Radio Astronomy -- Other Than ALFA Surveys

1. Chris Salter (NAIC/Arecibo Observatory)‏ Radio Astronomy -- Other Than ALFA Surveys FVW39.0+4.0: An HI Forbidden Velocity Wing, Blue = +80 – +95 km/s Green = +95 – +110 km/s Red = +110 – +135 km/s Stars = Early-type stars in field Triangles = Pulsars (Courtesy: Ji-hyun Kang )‏

2. The Official Rules of the Game • Post-Nov 2006: -- 20% of R.A. telescope time for non ALFA- survey astronomy (~750 hr per yr). -- Rxs available: 327, 430 & 750 MHz, ALFA, LBW, SBW, CB & XB; (plus SBH & CBH on a “campaign” basis).

3. Radio and γ-Ray Pulsars Arecibo timing of 'unidentified' Fermi source, J2214+3002, has permitted the detection of the object as a γ-ray pulsar. • Arecibo pulsar, J2021+3651 is found to be one of the strongest γ-ray emitters by Fermi/GLAST. • Of 9 new γ-ray pulsars in the Arecibo sky from Fermi/GLAST, J1907+0602 is found to be a radio pulsar (P=0.10664 s). With S1.4 GHz= 3 μJy, and a distance ~ 3 kpc, it is the second least luminous pulsar known! Fermi pulsar, J2017+0603, has been observed several times at Arecibo, and found to have a 'super-sharp' pulse profile. As it is likely a MSP-WD binary, it is a good NANOGrav candidate.

4. Four-Frequency High Precision Timing of a Msec Pulsar The detection of gravitational waves with pulsars will requires high timing precision: effects at 10 ns level can limit the sensitivity to gravitational waves. Goals of project:Identify and mitigate the effect of variability in the ISM (interstellar weather) in precision pulsar timing observations. Tube size Radio waves travel through banana-shaped tube Tube offset from direct line-of-sight Earth Pulsar Solar System Barycentre ISM acts like warped glass, distorting the trajectory of the propagating radio waves (tube). As the volume of interstellar space changes, the tube wanders → arrival time variations. Target: PSR J1713+0747, the most stable millisecond pulsar in the Arecibo sky. Observations: 327 MHz, 430 MHz, L and S bands; 20 transits over 6 months. Data recorded simultaneously for timing (ASP, high time resolution), for ISM analysis (WAPP,higher frequency resolution), and a VLBI baseband recorder (Mark5A).

5. S-band observations, lower timing precision due to lower flux. L-band observations, systematic trends (associated with ISM?)‏ Ph.D. Thesis:Ryan Shannon ~1 microsec 430 MHz 327 MHz ~ 2 hours Combine all TOAs to form “grand” arrival time at this epoch Key Analysis: Connect residual ToA (top) and pulsar dynamic spectra (right) and determine if the dynamic spectra encode ISM delays?

6. Apparent > c Wave Propagation in the ISM HI Emission Spectrum PSR Absorption Spectrum PSR Delay Spectrum The group velocity of the ISM is > c near the HI resonance line due to “anomalous dispersion”. The plot above shows the expected absorption and delay spectra after propagation though a cloud of HI in the ISM with TS= 100 K, tau = 1. Delay Spectra for 3 Consecutive Days Potential tool for studying the HI properties of the ISM. (Note: It does NOT violate Special Relativity!)

7. HI Forbidden-Velocity Wings • Arecibo (LBW and ALFA) + GBT observations of 22 FVWs. • 12-13 show shell-type structure; “missing” SNRs? • 9-10 show cloud-type structure; halo clouds or HVCs? 004-6: HVC LDS b=−0.5° FVW's 173.0+1.5 & 173.0+0.0: 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 G40.0+0.5: Red = -100 – -90 km/s, Green = -90 – -80 km/s, Blue = -80 – -70 km/s.

8. Zeeman Effect in ULIRG Megamasers • The P.I.’s have been granted 450 hr to make a Zeeman survey all suitable ULIRG OHMs in the Arecibo sky. • Many OH megamasers in ULIRGs show Zeeman splitting of individual components yielding typical line-of-sight magnetic fields of 0.3-18 mG. Minimum energy and equipartition suggest ULIRG magnetic fields of 1 mG < B < 10 mG. • B is similar to the values in Galactic OH masers, suggesting conditions of massive star formation are similar to those in the Milky Way. • To resolve the Zeeman components spatially, VLBI has been made using the HSA (including Arecibo) allowing investigation of the origins of the magnetic fields.

9. Molecular Lines in Galaxies CH2NH H2CO HCN (v2=1)‏ H2O maser in host galaxy of QSO J0414+0534(z=2.64) monitored at 6-week intervals. Top Formaldehyde Absorption and (bottom) excited-line OH maser emission in LIRG, NGC 660 Excited OH (main line)‏ Molecules inZw 049.057

10. 700 – 800 MHz Gallery Globular Cluster Pulsar Observations HI absorption in the host galaxy of CTA 21 against the continuum emission of the central quasar M13C M15B M5A M13A M15A M15C • Observed at Arecibo on 20 & 21 September 2009 • Redshift, z = 0.906 • CTA 21 is seen at 46% of the present age of the Universe CH main line at 724 MHz in W51

11. An Arecibo Galactic Chemistry Survey • First proposal made in 2007 to make a 1 –10 GHz survey of a number of representative Galactic sources using the Mock Spectrometer in single-pixel mode. • Unbiased spectral line surveys → information needed to characterize physical and chemical conditions. • The full range 1 – 10 GHz is relatively unexplored for Galactic sources and many complex molecules have lines at λ < 3 cm. • “Line confusion” is very much less in this range than at millimeter wavelengths.

12. Precursor Observations • Observations made in Oct-Nov 2008. • Targets were star-forming region, NGC2264, and C-rich, evolved PPN, CRL618. • The single-pixel Mock mode was not ready, so the precursor observations were made with the WAPPs. • A shallow, but full, 1 – 10 GHz coverage was made for both objects with a velocity resolution of 0.7 kms-1. Excited satellite line OH maser in PPN, CRL 618 Methanol in NGC 2264-IRS1 HC3N in NGC 2264-IRS1

13. Test Set-Up:Oct 5th 2009 • A second proposal was submitted in Feb. 2009 to make a full 1 – 10 GHz survey of the ultra-compact source W51e2 in W51 IRS1. This was graded 'A', and awarded 112 hr. • A preliminary version of the single-pixel Mock mode was made available by Phil Perillat this fall. • An hour's test time was used to try out a first AGCS C-band set-up for the Mocks on October 5th 2009. • This had a velocity resolution of 0.3 kms-1, and covered a total band of about 500 MHz, about 50% of the potential coverage (only a single Mock band being available.)‏ • 4 ON/OFF scans were acquired on W51e2 and the data reduced to get a check of the resulting spectra.

14. Radio Recombination Lines H138β H110α H139β H161γ H111α H140β H112α H141β

15. Molecular Lines H213CO H141β Excited OH Satellite Line (2Π½ J=½ F=0–1)‏ H2CO

16. Muchas Gracias

17. HI Absorption in the Host Galaxy of QSO CTA 21 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 CTA 21 against the continuum emission of the central quasar Optical Spectrum of CTA 21 CTA 21 at arcsec resolution: contours= radio; greyscale=optical Central Frequency = 745.5 MHz 10 Flux Density (Jy)‏ • Observed at Arecibo on 20 & 21 September 2009 • Redshift, z = 0.906 • Distance = 7,335,000,000 light years • CTA 21 is seen at 46% of the present age of the Universe 1 0.1 100 1000 10000 Frequency (MHz)‏ Radio Spectrum of CTA 21 CTA 21 at milliarcsec resolution

18. The Molecular Spectra of ULIRGs Zw 049.057 Arp 220 IC 860 CH2NH HCN v2=1, J=3 transition H2CO HCN (v2=1)‏ CH triplet (λ9 cm)‏ Excited OH (main line)‏ Co-added H119α-H127α (λ9 cm)‏ rms noise = 50 μJy/bm

19. Project in progress: (Ryan’s dissertation: coming in August 2010!)‏ Requirements for mitigating ISM effects: Wide bandwidth instrumentation: ISM effects are mitigated by both a) observing at higher frequencies and b) observing with wider bandwidths. Also require instruments with high frequency resolution to perform dynamic spectra analysis (i.e., Mock) complementary to wide bandwidth timing instruments (GUPPI-clone). Need sensitive telescope (i.e. Arecibo) to identify and mitigate propagation effects Ryan would like to thank the AO Staff (especially Tapasi Ghosh) for assistance with the observations The 10000 ASP Times of Arrival 6 months 6 months

20. Results • Detected 14 B fields. • Detected fields in 5/8 ULIRGs. • First extragalactic Zeeman splitting detections in emission lines. • Only previous extragalactic Zeeman detection was HI in absorption in high-velocity cloud around Perseus A (Kazes et al. 1991; Sarma et al. 2005). • B is similar to local sites of OH masers. • Conditions in regions of massive star formation are similar to those in Milky Way. • B is consistent with inferred synchrotron fields. • Probing gas closer to typical ISM density.