and the luminosity vs. colour relations, the peak B-band and H-band light curves provide distances that differ by ~ 14% and ~ 9%, respectively. These findings serve as a cautionary tale for the use of transitional SNe Ia located in early-type hosts in the quest to measure cosmological parameters. Interestingly, even though SN 2011iv is brighter and bluer at early times, by three weeks past maximum and extending over several months, its B - V colour is 0.12 mag redder than that of SN 2007on. To reconcile this unusual behaviour, we turn to guidance from a suite of spherical one-dimensional Chandrasekhar-mass delayed-detonation explosion models. In this context, 56 Ni production depends on both the so-called transition density and the central density of the progenitor white dwarf. To first order, the transition density drives the luminosity-width relation, while the central density is an important second-order parameter. Within this context, the differences in the B - V colour evolution along the Lira regime suggest that the progenitor of SN 2011iv had a higher central density than SN 2007on. © ESO 2018.Ítem Unraveling the Infrared Transient VVV-WIT-06: The Case for the Origin as a Classical Nova(Institute of Physics Publishing, 2018-11) Banerjee, D.P.K.; Hsiao, E.Y.; Diamond, T.; Galbany, L.; Morrell, N.; Minniti, D.; Kuncarayakti, H.; Mattila, S.; Harmanen, J.The enigmatic near-infrared transient VVV-WIT-06 underwent a large-amplitude eruption of unclear origin in 2013 July. Based on its light curve properties and late-time post-outburst spectra, various possibilities have been proposed in the literature for the origin of the object, namely a Type I supernova, a classical nova (CN), or a violent stellar merger event. We show that, of these possibilities, an origin in a CN outburst convincingly explains the observed properties of VVV-WIT-06. We estimate that the absolute K-band magnitude of the nova at maximum was M k = -8.2 ±0.5, its distance d = 13.35 ±2.18 kpc, and the extinction A v = 15.0 ±0.55 mag. © 2018. The American Astronomical Society. All rights reserved.