A5045838953- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- SAS software applications and methods
- Neutrino Physics Research
- Scientific Computing and Data Management
- Galaxies: Formation, Evolution, Phenomena
- Geological and Geophysical Studies
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Astrophysics and Star Formation Studies
- Nuclear Physics and Applications
- Mitochondrial Function and Pathology
- Metabolism and Genetic Disorders
- Historical Astronomy and Related Studies
- Spacecraft and Cryogenic Technologies
- Health and Medical Research Impacts
- Distributed and Parallel Computing Systems
- Radio Astronomy Observations and Technology
- Particle Detector Development and Performance
University of Virginia
2023-2024
McCormick (United States)
2023
New York University
2013-2022
Flatiron Health (United States)
2019-2020
Flatiron Institute
2019-2020
University of Nova Gorica
2018
University of California, Berkeley
1999-2017
Wyoming Department of Education
2012
Columbia University
2011
Berkeley College
2008-2010
This is the second paper of a series in which we present new measurements observed rates supernovae (SNe) local Universe, determined from Lick Observatory Supernova Search (LOSS). In this paper, complete SN sample constructed, and (uncorrected for host-galaxy extinction) luminosity functions (LFs) SNe are derived. These LFs solve two issues that have plagued previous rate calculations nearby SNe: distribution extinction. We select volume-limited 175 SNe, collect photometry every object fit...
We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11,500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains largest number homogeneously observed reduced nearby SNe Ia (z ≲ 0.08) published to date. It more than doubles sample, bringing SN cosmology point where systematic uncertainties dominate. Our natural system has a precision ≲0.02 mag in BVRIr'i' ≲0.04...
Variable X-ray and gamma-ray emission is characteristic of the most extreme physical processes in Universe, studying sources these energetic photons has been a major driver astronomy for past 50 years. Here we present multiwavelength observations unique selected transient, discovered by Swift, which was accompanied bright across electromagnetic spectrum, whose properties are unlike any previously observed source. We pinpoint event to center small, star-forming galaxy at redshift z=0.3534....
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...
In this first paper in a series we present 1298 low-redshift (z\leq0.2) optical spectra of 582 Type Ia supernovae (SNe Ia) observed from 1989 through 2008 as part the Berkeley SN Program (BSNIP). 584 199 SNe have well-calibrated light curves with measured distance moduli, and many been corrected for host-galaxy contamination. Most data were obtained using Kast double spectrograph mounted on Shane 3 m telescope at Lick Observatory typical wavelength range 3300-10,400 Ang., roughly twice wide...
We present 2603 spectra of 462 nearby Type Ia supernovae (SNe Ia), including 2065 previously unpublished spectra, obtained during 1993–2008 through the Center for Astrophysics Supernova Program. There are on average eight each 313 SNe with at least two spectra. Most were FAST spectrograph Fred Lawrence Whipple Observatory 1.5 m telescope and reduced in a consistent manner, making this data set well suited studies SN spectroscopic diversity. Using additional from literature, we study...
We present the first systematic investigation of spectral properties 17 Type Ic Supernovae (SNe Ic), 10 broad-lined SNe Ic-bl) without observed Gamma-Ray Bursts (GRBs) and 11 Ic-bl with GRBs (SN-GRBs) as a function time in order to probe their explosion conditions progenitors. analyze total 407 spectra, which were drawn from published spectra individual well densely time-sampled data Modjaz et al. (2014). In quantify diversity SN subtype, we construct average Ic, GRBs. find that 1994I is not...
Abstract We present the densely sampled early light curve of Type II supernova (SN) 2023ixf, first observed within hours explosion in nearby Pinwheel Galaxy (Messier 101; 6.7 Mpc). Comparing these data to recently updated models shock-cooling emission, we find that progenitor likely had a radius 410 ± 10 R ⊙ . Our estimate is model dependent but consistent with red supergiant. These provide good fit starting about 1 day after explosion, despite fact classification spectrum shows signatures...
We present extensive early photometric (ultraviolet through near-infrared) and spectroscopic (optical data on supernova (SN) 2008D as well X-ray analysis the associated Swift transient (XRT) 080109. Our span a time range of 5 hr before detection to 150 days after its detection, detailed allowed us derive constraints nature SN progenitor; throughout we draw comparisons with results presented in literature find several key aspects that differ. show spectrum XRT 080109 can be fit equally by an...
We present 645 optical spectra of 73 supernovae (SNe) Types IIb, Ib, Ic, and broad-lined Ic. All these types are attributed to the core collapse massive stars, with varying degrees intact H He envelopes before explosion. The SNe in our sample have a mean redshift 〈cz〉 = 4200 km s−1. Most were gathered at Harvard-Smithsonian Center for Astrophysics (CfA) between 2004 2009. For 53 SNe, first published spectra. data coverage ranges from mere identification (1–3 spectra) few extensive series...
We present ultraviolet, optical, and near-infrared photometry as well optical spectra of the peculiar supernova (SN) 2008ha. SN 2008ha had a very low peak luminosity, reaching only MV = −14.2 mag, line velocities ∼2000 km s−1 near maximum brightness, indicating small kinetic energy per unit mass ejecta. Spectroscopically, is member 2002cx-like class SNe, subclass SNe Ia; however, most extreme member, being significantly fainter having lower than typical which already ∼2 mag has ∼5000 smaller...
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...
We have obtained 1087 NIR (JHKs) measurements of 21 SNe Ia using PAIRITEL, nearly doubling the number well-sampled SN light curves. These data strengthen evidence that are excellent standard candles in NIR, even without correction for optical light-curve shape. construct fiducial templates normal from our sample, excluding only three known peculiar Ia: 2005bl, 2005hk, and 2005ke. The H-band absolute magnitudes this sample 18 an intrinsic rms 0.15 mag with no found a relationship between...
In the epoch of precise and accurate cosmology, cross-confirmation using a variety cosmographic methods is paramount to circumvent systematic uncertainties. Owing progenitor histories explosion physics differing from those Type Ia supernovae (SNe Ia), II-plateau II-P) are unlikely be affected by evolution in same way. Based on new analysis 17 SNe II-P, an improved methodology, we find that II-P good standardizable candles, almost comparable Ia. We derive tight Hubble diagram with dispersion...
We report on our early photometric and spectroscopic observations of the extremely luminous Type II supernova (SN) 2008es. SN 2008es, with an observed peak optical magnitude mV = 17.8 at a redshift z 0.213, has absolute MV −22.3, making it second most ever observed. The evolution 2008es exhibits fast decline rate (∼ 0.042 mag d−1), similar to II-Linear (II-L) 2005ap. show that spectroscopically resembles II-L 1979C. Although spectra lack narrow intermediate-width line emission typically...
Recent high-resolution spectra of the Type Ia supernova SN 2006X have revealed presence time-variable and blueshifted Na i D features, interpreted by Patat et al. as originating in circumstellar material within progenitor system. The variation seen induces relatively large changes total equivalent width (ΔEW ∼ 0.5 Å just over two weeks) that would be detectable at lower resolutions. We used a data set comprising 2400 low-resolution 450 supernovae (SNe Ia) obtained CfA Supernova Program to...
Owing to their utility for measurements of cosmic acceleration, Type Ia supernovae (SNe) are perhaps the best-studied class SNe, yet progenitor systems these explosions largely remain a mystery. A rare subclass SNe show evidence strong interaction with circumstellar medium (CSM), and in particular, hydrogen-rich CSM; we refer them as Ia-CSM. In first systematic search such systems, have identified 16 Ia-CSM, here present new spectra 13 them. Six Ia-CSM been well-studied previously, three...
We present a densely-sampled, homogeneous set of light curves 64 low redshift (z < 0.05) stripped-envelope supernovae (SN type IIb, Ib, Ic and Ic-bl). These data were obtained between 2001 2009 at the Fred L. Whipple Observatory (FLWO) on Mt. Hopkins in Arizona, with optical FLWO 1.2-m near-infrared PAIRITEL 1.3-m telescopes. Our dataset consists 4543 photometric measurements 61 SN, including combination UBVRI, UBVr'i', u'BVr'i', 2142 JHKs 25 SN. This sample constitutes most extensive...
What are Type II-Linear supernovae (SNe II-L)? This class, which has been ill defined for decades, now receives significant attention – both theoretically, in order to understand what happens stars the ∼15–25 M⊙ range, and observationally, with two independent studies suggesting that they cannot be cleanly separated photometrically from regular hydrogen-rich SNe II-P characterized by a marked plateau their light curve. Here, we analyse multiband curves extensive spectroscopic coverage of...
In Paper I of this series, we showed that the ratio between stripped-envelope (SE) supernova (SN) and Type II SN rates reveals a significant SE deficiency in galaxies with stellar masses $\lesssim 10^{10}~{\rm M}_\odot$. Here, test result by splitting volume-limited subsample Lick Observatory Supernova Search (LOSS) sample into low- high-mass comparing relative various types found them. The LOSS contains 180 SNe impostors is complete for Ia out to 80 Mpc core-collapse 60 Mpc. All these...
We present the final installment of an intensive 13 year study variations optical continuum and broad Hβ emission line in Seyfert 1 galaxy NGC 5548. The database consists 1530 measurements 1248 measurements. follow closely, with a typical time delay about 20 days. However, year-by-year analysis shows that magnitude emission-line is correlated mean flux. argue data are consistent simple model prediction between size broad-line region ionizing luminosity, r ∝ L. Moreover, apparently linear...
We present early photometric and spectroscopic data on the afterglow of GRB 060218 report evolution underlying supernova SN 2006aj. Our span a time range 4-23 days after clearly establish that 2006aj is fast-evolving broad-lined Type Ic with an extremely short rise (~10 days) large optical peak luminosity (MV = -18.7 mag). The properties are deduced well since gamma-ray burst (GRB) does not contribute significant amount to total light output. spectra show broad lines indicative expansion...
We present extensive photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2000cx in S0 galaxy NGC 524, which reveal it to be peculiar. Photometrically, SN is different from all known SNe Ia, its light curves cannot fitted well by fitting techniques currently available. There an apparent asymmetry B‐band peak, premaximum brightening relatively fast (similar that normal 1994D), but postmaximum decline slow overluminous 1991T). The color evolution also peculiar: (B−V)0...
We analyze the Type II plateau supernovae (SNe IIP) SN 2005cs and 2006bp with non-LTE model atmosphere code CMFGEN. fit 13 spectra in first month for 18 2006bp. Swift ultraviolet photometry ground-based optical calibrate each spectrum. Our analysis shows that both objects were discovered less than 3 days after they exploded, making these earliest IIP ever studied. They reveal broad very weak lines from highly ionized fast ejecta an extremely steep density profile. identify He λ4686 emission...
Double-peaked oxygen lines in the nebular spectra of two peculiar Type Ib/c supernovae (SNe Ib/c) have been interpreted as off-axis views a GRB jet or unipolar blob ejections. Here we present late-time eight SNe IIb, Ib, and Ic show that this phenomenon is common should not be so firmly linked to extraordinary explosion physics. The line profiles are most likely caused by ejecta expanding with torus- disk-like geometry. necessarily indicator misdirected jet.