Observations - February, 2012

Abstracts

The Arecibo Galaxy Environments Survey (AGES) (A2048)
PI �?? 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,Қ 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

The Alfa Ultra-Deep Survey: Deep HI Observations at 0<z<0.16 (A2133)
PI �?? 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 �??ALFA Ultra Deep Survey�?? (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 �??blind�?? 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

A Cm-wavelength Search for Prebiotic (and Other) Molecules in Arp 220-like Starburst Galaxies (A2334)
PI �?? Dr. Christopher J Salter, NAIC
Co-PI �?? 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 �??pre-biotic�?? 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 �??Arp-220�??-like galaxies, chosen such that emission and absorption lines of the strength found in Arp 220 would be clearly detected in them. Top

GASS - The GALEX Arecibo SDSS Survey (A2335)
PI �?? Dr. David Schiminovich, Columbia University
Co-PI �?? 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 �??transition mass�?? (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 �??transition�?? 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

Do the fundamental constants change with time? (A2525)
PI �?? Dr. Nissim Kanekar, National Radio Astronomy Observatory
Co-PI �?? Dr. Tapasi Ghosh
Proposal Date: September 30, 2009

Abstract: We propose to use the Arecibo L-band receiver to obtain deep, high resolution spectra in the redshifted 18cm satellite OH lines from the z = 0.247 source, PKS1413+135. The conjugate nature of the lines implies that these high-precision redshift measurements can be used to probe changes in the fine structure constant , the proton-electron mass ratio �� and the proton gyromagnetic ratio gp between z=0.247 and today. The sensitivity of the proposed observations to changes in and gp will be the highest from any astronomical technique and with the fewest systematics. The observations will directly confirm or deny the presence of a velocity offset between the satellite OH lines, tentatively detected (at 2.6 significance) in earlier Arecibo and WSRT spectra. If confirmed, this would be evidence for changes in , �� or gp, providing an avenue to probe new and fundamental physics. Our total time request is 160 hours, including all calibration. Top

Are molecular clouds magnetically subcritical or supercritical overall? A survey of Zeeman observations of OH in absorption II. (A2600)
PI �?? Dr. Kristen L Thompson, University of Kentucky
Co-PI �?? 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

Surveying the Zone of Avoidance with ALFA: Outer Galaxy Region (A2611)
PI �?? Dr. Patricia Henning, University of New Mexico
Co-PI �?? 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 �??A�?? 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

A truly promising attempt to discover 6.7 GHz methanol masers outside the Local Group (A2622)
PI �?? Dr. Andrea Tarchi, INAF - Osservatorio Astronomico di Cagliari
Co-PI �?? Dr. Paola Castangia
Proposal Date: February 4th, 2011

Abstract: Taking profit of the large collecting area of the Arecibo telescope and the availability of the C-high receiver, we propose a very sensitive search for 6.7 GHz methanol masers in a promising sample of nearby galaxies outside the Local Group. The aim of this project is to detect strong Galactic-type CH3OH masers in the closest galaxies of the sample and to investigate the possible existence in any of the target galaxies of methanol kilomaser and megamaser sources, like those produced by H2O and OH. Any detection would constitute the first confident discovery of a methanol maser outside the Local Group and would open up the chance for interferometric follow-ups aimed at deriving proper motions and distances of galaxies. Top

A search for radio emission from ultracool dwarfs (A2623)
PI �?? Dr. Alexander Wolszczan, Penn State University
Co-PI �?? Dr. Matthew Route
Proposal Date: February 4th, 2011

Abstract: We propose to continue our nearly completed pilot project (a2471) and use the Arecibo telescope with its C-band receiver and the Mock spectrometer to conduct a survey of ultracool dwarfs in search for a burst component of radio emission from these objects. The design of our search has been guided by the unexpected detection of gigahertz radio emission from several ultracool dwarfs, including our own recent first detection of polarized bursts from a T7 brown dwarf, J1047+21. The objectives of this project are to increase the number of detections of ultracool dwarfs to explore the mechanism of both the magnetic field and the radio emission generation in these objects. We are particularly excited about a possibility to explore the brown dwarf - massive planet boundary using magnetic fields as a diagnostic tool. A possibility to probe magnetic fields of the coolest, lowest-mass dwarfs may shed new light on the much debated transition from brown dwarfs to planets, the associated differences in structure, and the most proper way to distinguish between these two types of objects. Top

HI Absorption Line Study Toward The Perseus Molecular Cloud (A2644)
PI �?? Dr. Min-Young Lee, University of Wisconsin-Madison
Co-PI �?? 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 = 6�??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 KMT09�??s prediction. Our preliminary estimate of the HI surface density using the GALFA�??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 6�??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 GALFA�??HI emission spectra we will derive the optical depth correction for the GALFA�??HI data for Perseus to test the KMT09�??s prediction. Top

Continuing the Monitoring of High Latitude OH/IR Stars (A2645)
PI �?? 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 �??dead�?? 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 band�??s importance to astronomers. Top

Pilot Observations for a Drift-Scan Pulsar Search at 327 Mhz (P1693)
PI �?? Dr. Paulo C. Freire, NAIC
Co-PI �?? 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

An ALFA Pulsar Survey of the Galactic Plane (P2030)
PI �?? Dr. James Cordes, Cornell University
Co-PI �?? 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. Arecibo�??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

Expansion of the NANOGrav Pulsar Timing Array (P2554)
PI �?? Dr. Paulo C Freire, Max-Planck-Institut fur Radioastronomie
Proposal Date: February 11, 2010

Abstract: Timing 3 new millisecond pulsars found in previously unidentified Fermi sources. Apart from assisting with finding the timing solutions and detect the gamma-ray pulsations, we want to check the timing precision of these pulsars with Arecibo. Preliminary indications are that at least two of these pulsars might be suitable for inclusion in the pulsar timing array now being used to attempt to detect very low-frequency gravitational waves. Top

Expansion of the NANOGrav Pulsar Timing Array (P2624)
PI �?? Dr. Paul B. Demorest, NRAO
Co-PI �?? 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 �?? 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

PSR J1713+0747 with PUPPI: aiming for the best timing even and a new test of general relativity (P2625)
PI �?? Dr. Paulo C. Freire, MPIfR
Co-PI �?? 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 Arecibo�??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

Long-term Timing of the Double Neutron Star PSR B1534+12 (P2628)
PI �?? Dr. Ingrid H Stairs, University of British Columbia
Co-PI �?? 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 pulsar�??s spin axis. Here we request 6 90-minute observing sessions (approximately LST 1430�??1600) 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

An L-band Search for Giant Pulses and Radio Transients in Local Group Galaxies (P2647)
PI �?? Dr. Julia Deneva, Arecibo Observatory
Co-PI �?? 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, ALFA�??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

Measuring Two Neutron-Star Masses Using Shapiro Delay (P2649)
PI �?? Dr. Patrick Lazarus, McGill University
Co-PI �?? Victoria Kaspi
Proposal Date: June 2nd, 2011

Abstract: Very recently, Demorest et al. (2010, Nature, 467, 1081) measured a pulsar mass of 1.97��0.04 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

Long Term Timing of PSR J0348+0432: An Exquisite Laboratory for Testing Extreme Physics (P2650)
PI �?? Dr. Ryan S Lynch, University of Virginia
Co-PI �?? 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 counterpartҚ 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

Pulsar Mass Measurements (P2653)
PI �?? Dr. Joris P. Verbiest, Max-Planck-Institut fuer Radioastronomie
Co-PI �?? 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

Longer, RFI-Protected, Polarimetry of Selected Arecibo Pulsars (P2679)
PI �?? Dr. Joanna M Rankin, Physics Dept., University of Vermont
Co-PI �?? Dr. Dipanjan Mitra
Proposal Date: September 30, 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 scientifically competent analysis. Given the considerable success of past efforts and the unique significance of polarimetric pulse-sequence (PPS) measurements made with the Arecibo telescope, we suggest a continuing, long term (2 years, 6 cycles) program to acquire observations of longitudinal importance both immediately for the proposers and students as well ultimately for the pulsar-emission-problem community at large. We request about 30 hours/cycle of which about 40% (or typically 12 hours/cycle) would be in the crowded 18-21-hour RA region. These newer observations will benefit greatly from the now fully implemented Mock spectrometers, the cooled P-band system, its 50-MHz bandwidth and on an experimental basis the excellent and little used C-band system. Top

Radar Observations of Mars during the 2012 Opposition (R2656)
PI �?? Dr. John K Harmon, Arecibo Observatory
Co-PI �?? Dr. Michael C Nolan
Proposal Date: June 2nd, 2011

Abstract: We propose to conduct a campaign of S-band radar observations of Mars during the planet�??s next opposition in February-March 2012. The objective will be to make high-resolution radar reflectivity images of selected portions of the planet. These will be used to map enhanced decimeter-scale surface roughness, radar-dark regions indicative of surface mantling and/or pyroclastic deposits, circular polarization ratios (a diagnostic for surface texture), coherent backscatter from north polar ice, and reflectivity features possibly related to aqueous alteration. Our proposed 2012 observing program is designed to complement Arecibo imaging results obtained from earlier Mars oppositions since 2005. This will be the last opportunity to make Arecibo radar observations of Mars until the 2020 opposition. Top

Arecibo Radar Observations of 21 Near-Earth Asteroids During February-August 2012 (R2658)
PI �?? Dr. Jean-Luc Margot, University of California, Los Angeles
Co-PI �?? Dr. Michael C Nolan
Proposal Date: June 2nd, 2011

Abstract: We request 75 sessions (163 hours observing + 75 hours setup = 238 hours total) to observe 21 Near-Earth Asteroids, 8 of which are likely larger than a kilometer, 7 of which offer opportunities for shape modeling at high signal-to-noise ratio (>1000/day), a few of which may be binaries, and several of which may reveal non-gravitational perturbations such as the Yarkovsky effect. Not much is known about the majority of the objects in this sample. Our goals include detailed physical characterization, determination of binarity or multiplicity, orbital refinement, and shape modeling when possible. Top

Bistatic Radar Observations of the Moon with the Lunar Reconnaissance Orbiter (R2696)
PI �?? Dr. Ben Bussey, JHU/APL
Co-PI �?? Dr. Michael C Nolan
Proposal Date: October 24, 2011

Abstract: The Arecibo Planetary Radan Transmitter combined with the Mini-RF radar instrument in lunar orbit enables a bistatic radar experiment which can provide additional information as to whether lunar polar permanently shadowed areas contain water ice. This experiment would consist of the Arecibo Observatory planetary radar transmitting a 12.6 cm wavelength signal which is reflected off the lunar surface and received by the Mini-RF instrument on LRO. These would be the first ever planetary non beta-zero radar images ever collected.Top

Arecibo observations of E region at 600m resolution in support of the EUV Variability Experiment (EVE) mission. (T2699)
PI �?? Dr. Qihou Zhon, Arecibo Observatory
Proposal Date: February 3rd, 2012

Abstract: We request ISR observations of the ionosphere from 1hour or so before sunrise in the F-region to an hour or so after sunset in the F-region for one day (ASAP). The selected day needs to be coordinated with the EVE satellite team of Tom Woods, Frank et al. so that EVE is operating across its full range. The ISR mode we would be interested in is one that generates full ionospheric profiles E- through F- layer, topside. But with 1 km type resolution through the E-layer. I hope the day we pick is �??quiet�??, although at Arecibo these really is no quiet day say. I think the main idea is that there are no major solar active events or super-storms. The request is urgent because an instrument on the spacecraft is failing and may cease operations at any time. Top