Peter Plavchan
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Pamela Effect
Physics & Astronomy International Journal Mini Review Open Access Pamela effect Abstract Volume 2 Issue 3 - 2018 The “PAMELA effect” is a mystery for astrophysicists for 10 years, since its Konstantinov Stanislav Ivanovich discovery. The article assumes that the effect may be due to imperfections in the Department of Physical Electronics, Russian State Pedagogical equipment of detectors. The creators of the cosmic detectors PAMELA and AMS–02 University, Russia were guided in their calculations by classical electrodynamics, which differs from of the real electrodynamics of the behavior of relativistic protons in of the magnetic Correspondence: Konstantinov Stanislav Ivanovich, spectrometers of detectors. Department of Physical Electronics, Russian State Pedagogical University, St.Petersburg, RSC “Energy”, Russia, Tel +8911 7159 Keywords: vacuum, polarization, photon, electron, positron, proton, energy, range 176, Email [email protected] Received: May 03, 2018 | Published: May 31, 2018 Introduction positrons are registered in the observed gamma–radiation spectrum than the Earth could reach and the form of the energy spectrum of high The “PAMELA effect” consists in an inexplicable increase in energy positrons (peak formation) differs from the spectrum observed the number of positrons with respect to electrons detected by the in the Pamela detector (of spectrum with exponent of degree). Thus, PAMELA magnetic spectrometer, with an increase in the energy of researchers came to the conclusion that excess positrons should have 1,2 cosmic radiation and relativistic protons starting from 5GeV. The a different source.5 Let’s consider physical features of registration of same effect is observed in the registration of the electron–positron elementary particles by magnetic spectrometer PAMELA and AMS– 3,4 ratio in AMS–02 and FERMI–LAT but at higher energy values. -
Adaptive Optics Imaging of Circumstellar Environments
Star Formation at High Angular Resolution IAU Symposium, Vol. 221, 2004 M. G. Burton, R. Jayawardhana & T.L. Bourke, eds. Adaptive Optics Imaging of Circumstellar Environments Daniel Apai, Ilaria Pascucci, Hongchi Wang, Wolfgang Brandner and Thomas Henning Max Planck Institute for Astronomy, Kimiqsiuhl 17., Heidelberg, Germany D-69117 Carol Grady NOAO/STIS, Goddard Space Flight Center, Code 681, NASA/GSFC, Greenbelt, MD 20771, USA Dan Potter Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721, USA Abstract. We present results from our high-resolution, high-contrast imaging campaign targeting the circumstellar environments of young, nearby stars of different masses. The observations have been conducted using the ALFA/CA 3.5m and NACO UT4/VLT adaptive optics systems. In order to enhance the contrast we applied the methods PSF-subtraction and polarimetric differential imaging (PDI). The observations of young stars yielded the identification of numerous new companion candidates, the most interesting one being rv 0.5" from FU Ori. We also obtained high-resolution near-infrared imaging of the circumstellar envelope of SU Aur and AB Aur. Our PDI of the TW Hya circumstellar disk traced back the disk emission as close as 0.1" ~ 6 AU from the star, the closest yet. Our results demonstrate the potential of the adaptive optics systems in achieving high-resolution and high-contrast imaging and thus in the study of circumstellar disks, envelopes and companions. 1. Introduction Young, nearby stars are our prime source of information to study the circum- stellar disk structure and evolution. They are also the ideal targets for adaptive optics (AO) observations, as they are usually bright enough to provide excellent wavefront reference. -
Comparison of Long-Term Variations of the Cosmic Ray Flux from the Network
Cosmic ray studies with neutron detectors | Volume 1 (2021) 15 KIEL-UP • DOI: 10.38072/2748-3150/p2 Comparison of long-term variations of the cosmic ray fux from the network of ground-based detectors, PAMELA and AMS-02 data Anatoly V. Belov , Victor G. Yanke , Raisa Gushchina , Nataly Shlyk Correspondence Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, (IZMIRAN) Moscow, Russia, [email protected], [email protected], [email protected], [email protected] OPEN ACCESS Keywords This work is published under the Creative Commons Attribution 4.0 long-term variations; PAMELA, AMS-02; ground-based detectors; balloon stratospheric sounding International license (CC BY 4.0). Please note that individual, appro- priately marked parts of the work Abstract may be excluded from the license mentioned or may be subject to The paper presents preliminary results of a comparison of long-term variations of the cosmic ray fux using other copyright conditions. If such third party material is not data from the network of ground-based detectors with direct fux measurements on the PAMELA and AMS-02 under the Creative Commons license, any copying, editing or public repro- magnetic spectrometers and a series of balloon stratospheric soundings. The analysis showed good agreement duction is only permitted with the prior consent of the respective copy- for the entire period of continuous ground-based monitoring of cosmic ray variations. right owner or on the basis of relevant legal authorization regulations. 1. Introduction Galactic cosmic rays with rigidity up to one hundred GV are constantly modulated by the solar wind. On the one hand, this galactic cosmic rays fux is recorded by a network of ground-based detectors under the atmosphere: ionization chambers, muon telescopes, and neutron monitors. -
Pushing the Limits of the Coronagraphic Occulters on Hubble Space Telescope/Space Telescope Imaging Spectrograph
Pushing the limits of the coronagraphic occulters on Hubble Space Telescope/Space Telescope Imaging Spectrograph John H. Debes Bin Ren Glenn Schneider John H. Debes, Bin Ren, Glenn Schneider, “Pushing the limits of the coronagraphic occulters on Hubble Space Telescope/Space Telescope Imaging Spectrograph,” J. Astron. Telesc. Instrum. Syst. 5(3), 035003 (2019), doi: 10.1117/1.JATIS.5.3.035003. Downloaded From: https://www.spiedigitallibrary.org/journals/Journal-of-Astronomical-Telescopes,-Instruments,-and-Systems on 02 Jul 2019 Terms of Use: https://www.spiedigitallibrary.org/terms-of-use Journal of Astronomical Telescopes, Instruments, and Systems 5(3), 035003 (Jul–Sep 2019) Pushing the limits of the coronagraphic occulters on Hubble Space Telescope/Space Telescope Imaging Spectrograph John H. Debes,a,* Bin Ren,b,c and Glenn Schneiderd aSpace Telescope Science Institute, AURA for ESA, Baltimore, Maryland, United States bJohns Hopkins University, Department of Physics and Astronomy, Baltimore, Maryland, United States cJohns Hopkins University, Department of Applied Mathematics and Statistics, Baltimore, Maryland, United States dUniversity of Arizona, Steward Observatory and the Department of Astronomy, Tucson Arizona, United States Abstract. The Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) contains the only currently operating coronagraph in space that is not trained on the Sun. In an era of extreme-adaptive- optics-fed coronagraphs, and with the possibility of future space-based coronagraphs, we re-evaluate the con- trast performance of the STIS CCD camera. The 50CORON aperture consists of a series of occulting wedges and bars, including the recently commissioned BAR5 occulter. We discuss the latest procedures in obtaining high-contrast imaging of circumstellar disks and faint point sources with STIS. -
Solar Energetic Particle Events Observed by the Pamela Mission
SOLAR ENERGETIC PARTICLE EVENTS OBSERVED BY THE PAMELA MISSION Alessandro Bruno NASA/GSFC on behalf of the PAMELA collaboration IRENE Space Radiation Modelling and Data Analysis Workshop 2019 29-31 May 2019, Sykia, Greece Motivation • Two class scenario of SEP origin • Impulsive events: related to flares, short duration, small intensity, Type III bursts, 3He e- Fe enriched, … • Gradual events: related to CME-driven shocks, long duration, large intensity, Type II bursts, … • Recent studies have shown that SEP events are, in general, originated by a mixture of impulsive and gradual processes, and the event evolution depends on their relative importance and on the magnetic connection to Earth • albeit there is still no consensus about the details of the individual mechanisms • However, the characterization of high energy (>100 MeV) SEP fluxes is still affected by large uncertainties, in part due to the relatively low observations in this range A. Bruno SEP events observed by PAMELA !2 Motivation •The most energetic SEP events induce atmospheric showers whose secondary products are measured by ground-based detectors (e.g. NMs) during the so-called Ground Level Enhancements (GLEs) •However, ground-based observations rely on a number of assumption (CR interactions with terrestrial magnetosphere and atmosphere) —> large uncertainties •Aside from the relevant Space Weather implications, GLEs are of particular interest since they represent SEP acceleration at its most efficient. The HE protons of GLE events can reach 1 AU with minimal interplanetary -
CURRICULUM VITAE for DANIEL APAI Research Interests: Extrasolar Planets; Planet Formation; Planetary Atmospheres; Astrobiology; Space Telescope Architectures
CURRICULUM VITAE FOR DANIEL APAI Research Interests: Extrasolar Planets; Planet formation; Planetary atmospheres; Astrobiology; Space telescope architectures Professional Appointments 2017 – Associate Professor, Depts. of Astronomy and Planetary Sciences, Univ. of Arizona 2011 – 2017 Assistant Professor, Depts. of Astronomy and Planetary Sciences, Univ. Arizona 2008 – 2011 Assistant Astronomer, Space Telescope Science Institute Education 2004 PhD, University of Heidelberg and Max Planck Institute of Astronomy 2000 MSc in Physics, University of Szeged Recent International Service: Chair, HST–TESS Advisory Committee, Space Telescope Science Institute Science Advisory Committee member, Giant Magellan Telescope Executive Committee member, NASA Exoplanet Program Analysis Group (EXOPAG) Steering Committee member, NASA Nexus for Exoplanet System Science (NExSS) Chair, Exoplanet Science Questions for Direct Imaging Missions, SAG15/EXOPAG Member, Hubble Space Telescope Financial Review Committee Major Approved Programs as Principal Investigator 9 Hubble Space Telescope + 4 Spitzer Space Telescope programs, including: - Extrasolar Storms: Spitzer Exploration Science Program (1,144 Spitzer hour, 24 HST orbits) - Cloud Atlas: Hubble Space Telescope (112 orbits), 12+ refereed papers Earths in Other Solar Systems: $5.7M program (R&A), 45-member team, 140 refereed papers Nautilus: A large-aperture space telescope for a biosignature survey based on diffractive optics, Co-PI of $1.1M Gordon & Betty Moore Foundation grant Advising/Mentoring: Postdoc. Researchers -
Poster Abstracts
Aimée Hall • Institute of Astronomy, Cambridge, UK 1 Neptunes in the Noise: Improved Precision in Exoplanet Transit Detection SuperWASP is an established, highly successful ground-based survey that has already discovered over 80 exoplanets around bright stars. It is only with wide-field surveys such as this that we can find planets around the brightest stars, which are best suited for advancing our knowledge of exoplanetary atmospheres. However, complex instrumental systematics have so far limited SuperWASP to primarily finding hot Jupiters around stars fainter than 10th magnitude. By quantifying and accounting for these systematics up front, rather than in the post- processing stage, the photometric noise can be significantly reduced. In this paper, we present our methods and discuss preliminary results from our re-analysis. We show that the improved processing will enable us to find smaller planets around even brighter stars than was previously possible in the SuperWASP data. Such planets could prove invaluable to the community as they would potentially become ideal targets for the studies of exoplanet atmospheres. Alan Jackson • Arizona State University, USA 2 Stop Hitting Yourself: Did Most Terrestrial Impactors Originate from the Terrestrial Planets? Although the asteroid belt is the main source of impactors in the inner solar system today, it contains only 0.0006 Earth mass, or 0.05 Lunar mass. While the asteroid belt would have been much more massive when it formed, it is unlikely to have had greater than 0.5 Lunar mass since the formation of Jupiter and the dissipation of the solar nebula. By comparison, giant impacts onto the terrestrial planets typically release debris equal to several per cent of the planet’s mass. -
New Metallicity Calibration Down to [Fe/H]=−2.75
CSIRO PUBLISHING www.publish.csiro.au/journals/pasa Publications of the Astronomical Society of Australia, 2003, 20, 165–172 New Metallicity Calibration Down to [Fe/H] =−2.75 dex S. Karaali, S. Bilir, Y. Karata¸sand S. G. Ak Department of Astronomy and Space Sciences, Science Faculty, Istanbul University, 34452 Istanbul, Turkey [email protected] Received 2002 August 29, accepted 2003 February 1 Abstract: We have taken 88 dwarfs, covering the colour-index interval 0.37 ≤ (B−V)0 ≤ 1.07 mag, with metallicities −2.70 ≤ [Fe/H] ≤+0.26 dex, from three different sources for new metallicity calibration. The catalogue of Cayrel de Strobel et al. (2001), which includes 65% of the stars in our sample, supplies detailed information on abundances for stars with determination based on high-resolution spectroscopy. In constructing the new calibration we have used as ‘corner stones’ 77 stars which supply at least one of the following conditions: (i) the parallax is larger than 10 mas (distance relative to the Sun less than 100 pc) and the galactic latitude is absolutely higher than 30◦; (ii) the parallax is rather large, if the galactic latitude is absolutely low and vice versa. Contrary to previous investigations, a third-degree polynomial is fitted for the new calibration: [Fe/H] = 0.10 − 2.76δ − 24.04δ2 + 30.00δ3. The coefficients were evaluated by the least-squares method, without regard to the metallicity of Hyades. However, the constant term is in the range of metallicity determined for this cluster, i.e. 0.08 ≤ [Fe/H] ≤ 0.11 dex. The mean deviation and the mean error in our work are equal to those of Carney (1979), for [Fe/H] ≥−1.75 dex where Carney’s calibration is valid Keywords: stars: abundances — stars: metallicity calibration — stars: metal-poor 1 Introduction recent analyses (Rosenberg et al. -
Hubble Space Telescope Primer for Cycle 18
January 2010 Hubble Space Telescope Primer for Cycle 18 An Introduction to HST for Phase I Proposers Space Telescope Science Institute 3700 San Martin Drive Baltimore, Maryland 21218 [email protected] Operated by the Association of Universities for Research in Astronomy, Inc., for the National Aeronautics and Space Administration How to Get Started If you are interested in submitting an HST proposal, then proceed as follows: • Visit the Cycle 18 Announcement Web page: http://www.stsci.edu/hst/proposing/docs/cycle18announce Then continue by following the procedure outlined in the Phase I Roadmap available at: http://apst.stsci.edu/apt/external/help/roadmap1.html More technical documentation, such as that provided in the Instrument Handbooks, can be accessed from: http://www.stsci.edu/hst/HST_overview/documents Where to Get Help • Visit STScI’s Web site at: http://www.stsci.edu • Contact the STScI Help Desk. Either send e-mail to [email protected] or call 1-800-544-8125; from outside the United States and Canada, call [1] 410-338-1082. The HST Primer for Cycle 18 was edited by Francesca R. Boffi, with the technical assistance of Susan Rose and the contributions of many others from STScI, in particular Alessandra Aloisi, Daniel Apai, Todd Boroson, Brett Blacker, Stefano Casertano, Ron Downes, Rodger Doxsey, David Golimowski, Al Holm, Helmut Jenkner, Jason Kalirai, Tony Keyes, Anton Koekemoer, Jerry Kriss, Matt Lallo, Karen Levay, John MacKenty, Jennifer Mack, Aparna Maybhate, Ed Nelan, Sami-Matias Niemi, Cheryl Pavlovsky, Karla Peterson, Larry Petro, Charles Proffitt, Neill Reid, Merle Reinhart, Ken Sembach, Paula Sessa, Nancy Silbermann, Linda Smith, Dave Soderblom, Denise Taylor, Nolan Walborn, Alan Welty, Bill Workman and Jim Younger. -
EOS Newsletter May 2019
PROJECT EOS May 24, 2019 EARTHS IN OTHER SOLAR SYSTEMS Recent Publications On the Mass Function, Multiplicity, and Origins of Wide-Orbit Giant Planets ………………………………. Unlocking CO Depletion in PROJECT EOS Protoplanetary Disks II. Primordial C/H Predictions Inside the CO Snowline ……………………………….. Laboratory evidence for co- condensed oxygen- and carbon-rich meteoritic is part of NASA’s Nexus for stardust from nova outbursts Earths in Other Solar Systems Exoplanetary System Science program, which carries out ……………………………….. coordinated research toward to the goal of searching for and + Line Ratios Reveal N2H determining the frequency of habitable extrasolar planets with Emission Originates above the atmospheric biosignatures in the Solar neighborhood. Midplane in TW Hydrae Our interdisciplinary EOS team includes astrophysicists, ……………………………….. planetary scientists, cosmochemists, material scientists, No Clear, Direct Evidence for chemists and physicists. Multiple Protoplanets The Principal Investigator of EOS is Daniel Apai (University of Orbiting LkCa 15: LkCa 15 Arizona). The project’s lead institutions are The University of bcd are Likely Inner Disk Arizona‘s Steward Observatory and Lunar and Planetary Signals Laboratory. ……………………………….. The EOS Institutional Consortium consists of the Steward The Exoplanet Population Observatory and the Lunar and Planetary Laboratory of the Observation Simulator. II - University of Arizona, the National Optical Astronomy Population Synthesis in the Observatory, the Department of Geophysical Sciences at the Era of Kepler University of Chicago, the Planetary Science Institute, and the Catholic University of Chile. For a complete list of publications, please visit the EOS Library on the SAO/NASA Astrophysics Data System. eos-nexus.org !1 PROJECT EOS May 24, 2019 On the Mass Function, Multiplicity, and Origins of Wide-Orbit Giant Planets Kevin Wagner, Dániel Apai, Kaitlin M. -
EOS Newsletter MARCH 2020
PROJECT EOS March 15, 2020 EARTHS IN OTHER SOLAR SYSTEMS Recent Publications ACCESS: A Visual toNear-infrared Spectrum of the Hot Jupiter WASP-43b with Evidence of H2O, but No Evidence of Na or K ………………………………. Identifying Exo-Earth Candidates in Direct Imaging Data through PROJECT EOS Bayesian Classification ………………………………. Nautilus: A Very Large-Aperture, Ultralight Space Telescope for Exoplanet Exploration, Time- domain Astrophysics, and Faint Objects ………………………………. EPOS: Exoplanet Population Earths in Other Solar Systems is part of NASA’s Nexus for Observation Simulator Exoplanetary System Science program, which carries out ……………………………….. coordinated research toward to the goal of searching for and ACCESS: the Arizona-CfA- determining the frequency of habitable extrasolar planets with Catolica-Carnegie Exoplanet atmospheric biosignatures in the Solar neighborhood. Spectroscopy Survey Our interdisciplinary EOS team includes astrophysicists, ……………………………….. Exoplanet Population Synthesis in planetary scientists, cosmochemists, material scientists, the Era of Large Exoplanets chemists and physicists. Surveys The Principal Investigator of EOS is Daniel Apai (University of ……………………………….. Arizona). The project’s lead institutions are The University of The Sun-like Stars Opportunity ……………………………….. Arizona‘s Steward Observatory and Lunar and Planetary Life Beyond the Solar System: Laboratory. Remotely Detectable The EOS Institutional Consortium consists of the Steward Biosignatures Observatory and the Lunar and Planetary Laboratory of the ……………………………….. Planet formation and migration University of Arizona, the National Optical Astronomy near the silicate sublimation front Observatory, the Department of Geophysical Sciences at the in protoplanetary disks University of Chicago, the Planetary Science Institute, and the ……………………………….. Catholic University of Chile. Search for L5 Earth Trojans with For a complete list of publications, please visit the DECam EOS Library on the SAO/NASA Astrophysics Data System. -
121012-AAS-221 Program-14-ALL, Page 253 @ Preflight
221ST MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY 6-10 January 2013 LONG BEACH, CALIFORNIA Scientific sessions will be held at the: Long Beach Convention Center 300 E. Ocean Blvd. COUNCIL.......................... 2 Long Beach, CA 90802 AAS Paper Sorters EXHIBITORS..................... 4 Aubra Anthony ATTENDEE Alan Boss SERVICES.......................... 9 Blaise Canzian Joanna Corby SCHEDULE.....................12 Rupert Croft Shantanu Desai SATURDAY.....................28 Rick Fienberg Bernhard Fleck SUNDAY..........................30 Erika Grundstrom Nimish P. Hathi MONDAY........................37 Ann Hornschemeier Suzanne H. Jacoby TUESDAY........................98 Bethany Johns Sebastien Lepine WEDNESDAY.............. 158 Katharina Lodders Kevin Marvel THURSDAY.................. 213 Karen Masters Bryan Miller AUTHOR INDEX ........ 245 Nancy Morrison Judit Ries Michael Rutkowski Allyn Smith Joe Tenn Session Numbering Key 100’s Monday 200’s Tuesday 300’s Wednesday 400’s Thursday Sessions are numbered in the Program Book by day and time. Changes after 27 November 2012 are included only in the online program materials. 1 AAS Officers & Councilors Officers Councilors President (2012-2014) (2009-2012) David J. Helfand Quest Univ. Canada Edward F. Guinan Villanova Univ. [email protected] [email protected] PAST President (2012-2013) Patricia Knezek NOAO/WIYN Observatory Debra Elmegreen Vassar College [email protected] [email protected] Robert Mathieu Univ. of Wisconsin Vice President (2009-2015) [email protected] Paula Szkody University of Washington [email protected] (2011-2014) Bruce Balick Univ. of Washington Vice-President (2010-2013) [email protected] Nicholas B. Suntzeff Texas A&M Univ. suntzeff@aas.org Eileen D. Friel Boston Univ. [email protected] Vice President (2011-2014) Edward B. Churchwell Univ. of Wisconsin Angela Speck Univ. of Missouri [email protected] [email protected] Treasurer (2011-2014) (2012-2015) Hervey (Peter) Stockman STScI Nancy S.