Observations - January, 2012
Abstracts
The Arecibo Galaxy Environments Survey (AGES) (A2048)
PI ò?? 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,Òš 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 ò?? 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 ò??ALFA Ultra Deep Surveyò?? (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 ò??blindò?? 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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A Cm-wavelength Search for Prebiotic (and Other) Molecules in Arp 220-like Starburst Galaxies (A2334)
PI ò?? Dr. Christopher J Salter, NAIC
Co-PI ò?? Dr. Tapasi Ghosh
Proposal Date: June 1st, 2007
Abstract: Our on-going Arecibo line search (Project A2234) of the prototypical starburst/megamaser galaxy, Arp 220, has revealed a spectrum rich in molecular transitions. These include the ò??pre-bioticò?? molecules, methanimine (CH2NH) in emission, three v2=1 absorption lines of HCN, and possibly formic acid (HCOOH). In particular, the (rest) frequency range 4450-5300 MHz contains methanimine, formaldehyde, CH and formamide (NH2CHO) in emission, plus HCN (v2=1, J=4) and three lines of excited-OH in absorption. Our results mark the first distant extragalactic detection of methanimine, a molecule with high relevance to the origins of life. Further, the strong, but previously undetected, cm-wave HCN v2=1 direct l-type lines can aid the study of dense molecular gas and active star-forming regions in starburst galaxies. Consequently, we now propose observing the 4450-5300 MHz band towards 21 ò??Arp-220ò??-like galaxies, chosen such that emission and absorption lines of the strength found in Arp 220 would be clearly detected in them. Top
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Water in the distant Universe: An Arecibo survey for gravitationally lensed water masers (A2468)
PI ò?? Dr. John P. McKean, Astron
Co-PI ò?? Violette Impellizzeri
Proposal Date: February 1, 2009
Abstract: Powerful extragalactic water masers are found in regions of dense gas within a few to a few tens of parsec from the central engine of AGN, providing valuable information on the properties of the supermassive black hole and its environment. To date, water masers have mainly been found in the local Universe only, due to the limited sensitivity of current radio telescopes. However, we have recently found the most distant water maser system known, at z = 2.64, in the gravitationally lensed quasar MG 0414+0534. This detection implies that powerful water masers are more abundant in the distant Universe than previously thought. Here we request observations with Arecibo to survey a sample of 25 distant gravitationally lensed quasars to i) confirm that water maser systems are more abundant at high redshift and ii) find further maser systems to study the properties of distant AGN. Top
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HI and Molecular Line Observations of the 2 Jy IRAS-NVSS Sample at L-Band: Part III, Survey Completion (A2507)
PI ò?? Bevin A Zauderer, University of MD
Co-PI ò?? Emmanuel Momjian
Proposal Date: June 1, 2009
Abstract: We propose using the Arecibo telescope to study 140 infrared galaxies from the 2 Jy IRAS-NVSS sample for which there are no HI measurements. These observations will provide a complete, homogeneous set of high-sensitivity data for all Arecibo-accessible objects and complement our previous studies (a1908 and a2361) covering the other 12 hours in right ascension for which we have obtained observations of 155 galaxies. The observations will be carried out simultaneously for eight bands, namely the HI 21 cm and four 16OH 18 cm lines, HCN, HCO+, and the 18OH isotope, using the full capabilities of the WAPP spectrometer. Among the scientific goals are to: 1) investigate the differences in physical characteristics for sources with AGNs and those with pure starbursts; 2) search for statistical trends with increasing infrared luminosity; 3) study OH gas properties, especially the occurrence of masers and activity in the OH satellite lines. 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 ò?? Dr. Kristen L Thompson, University of Kentucky
Co-PI ò?? 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 ò?? Dr. Patricia Henning, University of New Mexico
Co-PI ò?? 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 ò??Aò?? 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 ò?? Dr. Ellen S. Howell, Arecibo Observatory
Co-PI ò?? 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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HI Absorption Line Study Toward The Perseus Molecular Cloud (A2644)
PI ò?? Dr. Min-Young Lee, University of Wisconsin-Madison
Co-PI ò?? Dr. Snezana Stanimirovic
Proposal Date: June 3, 2011
Abstract: Recent analytical model for H2 formation in giant molecular clouds by Krumholz et al. (2009; KMT09) predicts that the minimum HI surface density = 6ò??10 solar mass/pc2 (at solar metallicity) is required for shielding H2 against photodissociation. We propose HI absorption measurements toward 19 radio continuum sources behind the Perseus molecular cloud to test KMT09ò??s prediction. Our preliminary estimate of the HI surface density using the GALFAò??HI emission data and under the assumption of optically thin HI gas shows that HI surface density is almost constant across Perseus with a value of 6ò??8 solar mass/pc2. However, the HI surface density may be underestimated due to the existence of high optical depth gas. With the proposed HI absorption and GALFAò??HI emission spectra we will derive the optical depth correction for the GALFAò??HI data for Perseus to test the KMT09ò??s prediction. Top
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Continuing the Monitoring of High Latitude OH/IR Stars (A2645)
PI ò?? 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 ò??deadò?? 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 bandò??s importance to astronomers. Top
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Harvesting ALFALFA: L-band Wide Followup of Enigmatic ALFALFA sources (A2669)
PI ò?? Dr. Martha P Haynes, Cornell University
Co-PI ò?? Dr. Riccardo Giovanelli
Proposal Date: September 27, 2011
Abstract: We propose to conduct targeted L-band wide observations of selected sources detected by the ALFALFA survey in four categories: (1) high quality ALFALFA detections without optical counterparts and not associated with known tidal debris fields: the ò??dark galaxyò?? candidates; (2) ALFALFA sources without optical counterparts which are candidate OH megamasers because of their coincidence with optical sources at the appropriate redshift; (3) low signal-to-noise, low velocity (nearby), narrow line width ALFALFA sources without optical counterparts: the extreme gas-dominated dwarf galaxy candidates; and (4) statistical samples of the low signal-to-noise ratio detections possibly associated with optical galaxies. The objectives of the LBW observations are to confirm the reality of the (almost) ò??darkò?? galaxy and OH megamaser candidate signals and to enable the extension of the ALFALFA catalog at the low HI line flux density regime for science applications that can benefit from higher source density. Top
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Pilot Observations for a Drift-Scan Pulsar Search at 327 Mhz (P1693)
PI ò?? Dr. Paulo C. Freire, NAIC
Co-PI ò?? 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 ò?? Dr. James Cordes, Cornell University
Co-PI ò?? 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. Areciboò??s 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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Expansion of the NANOGrav Pulsar Timing Array (P2624)
PI ò?? Dr. Paul B. Demorest, NRAO
Co-PI ò?? 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 ò?? 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 ò?? Dr. Paulo C. Freire, MPIfR
Co-PI ò?? 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 Areciboò??s 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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An L-band Search for Giant Pulses and Radio Transients in Local Group Galaxies (P2647)
PI ò?? Dr. Julia Deneva, Arecibo Observatory
Co-PI ò?? 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, ALFAò??s 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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Measuring Two Neutron-Star Masses Using Shapiro Delay (P2649)
PI ò?? Dr. Patrick Lazarus, McGill University
Co-PI ò?? Victoria Kaspi
Proposal Date: June 2nd, 2011
Abstract: Very recently, Demorest et al. (2010, Nature, 467, 1081) measured a pulsar mass of 1.97ÒÁ0.04 M, thereby greatly extending the known range of precisely measured neutron-star masses, and significantly constraining the equation of state for supra-nuclear-density matter. This major result further emphasizes the questions of (i) how high a neutron-star mass can be?and (ii) what is the true distribution of neutron-star masses? Only through additional, new neutron-star mass measurements can these fundamental questions be answered, but opportunities for this are rare. Here we request 45 hr of Arecibo time in order to measure the Shapiro delay in two PALFA-discovered binary pulsars that are very likely to enable two new precise neutron-star mass measurements. Top
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Long Term Timing of PSR J0348+0432: An Exquisite Laboratory for Testing Extreme Physics (P2650)
PI ò?? Dr. Ryan S Lynch, University of Virginia
Co-PI ò?? 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 counterpartÒš 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 ò?? Dr. Joanna M. Rankin, University of Vermont
Co-PI ò?? 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 ò?? Dr. Joris P. Verbiest, Max-Planck-Institut fuer Radioastronomie
Co-PI ò?? 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 ò?? Dr. Marina Brozovic, JPL/Caltech
Co-PI ò?? 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 Û?400 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 ò?? Dr. Michael K Shepard, Bloomsburg University
Co-PI ò?? 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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Radar Observations of C/2010 X1 Elenin and C/2006 T1 Levy (R2657)
PI ò?? Dr. Ellen S Howell, NAIC
Co-PI ò?? Dr. John K Harmon
Proposal Date: June 1st, 2011
Abstract: We propose radar observations to detect large grains in the coma and to image the nucleus of two comets. C/2010 X1 Elenin is 0.23 AU from the Earth in October, 2011. We expect to obtain CW spectra of the coma of this comet, and to detect cm -sized grains in the coma if possible. We may obtain images of the nucleus if it is large enough. C/2006 T1 Lev y is a periodic comet which comes to 0.18 AU from the Earth in January, 2012. If the SNR is 50 or more for either, we could get images of the nucleus to reveal its size and shape. Such opportunities are extremely rare, but have yielded very valuable information for the four comets imaged to date. Top
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Coordinated Incoherent Scatter Radar and Optical Observations during the World Days during 1999-2000 (T1193)
PI ò?? Dr. Qihou Zhon, Arecibo Observatory
Co-PI ò?? Dr. Nestor Aponte
Proposal Date: October 11, 1998
Abstract: We request the continuation of the World Day program from 1999 through 2000. This is a cooperative effort among all the incoherent scatter radar and optical sites worldwide to investigate the structure, dynamics and composition of the upper atmosphere. The incoherent scatter radar and optical facilities at Arecibo will be used to measure and derive various atmospheric and ionospheric parameters, such as, electron concentration, ion and electron temperature, plasma drift velocity, and neutral wind velocity. The data from all World Day experiments are processed in a common format and archived in the NCAR data base, and are available to investigators from all over the world. Top