A5081952162- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- History and Developments in Astronomy
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Non-Destructive Testing Techniques
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Electrical Fault Detection and Protection
- Nuclear physics research studies
- Solar and Space Plasma Dynamics
- Particle Detector Development and Performance
- Neutrino Physics Research
- Liver Disease Diagnosis and Treatment
- Real-time simulation and control systems
European Southern Observatory
2014-2023
Technical University of Munich
2009-2023
Excellence Cluster Universe
2009-2022
University of Southampton
2017
Sto (Germany)
2016
Max Planck Institute for Extraterrestrial Physics
2011
Trieste Astronomical Observatory
2007
University of Oklahoma
2007
AlbaNova
2007
Stockholm University
2007
We present spectral and photometric observations of 10 Type Ia supernovae (SNe Ia) in the redshift range 0.16 ≤ z 0.62. The luminosity distances these objects are determined by methods that employ relations between SN light curve shape. Combined with previous data from our High-z Supernova Search Team recent results Riess et al., this expanded set 16 high-redshift a 34 nearby used to place constraints on following cosmological parameters: Hubble constant (H0), mass density (ΩM), (i.e.,...
We have discovered 16 Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and used them to provide first conclusive evidence for cosmic deceleration that preceded current epoch of acceleration. These objects, during course GOODS ACS Treasury program, include 6 7 highest redshift SNe known, all at z > 1.25, populate diagram in unexplored territory. The luminosity distances these objects 170 previously reported been determined using empirical relations between light-curve shape...
The High-z Supernova Search Team has discovered and observed 8 new supernovae in the redshift interval z=0.3-1.2. These independent observations, confirm result of Riess et al. (1998a) Perlmutter (1999) that supernova luminosity distances imply an accelerating universe. More importantly, they extend range consistently SN Ia to z~1, where signature cosmological effects opposite sign some plausible systematic effects. Consequently, these measurements not only provide another quantitative...
The High-Z Supernova Search is an international collaboration to discover and monitor Type Ia supernovae (SNe Ia) at z > 0.2 with the aim of measuring cosmic deceleration global curvature. Our has pursued a basic understanding in nearby universe, discovering observing large sample objects developing methods measure accurate distances SNe Ia. This paper describes extension this program ≥ 0.2, outlining our search techniques follow-up program. We have devised high-throughput filters that...
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...
We use Type Ia supernovae studied by the High-z Supernova Search Team to constrain properties of an energy component that may have contributed accelerating cosmic expansion. find for a flat geometry equation-of-state parameter unknown component, αx = Px/ρx, must be less than -0.55 (95% confidence) any value Ωm, and it is further limited < -0.60 if Ωm assumed greater 0.1. These values are inconsistent with being topological defects such as domain walls, strings, or textures. The supernova...
We have coordinated Hubble Space Telescope (HST) photometry with ground-based discovery for three supernovae: Type Ia supernovae near z ≈ 0.5 (SN 1997ce, SN 1997cj) and a third event at = 0.97 1997ck). The superb spatial resolution of HST separates each supernova from its host galaxy leads to good precision in the light curves. use these curves relations between luminosity, light-curve shape, color calibrated low-z samples derive relative luminosity distances that are accurate 10% 20% 1....
The first cosmological results from the ESSENCE supernova survey (Wood-Vasey and coworkers) are extended to a wider range of models including dynamical dark energy nonstandard models. We fold in greater number external data sets such as recent Higher-z release high-redshift supernovae (Riess coworkers), well several complementary probes. Model comparison statistics Bayesian Akaike information criteria applied gauge worth These favor that give good fit with fewer parameters. Based on this...
We present photometric and spectroscopic observations of 23 high-redshift supernovae (SNe) spanning a range z = 0.34-1.03, nine which are unambiguously classified as Type Ia. These SNe were discovered during the IfA Deep Survey, began in 2001 September observed total 2.5 deg2 to depth approximately m ≈ 25-26 RIZ over 9-17 visits, typically every 1-3 weeks for nearly 5 months, with additional continuing until 2002 April. give brief description survey motivations, observational strategy,...
We present and discuss the photometric spectroscopic evolution of peculiar SN 1998bw, associated with GRB 980425, through an analysis optical near-IR data collected at ESO-La Silla. The data, spanning period from day -9 to +376 (relative B maximum), have shown that this supernova (SN) was unprecedented, although somewhat similar 1997ef. Maximum expansion velocities as high 3 × 104 km s-1 some extent mask its resemblance other Type Ic SNe. At intermediate phases, between photospheric fully...
We present 13 spectra and 31 photometric observations covering the first 150 days of SN 1991bg in NGC 4374 (M 84). Although was a type Ia supernova displaying characteristic Si II absorption at 6150 A near maximum Fe emission lines late phases, it varied from well-defined norm for SNe several important respects. The peculiarities include faster declines B V light curves after maximum, distinct color evolution, very red - relatively faint peak luminosity, spectral short phase. narrow...
We present results from the Hubble Higher z Supernova Search, first space-based open field survey for supernovae (SNe). In cooperation with Great Observatories Origins Deep Survey, we have used Space Telescope Advanced Camera Surveys to cover ~300 arcmin2 in area of Chandra Field South and North on five separate search epochs (separated by ~45 day intervals) a limiting magnitude F850LP ≈ 26. These deep observations allowed us discover 42 SNe redshift range 0.2 < 1.6. As these data span large...
Optical spectra of SN 1991T obtained approximately one week before B maximum showed no evidence the Si, Ca, and S absorption lines which normally dominate type Ia supernovae at early phases. Nevertheless, within two weeks after maximum, spectrum had evolved to resemble closely that other events. These observations suggest abundances in outer ejecta were unusually low. The V light curves resembled those supernovae, but slope initial decline following was less steep than normal both colors. In...
▪ Abstract Distant type Ia supernovae (SNe Ia) appear fainter than their local counterparts. Independent of what explanation will eventually be found to correct, this implies a significant change in how we see the distant universe and understand these stellar explosions. The observational characteristics nearby SNe show some differences from event event. Despite considerable range observed peak luminosity, they can normalized by light-curve shape. Through normalization, used as exquisite...
We present photometry of SN 1993J in M81 (NGC 3031) the Johnson- Cousins UBVRI system, starting within three days probable time explosion and ending 120 later. The reddening along line sight to this supernova is uncertain-there evidence for small (E(B- V) ~ 0.08 mag] moderate [E(B- 0.32 values. For each value, we correct observed fluxes extinction calculate evolution sum all optical flux, which contains roughly half supernova's total flux during period observation. also fit colors a Planck...
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...
view Abstract Citations (200) References (89) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS SN 1992A: Ultraviolet and Optical Studies Based on HST, IUE, CTIO Observations Kirshner, Robert P. ; Jeffery, David J. Leibundgut, Bruno Challis, Peter M. Sonneborn, George Phillips, Suntzeff, N. B. Smith, R. Chris Winkler, Frank Winge, Claudia Hamuy, Mario Hunter, Deidre A. Roth, Katherine C. Blades, Branch, Chevalier, Roger Fransson, Claes Panagia, Nino Wagoner, V....
We present observations of the Type Ia supernovae (SNe) 1999M, 1999N, 1999Q, 1999S, and 1999U, at redshift z ≈ 0.5. They were discovered in early 1999 with 4.0 m Blanco telescope Cerro Tololo Inter-American Observatory by High-z Supernova Search Team (HZT) subsequently followed many ground-based telescopes. SNe 1999Q 1999U also observed Hubble Space Telescope. computed luminosity distances to new using two methods added them high-z diagram that HZT has been constructing since 1995. The...
We present new data for five under-luminous type II-plateau supernovae (SNe IIP), namely SN 1999gn, 2002gd, 2003Z, 2004eg and 2006ov. This sample of low-luminosity SNe IIP (LL IIP) is analyzed together with similar objects studied in the past. All them show a flat light curve plateau lasting about 100 days, an under luminous late-time exponential tail, intrinsic colours that are unusually red, spectra showing prominent narrow P-Cygni lines. A velocity ejected material below 10^3 km/s...
The most precise local measurements of H 0 rely on observations Type Ia supernovae (SNe Ia) coupled with Cepheid distances to SN host galaxies. Recent results have shown tension comparing the value inferred from CMB assuming ΛCDM, making it important check for potential systematic uncertainties in either approach. To date, used based optical photometry, corrections light curve shape and colour. Here, we analyse SNe as standard candles near-infrared (NIR), where luminosity variations...
We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from Cluster Lensing And Supernova survey with Hubble (CLASH). Using Advanced Camera for Surveys Wide Field 3 on Space Telescope (HST), we have imaged 25 galaxy-cluster fields parallel of non-cluster galaxies. report a 27 SNe discovered in fields. Of these SNe, ∼13 are classified as Ia candidates, including four candidates at redshifts z > 1.2. measure volumetric to redshift 1.8 add first upper limit rate range < 2.4. The...