A5022259389- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Neutrino Physics Research
- Calibration and Measurement Techniques
- Cosmology and Gravitation Theories
- Planetary Science and Exploration
- Inorganic Fluorides and Related Compounds
- CCD and CMOS Imaging Sensors
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Nuclear Physics and Applications
- Scientific Research and Discoveries
- Geological and Geophysical Studies
Mitchell Institute
2015-2024
Texas A&M University
2015-2024
Ludwig-Maximilians-Universität München
2024
Lancaster University
2024
Aix-Marseille Université
2024
Austin Peay State University
2024
University of Zurich
2024
American Public University System
2024
Stanford University
2024
Oak Ridge National Laboratory
2024
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.,...
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...
We present a new compilation of Type Ia supernovae (SNe Ia), dataset low-redshift nearby-Hubble-flow SNe and analysis procedures to work with these heterogeneous compilations. This ``Union'' 414 SN Ia, which reduces 307 after selection cuts, includes the recent large samples from Supernova Legacy Survey ESSENCE Survey, older datasets, as well recently extended distant observed HST. A single, consistent blind procedure is used for all various subsamples, implemented that consistently weights...
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 develop a method for estimating the host galaxy dust extinction type Ia supernovae based on an observational coincidence first noted by Lira, who found that B-V evolution during period from 30 to 90 days after V maximum is remarkably similar all events, regardless of light-curve shape. This fact used calibrate dependence Bmax-Vmax and Vmax-Imax colors decline rate parameter Δm15(B), which can, in turn, be separately estimate extinction. Using these methods eliminate effects reddening, we...
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 have obtained new observations of both secondary and tertiary spectrophotometric standards with the RC spectrographs CCD cameras on 1.5-m 4-m telescopes at CTIO in wavelength range 3300-7550 angstroms, as well UBV(RI)KC photometry for these stars. modified monochromatic fluxes published by Taylor (1984) according to calibration Vega provided Hayes (1985). also uned zero-point energy distribution stars matching their V synthetic magnitudes observed magnitudes. use adjusted order calculate...
We have obtained new observations of both secondary and tertiary spectrophotometric standards with the RC spectrographs CCD cameras on 1.5-m 4-m telescopes at CTIO in wavelength range 6000-10500 A. use order to calculate fluxes for Stone Baldwin (1983), as well three stars northern hemisphere from (1977). find that synthetic magnitudes calculated our spectra through IKC band agree extremely observed photometry, better than 1% average. For monochromatic fluxes, we an internal precision 0.01...
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,...
The Carnegie Supernova Project (CSP) is a five-year survey being carried out at the Las Campanas Observatory to obtain high-quality light curves of ∼100 low-redshift Type Ia supernovae (SNe Ia) in well-defined photometric system. Here we present first release data that contains optical 35 SNe Ia, and near-infrared for subset 25 events. comprise 5559 (ugriBV) 1043 (Y JHKs) points natural system Swope telescope. Twenty-eight have pre-maximum data, 15 these, observations begin least 5 days...
We present an analysis of the diversity V-band light-curves hydrogen-rich type II supernovae. Analyzing a sample 116 supernovae, several magnitude measurements are defined, together with decline rates at different epochs, and time durations phases. It is found that magnitudes measured maximum light correlate more strongly than those other epochs: brighter supernovae generally have faster declining all epochs. find relation between rate during 'plateau' phase peak magnitudes, which has...
The Carnegie Supernova Project (CSP) was a five-year observational survey conducted at Las Campanas Observatory that obtained, among other things, high-quality light curves of ~100 low-redshift Type Ia supernovae (SNe Ia). Presented here is the second data release nearby SN photometry consisting 50 objects, with subset 45 having near-infrared follow-up observations. Thirty-three objects have optical pre-maximum coverage 15 beginning least 5 days before maximum light. In near-infrared, 27...
In providing an independent measure of the expansion history universe, Carnegie Supernova Project (CSP) has observed 71 high-z Type Ia supernovae (SNe Ia) in near-infrared bands Y and J. These can be used to construct rest-frame i-band light curves which, when compared a low-z sample, yield distance moduli that are less sensitive extinction and/or decline-rate corrections than optical. However, working with NIR photometry presents unique challenges necessitated development new set...
High-dispersion observations of the Na i D λλ5890, 5896 and K λλ7665, 7699 interstellar lines, diffuse band at 5780 Å in spectra 32 Type Ia supernovae are used as an independent means probing dust extinction. We show that extinction objects where is detected consistent with visual derived from supernova colors. This strongly suggests producing predominantly located medium host galaxies not circumstellar material associated progenitor system. One quarter display anomalously large column...
We present an updated analysis of the intrinsic colors Type Ia supernova (SNe Ia) using latest data release Carnegie Supernova Project. introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find these peculiar types can be seen as extensions population "normal" SNe Ia. With larger number objects, fit Lira relation presented along with evidence dependence on late-time slope B − V light-curves color. Using full wavelength range from...
We present final natural system optical (ugriBV) and near-infrared (YJH) photometry of 134 supernovae (SNe) with probable white dwarf progenitors that were observed in 2004-2009 as part the first stage Carnegie Supernova Project (CSP-I). The sample consists 123 Type Ia SNe, 5 Iax 2 super-Chandrasekhar SN candidates, SNe interacting circumstellar matter, 2006bt-like events. redshifts objects range from z = 0.0037 to 0.0835; median redshift is 0.0241. For 120 (90%) these was obtained. Average...
We formulate a new and coherent understanding of the structure dynamics Large Magellanic Cloud (LMC) its orbit around interaction with Milky Way. Much our these issues hinges on studies LMC line-of-sight kinematics. The observed velocity field includes contributions from rotation curve V(R'), transverse vector vt, rate inclination change di/dt. All previous have assumed di/dt = 0. show that this is incorrect that, combined uncertainties in has led to estimates many important structural...
We examine the absolute luminosities of 29 SNe Ia in Calan/Tololo survey. confirm a relation between peak luminosity and decline rate as measured by light curve, suggested Phillips (1993). derive linear slopes to this magnitude-decline BV(I)kc colors, using sample with Bmax-Vmax < 0.2 mag. The scatter around (and thus ability measure distances) ranges from 0.13 mag (in I band) 0.17 B band). also find evidence for significant correlations magnitudes or morphological type host galaxy.
We have constructed Hubble diagrams in B and V for 13 Type Ia supernovae (SNe Ia) found the course of Calan/Tololo survey covering an unprecedented range redshift (0.01< z <0.1). As opposed to other published diagrams, these are solely based on light curves obtained with CCDs, which been carefully reduced order avoid background contamination. Special care was also taken extrapolation peak magnitudes SNe that were discovered after maximum by using five different template representing observed...
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...