Lindsey A. Kwok
A5013050822- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Calibration and Measurement Techniques
- Advanced Sensor Technologies Research
- Sensor Technology and Measurement Systems
- Nuclear Physics and Applications
- Astronomical Observations and Instrumentation
- Laser-Plasma Interactions and Diagnostics
- Atmospheric and Environmental Gas Dynamics
- Mitochondrial Function and Pathology
- Spectroscopy Techniques in Biomedical and Chemical Research
Rutgers, The State University of New Jersey
2020-2024
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...
Abstract We present high-cadence photometric and spectroscopic observations of supernova (SN) 2024ggi, a Type II SN with flash spectroscopy features, which exploded in the nearby galaxy NGC 3621 at ∼7 Mpc. The light-curve evolution over first 30 hr can be fit by two power-law indices break after 22 hr, rising from M V ≈ −12.95 mag +0.66 day to −17.91 7 days. In addition, densely sampled color curve shows strong blueward few days then behaves as normal redward ejecta cool. Such deviations...
Abstract We present a JWST/MIRI low-resolution mid-infrared (MIR) spectroscopic observation of the normal Type Ia supernova (SN Ia) SN 2021aefx at +323 days past rest-frame B -band maximum light. The spectrum ranges from 4 to 14 μ m and shows many unique qualities, including flat-topped [Ar iii ] 8.991 profile, strongly tilted [Co 11.888 feature, multiple stable Ni lines. These features provide critical information about physics explosion. observations are compared synthetic spectra detailed...
Abstract We present an analysis of ground-based and JWST observations SN 2022pul, a peculiar “03fg-like” (or “super-Chandrasekhar”) Type Ia supernova (SN Ia), in the nebular phase at 338 days postexplosion. Our combined spectrum continuously covers 0.4–14 μ m includes first mid-infrared 03fg-like Ia. Compared to normal 2021aefx, 2022pul exhibits lower mean ionization state, asymmetric emission-line profiles, stronger emission from intermediate-mass elements (IMEs) argon calcium, weaker...
Abstract We present high-cadence photometric and spectroscopic observations of SN 2023axu, a classical Type II supernova with an absolute V -band peak magnitude –17.2 ± 0.1 mag. 2023axu was discovered by the Distance Less Than 40 Mpc (DLT40) survey within 1 day last nondetection in nearby galaxy NGC 2283 at 13.7 Mpc. modeled early light curve using recently updated shock cooling model that includes effects line blanketing found explosion epoch to be MJD 59971.48 0.03 probable progenitor red...
We present high-cadence optical and ultraviolet light curves of the normal Type Ia supernova (SN) 2021aefx, which shows an early bump during first two days observation. This may be a signature interaction between exploding white dwarf nondegenerate binary companion, or it intrinsic to explosion mechanism. In case former, short duration implies relatively compact main-sequence companion star, although this conclusion is viewing-angle dependent. Our best-fit companion-shocking...
A large fraction of Type Ia supernova (SN Ia) observations over the next decade will be in near-infrared (NIR), at wavelengths beyond reach current standard light-curve model for SN cosmology, SALT3 ($\sim 2800$--8700$A$ central filter wavelength). To harness this new sample and reduce future standardization systematic uncertainties, we train NIR (SALT3-NIR) up to 2 $\mu$m with open-source model-training software SALTShaker, which can easily accommodate observations. Using simulated data...
We present optical and near-infrared (NIR) observations of the Type Icn supernova (SN Icn) 2022ann, fifth member its newly identified class SNe. Its early spectra are dominated by narrow carbon oxygen P-Cygni features with absorption velocities 800 km/s; slower than other SNe indicative interaction a dense, H/He-poor circumstellar medium (CSM) that is outflowing typical Wolf-Rayet wind velocity $>$1000 km/s. identify helium in NIR obtained two weeks after maximum at three weeks,...
Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe the more common, cosmologically useful Ia. We present from an extensive ground-based space-based follow-up campaign to characterize SN 2022pul, a "super-Chandrasekhar" mass (alternatively "03fg-like" SN), before peak brightness well into nebular phase across optical mid-infrared (MIR) wavelengths. The early rise light curve is...
Abstract We present very early photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2023bee, starting about 8 hr after explosion, which reveal a strong excess in optical nearest UV ( U UVW1 ) bands during first several days explosion. This data set allows us to probe nature binary companion exploding white dwarf conditions leading its ignition. find good match Kasen model main-sequence star stings ejecta with shock as they buzz past. Models double detonations, shells...
Abstract We present five far- and near-ultraviolet spectra of the Type II plateau supernova, SN 2022acko, obtained 5, 6, 7, 19, 21 days after explosion, all observed with Hubble Space Telescope/Space Telescope Imaging Spectrograph. The first three epochs are earlier than any supernova has been in far-ultraviolet revealing unprecedented characteristics. These dominated by strong lines, primarily from metals, which contrasts featureless early optical spectra. flux decreases over initial time...
Abstract We present an analysis of 102 Type Ia supernovae (SNe Ia) in nearby ( z < 0.1), x-ray-selected galaxy clusters. This is the largest such sample to date and based on archival data primarily from ZTF ATLAS. divide our SNe into inner cluster projected within r 500 center outer between 2 . compare these field samples at similar redshifts both quiescent star-forming host galaxies. Based SALT3 fits light curves, we find that have a higher fraction fast-evolving objects (SALT3 x 1 −1)...
We present multi-band photometry and spectroscopy of SN 2018cuf, a Type IIP ("P" for plateau) supernova (SN) discovered by the Distance Less Than 40 Mpc survey (DLT40) within 24 hours explosion. 2018cuf appears to be typical SN, with an absolute $V$-band magnitude $-$16.73 $\pm$ 0.32 at maximum decline rate 0.21 0.05 mag/50d during plateau phase. The distance object is constrained 41.8 5.7 using expanding photosphere method. use spectroscopic photometric observations from first year after...
Abstract We present the Keck Infrared Transient Survey, a NASA Key Strategic Mission Support program to obtain near-infrared (NIR) spectra of astrophysical transients all types, and its first data release, consisting 105 NIR 50 transients. Such set is essential as we enter new era IR astronomy with James Webb Space Telescope (JWST) upcoming Nancy Grace Roman (Roman). spectral templates will be search JWST images for stellar explosions stars plan an effective SN Ia cosmology survey, both key...
We present early-time ($t < +50$ days) observations of SN 2019muj (= ASASSN-19tr), one the best-observed members peculiar Iax class. Ultraviolet and optical photometric near-infrared spectroscopic follow-up started from $\sim$5 days before maximum light ($t_{max}(B)$ on $58707.8$ MJD) covers photospheric phase. The early allow us to estimate physical properties ejecta characterize possible divergence a uniform chemical abundance structure. estimated bolometric curve peaks at 1.05 $\times$...
With the advent of high cadence, all-sky automated surveys, supernovae (SNe) are now discovered closer than ever to their dates explosion. However, young pre-maximum light follow-up spectra Type Ic (SNe Ic), probably arising from most stripped massive stars, remain rare despite importance. In this paper we present a set 49 optical observed with Las Cumbres Observatory through Global Supernova Project for 6 SNe Ic, including total 17 spectra, which 8 more week before V-band maximum light....
Abstract We present new 0.3–21 μ m photometry of SN 2021aefx in the spiral galaxy NGC 1566 at +357 days after B -band maximum, including first detection any Type Ia supernova (SN Ia) >15 m. These observations follow earlier JWST +255 time maximum brightness, allowing us to probe temporal evolution emission properties. measure fraction flux emerging different wavelengths and its evolution. Additionally, integrated 0.3–14 decay rate Δ = 1.35 ± 0.05 mag/100 is higher than decline from...
We present an analysis of ground-based and JWST observations SN~2022pul, a peculiar "03fg-like" (or "super-Chandrasekhar") Type Ia supernova (SN Ia), in the nebular phase at 338d post explosion. Our combined spectrum continuously covers 0.4--14 $\mu$m includes first mid-infrared 03fg-like SN Ia. Compared to normal 2021aefx, 2022pul exhibits lower mean ionization state, asymmetric emission-line profiles, stronger emission from intermediate-mass elements (IMEs) argon calcium, weaker iron-group...
Abstract Few published ultraviolet (UV) spectra exist for stripped-envelope supernovae and none to date broad-lined Type Ic (SNe Ic-bl). These objects have extremely high ejecta velocities are the only supernova type directly linked gamma-ray bursts (GRBs). Here we present two epochs of HST/STIS SN Ic-bl 2014ad, first UV this class. We supplement with 26 new ground-based optical spectra, augmenting a rich spectral time series. The do not show strong features consistent broadened versions...
We present observations of SN 2021csp, a unique supernova (SN) which displays evidence for interaction with H- and He- poor circumstellar material (CSM) at early times. Using high-cadence spectroscopy taken over the first week after explosion, we show that spectra 2021csp are dominated by C III lines velocity 1800 km s$^{-1}$. associate this emission CSM lost progenitor prior to explosion. Subsequently, narrow He before metamorphosing into broad-lined Type Ic SN. model bolometric light curve...
We present an analysis of 102 type Ia supernovae (SNe Ia) in nearby (z < 0.1), x-ray selected galaxy clusters. This is the largest such sample to date and based on archival data primarily from ZTF ATLAS. divide our SNe into inner cluster projected within $r_{500}$ center outer between $2\,r_{500}$. compare these field samples at similar redshifts both quiescent star-forming host galaxies. Based SALT3 fits light curves, we find that have a higher fraction fast-evolving objects (SALT3 $x_1...
We present optical and near-infrared observations of SN~2022crv, a stripped envelope supernova in NGC~3054, discovered within 12 hrs explosion by the Distance Less Than 40 Mpc Survey. suggest SN~2022crv is transitional object on continuum between SNe Ib IIb. A high-velocity hydrogen feature ($\sim$$-$20,000 -- $-$16,000 $\rm km\,s^{-1}$) was conspicuous at early phases, then quickly disappeared around maximum light. By comparing with hydrodynamic modeling, we find that $\sim 10^{-3}$ \msun{}...
Abstract We present optical, infrared, ultraviolet, and radio observations of SN 2022xkq, an underluminous fast-declining Type Ia supernova (SN Ia) in NGC 1784 ( D ≈ 31 Mpc), from <1 to 180 days after explosion. The high-cadence a photometrically transitional spectroscopically 91bg-like Ia, cover the first weeks following explosion, which are critical distinguishing between explosion scenarios. early light curve 2022xkq has red color exhibits flux excess that is more prominent redder...
We present new 0.3-21 micron photometry of SN 2021aefx in the spiral galaxy NGC 1566 at +357 days after B-band maximum, including first detection any Ia >15 micron. These observations follow earlier JWST +255 time maximum brightness, allowing us to probe temporal evolution emission properties. measure fraction flux emerging different wavelengths and its evolution. Additionally, integrated 0.3-14 decay rate $Δm_{0.3-14} = 1.35 \pm 0.05$ mag/100 is higher than decline from radioactive...
Abstract Type Iax supernovae (SNe Iax) are the largest known class of peculiar white dwarf SNe, distinct from normal Ia Ia). The unique properties SNe Iax, especially their strong photospheric lines out to extremely late times, allow us model optical spectra and derive physical parameters long-lasting photosphere. We present an extensive spectral timeseries, including 21 new spectra, SN 2014dt +11 +562 days after maximum light. able reproduce entire timeseries with a self-consistent, nearly...