Observations - December, 2011
Abstracts
The Arecibo Galaxy Environments Survey (AGES) (A2048)
PI òÀÓ Dr. Jonathan I Davies, Cardiff University, UK
Proposal Date: January 27, 2006
Abstract: In this Extragalactic ALFA consortium proposal we are requesting 2000 hours of observing time over a 4 year period. The survey is specifically designed to investigate various galactic environments to higher sensitivity with better spatial, and velocity resolution than previous, fully sampled, 21cm multi-beam surveys. We have chosen specific objects in the nearby Universe upon which to centre our observations,ˆà but will also use the full depth of the survey to quantify the HI properties of more distant galaxies. Our science goals include: the HI mass function in different environments, the contribution of neutral gas to the baryonic mass density, the nature of and link between high velocity hydrogen clouds and dwarf galaxies, the identification of gaseous tidal features as signatures of galaxy interactions and mergers, the low column density extent of galaxies, a comparison with atomic hydrogen detected by QSO absorption lines, the identification of isolated neutral gas clouds, the spatial distribution and properties of HI-selected galaxies and comparisons with numerical models of galaxy formation. Top
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The Alfa Ultra-Deep Survey: Deep HI Observations at 0<z<0.16 (A2133)
PI òÀÓ Dr. Wolfram Freudling, Space Telescope - European Coordinating Facility
Proposal Date: June 8, 2008
Abstract: The improved spatial and spectral survey capabilities available with ALFA opened a new era of high sensitivity observations for the Arecibo telescope. In a precursor experiment, we have demonstrated that it is possible to achieve noise of less than 50micro-Jy with integration times of about 40 hours per pointing, which translates into a HI mass sensitivity of a few 10E8 Msun at a redshift of about 0.16. We propose to use the new 200 MHz spectrometer available in late 2005 to carry out a blind HI survey with unprecedented sensitivity of 50micro-Jy for the redshift range of 0<z<0.16 over a total area of 0.36 square degrees. The òÀÜALFA Ultra Deep SurveyòÀÝ (AUDS) survey is more than an order of magnitude more sensitive than other HI surveys currently being carried out at Arecibo. The main scientific goals of the survey are to investigate the evolution of HI gas in the universe and explore the low-density gas around the edges of galaxies. The survey will be the deepest òÀÜblindòÀÝ HI survey ever conducted. It will provide for the first time a direct link between HI absorption line measurements at high and intermediate redshifts and 21-cm emission line measurements at low redshifts. The expected number of HI detections at z>0.1 will be larger than that of all previous targeted and blind surveys combined. Top
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GASS - The GALEX Arecibo SDSS Survey (A2335)
PI òÀÓ Dr. David Schiminovich, Columbia University
Co-PI òÀÓ Dr. Barbara Cantinella
Proposal Date: June 1st, 2007
Abstract: We propose the GALEX Arecibo SDSS Survey (GASS) a large targeted survey designed to measure the HI content of about 1000 galaxies at redshift 0.025<z<0.05 uniformly selected from the SDSS spectroscopic and GALEX imaging surveys to have stellar mass greater than 1e10 Msun. Our selected mass range straddles the recently identified òÀÜtransition massòÀÝ (3e10 Msun) above which galaxies show a marked decrease in their present to past-averaged star formation rates. GASS will produce the first statistically significant sample of massive òÀÜtransitionòÀÝ galaxies with homogeneously measured stellar masses, star formation rates and gas properties. By observing these galaxies down to a low gas mass fraction limit (1.5%), GASS will provide new insight into the physical mechanisms that shape the stellar mass function, regulate gas accretion and quench further galaxy growth by conversion of gas into stars. GASS will be of considerable legacy value not only in isolation but also by complementing on-going HI-selected surveys. Top
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The water megamaser in MGJ0414+0534: jet-maser or disk-maser? (A2547)
PI òÀÓ Dr. Paola Castangia, INAF-OAC
Co-PI òÀÓ Violette Impellizzeri
Abstract:
The water maser line from the gravitationally lensed quasar MGJ0414+0534 has been monitored with Arecibo since October 2008 at 6 weeks intervals with the aim of shedding light on the origin of the maser emission. Although the stability of the main maser line throughout the monitoring and presence of a satellite line suggest that the maser originates in the accretion disk rather than in the relativistic jet(s) detected in the quasar, the current data do not allow us to draw a definitive conclusion on its nature. Therefore, we propose to prolong the monitoring for two additional years, at a slower rate, in order to i) be able to detect any possible serendipitous flare-up that can be followed-up with VLBI; ii) confirm the presence of the satellite line that is clearly seen in one epoch and is believed to be variable and iii) investigate the hypothesis of a velocity drift smaller than 8 km/s per year. The presence of satellite lines and velocity drifts in the maser spectrum is important since it can be used to estimate the mass of the supermassive black hole and the radius of the accretion disk in a quasar at redshift 2.64. Top
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The Molecular ISM in High Redshift Objects (A2597)
PI òÀÓ Dr. Tapasi Ghosh
Co-PI òÀÓ Dr. Christopher Slater
Proposal Date: October 1, 2011
Abstract: Using eight, low-energy K-doublet transitions of Formaldehyde, this proposal aims to study the molecular interstellar medium in nine high-redshift objects. Detections of these multiple transitions (4-5 in each source accessible via the receiver systems at Arecibo) will help determining physical conditions in these galaxies. The derived parameters such as column density, spatial density (or their upper limits) will help constrain chemical models of star formation in early universe. Top
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Are molecular clouds magnetically subcritical or supercritical overall? A survey of Zeeman observations of OH in absorption II. (A2600)
PI òÀÓ Dr. Kristen L Thompson, University of Kentucky
Co-PI òÀÓ Dr. Thomas Troland
Proposal Date: September 30, 2011
Abstract: Although much Zeeman work has been done to study the effect of magnetic fields on molecular cloud cores, very little is known about fields in the general envelopes of molecular clouds. Are molecular clouds as a whole magnetically subcritical or supercritical?Using Arecibo, Thompson and Troland have begun the first systematic observational survey to address this question using the Zeeman effect in OH absorption toward extra-galactic continuum sources that lie behind molecular clouds. In this first survey we have studied 7 lines-of-sight. However, the Zeeman effect can only reveal the line-of-sight magnetic field, which makes this study inherently statistical in nature. To obtain statistically meaningful results for this project, we require magnetic field information for more than 7 lines-of-sight. We have identified 26 additional extra-galactic sources. We will chose about 10 of these sources based upon a short survey of OH optical depths and conduct Zeeman observations, spending about 20 hours on each source. Top
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Surveying the Zone of Avoidance with ALFA: Outer Galaxy Region (A2611)
PI òÀÓ Dr. Patricia Henning, University of New Mexico
Co-PI òÀÓ Dr. Travis McIntyre
Proposal Date: December 10th, 2010
Abstract: We propose to survey the Zone of Avoidance (ZOA) deeply at 21-cm using the ALFA system, mapping hidden galaxies and large-scale structures at low Galactic latitudes. Mapping galaxies in the ZOA is one of four large blind surveys endorsed by the Extragalactic ALFA consortium, and is the only low-Galactic latitude project so endorsed. Our project A2152, to conduct deep observations commensally with PALFA, received an òÀÜAòÀÝ grade, and was to observe both the inner and outer Galaxy regions. We are proceeding commensally with PALFA (P2130) in the inner Galaxy region, and propose here that ZOA become primary project in the outer Galaxy region. We refer to our A2152 proposal for full scientific justification. Top
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OH Observations of four comets June 2011 - January 2012 (A2616)
PI òÀÓ Dr. Ellen S. Howell, Arecibo Observatory
Co-PI òÀÓ Dr. Amy J. Lovell
Proposal Date: February 6, 2011
Abstract: We propose to continue our measurements of OH lines in cometary comae to measure the water production rates, outflow velocity and study effects of collisional quenching in the inner coma. The radio lines at 1667 and 1665 MHz are ideally suited for study of water in comets from the ground, and can be done in daylight. Two short-period comets and two long-period comets are available in this time period. Top
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21 cm HI Observations of intermediate-z Clusters of Galaxies (A2642)
PI òÀÓ Dr. Macarena Garcia, Physikalisches Institut, Cologne University, Germany
Co-PI òÀÓ Dr. Andrea Eckart
Proposal Date: June 2, 2011
Abstract: We propose to detect and study the global neutral atomic gas properties of a sample of 4 intermediate-redshifts (0.15 <z <0.2) clusters of galaxies with the Arecibo telescope. The data will be compared with the results of our clusters observations with the GBT. We plan to study the neutral gas content in these structures, not only to derive the masses, but to understand the evolution of the clusters space density. As the clusters have been selected using ROSAT and SDSS, we will be able to compare our results with X-ray data. In fact, we will test the correlation between the HI deficiency and the X-ray emitting intra-cluster medium. Top
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Continuing the Monitoring of High Latitude OH/IR Stars (A2645)
PI òÀÓ Dr. Murray Lewis
Proposal Date: June 1st, 2011
Abstract: This is a proposal to continue the monitoring of OH masers in high latitude OH/IR stars. It is only ever accorded scraps of time, most in the daytime / twilight gaps of the telescope schedule. Nevertheless, it has resulted in a number of discoveries, including the identification of both òÀÜdeadòÀÝ OH/IR stars, stars with revived masers, and a star that has changed from a classic double-peaked to single-peaked spectrum, among others. The proposal seeks to continue this fruitful study, in part by filling in gaps in pulsation-phase coverage that result from the episodic (rather than regular) availability of time. There are two institutional byproducts: (i) more telescope hours are used gainfully, and (ii) OH observations are continued in the 1612 MHz band adjacent to the Iridium satellite band, which helps to maintain the record of this bandòÀÙs importance to astronomers. Top
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Galaxy observations by the òÀÝHands on the UniverseòÀÝ undergraduate class at UW-Madison (A2695)
PI òÀÓ Dr. Snezana Stanimirovic, UW-Madison
Proposal Date: October 20, 2011
Abstract: òÀÜHands on the UniverseòÀÝ is a lab-based class for non-science majors at UW-Madison. We have 5 class sections, each with about 20 students. The final class lab (planned for early Dec 2011) explores the Hubble flow by obtaining computer-simulated optical observations of galaxies. We would like to request 5 hours of Arecibo time to conduct remotely complementary radio observations. We plan to use ON/OFF observing method and target bright galaxies which need a few minutes of integration time. We will ftp data files and run them through a data reduction pipeline, producing galaxy spectra essentially in real time. Students will then measure the recessional velocity for each galaxy and add these òÀÝreal observationsòÀÝ to their Hubble graphs of simulated galaxies. We have experience in conduction remote observations with students and this to be highly motivational and exciting exercise for students. Top
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Pilot Observations for a Drift-Scan Pulsar Search at 327 Mhz (P1693)
PI òÀÓ Dr. Paulo C. Freire, NAIC
Co-PI òÀÓ Dr. James Cordes
Proposal Date: June 1st, 2002
Abstract: We request 100hr of telescope time to conduct a pilot drift-scan pulsar search using the new 327 MHz Gregorian receiver and the Wideband Arecibo Pulsar Processor (WAPP). Using a 30-MHz band expected to be available from the new receiver, we will be twice as sensitive to nearby low-DM pulsars as the present 430-MHz drift-scan surveys for pulsars with average spectral indices. The number detectable at 327 MHz should increase by at least a factor of 2. If these expectations are confirmed, we intent to propose a more ambitious all-sky 327-MHz drift-scan survey, which would complement future ALFA (Arecibo L-Band Feed Array) pulsar surveys that would favor pulsars with flatter spectra. Top
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An ALFA Pulsar Survey of the Galactic Plane (P2030)
PI òÀÓ Dr. James Cordes, Cornell University
Co-PI òÀÓ Dr. Fernando Camilo
Proposal Date: October 1st, 2004
Abstract: We propose the first year of a large-scale survey of the Galactic plane using ALFA. Primary emphasis will be on the inner Galaxy but we also propose a search of the Galactic anticenter region. AreciboòÀÙs high gain and wide-band spectrometers allow surveys of much greater volumes (per unit solid angle) than the eminently successful Parkes Multibeam Survey, particularly for short-period pulsars. The survey will thus find not only a large sample of pulsars, but also rare objects that are especially useful for probing fundamental aspects of neutron stars, testing theories of gravity, and detecting gravitational backgrounds, among other enterprises. We estimate that with our eventual software processing, we will discover a pulsar about every 1.5 hr of on-sky observing time. In addition, our analysis also will detect transient signals from pulsars that are intermittent or from other kinds of objects. Preliminary observations in 2004 Aug-Sep have yielded discovery of eight new pulsars in a quick-look analysis, including one from detection of its single pulses. Many more are expected in the data we already have. Given the pace of observations so far, our ability to glean from them new pulsar discoveries, and our expectation that full resolution code will complete the processing of precursor-survey data by the end of 2005 January, a comprehensive pulsar survey using existing WAPP spectrometers can be initiated on or after 2005 Feb 1. Top
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Characterizing Rotating Radio Transient J0627+16 (P2558)
PI òÀÓ Dr. David J Nice, Bryn Mawr College
Co-PI òÀÓ Dr. Julia Deneva
Proposal Date: February 11, 2010
Abstract: We request 4 hr of Arecibo time for pulse timing measurements of rotating radio transit (RRAT) J0627+16. This source, discovered in the PALFA pulsar survey during observations of the Galactic anti-center region, rotates with a period of 2.180 s and shows a highly erratic pattern of pulse emission. The proposed observations are part of the PALFA effort to measure of positions and spin-down rates of all newly discovered sources. The new observations will also add to our growing knowledge about the emission properties of RRATs. Top
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Expansion of the NANOGrav Pulsar Timing Array (P2624)
PI òÀÓ Dr. Paul B. Demorest, NRAO
Co-PI òÀÓ Dr. David J. Nice
Proposal Date: February 4, 2011
Abstract: Direct detection of gravitational waves (GW) is a major goal in experimental physics and will revolutionize astrophysics, opening an entirely new spectrum for exploration. Precision pulsar timing stands an excellent chance of being the first method to accomplish this feat. Combining data from many objects into a Pulsar Timing Array (PTA) makes GW detection possible. Increasing the number of pulsars in the array improves sensitivity òÀÓ the detection significance improves approximately linearly with the number of pulsars. Observing more pulsars also helps mitigate intrinsic systematic timing effects. The past year has seen a unexpected and unprecedented number of new millisecond pulsars (MSPs) discovered, due to several ongoing radio sky surveys (GBT 350-MHz surveys; PALFA) and targeted radio searches of Fermi-identified gamma-ray point sources. Here we propose an expansion of our ongoing PTA project to take advantage of these new sources. Top
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PSR J1713+0747 with PUPPI: aiming for the best timing even and a new test of general relativity (P2625)
PI òÀÓ Dr. Paulo C. Freire, MPIfR
Co-PI òÀÓ Dr. Paul Demorest
Proposal Date: February 4th, 2011
Abstract: We request time for precise timing of PSR J1713+0747 with the new broadband coherent dedispersion machine, PUPPI. This should result in the most precise pulsar timing ever achieved. We plan a campaign of dense observations that will greatly improve the precision of the orbital and astrometric parameters and enhance the sensitivity of AreciboòÀÙs timing array to gravitational waves. The improved measurement of the orbital parameters will provide a precise mass value for the pulsar and its companion and greatly improve the precision of a new test of general relativity. The requirements for this (high timing precision and continued timing) are the same as for the detection of gravitational waves. Top
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Long-term Timing of the Double Neutron Star PSR B1534+12 (P2628)
PI òÀÓ Dr. Ingrid H Stairs, University of British Columbia
Co-PI òÀÓ Dr. Emmanuel Fonseca
Proposal Date: February 4, 2011
Abstract: Our timing and profile-variation observations of the double-neutron-star binary PSR B1534+12 continue to provide high-precision tests of strong-field gravity and a probe of the general-relativistic geodetic precession rate of the pulsaròÀÙs spin axis. Here we request 6 90-minute observing sessions (approximately LST 1430òÀÓ1600) over the course of the next year to monitor changes in the spin properties of and the dispersion measure to this pulsar. These observations are vital to ensure the long-term quality of the data set on this pulsar. Top
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An L-band Search for Giant Pulses and Radio Transients in Local Group Galaxies (P2647)
PI òÀÓ Dr. Julia Deneva, Arecibo Observatory
Co-PI òÀÓ Dr. Ramesh Bhat
Proposal Date: June 2nd, 2011
Abstract: We propose to conduct a search for giant pulses (GPs) from Crab-like pulsars in M33 and four dwarf spheroidal (dSph) Local Group galaxies. Using the Mock spectrometer will allow us to achieve superior sensitivity to prior extragalactic pulsar surveys at Arecibo due to its wider bandwidth and better response to radio-frequency interference (RFI) compared with older backends. For M33 observations, ALFAòÀÙs multibeam capability will provide large instantaneous coverage as well as enable efficient elimination of false positives due to sporadic RFI. For observations of dSph galaxies, we will use the even wider-bandwidth L-wide receiver. Both receivers are capable of detecting GPs from Crab-like pulsars in our target galaxies. In addition to important science that will be enabled by extragalactic pulsar discoveries (studies of pulsar population and ISM in each galaxy, and probing the IGM), the algorithms that we develop will also be applicable to science planned with next-generation arrays. Top
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Long Term Timing of PSR J0348+0432: An Exquisite Laboratory for Testing Extreme Physics (P2650)
PI òÀÓ Dr. Ryan S Lynch, University of Virginia
Co-PI òÀÓ Dr. Paulo Freire
Proposal Date: 2011
Abstract:
We propose to continue long-term timing of the binary pulsar J0348+0432 so as to measure the decay of the orbital period due to the emission of gravitational waves. The pulsar has an optical counterpartˆà determined to be a 0.17 Msun white dwarf, which implies an 80% probability that the pulsar is >2 Msun. Alternate theories of gravity predict that this system should be a strong emitter of dipolar gravitational waves, which differs from general relativity. With an additional two years of timing (the first of which we are requesting here), we should be able to make a 10-detection of the orbit decay and test these alternative theories. This will also allow us to confirm the optical mass measurement, which will be important for testing the neutron star equation of state if the pulsar is >2 Msun. Top
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Longer, RFI-Protected, Polarimetry of Selected Faster Arecibo Pulsars (P2651)
PI òÀÓ Dr. Joanna M. Rankin, University of Vermont
Co-PI òÀÓ Dr. Dipanjan Mitra
Proposal Date: June 2, 2011
Abstract: We propose a further program of often lengthy polarimetric observations on a set of pulsars for which shorter observations have been made and found inadequate for a full analysis. Given the considerable success of past efforts and the unique significance of polarimetric pulse-sequence measurements made with the Arecibo telescope, we suggest a continuing, long term program to acquire observations of longitudinal importance both immediately for the proposers and ultimately for the pulsar-emission-problem community at large. These newer observations will benefit significantly from the fully implemented Mock spectrometers, the cooled P-band system, its 50-MHz bandwidth and in a few cases the excellent and little used C-band system. Top
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Pulsar Mass Measurements (P2653)
PI òÀÓ Dr. Joris P. Verbiest, Max-Planck-Institut fuer Radioastronomie
Co-PI òÀÓ Dr. Paulo C. Freire
Proposal Date: June 2nd, 2011
Abstract: We plan to use the unique sensitivity of the Arecibo telescope to observe the millisecond pulsar PSR J1640+2224 intensively near superior conjunction, and less intensely during the remainder of the orbit, with the objective of measuring the Shapiro delay for this binary millisecond pulsar. This might confirm the first ever neutron star mass below 1 solar mass. However, even if this is not the case, the planned observations will improve our knowledge of the neutron star mass distribution. Top
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Arecibo Radar Observations of Nineteen Near-Earth Asteroids During October 2011-January, 2012 (R2629)
PI òÀÓ Dr. Marina Brozovic, JPL/Caltech
Co-PI òÀÓ Dr. Michael Nolan
Proposal Date: February 4th, 2011
Abstract: We propose to observe 19 near-Earth asteroids via S-band. Due to a high number of exciting objects in period from Oct 2011 to Feb 2012, we propose an ambitious schedule of 153 hours of observing time. Asteroid 2005 YU55 stands out as once-per-decade radar target. This ¸Ü400 m diameter object will be at 0.85 lunar distances (LD) on Nov 8, 2011 and the radar data quality will truly be comparable to a spacecraft flyby. Another outstanding target coming in mid-October is Ganymed, which at 40 km diameter is the largest near-Earth object. In the case of Ganymed, we are particularly interested in satellite search. The third highlight is a binary asteroid 1996 FG3 that has been mentioned as the target of interest for the future space missions. We are also very interested in observing asteroids that have been scheduled as targets in the complementary programs such as Spitzer Space Telescope, Wide-field Infrared Survey Explorer (WISE) or NASA InfraRed Telescope Facility (IRTF). We expect that at least 10 out of 19 radar targets will produce datasets suitable for shape modeling. Top
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Radar Detection of Six M-class Asteroids (R2632)
PI òÀÓ Dr. Michael K Shepard, Bloomsburg University
Co-PI òÀÓ Dr. Michael Nolan
Proposal Date: February 4th, 2011
Abstract
We propose to observe six M-class asteroids, five of which have never been observed. Our purpose is to continue our systematic investigation into the properties of the M-class asteroids, long thought to be remnant cores of early planetesimals. Successful observation of these six objects will: (1) increase our total sample size of observed M-asteroids by 25% to 25 total objects; and (2) provide a second look at a potential M-class contact binary, 678 Fredegundis. Top
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Two-dimensional, high-resolution measurements of gravity waves in the Arecibo thermosphere: Fall and Winter Observations (T2573)
PI òÀÓ Dr. Michael J Nicolls, SRI
Co-PI òÀÓ Dr. Sharon Vadas
Proposal Date: January 29, 2011
Abstract
Tracers of atmospheric gravity waves (GWs) have been observed in the Arecibo thermosphere using a very sensitive measurement of electron density afforded by the incoherent scatter plasma line [2òÀÙòÀÜ4]. The electron density fluctuations as a function of time and altitude give information on the properties of the GWs that perturb the neutral atmosphere and indirectly the ionosphere through periodic plasma advection and compression. An initial measurement campaign by the authors of this proposal (proposal T2485) afforded dual beam measurements on 23-26 July 2009 to obtain information on the horizontal wavelengths of the GWs. This technique has proven successful, and will allow for (a) estimates of GW spatial scales, periods, amplitudes, directions of propagation, and GW transport and deposition of momentum, (b) testing of the predictions of a viscous dispersion relation for GWs in the thermosphere, and (c) an assessment of the GW sources that are most influential on thermospheric circulation, structure, and variability. In this proposal, we request time for two observing campaigns: one in the Fall of 2010 (September, October, or November) and the other in the Winter of 2010/2011 (December, January or February). These observations should help characterize the propagation directions, periods, and horizontal wavelengths, and thus the major source regions, of gravity waves in different seasons. Top
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Radar and lidar study of mesopause dynamics and chemistry (T2574)
PI òÀÓ Dr. Qihou Zhou, Miami University
Co-PI òÀÓ Dr. Yun Jong
Abstract:
We propose to study mesopause dynamics and chemistry using the Arecibo ISR and resonance lidars. The scientific objectives include the study of : 1. ion neutral collision frequency; 2. tides and planetary waves in wind, temperature and density; 3. ion composition in sporadic layers; 4. chemistry of metal layers. We also propose to explore the development and calibration of potassium lidar wind measurement capability. We request a total of 10 days of radar time over two years. In order to maximize the scientific output, we request radar time scheduled in conjunction with World Days focusing on lower thermosphere and mesosphere. Top
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GMOS Diagnosis of Whistler and HF Wave-Induced Micropulsations (T2604)
PI òÀÓ Dr. Min-Chang Lee, MIT
Co-PI òÀÓ Dr. Michael Sulzer
Abstract:
A long-term (two-year extent) experimental program is proposed for supporting Ph.D. studentsòÀÙ thesis research continuously on the subject of òÀÝwhistler and HF wave-induced micropulsationsòÀÝ. It is expected theoretically [Rezy Pradipta, Ph.D. Thesis Prospectus, 2009 (updated)] that NAU-launched whistler waves can be backscattered to parametrically generate a daughter whistler wave and a forced ion acoustic mode in the ionosphere. To facilitate the coupling of NAU signals with the ionosphere, either naturally-occurring or HF wave-created ducts will be desirable for proposed experiments. Diagnostic instruments include Arecibo radar, CADI, magnetometer, optical instruments, and GPS satellites together with our All Sky Imaging System (ASIS) and the newly acquired Geo-Magnetic Observatory System (GMOS). They will be used to diagnose whistler or HF-induced micropulsations as well as the concomitantly induced plasma density fluctuations in the ionosphere, and the subsequent electron precipitation from inner radiation belts (see attached proposal for details). Top
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Electron Line Measurements at Arecibo: Electron Temperature and Collision Frequency (T2698)
PI òÀÓ Dr. Michael J Nicolls, SRI
Co-PI òÀÓ Dr. Hasan Bahcivan
Proposal Date: November 10, 2011
Abstract
While typical incoherent scatter (IS) measurements focus on the ion contributions to the IS spectrum, which provide sensitivity to parameters like the electron density, ion composition, electron and ion temperatures, ion-neutral interactions, electric fields, more recent measurements have made use of AreciboòÀÙs extreme sensitivity combined with advances in electronics and computational capabilities to detect and study electron components of the incoherent scatter spectrum, such as the gyro line and plasma line. In this proposal, we attempt to measure an additional feature of the incoherent scatter spectrum in the lower ionosphere associated with collisional effects on the electrons. If successful, these measurements may lead to a diagnostic tool to assess the electron temperature and / or electron collision frequency in the lower ionosphere, where such effects are particularly hard to diagnose. Such measurements would be applicable to future ionospheric heating campaigns at Arecibo. Top