Paula Szkody
A5043579242- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Astro and Planetary Science
- Particle Accelerators and Free-Electron Lasers
- Galaxies: Formation, Evolution, Phenomena
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Adaptive optics and wavefront sensing
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Molecular Physics
- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Geophysics and Gravity Measurements
- Particle accelerators and beam dynamics
- Quantum Chromodynamics and Particle Interactions
- Scientific Measurement and Uncertainty Evaluation
- Ionosphere and magnetosphere dynamics
University of Washington
2015-2024
Kitt Peak National Observatory
1985-2013
U.S. National Science Foundation
1995-2013
Association of Universities For Research In Astronomy
1995-2013
Optica
2013
University of Canterbury
2012
Seattle University
1989-2011
United States Naval Observatory
2011
Middle East Technical University
2011
European Space Astronomy Centre
2011
The Sloan Extension for Galactic Understanding and Exploration (SEGUE) Survey obtained ≈240,000 moderate-resolution (R ∼ 1800) spectra from 3900 Å to 9000 of fainter Milky Way stars (14.0 < g 20.3) a wide variety spectral types, both main-sequence evolved objects, with the goal studying kinematics populations our Galaxy its halo. are clustered in 212 regions spaced over three quarters sky. Radial velocity accuracies at 18, degrading 20. For signal-to-noise ratio >10 per resolution element,...
An extensive sample of M, L and T dwarfs identified in the Sloan Digital Sky Survey (SDSS) has been compiled. The 718 includes 677 new objects (629 M dwarfs, 48 dwarfs) together with 41 that have previously published. All some published ones optical spectra obtained either SDSS spectrographs or Apache Point Observatory 3.5m ARC telescope. Spectral types colors are available for all objects; approximately 35% also near-infrared magnitudes measured by 2MASS on Mauna Kea system. We use this to...
Abstract We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 Gaia DR3 using an X-ray + optical color–color diagram (the “X-ray Main Sequence”). This tool identifies all CV subtypes, including magnetic low-accretion rate systems, in contrast to most previous surveys. find 23 CVs, 3 which are CVns, out 150 pc the Western Galactic Hemisphere. Our sample is spectroscopically verified complete down L X = 1.3 × 10 29 erg s...
We discuss the properties of 137 cataclysmic variables (CVs) which are included in Sloan Digital Sky Survey (SDSS) spectroscopic data base, and for accurate orbital periods have been measured. 92 these systems new discoveries from SDSS were followed-up more detail over past few years. 45 previously identified as CVs because detection optical outbursts and/or X-ray emission, subsequently re-identified spectroscopy. The period distribution differs dramatically that all known CVs, particular it...
We present the full spectroscopic white dwarf and hot subdwarf sample from Sloan Digital Sky Survey (SDSS) first data release, DR1. find 2551 stars of various types, 240 stars, an additional 144 objects we have identified as uncertain stars. Of 1888 are nonmagnetic DA types 171 DBs. The remaining (492) consist all different stars: DO, DQ, DC, DH, DZ, hybrid such DAB, etc., those with nondegenerate companions. fit DB spectra a grid models to determine Teff log g for each object. For objects,...
We present Kepler observations of the bright (V=8.3), oscillating star HD 179070. The show transit-like events which reveal that is orbited every 2.8 days by a small, 1.6 R_Earth object. Seismic studies 179070 using short cadence has frequencypower spectrum consistent with solar-like oscillations are acoustic p-modes. Asteroseismic analysis provides robust values for mass and radius 179070, 1.34{\pm}0.06 M{\circ} 1.86{\pm}0.04 R{\circ} respectively, as well yielding an age 2.84{\pm}0.34 Gyr...
The Large Synoptic Survey Telescope is designed to provide an unprecedented optical imaging dataset that will support investigations of our Solar System, Galaxy and Universe, across half the sky over ten years repeated observation. However, exactly how LSST observations be taken (the observing strategy or "cadence") not yet finalized. In this dynamically-evolving community white paper, we explore detailed performance anticipated science expected depend on small changes strategy. Using...
The Zwicky Transient Facility is a large optical survey in multiple filters producing hundreds of thousands transient alerts per night. We describe here various machine learning (ML) implementations and plans to make the maximal use data set by taking advantage temporal nature data, further combining it with other sets. start initial steps separating bogus candidates from real ones, stars galaxies, go on classification objects into classes. Besides usual methods (e.g., based features...
We report on the masses ($M_\mathrm{WD}$), effective temperatures ($T_\mathrm{eff}$) and secular mean accretion rates ($\langle \dot{M} \rangle$) of 43 cataclysmic variable (CV) white dwarfs, 42 which were obtained from combined analysis their $\mathit{Hubble~Space~Telescope}$ ultraviolet data with parallaxes provided by Early Third Data Release $\mathit{Gaia}$ space mission, one dwarf gravitational redshift. Our results double number CV dwarfs an accurate mass measurement, bringing total...
The commissioning year of the Sloan Digital Sky Survey (SDSS) has demonstrated that many cataclysmic variables (CVs) have been missed in previous surveys with brighter limits. We report identification 22 CVs, which 19 are new discoveries and three known systems (SW UMa, BH Lyn, OU Vir). A compendium positions, colors, characteristics these obtained from SDSS photometry spectroscopy is presented, along data during follow-up studies Apache Point Observatory Manastash Ridge telescopes....
The first full year of operation following the commissioning Sloan Digital Sky Survey (SDSS) has revealed a wide variety newly discovered cataclysmic variables (CVs). We show SDSS spectra 42 CVs observed in 2002, which 35 are new classifications, four known dwarf novae (CT Hya, RZ Leo, T and BZ UMa), one is CV identified from previous quasar survey (Aqr1), two ROSAT or FIRST (RX J09445+0357, J102347.6+003841). positions, colors, all systems presented. In addition, results follow-up studies...
Beyond its goals related to the extragalactic universe, Sloan Digital Sky Survey (SDSS) is an effective tool for identifying stellar objects with unusual spectral energy distributions. Here we report on 53 new magnetic white dwarfs discovered during first two years of survey, including 38 whose data are made public in 1500 square-degree First Data Release. Discoveries span magnitude range 16.3 < 20.5, and based recovery rate previously-known dwarfs, completeness SDSS appears be high...
This paper identifies the cataclysmic variables that appear in spectra obtained 2004 as part of Sloan Digital Sky Survey. Spectra 41 objects, including seven systems were previously known (CC Cnc, DW PQ Gem, AR UMa, AN RX J1131.3+4322, and UMa 6) 34 new are presented. The positions ugriz photometry all given, well additional follow-up spectroscopic, photometric, and/or polarimetric observations eight systems. objects include three eclipsing systems, six with prominent He II emission, show...
view Abstract Citations (194) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS X-Ray and Optical Observations of the Ultrashort Period Dwarf Nova SW Ursae Majoris: A Likely New DQ Herculis Star Shafter, A. W. ; Szkody, P. Thorstensen, J. R. photometric spectroscopic X-ray observations dwarf nova UMa are presented. Moderate resolution data have established an orbital period 81.8 min revealed that Balmer emission lines a multiple structure....
We present a spectroscopic sample of 747 detached close binary systems from the Sloan Digital Sky Survey (SDSS) Fourth Data Release. The majority these binaries consist white dwarf primary and low-mass secondary (typically M dwarf) companion. have determined temperature gravity for 496 primaries spectral type magnetic activity properties 661 secondaries. estimated distances each dwarf-main-sequence star use evolutionary grids to establish age system cooling times. With respect...
This paper completes the series of cataclysmic variables (CVs) identified from Sloan Digital Sky Survey I/II. The coordinates, magnitudes and spectra 33 CVs are presented. Among eight systems known previous to SDSS (CT Ser, DO Leo, HK IR Com, V849 Her, V405 Peg, PG1230+226 HS0943+1404), as well nine objects recently found through various photometric surveys. since two polar candidates, intermediate candidates one candidate for containing a pulsating white dwarf. Our followup data have...
We present HST spectroscopy for 45 cataclysmic variables (CVs), observed with HST/COS and HST/STIS. For 36 CVs, the white dwarf is recognisable through its broad Ly α absorption profile we measure effective temperatures (Teff) by fitting data assuming log g = 8.35, which corresponds to average mass CV dwarfs (≃0.8 M⊙). Our results nearly double number of an accurate temperature measurement. find that CVs above period gap have, on average, higher (〈Teff〉 ≃ 23 000 K) exhibit much more scatter...
We report observations of a possible young transiting planet orbiting previously known weak-lined T-Tauri star in the 7-10 Myr old Orion-OB1a/25-Ori region. The candidate was found as part Palomar Transient Factory (PTF) Orion project. It has photometric transit period 0.448413 +- 0.000040 days, and appears both 2009 2010 PTF data. Follow-up low-precision radial velocity (RV) adaptive optics imaging suggest that is not an eclipsing binary, it unlikely background source blended with target...
We report the discovery of first short period binary in which a hot subdwarf star (sdOB) fills its Roche lobe and started mass transfer to companion. The object was discovered as part dedicated high-cadence survey Galactic Plane named Zwicky Transient Facility exhibits $P_{\rm orb}=39.3401(1)$ min, making it most compact currently known. Spectroscopic observations are consistent with an intermediate He-sdOB effective temperature $T_{\rm eff}=42,400\pm300$ K surface gravity...
Magnetic CVs are luminous Galactic X-ray sources but have been difficult to find in purely optical surveys due their lack of outburst behavior. The eROSITA telescope aboard the Spektr-RG (SRG) mission is conducting an all-sky survey and recently released public Final Equatorial Depth Survey (eFEDS) catalog. We crossmatched eFEDS catalog with photometry from Zwicky Transient Facility (ZTF) discovered two new magnetic cataclysmic variables (CVs). obtained high-cadence phase-resolved...
Abstract The Vera C. Rubin Legacy Survey of Space and Time (LSST) holds the potential to revolutionize time domain astrophysics, reaching completely unexplored areas Universe mapping variability scales from minutes a decade. To prepare maximize LSST data for exploration transient variable Universe, one four pillars science, Transient Variable Stars Science Collaboration, eight Collaborations, has identified research interest requirements, paths enable them. While our roadmap is...
Abstract White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host strong ( B ≳ 1 MG) magnetic field. However, origin evolution WD magnetism remain under debate. Two pulsars, AR Sco J191213.72–441045.1 (J1912), been found, which non-accreting hosting rapidly spinning (1.97 minutes 5.30 minutes, respectively) WDs. The is slowing down on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
This paper continues the series presenting cataclysmic variables identified during fourth year (2003) of Sloan Digital Sky Survey. We describe 44 close binary systems, which 12 are previously known systems EN Cet, EG Cnc, V844 Her, GG Leo, Leo 7, CY UMa, DV EK EV UMa 8, EUVE J0854+390, and RX J0859.1+0537 32 new variables. As in previous papers, positions, colors, spectra all shown, along with follow-up spectroscopic, photometric, and/or polarimetric observations 15 systems. The objects...
view Abstract Citations (141) References (71) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Tremendous Outburst Amplitude Dwarf Novae Howell, Steve B. ; Szkody, Paula Cannizzo, John K. For many years, observers have noted the existence of a number tremendous outburst amplitude dwarf novae. We present summary known observational parameters for these exceptional systems. They show amplitudes 6-10 mag, rare outbursts (interoutburst times being months to...