A5029856662- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- Reservoir Engineering and Simulation Methods
- Pulsars and Gravitational Waves Research
- GNSS positioning and interference
- earthquake and tectonic studies
- Ionosphere and magnetosphere dynamics
- Seismic Waves and Analysis
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
University of Arizona
2022-2023
The Ohio State University
2021-2022
Columbus Center
2022
GRB 221009A ($z=0.151$) is one of the closest known long $\gamma$-ray bursts (GRBs). Its extreme brightness across all electromagnetic wavelengths provides an unprecedented opportunity to study a member this still-mysterious class transients in exquisite detail. We present multi-wavelength observations extraordinary event, spanning 15 orders magnitude photon energy from radio $\gamma$-rays. find that data can be partially explained by forward shock (FS) highly-collimated relativistic jet...
Abstract We present the discovery of a second radio flare from tidal disruption event (TDE) AT2020vwl via long-term monitoring observations. Late-time flares TDEs are being discovered more commonly, with many showing emission thousands days after stellar disruption, but mechanism that powers these late-time is uncertain. Here, we spectral observations first and observed TDE AT2020vwl. Through detailed monitoring, find evidence for two distinct outflow ejection episodes or period renewed...
ABSTRACT The All-Sky Automated Survey for Supernovae (ASAS-SN) is the first optical survey to monitor entire sky, currently with a cadence of ≲ 24 h down g 18.5 mag. ASAS-SN has routinely operated since 2013, collecting ∼ 2 000 over 7 500 epochs V- and g-band observations per field date. This work illustrates analysis ASAS-SN’s newer, deeper, higher data. From an input source list ∼55 million isolated sources < 18 mag, we identified 1.5 × 106 variable star candidates using random...
Abstract We present a comprehensive multi-epoch photometric and spectroscopic study of SN 2024bch, nearby (19.9 Mpc) Type II supernova (SN) with prominent early high-ionization emission lines. Optical spectra from 2.8 days after the estimated explosion reveal narrow lines H i , He ii C iv N that disappear by day 6. High-cadence photometry ground Transiting Exoplanet Survey Satellite show brightened quickly reached peak M V ~ −17.8 mag within week explosion, late-time suggests 56 Ni mass...
Abstract We present results from an extensive follow-up campaign of the tidal disruption event (TDE) ASASSN-15oi spanning δt ∼ 10–3000 days, offering unprecedented window into multiwavelength properties a TDE during its first ≈8 yr evolution. is one few TDEs with strong detections at X-ray, optical/UV, and radio wavelengths it also featured two delayed flares 180 days 1400 days. Our observations > reveal absence thermal X-rays, late-time variability in nonthermal X-ray emission, sharp...
Abstract We present detailed radio observations of the tidal disruption event (TDE) ASASSN-19bt/AT 2019ahk, obtained with Australia Telescope Compact Array, Atacama Large Millimeter/submillimeter and MeerKAT telescopes, spanning 40–1464 days after onset optical flare. find that ASASSN-19bt displays unusual evolution compared to other TDEs, as peak brightness its emission increases rapidly until 457 post-optical discovery then plateaus. Using a generalized approach standard equipartition...
Abstract We present the first results from Citizen ASAS-SN, a citizen science project for All-Sky Automated Survey Supernovae (ASAS-SN) hosted on Zooniverse platform. ASAS-SN utilizes newer, deeper, higher cadence g -band data and tasks volunteers to classify periodic variable star candidates based their phased light curves. started 40,640 new an input list of ∼7.4 million stars with δ < −60° identified 10,420 discoveries which they classified as 4234 pulsating variables, 3132 rotational...
ABSTRACT We examine the properties of ∼50 000 rotational variables from ASAS-SN survey using distances, stellar properties, and probes binarity Gaia DR3 SDSS APOGEE survey. They have higher amplitudes span a broader period range than previously studied Kepler rotators. find they divide into three groups main sequence stars (MS1, MS2s, MS2b) four giants (G1/3, G2, G4s, G4b). MS1 are slowly rotating (10–30 d), likely single with limited temperatures. MS2s more rapidly (days) spanning lower up...
We examine the properties of $\sim50,000$ rotational variables from ASAS-SN survey using distances, stellar properties, and probes binarity $\textit{Gaia}$ DR3 SDSS APOGEE survey. They have high amplitudes span a broader period range than previously studied $\textit{Kepler}$ rotators. find they divide into three groups main sequence stars (MS1, MS2s, MS2b) four giants (G1/3, G2, G4s, G4b). MS1 are slowly rotating (10-30 days), likely single with limited temperatures. MS2s more rapidly (days)...
We present detailed radio observations of the tidal disruption event (TDE) ASASSN-19bt/AT2019ahk, obtained with Australia Telescope Compact Array (ATCA), Atacama Large Millimeter/submillimeter (ALMA), and MeerKAT telescopes, spanning 40 to 1464 days after onset optical flare. find that ASASSN-19bt displays unusual evolution compared other TDEs, as peak brightness its emission increases rapidly until 457 post-optical discovery then plateaus. Using a generalized approach standard equipartition...
We present the results from an extensive follow-up campaign of Tidal Disruption Event (TDE) ASASSN-15oi spanning $\delta t \sim 10 - 3000$ d, offering unprecedented window into multiwavelength properties a TDE during its first $\approx 8$ years evolution. is one few TDEs with strong detections at X-ray, optical/UV, and radio wavelengths featured two delayed flares 180$ d 1400$ d. Our observations $> reveal absence thermal X-rays, late-time variability in non-thermal X-ray emission, sharp...
We present the second results from Citizen ASAS-SN, a citizen science project for All-Sky Automated Survey Supernovae (ASAS-SN) hosted on Zooniverse platform. ASAS-SN tasks users with classifying variable stars based their light curves. started 94975 new candidates and identified 4432 stars. The classified variables as 841 pulsating variables, 2995 rotational 350 eclipsing binaries, 246 unknown variables. found 68% user agreement user-classified 51% 77% binaries. investigate statistics...
We present the discovery of a second radio flare from tidal disruption event (TDE) AT2020vwl via long-term monitoring observations. Late-time flares TDEs are being discovered more commonly, with many showing emission 1000s days after stellar disruption, but mechanism that powers these late-time is uncertain. Here we spectral observations first and observed TDE AT2020vwl. Through detailed monitoring, find evidence for two distinct outflow ejection episodes, or period renewed energy injection...
We present a comprehensive multi-epoch photometric and spectroscopic study of SN 2024bch, nearby (19.9 Mpc) Type II supernova (SN) with prominent early high ionization emission lines. Optical spectra from 2.9 days after the estimated explosion reveal narrow lines H I, He II, C IV, N IV that disappear by day 6. High cadence photometry ground TESS show brightened quickly reached peak M$_V \sim$ $-$17.8 mag within week explosion, late-time suggests $^{56}$Ni mass 0.050 M$_{\odot}$....
GRB 221009A ($z=0.151$) is one of the closest known long $γ$-ray bursts (GRBs). Its extreme brightness across all electromagnetic wavelengths provides an unprecedented opportunity to study a member this still-mysterious class transients in exquisite detail. We present multi-wavelength observations extraordinary event, spanning 15 orders magnitude photon energy from radio $γ$-rays. find that data can be partially explained by forward shock (FS) highly-collimated relativistic jet interacting...
The All-Sky Automated Survey for Supernovae (ASAS-SN) is the first optical survey to monitor entire sky, currently with a cadence of $\lesssim 24$ hours down $g \lesssim 18.5$ mag. ASAS-SN has routinely operated since 2013, collecting $\sim$ 2,000 over 7,500 epochs $V$ and $g-$band observations per field date. This work illustrates analysis ASAS-SN's newer, deeper, higher data. From an input source list ${\sim}55$ million isolated sources $g<18$~mag, we identified $1.5\times10^6$ variable...
Abstract We present “Citizen ASAS-SN,” a citizen science project hosted on the Zooniverse platform which utilizes data from All-Sky Automated Survey for SuperNovae (ASAS-SN). Volunteers are presented with ASAS-SN g -band light curves of variable star candidates. The classification workflow allows volunteers to classify these sources into major groups, while also allowing identification unique stars additional follow-up.