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Your search keyword '"Laura DeGroot"' showing total 5 results
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5 results on '"Laura DeGroot"'

1. Chemistry does general relativity: reaction-diffusion waves can model gravitational lensing

Author

Daniel Cohen-Cobos, Kiyomi Sanders, Laura DeGroot, Heather Guarnera, Cody Leary, John F. Lindner, and Niklas Manz

Subjects
Belousov-Zhabotinsky reaction, gravitational lensing, reaction-diffusion waves, general relativity, Barkley model, Python (programming language), Physics, QC1-999
Abstract

Gravitational lensing is a general relativistic (GR) phenomenon where a massive object redirects light, deflecting, magnifying, and sometimes multiplying its source. We use reaction-diffusion (RD) Belousov-Zhabotinsky (BZ) chemistry to study this astronomical effect in a table-top experiment. We experimentally observe BZ waves passing through non-planar, quasi-two-dimensional molds and reproduce the waveforms in computer simulations using planar RD waves propagating with variable diffusion. We tune the variable diffusion to match the Schwarzschild-coordinate light speed near a spherical mass so the RD propagation approximates Einstein’s famous light deflection relation. We discuss varying the diffusion or reaction rates with a gel matrix or with illumination, electric field, or temperature gradients.

Published
2024
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2. The MOSDEF Survey: First Measurement of Nebular Oxygen Abundance at $z>4$

Author

Irene Shivaei, Gene C. K. Leung, Mojegan Azadi, Mariska Kriek, James Aird, Alison L. Coil, Brian Siana, Naveen A. Reddy, Ryan L. Sanders, Laura DeGroot, Bahram Mobasher, William R. Freeman, Alice E. Shapley, and Sedona H. Price

Subjects
Physics, Stellar mass, 010308 nuclear & particles physics, Star formation, Balmer series, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Spectral line, symbols.namesake, Space and Planetary Science, 0103 physical sciences, symbols, Spectral energy distribution, Emission spectrum, 010303 astronomy & astrophysics, Equivalent width
Abstract

We present the first spectroscopic measurement of multiple rest-frame optical emission lines at $z>4$. During the MOSFIRE Deep Evolution Field (MOSDEF) survey, we observed the galaxy GOODSN-17940 with the Keck I/MOSFIRE spectrograph. The K-band spectrum of GOODSN-17940 includes significant detections of the [OII]$\lambda\lambda 3726,3729$, [NeIII]$\lambda3869$, and H$\gamma$ emission lines and a tentative detection of H$\delta$, indicating $z_{\rm{spec}}=4.4121$. GOODSN-17940 is an actively star-forming $z>4$ galaxy based on its K-band spectrum and broadband spectral energy distribution. A significant excess relative to the surrounding continuum is present in the Spitzer/IRAC channel 1 photometry of GOODSN-17940, due primarily to strong H$\alpha$ emission with a rest-frame equivalent width of $\mbox{EW(H}\alpha)=1200$ \AA. Based on the assumption of $0.5 Z_{\odot}$ models and the Calzetti attenuation curve, GOODSN-17940 is characterized by $M_*=5.0^{+4.3}_{-0.2}\times 10^9 M_{\odot}$. The Balmer decrement inferred from H$\alpha$/H$\gamma$ is used to dust correct the H$\alpha$ emission, yielding $\mbox{SFR(H}\alpha)=320^{+190}_{-140} M_{\odot}\mbox{ yr}^{-1}$. These $M_*$ and SFR values place GOODSN-17940 an order of magnitude in SFR above the $z\sim 4$ star-forming "main sequence." Finally, we use the observed ratio of [NeIII]/[OII] to estimate the nebular oxygen abundance in GOODSN-17940, finding $\mbox{O/H}\sim 0.2 \mbox{ (O/H)}_{\odot}$. Combining our new [NeIII]/[OII] measurement with those from stacked spectra at $z\sim 0, 2, \mbox{ and } 3$, we show that GOODSN-17940 represents an extension to $z>4$ of the evolution towards higher [NeIII]/[OII] (i.e., lower $\mbox{O/H}$) at fixed stellar mass. It will be possible to perform the measurements presented here out to $z\sim 10$ using the James Webb Space Telescope., Comment: 7 pages, 3 figures, accepted to ApJ Letters

Published
2017

3. The MOSDEF Survey: Broad Emission Lines at z = 1.4–3.8

Author

Bahram Mobasher, Dušan Kereš, Mojegan Azadi, Brian Siana, Irene Shivaei, Alison L. Coil, Ryan L. Sanders, Alice E. Shapley, Mariska Kriek, Naveen A. Reddy, William R. Freeman, Alexander L. Muratov, Laura DeGroot, Sedona H. Price, and Gene C. K. Leung

Subjects
Physics, 010504 meteorology & atmospheric sciences, Spitzer Space Telescope, Space and Planetary Science, 0103 physical sciences, Foundation (engineering), Astronomy, Astronomy and Astrophysics, Emission spectrum, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

NSF AAG [AST-1312780, 1312547, 1312764, 1313171]; NASA through Space Telescope Science Institute [AR-13907]; NASA [NAS 5-26555]; Alfred P. Sloan Research Fellowship; W. M. Keck Foundation

Published
2019
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4. The host galaxies of X-ray selected active galactic nuclei to z = 2.5: Structure, star formation, and their relationships from CANDELS and Herschel/PACS

Author

Maksym Bernyk, Anton M. Koekemoer, S. Avadhuta, Marie Martig, Roberto Maiolino, D. D. Kocevski, Olivia Telford, Jessica Herrington, Henry C. Ferguson, Norman A. Grogin, Eric F. Bell, Franz E. Bauer, Darren J. Croton, P. Wandro, Jennifer L. Donley, Reinhard Genzel, A. Bell, Javiera Guedes, Amber Straughn, Annalisa Pillepich, Dieter Lutz, David C. Koo, David J. Rosario, J. Kartaltepe, Erin M. O'Leary, Stijn Wuyts, Daniel H. McIntosh, Conor McPartland, Matt Hilton, Linda J. Tacconi, Avishai Dekel, James Mullaney, Robert Bassett, Jennifer M. Lotz, C. Tonini, C. Lani, Simon J. Mutch, D. Snyder, Elizabeth J. McGrath, Nimish P. Hathi, Gregory B. Poole, S. M. Faber, Jonathan R. Trump, Marc Rafelski, Paola Santini, Benjamin Magnelli, Philipp Lang, Paolo Cassata, Carolin Villforth, C. J. Conselice, Laura DeGroot, P. Popesso, A. van der Wel, Kamson Lai, W. N. Brandt, Mark Mozena, S. Berta, Alice Mortlock, Casey Papovich, David M. Alexander, Frederic Bournaud, Edmond Cheung, Michael Peth, Max-Planck-Institut für Extraterrestrische Physik (MPE), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), University of St Andrews. School of Physics and Astronomy, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), ITA, USA, GBR, FRA, DEU, AUS, CHL, ISR, and CHE

Subjects
statistical [Methods], structure [Galaxies], active, galaxies: structure, galaxies: star formation, surveys, methods: statistical, X-rays: galaxies [galaxies], Astrophysics, Surveys, Galaxies: active, Galaxies: star formation, Galaxies: structure, Methods: statistical, X-rays: galaxies, Astronomy and Astrophysics, Space and Planetary Science, Luminosity, MERGER-AGN CONNECTION, SUPERMASSIVE, Bulge, SPECTRAL, QB Astronomy, QC, QB, Physics, COSMIC cancer database, X-ray, MASSIVE GALAXIES, 3rd-DAS, galaxies [X-rays], GALAXIES, ULTRALUMINOUS INFRARED GALAXIES, Active galactic nucleus, SIMILAR-TO 2, active [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, galaxies. [X-rays], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, ENERGY-DISTRIBUTIONS, star formation [Galaxies], DEEP FIELD-SOUTH, EXTRAGALACTIC LEGACY SURVEY, BLACK-HOLES, Astrophysics::Galaxy Astrophysics, Star formation, Near-infrared spectroscopy, Astrophysics - Astrophysics of Galaxies, Galaxy, QC Physics, Physics and Astronomy, Astrophysics of Galaxies (astro-ph.GA), DIGITAL SKY SURVEY, HIGH-REDSHIFT, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

We study the relationship between the structure and star-formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed distributions of structural parameters and FIR luminosities from carefully constructed control samples of galaxies, which we then compare to those of the AGNs. At z~1, AGNs show slightly diskier light profiles than massive inactive (non-AGN) galaxies, as well as modestly higher levels of gross galaxy disturbance (as measured by visual signatures of interactions and clumpy structure). In contrast, at z~2, AGNs show similar levels of galaxy disturbance as inactive galaxies, but display a red central light enhancement, which may arise due to a more pronounced bulge in AGN hosts or due to extinguished nuclear light. We undertake a number of tests of these alternatives, but our results do not strongly favour one interpretation over the other. The mean SFR and its distribution among AGNs and inactive galaxies are similar at z>1.5. At z1.5., 25 pages (double-column), 17 Figures, under review at A&A

Published
2015
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5. Candels visual classifications: Scheme, data release, and first results

Author

Jeyhan S. Kartaltepe, Mark Mozena, Dale Kocevski, Daniel H. McIntosh, Jennifer Lotz, Eric F. Bell, Sandy Faber, Harry Ferguson, David Koo, Robert Bassett, Maksym Bernyk, Kirsten Blancato, Frederic Bournaud, Paolo Cassata, Marco Castellano, Edmond Cheung, Christopher J. Conselice, Darren Croton, Tomas Dahlen, Duilia F. de Mello, Laura DeGroot, Jennifer Donley, Javiera Guedes, Norman Grogin, Nimish Hathi, Matt Hilton, Brett Hollon, Anton Koekemoer, Nick Liu, Ray A. Lucas, Marie Martig, Elizabeth McGrath, Conor McPartland, Bahram Mobasher, Alice Morlock, Erin O’Leary, Mike Peth, Janine Pforr, Annalisa Pillepich, David Rosario, Emmaris Soto, Amber Straughn, Olivia Telford, Ben Sunnquist, Jonathan Trump, Benjamin Weiner, Stijn Wuyts, Hanae Inami, Susan Kassin, Caterina Lani, Gregory B. Poole, Zachary Rizer, ITA, USA, GBR, FRA, DEU, ESP, Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Space Telescope Science Institute (STSci), Centre for Astrophysics and Supercomputing, and Swinburne University of Technology [Melbourne]

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), FOS: Physical sciences, Magnitude (mathematics), Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, cosmology: observations, galaxies: evolution, galaxies: high-redshift, Space and Planetary Science, Cosmology, Galaxy, Field (geography), Hubble sequence, symbols.namesake, Astrophysics of Galaxies (astro-ph.GA), observations, galaxies: evolution, galaxies: high-redshift [cosmology], symbols, Range (statistics), Galaxy formation and evolution, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Focus (optics), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H, 15 pages, 14 figures, Accepted for publication in The Astrophysical Journal Supplement Series For access to data tables prior to publication contact jeyhan@astro.rit.edu

Published
2015
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