K. Krisciunas
A5089132014- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Historical Astronomy and Related Studies
- Astrophysics and Star Formation Studies
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Planetary Science and Exploration
- Spectroscopy and Laser Applications
- Historical and Architectural Studies
- Medical Imaging Techniques and Applications
- Impact of Light on Environment and Health
- History of Science and Medicine
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Protein Tyrosine Phosphatases
- Atmospheric Ozone and Climate
Texas A&M University
2015-2024
Mitchell Institute
2015-2024
University of Copenhagen
2007-2010
University of Notre Dame
2004-2008
Cerro Tololo Inter-American Observatory
2001-2007
Indian Institute of Astrophysics
2007
Queen's University Belfast
2007
AlbaNova
2007
Stockholm University
2007
Mount Stromlo Observatory
2007
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 early observations of the afterglow GRB 030329 and spectroscopic discovery its associated supernova SN 2003dh. obtained spectra each night from March 30.12 (0.6 days after burst) to April 8.13 (UT) (9.6 burst). The cover a wavelength range 350-850 nm. consist power-law continuum (Fν ∝ ν-0.9) with narrow emission lines originating H II regions in host galaxy, indicating low redshift z = 0.1687. However, our taken 2003 5 show broad peaks flux characteristic supernova. Correcting for...
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...
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 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...
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 present the analysis of first set low-redshift Type Ia supernovae (SNe Ia) by Carnegie Supernova Project. Well-sampled, high-precision optical (ugriBV) and near-infrared (NIR; YJHKs) light curves obtained in a well-understood photometric system are used to provide light-curve parameters, ugriBVYJH template curves. The intrinsic colors at maximum calibrated compute optical--NIR color excesses for full sample, thus allowing properties reddening law host galaxies be studied. A low value...
We present a sample of 148 candidate RR Lyrae stars selected from Sloan Digital Sky Survey (SDSS) commissioning data for about 100 deg 2 sky surveyed twice with Δ t = 1.9946 days. Although the faint-magnitude limit SDSS allows us to detect large Galactocentric distances (∼100 kpc, or r * ∼ 21), we find no candidates fainter than 20, i.e., farther ∼65 kpc Galactic center. On assumption that all are indeed (contamination by other species variable star is probably less 10%), their volume...
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...
We present extensive optical and infrared photometry of the afterglow gamma-ray burst (GRB) 030329 its associated supernova (SN) 2003dh over first two months after detection (2003 March 30-May 29 UT). Optical spectroscopy from a variety telescopes is shown and, when combined with photometry, allows an unambiguous separation between SN contributions. The GRB initially power-law continuum but shows significant color variations during week that are unrelated to presence SN. early light curve...
We present extensive u'g'r'i'BVRIYJHKs photometry and optical spectroscopy of the Type Ia supernova (SN) 2005hk. These data reveal that SN 2005hk was nearly identical in its observed properties to 2002cx, which has been called "the most peculiar known supernova." Both supernovae exhibited high‐ionization 1991T–like premaximum spectra, yet low peak luminosities like 1991bg. The spectra 2005hk, expansion velocities were roughly half those typical supernovae. R I light curves both also not...
We present extensive optical (UBVRI), near-infrared (JK) light curves and spectroscopy of the Type Ia supernova SN 2006X in nearby galaxy NGC 4321 (M100). Our observations suggest that either has an intrinsically peculiar color evolution or it is highly reddened [E(B − V)host = 1.42 ± 0.04 mag ] with RV 1.48 0.06, much lower than canonical value 3.1 for average Galactic dust. also one highest expansion velocities ever published Ia. Compared other SNe we analyzed, a broader curve U band, more...
We present extensive photometry at ultraviolet (UV), optical, and near-infrared (NIR) wavelengths, as well dense sampling of optical spectra, for the normal type Ia supernova (SN Ia) 2005cf. From well-sampled light curves, we find that SN 2005cf reached a B-band maximum 13.63+/-0.02 mag, with an observed luminosity decline rate dm_15(B) = 1.05+/-0.03 mag. The correlations between various color indexes, recalibrated on basis expanded sample, yielded E(B-V)_host=0.09+/-0.03 mag SN2005cf. UV...
This is the first release of optical spectroscopic data low-redshift Type Ia supernovae (SNe Ia) by Carnegie Supernova Project including 604 previously unpublished spectra 93 SNe Ia. The observations cover a range phases from 12 days before to over 150 after time B-band maximum light. With addition 228 near-maximum literature, we study diversity among in quantitative manner. For that purpose, parameters are employed such as expansion velocities spectral line blueshifts and pseudo-equivalent...
Abstract We present 888 visual-wavelength spectra of 122 nearby type II supernovae (SNe II) obtained between 1986 and 2009, ranging 3 363 days post-explosion. In this first paper, we outline our observations data reduction techniques, together with a characterization based on the spectral diversity SNe II. A statistical analysis matching technique is discussed as an alternative to nondetection constraints for estimating SN explosion epochs. The time evolution lines presented analyzed in...
ABSTRACT We present a compilation of UBVRIz light curves 51 type II supernovae discovered during the course four different surveys 1986–2003: Cerro Tololo Supernova Survey, Calán/Tololo Program (C&T), Optical and Infrared Survey (SOIRS), Carnegie Type (CATS). The photometry is based on template-subtracted images to eliminate any potential host galaxy contamination, calibrated from foreground stars. This work presents these photometric data, studies color evolution using bands, explores...
We study optical light curve(LC) relations of type Ia supernovae(SNe~Ia) for their use in cosmology using high-quality photometry published by the Carnegie-Supernovae-Project (CSP-I). revisit classical luminosity-decline-rate ($Δm_{15}$) relation and Lira-relation, as well investigate time evolution ($B-V$) color $B(B-V)$, which serves basis color-stretch Color-MAGnitude-Intercept-Calibrations(CMAGIC). Our analysis is based on explosion radiation transport simulations spherically-symmetric...
Abstract We present JWST near-infrared (NIR) and mid-infrared (MIR) spectroscopic observations of the nearby normal Type Ia supernova (SN) SN 2021aefx in nebular phase at +255 days past maximum light. Our Near Infrared Spectrograph (NIRSpec) Mid Instrument observations, combined with ground-based optical data from South African Large Telescope, constitute first complete optical+NIR+MIR spectrum covering 0.3–14 μ m. This unveils previously unobserved 2.5−5 m region, revealing strong iron...
In this paper we describe a new class of pulsating stars, the prototype which is bright, early, F‐type dwarf γ Doradus. These stars typically have between 1 and 5 periods ranging from 0.4 to 3 days with photometric amplitudes up 0.1 mag in Johnson V. The mechanism for these observed variations high‐order, low‐degree, nonradial, gravity‐mode pulsation.
We present well sampled optical (UBVRI) and infrared (JHK) light curves of the nearby (~18.0 Mpc) Type Ia supernova SN 2001el, from 11 days before to 142 after time B-band maximum. The data represent one best sets photometry ever obtained for a supernova. Based on synthetic using spectra 2001el 1999ee, we were able devise filter corrections BVJHK which some extent resolve systematic differences between datasets with different telescope/filter/instrument combinations. also calculated V minus...
In this paper, measurements of the sky brightness from 2800-m level Mauna Kea are reported. addition, a model is presented for predicting moonlight as function moon's phase, zenith distance moon, position, angular separation moon and local extinction coefficient. The equations can be quickly calculated on pocket calculator. A comparison with lunar data some Russian solar shows accuracy predictions to range 8 percent 23 percent.
We present the discovery and follow-up observations of afterglow gamma-ray burst GRB 011121 its associated supernova SN 2001ke. Images were obtained with Optical Gravitational Lensing Experiment 1.3 m telescope in BVRI passbands, starting 10.3 hr after burst. The temporal analysis our early data indicates a steep decay, independent wavelength, Fν ∝ t-1.72±0.05. There is no evidence for break light curve earlier than 2.5 days spectral energy distribution determined from broadband photometry...
We present UBVRIJHK photometry and optical spectroscopy of the so-called peculiar Type Ia supernova 1999by in NGC 2841. The observations began 1 week before visual maximum light, which is well defined by daily observations. light curves spectra are similar to those prototypical subluminous event SN 1991bg. find that B occurred on 1999 May 10.3 UT (JD 2,451,308.8 ± 0.3) with = 13.66 0.02 a color Bmax - Vmax 0.51 0.03. late-time implies minimal dust extinction from host galaxy. Our photometry,...