A5013573187- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Scientific Research and Discoveries
- Atmospheric Ozone and Climate
- CCD and CMOS Imaging Sensors
- Atmospheric and Environmental Gas Dynamics
- Solar and Space Plasma Dynamics
- Blind Source Separation Techniques
- Astrophysics and Cosmic Phenomena
University of Colorado Boulder
2022-2024
University of Denver
2018
With just a month of data, JWST is already transforming our view the Universe, revealing and resolving starlight in unprecedented populations galaxies. Although ``HST-dark" galaxies have previously been detected at long wavelengths, these observations generally suffer from lack spatial resolution which limits ability to characterize their sizes morphologies. Here we report on first subset HST-dark population that are bright with JWST/NIRCam (4.4$\mu$m<24.5mag) very faint or even invisible...
Abstract We present the first spatially resolved measurements of galaxy properties in JWST ERO SMACS 0723 field. perform a comprehensive analysis five 5 < z 9 galaxies with spectroscopic redshifts from NIRSpec observations. spectral energy distribution fitting Bagpipes , using six NIRCam imaging bands spanning wavelength range 0.8–5 μ m. This approach allows us to study internal structure and assembly generations galaxies. find clear gradients both empirical color maps most estimated...
Abstract Using deep JWST imaging from JADES, JEMS, and SMILES, we characterize optically faint extremely red galaxies at z > 3 that were previously missing galaxy census estimates. The data indicate the existence of abundant, dusty, poststarburst-like down to 10 8 M ⊙ , below sensitivity limit Spitzer Atacama Large Millimeter/submillimeter Array (ALMA). Modeling NIRCam Hubble Space Telescope (HST) photometry these sources can result in high values for both stellar mass star formation rate...
Abstract GN-z11 is the highest redshift galaxy spectroscopically confirmed with Hubble Space Telescope (HST). Previous measurements of effective radius utilized galfit , which not optimized to measure structural parameters for such a faint, distant object. Using new software called forcepho we derive size from images in F160W band obtained both complete CANDELS survey and additional midcycle observations order contribute knowledge base on evolution, size–luminosity, size–mass relation early...
Abstract With the remarkable sensitivity and resolution of JWST in infrared, measuring rest-optical kinematics galaxies at z > 5 has become possible for first time. This study pilots a new method galaxy dynamics highly multiplexed, unbiased samples by combining FRESCO NIRCam grism spectroscopy JADES medium-band imaging. Here we present one kinematic measurements 5. We find significant velocity gradient, which, if interpreted as rotation, yields V rot = 305 ± 70 km s −1 , hence refer to...
Metallicity estimates of circumgalactic gas based on absorption line measurements typically require photoionization modeling to account for unseen ionization states. We explore the impact uncertainties in extreme ultraviolet background (EUVB) radiation such metallicity determinations z < 1 medium (CGM). In particular, we study how power-law slope EUV radiation, $\mathrm{\alpha_{EUVB}}$, from active galactic nuclei affect a sample 34 absorbers with HI column densities between 15.25 log...
Abstract Artificial neural network emulators have been demonstrated to be a very computationally efficient method rapidly generate galaxy spectral energy distributions, for parameter inference or otherwise. Using highly flexible and fast mathematical structure, they can learn the nontrivial relationship between input parameters output observables. However, do so imperfectly, small errors in flux prediction yield large differences recovered parameters. In this work, we investigate an...
Using deep JWST imaging from JADES, JEMS and SMILES, we characterize optically-faint extremely red galaxies at $z>3$ that were previously missing galaxy census estimates. The data indicate the existence of abundant, dusty post-starburst-like down to $10^8$M$_\odot$, below sensitivity limit Spitzer ALMA. Modeling NIRCam HST photometry these sources can result in extreme, high values for both stellar mass star formation rate (SFR); however, including 7 MIRI filters out 21$\mu$m results...
One of the more surprising findings after first year JWST observations is large number spatially extended galaxies (ultra-red flattened objects, or UFOs) among optically-faint galaxy population otherwise thought to be compact. Leveraging depth and survey area JADES survey, we extend an additional 112 56 which are well-resolved in F444W with effective sizes, $R_e > 0.25''$, than tripling previous UFO counts. These have redshifts around $2 < z 4$, high stellar masses...
Using MESA code (Modules for Experiments in Stellar Astrophysics, version 9575), an evaluation was made of the evolutionary state epsilon Aurigae binary system (HD 31964, F0Iap + disk). We sought to satisfy several observational constraints: 1) requiring tracks pass close current temperature and luminosity primary star; 2) obtaining a period near observed value 27.1 years; 3) matching mass function 3.0; 4) concurrent Roche lobe overflow transfer; 5) isotopic ratio 12 C/ 13 C = 5 and, (6)...
We present the first spatially resolved measurements of galaxy properties in JWST ERO SMACS0723 field. perform a comprehensive analysis five $5
GN-z11 is the highest redshift galaxy spectroscopically confirmed with Hubble Space Telescope (HST). Previous measurements of effective radius utilized galfit, which not optimized to measure structural parameters for such a faint, distant object. Using new software program called forcepho on HST data first time, we derive size from images in F160W band obtained both complete CANDELS survey and additional midcycle observations order contribute knowledge base evolution, size-luminosity,...
Hubble Space Telescope imaging shows that most star-forming galaxies at cosmic noon -- the peak of star formation history appear disk-dominated, leaving origin dense cores in their quiescent descendants unclear. With James Webb Telescope's (JWST) high-resolution to 5 {\mu}m, we can now map rest-frame near-infrared emission, a much closer proxy for stellar mass distribution, these massive galaxies. We selected 70 with 10$<$log(M)$<$12 and 1.5$<$z$<$3 CEERS survey compare morphologies optical...
With the remarkable sensitivity and resolution of JWST in infrared, measuring rest-optical kinematics galaxies at $z>5$ has become possible for first time. This study pilots a new method galaxy dynamics highly multiplexed, unbiased samples by combining FRESCO NIRCam grism spectroscopy JADES medium-band imaging. Here we present one kinematic measurements $z>5$. We find significant velocity gradient, which, if interpreted as rotation yields $V_{rot} = 240\pm50$km/s hence refer to this...
Context: Worldwide interest in the recent eclipse of epsilon Aurigae resulted generation several extensive data sets, including those related to high resolution spectroscopic monitoring. This lead discovery, among other things, existence a mass transfer stream, seen notably during third contact. Aims: We explored facets stream contact, using spectra obtained with ARCES and TripleSpec instruments at Apache Point Observatory. Methods: One hundred sixteen epochs between 2009 2012 were obtained,...
Artificial neural network emulators have been demonstrated to be a very computationally efficient method rapidly generate galaxy spectral energy distributions (SEDs), for parameter inference or otherwise. Using highly flexible and fast mathematical structure, they can learn the nontrivial relationship between input parameters output observables. However, do so imperfectly, small errors in flux prediction yield large differences recovered parameters. In this work, we investigate an emulator's...