1 / 32

Junzhi Wang SHAO On behalf of the Shanghai 65m RT Team

Spectroscopy with TianMa 65m and also FAST. Junzhi Wang SHAO On behalf of the Shanghai 65m RT Team. Outline. Introduction of TianMa telescope Capability of radio spectroscopy with TianMa Our ongoing observational projects with TianMa Spectroscopy with FAST early science.

eelliott
Download Presentation

Junzhi Wang SHAO On behalf of the Shanghai 65m RT Team

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Spectroscopy with TianMa 65m and also FAST Junzhi Wang SHAO On behalf of the Shanghai 65m RT Team

  2. Outline Introduction of TianMa telescope Capability of radio spectroscopy with TianMa Our ongoing observational projects with TianMa Spectroscopy with FAST early science

  3. 65-m in diameter, fully steerable radio telescope Active surface system installed Covering 1 – 50 GHz with 8 bands L(1.6GHz), S/X(2.3/8.4GHz) C(5GHz), Ku(15GHz), K(22GHz) Ka(30GHz), Q(43GHz) General-purpose (radio astronomy, single-dish, VLBI, geodynamics) Shanghai 65m Radio Telescope • Funding Agencies: • Chinese Academy of Sciences (CAS) • Shanghai Municipality • Chinese Lunar Exploration Project Cost ≈ 32M USD

  4. 2008：funded;contract to CETC54 for the antenna construction 2009: complete design (international review panel); start manufacturing; foundation laying ceremony on December 29 2010-11:site constructionstarted on March 19, 2010; foundation completed; antenna construction (wheel-on-track, BUS, alidade, panels, …); active surface system (contract, design, fabrication, installation of actuators) 2012-13:L/S/X and C band Rxs in place; first light on October 26, 2012 & inauguration 2 days later; start commissioning; got named (天马); participation in the Chinese Lunar Mission (ChangE); DIBAS installed & tested 2014-16: on-site system testing; science observations at L/S/C/X bands; active surface tested; Ku/K/Ka/Q band commissioning; project accomplished Project Timeline

  5. Frequency coverage: 1 ~ 50 GHz Primary reflector adjustable with 1104 actuators Surface accuracy (nominal)： 0.53mm RMS (without active surface) 0.29mm RMS (with active surface) Aperture Efficiency： L/S/C > 60%, X > 55%, Ku > 40%, K > 20% Ka > 50%, Q > 45% (with active surface) Pointing accuracy： 6 arcsec (wind < 4m/s) [c.f. beam ~ 22 arcsec @43 GHz] 10 arcsec (wind < 10m/s) 30 arcsec (wind < 20m/s) Elevation limits: 5~90 degree Slew rates: 0.5 degree/s (azimuth), 0.3 degree/s (elevation) Telescope Specs 5

  6. Receiver specs

  7. DIBAS: DIgital BAckend System An updated version of the NRAO-VEGAS (Versatile GBT Astronomical Spectrometer), customized with the addition of NRAO-GUPPI (Green Bank Ultimate Pulsar Processing Instrument) Support two types of observing modes Spectral line modes: support 29 modes, including wideband up to 16,384 channels, narrowband up to 524,288 channels and, sub-band modes (higher spectral-resolution over multiple narrow bands (sub-bands) within the sampled bandwidth) Pulsar modes: support the incoherent/coherent search and pulsar timing modes. 7

  8. DIBAS Spectrometer Specs 8

  9. DIBAS Spectrometer Specs

  10. DIBAS Spectrometer Specs(cont’d)

  11. K-band specifications 11

  12. RFI Environment • Two site surveys (2008 May and 2009 October) are consistent in that，most RFIs appear at the outside of the designed bands, and at C-band and above RFI is not a problem. Some RFIs at L-band!!! L 1.25~1.75GHz S 2.15~2.45GHz C 4.5~7GHz X 8~9GHz EAVWS2010, Kagoshima, Japan, 22-24 April 2010 12

  13. RFI @ SH65m site

  14. RFI protection

  15. site meteorology - PWV Precipitable Water Vapor (PWV) Good in Autumn/winter !

  16. site meteorology - optical depth (τ) 22GHz：about 1/3 days with less than 0.1 optical depth 43GHz：about 1/4days with less than 0.1 optical depth

  17. Capability of Spectral line high sensitivity, wide frequency coverage Suitable for spectral line observations. Standard PS mode and OTF mode can be used now. Data from 2IFs (~1GHz) obtained Simultaneously • Discovery of new lines (masers or thermal) • Search for some important line emissions, such as high-z CO(bw=4MHz, T=20hr, sigma=0.2 mJy@22GHz, or, 0.9mJy @ 43 GHz) • Multiple-line observation towards SFRs • Deep K-band Galactic Plane Survey 17

  18. Spectral line emission in ~10 - 50 GHz K 18

  19. Molecular lines at cm-band Menten 2004 19

  20. C-band（4-8 GHz） > 1K：6.7 GHz CH3OH，4.765 & 6.035 GHz OH maser, CH2CNH (-1.3 K, Sgr B2, Lovas et al. 2006, no follow-up) >0.1K：H2CO absorption，NH2CHO (0.3 K, Sgr B2, Rub et al. 1971) > 0.01 K: HC5N, HC7N, HC9N… RRLs Ku (12-18.5 GHz) band is another important band for TianMa 20

  21. NSFC Major projectStudying Star formation and ISM with TianMa Chief Scientist : Prof. Zhiqiang Shen From 2016Jan to 2020Dec Group 1: Star formation in the Milky Way Group 2: ISM properties and star formation history in the Milky Way Group 3: Dense gas and Star formation in nearby galaxies Group 4: Mega-masers, starburst and AGN 21

  22. Group 1:Star formation in the Milky Way 6.7 GHz CH3OH maser survey toward candidates of massive star forming regions selected with WISE color (on-going, almost done) RRL survey toward massive star forming regions selected both with WISE YSO candidates and strong radio continuum emission (on-going) NH3 mapping observations toward massive star forming regions based on CH3OH and RRL survey (will start from the end of this year) Further high resolution observational studies with (sub-)millimeter observations for some of the sources 22

  23. Work Progress

  24. Group 2:ISM and Star formation history in the Milky Way Observing lines of long carbon chain molecules, such as HC5N, HC7N in Galactic molecular clouds Determining electron properties (density, temperatures, etc.) with the observations of multiple transition RRLs Isotopic abundances of 12C/13C, 14N/15N, 33S/34S with different distances to the Galactic center (DGC): star formation history? 24

  25. Left：HC3N 2-1 and its 13C isotopic lines; Right: Comparison between Serpens South 1a and TMC-1、Lupus-1A。 Lines of long carbon chain molecules in Serpens South 1a detected with TianMa HC5N, HC7N, HC9N,C3S, C6H, C8H and isotopic line of HC3N were detected Li, Juan et al., , 2016, ApJ,824, 136 “TMRT Observation of carbon-chain Molecules in Serpens South 1A” as the first refereed paper of spectroscopy observation with TianMa

  26. Li Juan et al. in preparation

  27. Group 3:Dense gas and star formation in nearby galaxies Dense gas tracers and star formation law: what can we do with TianMa? CS 1-0, HC3N 5-4 & 2-1 in nearby galaxies with TianMa Optically thin lines of dense gas tracers in galaxies: isotopic lines, such as 13CS 1-0 and C34S 1-0 Mapping massive star forming regions with the same lines as that for galaxies: obtain the conversion factor of luminosity to dense gas mass 27

  28. Detected dense gas tracers Nearby galaxy M66 HC3N 2-1 28 Will test CS 1-0 in coming months using Q band receiver

  29. Group 4:Mega-maser, starburst and AGN Searching for new H2O mega-maser sources Searching for CH3OH mega-masers Radio continuum properties of H2O and OH mega-maser host galaxies VLBI imaging for H2O and OH mega-masers 29

  30. Five-hundred-metre Aperture Spherical Telescope (FAST) • Diameter: 500m • Frequency range:70MHz-3GHz, early science (270MHz-1620MHz) • Pulsar, spectroscopy, VLBI • 2016 Sep 25 30

  31. Spectroscopy with FAST early science Capabilities: limited tracking time flux calibration is not perfect weak RFI is not well known bandpass stability is not perfect Good sensitivity Better choices: Known frequency and red-shift, relatively strong, but still weak lines hard for long integration time difficult for unknown frequency lines Largest OH MM sample highest red-shifted OH MM (?) OH mega-maser survey Long carbon chain lines (HC2n+1N) in low mass star forming regions Largest molecule (?) 31

  32. Thanks for your attention !

More Related