A5071236367- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Molecular Spectroscopy and Structure
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Laser-induced spectroscopy and plasma
- Atmospheric Ozone and Climate
- Spacecraft Design and Technology
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Astronomical Observations and Instrumentation
- Planetary Science and Exploration
- Advanced Thermodynamic Systems and Engines
- Radio Astronomy Observations and Technology
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Space exploration and regulation
- Economic Growth and Productivity
- Space Satellite Systems and Control
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- High-pressure geophysics and materials
TD Bank
2022-2024
Rochester Institute of Technology
2019-2022
Institut de Planétologie et d'Astrophysique de Grenoble
2019-2021
University of California, Santa Barbara
2013-2014
Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth society. We propose an orbital planetary defense system capable heating the surface hazardous objects vaporization point as feasible approach impact mitigation. call DE-STAR, for Directed Energy System Targeting exploRation. The DE-STAR is modular-phased array kilowatt class lasers powered by photovoltaic's. Modular design allows incremental development, minimizing...
Certain planetary nebulae contain shells, filaments, or globules of cold gas and dust whose heating chemistry are likely driven by UV X-ray emission from their central stars wind-collision-generated shocks. We present the results a survey molecular line in 88-236 GHz range nine nearby (<1.5 kpc) spanning luminosities, using 30 m telescope Institut de Radioastronomie Millimetrique. Rotational transitions thirteen molecules, including CO isotopologues chemically important trace species, were...
Current strategies for diverting threatening asteroids require dedicated operations every individual object. We propose a stand-off, Earth-orbiting system capable of vaporizing the surface as futuristic but feasible approach to impact risk mitigation. call DE-STAR (Directed Energy System Targeting Asteroids and exploRation). is modular phased array laser amplifiers, powered by solar photovoltaic panels. Lowcost development test systems possible with existing technology. Larger arrays could...
We present the results of a comprehensive, near-UV-to-near-IR Hubble Space Telescope WFC3 imaging study young planetary nebula (PN) NGC 6302, archetype class extreme bi-lobed, pinched-waist PNe that are rich in dust and molecular gas. The new emission-line image suite clearly defines dusty toroidal equatorial structure bisects 6302's polar lobes, fine structures (clumps, knots, filaments) within lobes. most striking aspect is bright, S-shaped 1.64 micron [Fe II] emission traces southern...
The iconic planetary nebula (PN) NGC 7027 is bright, nearby (D ~ 1 kpc), highly ionized, intricately structured, and well observed. This hence an ideal case study for understanding PN shaping evolution processes. Accordingly, we have conducted a comprehensive imaging survey of comprised twelve HST Wide Field Camera 3 images in narrow-band continuum filters spanning the wavelength range 0.243--1.67 microns. resulting panchromatic image suite reveals spatial distributions emission lines...
Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth society. Numerous mitigation strategies have been described, most involving dedicated missions threatening object. We propose an orbital planetary defense system capable heating the surface hazardous objects vaporization point as feasible approach impact mitigation. call DE-STAR for Directed Energy System Targeting exploRation. is modular phased array kilowatt class...
Abstract We present Submillimeter Array (SMA) mapping of 12 CO J = 2 → 1, 13 and CN N 1 emission from the ring-like planetary nebula NGC 3132, one subjects JWST Early Release Observation near-infrared imaging. The ∼5″ resolution SMA data demonstrate that Southern Ring’s main, bright, molecule-rich ring is indeed an expanding ring, as opposed to a limb-brightened shell, in terms its intrinsic (physical) structure. This suggests 3132 bipolar viewed more or less pole-on (inclination ∼15°–30°)....
Observations of molecular clouds, prestellar cores, and protoplanetary disks have established that the HNC/HCN ratio may be a potent diagnostic gas physical conditions. The processes govern relative abundances these molecules nevertheless remain poorly understood. We seek to exploit wide range UV irradiation strengths within 1 pc diameter Helix planetary nebula explore potential role radiation in driving HNC/HCN. performed IRAM 30 m APEX 12 radio line observations across six positions...
The young and well-studied planetary nebula NGC 7027 harbors significant molecular gas that is irradiated by luminous, point-like UV (central star) diffuse (shocked nebular) X-ray emission. This represents an excellent subject to investigate the chemistry physical conditions within photon- X-ray-dominated regions (PDRs XDRs). As yet, exact formation routes of CO$^+$ HCO$^+$ in PN environments remain uncertain. Here, we present $\sim$2$"$ resolution maps irradiation tracers HCO$^+$, obtained...
We present the first results from comprehensive, near-UV-to-near-IR Hubble Space Telescope Wide Field Camera 3 (WFC3) emission-line imaging studies of two young planetary nebulae (PNe), NGC 7027 and 6302. These objects represent key sources for purposes understanding PNe shaping processes. Both feature axisymmetric point-symmetric (bipolar) structures and, despite hot central stars high nebular excitation states, both harbor large masses molecular gas dust. The sweeping wavelength coverage...
We present Submillimeter Array (SMA) mapping of $^{12}$CO $J=2\rightarrow 1$, $^{13}$CO and CN $N=2\rightarrow 1$ emission from the Ring-like planetary nebula (PN) NGC 3132, one subjects JWST Early Release Observation (ERO) near-infrared imaging. The $\sim$5$''$ resolution SMA data demonstrate that Southern Ring's main, bright, molecule-rich ring is indeed an expanding ring, as opposed to a limb-brightened shell, in terms its intrinsic (physical) structure. This suggests 3132 bipolar viewed...
We present early results from our program of ALMA Band 6 (1.3mm) molecular line mapping a sample nearby, well-studied examples high-excitation, bipolar/pinched-waist and molecule-rich planetary nebulae (Hubble 5 NGC 2440, 2818, 2899, 6302, 6445). have mapped these (PNe) in isotopologues CO as well various tracers high-energy irradiation, such HCN, CN, HNC, HCO+, with the complementary goals establishing nebular kinematics zones UV-heated X-ray-ionized gas within each nebula. The resulting...
We analyse recent high-quality Atacama Large Millimeter Array (ALMA) molecular line mapping observations of the northeast jet young stellar object (YSO) OMC 2/FIR6b (HOPS-60) and find that these ALMA are much more likely to indicate a twin-jet structure than rotation, as previously hypothesized. The interpretation sight velocity gradient across (perpendicular its axis) Fir6b in terms rotation leads jet-launching radii ~2-3AU. However, velocities jets ~100-400 km/s larger escape speed from...
Background: Many planetary nebulae retain significant quantities of molecular gas and dust despite their signature hostile radiation environments energetic shocks. Photoionization dissociation by extreme UV (often) X-ray emission from central stars drive the chemical processing this material. Their well-defined geometries make ideal testbeds for modeling effects radiation-driven heating chemistry on in photodissociation regions. Methods: We have carried out IRAM 30m/APEX 12m/ALMA radio...
Planetary nebulae (PNe), the ejected envelopes of red giant stars, provide us with a history last, mass-losing phases 90 percent stars initially more massive than Sun. Here, we analyse James Webb Space Telescope (JWST) Early Release Observation (ERO) images PN NGC3132. A structured, extended H2 halo surrounding an ionised central bubble is imprinted spiral structures, likely shaped by low-mass companion orbiting star at 40-60 AU. The also reveal mid-IR excess interpreted as dusty disk,...