A5065227128- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Spectroscopy Techniques in Biomedical and Chemical Research
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Spectroscopy and Chemometric Analyses
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Geomagnetism and Paleomagnetism Studies
- Adaptive optics and wavefront sensing
- Science Education and Pedagogy
- Pulsars and Gravitational Waves Research
- Eicosanoids and Hypertension Pharmacology
- Space Exploration and Technology
- Mechanical and Optical Resonators
- Visual and Cognitive Learning Processes
- Molecular Spectroscopy and Structure
- Historical Astronomy and Related Studies
- Advanced Thermodynamics and Statistical Mechanics
- Inertial Sensor and Navigation
Harvard University
2024
Center for Astrophysics Harvard & Smithsonian
2018-2024
Community Farm Alliance
2021
University of Notre Dame
2016-2018
California Polytechnic State University
2011
We present optical light curves, redshifts, and classifications for 365 spectroscopically confirmed Type Ia supernovae (SNe Ia) discovered by the Pan-STARRS1 (PS1) Medium Deep Survey. detail improvements to PS1 SN photometry, astrometry calibration that reduce systematic uncertainties in distances. combine subset of 279 ($0.03 < z 0.68$) with useful distance estimates from SDSS, SNLS, various low-z HST samples form largest combined sample consisting a total 1048 ranging $0.01 2.3$, which we...
The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely-calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. calibration of the current SN is largest component systematic uncertainties cosmology, new data are necessary make progress. We present motivation, survey design, observation strategy, implementation, first results Survey. using Pan-STARRS telescope obtain photometry up 800 SNe at z < 0.1. This strategy has several unique...
A major question in the field of star formation is how molecular clouds form out diffuse Interstellar Medium (ISM). Recent advances 3D dust mapping are revolutionizing our view structure ISM. Using highest-resolution map to date, we explore a nearby star-forming region, which includes well-known Perseus and Taurus clouds. We reveal an extended near-spherical shell, 156 pc diameter, hereafter "Per-Tau Shell", embedded. also find large ring at location Taurus, hereafter, "Tau Ring". discuss...
Recent analyses suggest that distance residuals measured from Type Ia supernovae (SNe Ia) are correlated with local host galaxy properties within a few kpc of the SN explosion. However, well-established correlation global is nearly as significant, shift 0.06 mag across low to high mass boundary (the step). Here, 273 SNe at $z<0.1$, we investigate whether stellar masses and rest-frame $u-g$ colors regions 1.5 explosion site significantly better measurements than or random locations in hosts....
Undergraduate physics and astronomy students are expected to engage with scientific literature as they begin their research careers, yet reading comprehension skills rarely explicitly taught in major courses. We seek determine the efficacy of a assignment designed improve undergraduate (or related) majors’ perceived ability by using accessible summaries current written experts field. During 2022–2023 academic year, faculty members from six institutions incorporated assignments Astrobites...
We present a phase-space study of two stellar groups located at the core Orion complex: Brice\~no-1 and Belt Population-near (OBP-near). identify with unsupervised clustering algorithm, Shared Nearest Neighbor (SNN), which previously identified twelve new substructures in complex. For each groups, we derive 3D space motions individual stars using Gaia EDR3 proper supplemented by radial velocities from DR2, APOGEE-2, GALAH DR3. evidence for expansion common center. Unlike previous work, our...
Abstract Measurements of the dark energy equation-of-state parameter, w , have been limited by uncertainty in selection effects and photometric calibration z < 0.1 Type Ia supernovae (SNe Ia). The Foundation Supernova Survey is designed to lower these uncertainties creating a new sample SNe observed on Pan-STARRS system. Here we combine with from Medium Deep measure cosmological parameters 1338 single telescope single, well-calibrated For first time, both low- high- data are predominantly...
Barnard's Loop is a famous arc of H$\alpha$ emission located in the Orion star-forming region. Here, we provide evidence possible formation mechanism for and compare our results with recent work suggesting major feedback event occurred region around 6 Myr ago. We present 3D model large-scale region, indicating coherent, radial, expansion OBP-Near/Brice\~{n}o-1 (OBP-B1) cluster middle large dust cavity. The gas also appears to be expanding from central point, originally proposed X. OBP-B1...
Abstract The Sun moves through the interstellar medium (ISM) at a velocity of ∼19 pc Myr −1 , making conditions outside solar system vary with time over millions years. Today’s is protected from particles by heliosphere, bubble formed wind as ISM, which engulfs planets. There geological evidence 60 Fe that Earth was in direct contact ISM 2–3 and 5–7 million years ago (MYA). Recent work argues encountered massive cold cloud 2 MYA part Local Ribbon Cold Clouds shrunk heliosphere exposed to...
We search the COSMOS survey for pairs of galaxies consistent with gravitational lensing signature a cosmic string. The imaged 1.64 square degrees using Advanced Camera Surveys aboard Hubble Space Telescope. Our technique includes estimates efficiency finding lensed galaxy pair. find no evidence strings mass per unit length $G\ensuremath{\mu}/{c}^{2}<3.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ out to redshifts greater than 0.6 and set 95% upper limits. This corresponds...
The demonstration of efficient single-mode fiber (SMF) coupling is a key requirement for the development compact, ultra-precise radial velocity (RV) spectrograph. iLocater next generation instrument Large Binocular Telescope (LBT) that uses adaptive optics (AO) to inject starlight into SMF. In preparation commissioning iLocater, prototype SMF injection system was installed and tested at LBT in Y-band (0.970-1.065 $\mu$m). This designed verify capability AO as well characterize on-sky...
Big Bang Nucleosynthesis (BBN) explores the first few minutes of nuclei formation after Bang. We present updates that result in new constraints at 2{\sigma} level for abundances four primary light nuclides - D,3He,4He, and 7Li BBN. A modified standard BBN code was used a Monte Carlo analysis nucleosynthesis uncertainty as function baryon-to-photon ratio. Reaction rates were updated to those NACRE REACLIB, R-Matrix calculations. The results are then derive constraint on effective number neutrinos.
Numerous spherical ``shells" have been observed in young star-forming environments that host low- and intermediate-mass stars. These observations suggest these shells may be produced by isotropic stellar wind feedback from main-sequence However, the driving mechanism for remains uncertain because momentum injected winds is too low to explain their sizes dynamics due mass-loss rates. studies neglect how kinetic energy transferred ISM instead assume it instantly lost via radiation, suggesting...
The characterization of magnetic fields within molecular clouds is fundamental to understanding star formation processes. Accurately gauging the three-dimensional structure these presents a challenge, as observational techniques such dust polarization and Zeeman effect each provide only partial information on orientation line-of-sight strength, respectively. By analyzing suite AREPO simulations, this paper investigates how observables can relate underlying physical properties derive more...
Barnard’s Loop is a famous arc of hydrogen-alpha emission located in the Orion star-forming region. Here, we provide evidence possible formation mechanism for and compare our results with recent work suggesting major feedback event occurred region around 6 Myr ago. We expand on discovery coherent, radial, 3D expansion OBP-Near/Briceño-1 (OBP-B1) cluster at center from Swiggum et al. 2021. This appears to serve as another number young clusters identified Grosschedl 2021, which previously...
Abstract We leverage the 1 pc spatial resolution of Leike et al. three-dimensional (3D) dust map to characterize 3D structure nearby molecular clouds ( d ≲ 400 pc). start by “skeletonizing” in volume density space determine their “spines,” which we project on sky constrain cloud distances with ≈1% uncertainty. For each cloud, an average radial profile around its spine and fit profiles using Gaussian Plummer functions. The are well described a two-component function, consistent having broad,...
Barnard’s Loop is a famous arc of H <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" alttext="\alpha" display="inline"><m:mi>α</m:mi></m:math> emission located in the Orion star-forming region. Here, we provide evidence possible formation mechanism for and compare our results with recent work suggesting major feedback event occurred region around 6 Myr ago. We present 3D model large-scale region, indicating coherent, radial, expansion OBP-Near/Briceño-1 (OBP-B1) cluster middle large dust...
Undergraduate physics and astronomy students are expected to engage with scientific literature as they begin their research careers, but reading comprehension skills rarely explicitly taught in major courses. We seek determine the efficacy of lesson plans designed improve undergraduate (or related) majors' perceived ability by using accessible summaries current written experts field. During 2022-2023 academic year, twelve faculty members incorporated from Astrobites into courses, surveyed...
We describe a new inquiry design aimed at teaching advanced high-school to senior college students the basics of stellar populations. The is designed have come up with their own version Hertzsprung-Russell diagram as tool understand how stars evolve based on color, mass, and luminosity. makes use pictures spectra stars, which analyze interpret answer questions they beginning. undergo similar experience real astronomers, using same tools methods figure out phenomena are trying understand....