Single Dish Summer School: 11 July 2013 A Potpourri of Arecibo Single-Dish Highlights Chris Salter Arecibo Observatory (National Astronomy & Ionosphere Center) ‏

Single Dish Summer School: 11 July 2013 Receivers 800

Single Dish Summer School: 11 July 2013 PALFA -- Search for Low-b Pulsars PSR Period = 2.15 ms Binary Period = 95 day with 1M O main-seq. companion. Orbital Eccentricity = 0.44 PSR mass = 1.667±0.021M o → implications for EOS of cold ultra-dense matter. J Records 300-MHz bandwidth per beam. So far, 116 new PSRs detected. Some PSRs detected via periodicity analysis, some by strong single pulses. Sixteen msec PSRs discovered → PTA. PSR J shows secular pulsar-shape evolution due to geodetic precession. Eight sporadic pulsars/Rotating RAdio Transients (RRATs). Data processing in part via involving ~100k clients worldwide 23 new PSRs, including 4 MSPs.

Single Dish Summer School: 11 July 2013 Pulsar Timing Array: Gravitational Wave Search Now investigating astrophysically interesting parameter space. Requires well-distributed array of highly-stable pulsars (PALFA). Negligible cost compared with LIGO and LISA.

Single Dish Summer School: 11 July 2013 Hankins & Eilek find giant Crab PSR interpulses to differ in both time and frequency from giant main pulses! The main pulses can be resolved into brief nanoshots (see below) of “modest” fractional bandwidth, believed due to soliton collapse in strong plasma turbulence. However, unlike predictions if the pulses come from opposing magnetic poles, the giant main and interpulses are extremely different. A 2  10 6 Jy main pulse from the Crab pulsar showing “nanoshots”. These are unresolved with 0.4-ns resolution at 9.2 GHz. For the light- travel size (~12 cm), T b ~2  K (a record!) Giant Pulses from the Crab Pulsar (Courtesy: Tim Hankins)

Single Dish Summer School: 11 July 2013 Main Pulse: Typically, several bursts of < 1  sec per pulse, with width  -2. Occasional ≤1-ns “nanoshots”. Weakly polarized. More infrequent than interpulse, but more intense. 9.2 GHz Interpulse: Emission bands in dynamic spectrum. Structure of a few  sec duration. Bands seen in every interpulse, but never in the main pulse. Band spacing of  / ~0.06. Interpulse has slightly higher DM than main pulse (0.05%). Strongly linearly polarized. No existing model can explain the banded interpulse structure.

Single Dish Summer School: 11 July 2013 Pulsar Study: The “Planets Pulsar” Alex Wolszczan is completing a 17-yr study of the “planets pulsar”, PSR B His timing fits includes; All PSR parameters Astrometric parameters Three planets (including the mutual perturbations of Planets b & c) DM variations (3 rd panel). Highlights of 17-yr Study of B First exoplanets. First detection of planets in mean motion resonance (MMR 3:2). First multiplanet system. First terrestrial-mass system. First dynamical analog of the inner solar system (scaled down by a factor of ~2). 430-MHz Raw Residuals 1400-MHz Raw Residuals Residuals including DM Variations Dispersion Measure (DM) Variations (Courtesy: Alex Wolczszan)

Single Dish Summer School: 11 July 2013 The Coolest Radio Star Stokes- V

Single Dish Summer School: 11 July 2013 GALFACTS (GALFA Continuum Transit Survey) Full-Stokes, all-Arecibo-sky, continuum survey. Employs meridian NODding scans with subsequent “multi-beam” basket-weaving to optimize zero-levels. Use of an original multi-beam CLEAN. Bandwidth = 300 MHz → Faraday tomography, I p (x, y, RM). Full GALFACTS survey began on November 13, As of July 11, approaching 50% complete. Catalog of Poln. Percentage, Position Angle & RM for 50,000 sources. Studies of the Galactic Magnetic Field. Thermal-nonthermal separation of low-b Galactic continuum emission. Studies of discrete Galactic radio sources (e.g. SNRs & HII regions). Studies of high-b Galactic Loops. Foreground removal for the Planck full- Stokes CMB study. GALFA-TOG2 HI commensal project.

Single Dish Summer School: 11 July 2013 GALFACTS TECHNIQUES Stokes I Dirty Image Multi-beam Clean Image (HPBW=3.5')‏ NVSS Comparison (HPBW=0.7')‏ ALFA beams Tracks after several passes These are “woven” together to optimize zerolevels.

Single Dish Summer School: 11 July 2013 Effelsberg Survey Image on N1

Single Dish Summer School: 11 July 2013 GALFACTS

Single Dish Summer School: 11 July 2013 Stokes I Stokes U Stokes Q GALFACTS – FULL STOKES

Single Dish Summer School: 11 July 2013 WHY GALFA-HI? WHY GALFA-HI? With single-dish brightness temperature sensitivity and high spectral and angular resolution, it covers new parameter space:

Single Dish Summer School: 11 July 2013 I-GALFA – The Inner Galaxy ALFA low-b HI Survey I-GALFA covers 35°≤ l ≤85°, |b| ≤10°. Observations were completed in September HPBW=3.35', T rms = 0.25 K, Δv chan = 0.18 km/s, |v lsr | < 750 km/s. (Triple) Commensal with ZOA & GALFACTS2. Prominent is the HI/continuum supershell GS , probably lying in the Sagittarius spiral arm. (top) I-GALFA HI image – v lsr = +27 km/s; (bottom) GALFACTS2 L-band continuum image Disc-Halo Interface

Single Dish Summer School: 11 July 2013 GALFA-HI Pointing Record as of 2008 March 14 GALSPECT has 8192 channels over 7.14 MHz → 0.18 km/s/channel, and ± 750 km/s total coverage GALFA-H I TOGS/TOGS2 Observations GALFA-HI Pointing Record as of 2009 February 26 GALFA-HI Pointing Record as of 2010 April 4

Single Dish Summer School: 11 July 2013 TOGS/TOGS2 is commensal with GALFACTS, ALFALFA & AGES, mapping the whole Arecibo sky in HI at no overhead in observing time. Used to study, (a) Galactic structure, (b) correlation of HVC HI and dust contents, (c) HI clouds surrounding M33 attributed to M33–M31 tidal interactions, (d) HI content of Local Group dwarf galaxies, and (e) HI content of globular clusters. GALFA-TOGS/TOGS2 Wide-Area HI Survey TOGS = “Turn On GALFA Spectrometer!” HI for -2 km/ s HI for +18 km/ s

Single Dish Summer School: 11 July 2013 Red Dwarf “Pulsars” A number of ultra-cool dwarf stars have been observed at Arecibo displaying similarities between the pulses measured. Examples of (left) TVLM and (right) 2MASSW J in Stokes-V. Pulses have brightness temperature > K. For electron cyclotron maser emission, magnetic field strengths of ~1650 Gauss are implied. Simultaneous Arecibo, Hα, optical photometry, and NIR spectrophometry of TVLM 513, show in-phase variations for radio, Hα, [OI] and the optical continuum. (Courtesy: Greg Hallinan)

Single Dish Summer School: 11 July 2013 HI Forbidden-Velocity Wings LDS b=−0.5° HVC 004-6: Arecibo (LBW and ALFA) + GBT observations of 22 FVWs show shell-type structure; “missing” SNRs? 9-10 show cloud-type structure; halo clouds or HVCs? FVW's & : Red = +45 – +35 km/s, Green = +35 – +25 km/s, Blue = +25 – +15 km/s. The HI emission coincides with a weak continuum shell. FVW G : Red = +110 – +135 km/s, Green = +95 – 110 km/s, Blue = +80 – +95 km/s. Stars = Early-type stars in field; Triangles = Pulsars (Courtesy: Ji-hyun Kang)

Single Dish Summer School: 11 July 2013 An Arecibo Galactic Chemistry Survey To exploit the low “spectral line confusion” for 1 – 10 GHz to characterize the physical and chemical conditions in Galactic sources. Precursor observations made in 2008 on star-forming region, NGC2264, and C-rich, evolved PPN, CRL618. These were shallow 1 – 10 GHz coverages with Δv = 0.7 kms -1. Main survey commenced in 2010 studying W51e2 with Δv = 0.3 kms -1. Excited satellite line OH maser in PPN, CRL 618 CH 3 OH in NGC 2264-IRS1 HC 3 N in NGC 2264-IRS1 H112α in W51e2 H 2 13 CO and H141β in W51e2 H141β H 2 13 CO H 2 CO in W51e2 Excited Satellite OH in W51e ( 2 Π ½ J=½ F=0–1)‏

Single Dish Summer School: 11 July 2013 HI Absorption at z ~ 0.9 HI absorption in the host galaxy of CTA 21 against the continuum emission of the central quasar Observed at Arecibo on 20 & 21 September 2009  Observed at Arecibo on 20 & 21 September 2009  Redshift, z =  Distance = 5866 Mpc  CTA 21 is seen at 46% of the present age of the Universe Central Frequency = MHz Analog-to-Digital migration of TV transmissions in June 2009 temporarily freed up the 700–800 MHz band. Arecibo has provided and commissioned a receiver. HI absorption in the host galaxy of 4C against the continuum emission of the central quasar  Observed at Arecibo on 3, 4 & 5 October 2010  Redshift, z =  Distance = 5283 Mpc  Resolves optical disagreement between z=0.405 and Central Frequency = MHz

Single Dish Summer School: 11 July 2013 A Spectral Scan of Arp 220: 1.1 – 10 GHz Arp 220 is a star-burst galaxy at a distance of 78 Mpc. It is forming stars at 100 times the rate of the Milky Way. It is the result of a collision between two galaxies now in the final stages of merging. (HST:Optical)‏ (VLA:Radio Wavlength 6cm)‏

Single Dish Summer School: 11 July 2013 The Spectrum of Arp 220 – Prebiotic Molecules Methanimine (CH 2 NH) observed for the first time outside of the Milky Way (where it has only been observed in one source!)‏ This is probably a maser emitter. “Bending” (v 2 =1) transitions of HCN detected for the very first time in the radio region. These lines are at L-, C-, C-Hi & X-band. Recent News: Detection of v 2 =1, J=3, HCN in Arp 220 (2645 MHz) gives a line-center optical depth,  ~ 3 at 1630 MHz.

Single Dish Summer School: 11 July 2013 The Spectrum of Arp 220 – OH & Other Lines OH Absorption (6 cm) ‏ OH Absorption (5 cm) ‏ OH Absorption (4 cm)‏ 18 OH or Formic Acid? (18 cm)‏CH emission triplet (λ9 cm) Co-added Hydrogen Recombination Lines (H119α → H127α). Peak Intensity ≈ 600 μJy/beam; rms noise ≈ 50 μJy/beam.

Single Dish Summer School: 11 July 2013 H 2 CO at 4830 MHz OH at 4660 MHz OH at 4751 MHz OH at 4766 MHz HCN at 4488 MHz CH 2 NH at 5290 MHz Arecibo Spectra for Zw Is Arp 220 Unique?

Single Dish Summer School: 11 July 2013 Arecibo Spectra for NGC660 Variable Excited OH Masers at 4751 & 4766 MHz (Excited OH Line at 4660 MHz is below noise.)‏ H 2 CO at 4830 MHz 25 Dec 07 – 07 Jan 08 7 Aug 08 – 10 Sep Dec 08 Co-added RRLs H109α–H114α (λ6 cm)‏; rms noise = 70 μJy/beam

Single Dish Summer School: 11 July 2013 Zeeman Effect in ULIRG Megamasers Many OH megamasers (OHMs) in ULIRGs show Zeeman splitting of individual components yielding typical line-of-sight magnetic fields of mGauss. Following-up their initial detection of this phenomenon for ULIRGS, the P.I.’s are now making a Zeeman survey of all suitable ULIRG OHMs in the Arecibo sky. Linear polarization of the OHM in Arp 220 yields a Rotation Measure. To resolve the Zeeman components spatially, VLBI has been made using the HSA (including Arecibo) allowing investigation of the origins of the magnetic fields. (PI’s: Tim Robishaw & Carl Heiles)

Single Dish Summer School: 11 July 2013 Anticipated Developments over PY 2011 Continued development towards a 40-beam focal-plane phased feed array to give an HI mapping array with the observing speed of ASKAP or MeerKAT. Developments towards replacing the present four receivers covering 2 to 8 GHz with two broader-band systems. Developments towards bringing the RF signals directly to the Control Room. Completion of VLBI equipment upgrade to a digital backend and Mk5C recorders allowing regular recording at up to 4 Gbits/sec. Implementation of the VLBI “phase transfer” methodology from the 12-m calibration data to the 305-m target data.

Single Dish Summer School: 11 July 2013 Arecibo helps Protect the Earth against Space Invaders!!!! Space Invaders!!!! Asteroid 2001 SN263 and its two moonlets. Asteroid Hermes that was lost for 66 years. Asteroid 1999 JM8 about 2 miles in diameter. 65 million years ago? AD 1908: Tunguska, Siberia (Artist'sImpression) (Reality)  Sizes & shape  Rotation rates  If there are moonlets  Orbits For near-Earth asteroids, the Arecibo radar measures;

Single Dish Summer School: 11 July 2013 Muchas Gracias