Delingha 13.7-m mm-Wave Telescope

Yingxi Zuo, Ji YangPurple Mountain Observatory, CAS

Sino-German workshop on radioastronomy Sep 13, 2005 Urumqi

Delingha 13.7-m mm-Wave Telescope

OUTLINEOUTLINE

Site OverviewTelescope DescriptionTechnical Upgrade ActivitiesFuture PlansScience Activities

Site Overview Site Overview -- General Information-- General Information

Location:– 35km from Delingha City, Qi

nghai, China

Longitude: 9733.6E Latitude: 3722.4N Altitude: 3200 m

Dry & Cold in Winter

DelinhaNanjing

Site OverviewSite Overview-- Atmospheric Opacity @ -- Atmospheric Opacity @ ffLOLO=112.6 GHz=112.6 GHz

Telescope Description Telescope Description – – System Block DiagramSystem Block Diagram

IF Amp.,

PowerDevi der

&FrequencyConvertor

AOS1

AOS2

AOS3

PowerDetector

TP/SP

Chopper Wheel Control l er

Phase-LockedGunn

Osci l l ator

Synthesi zer Tel escope-Control Computer

AOSControl l er

Lock-i n Ampl i fi er

SI SMI X HEMT

Vacuum Pump&

4K Cryocooler

SIS & HEMTBias Supply

Center 2.64GHz/ BW 800MHz

70/70MHz

1790/800MHz

225/245MHz

70/70MHz

Be able to observe CO(1-0) and its isotopes simultaneously

Telescope Description Telescope Description ---- Current Status (1)Current Status (1)

Antenna Performance– Enclosed in a High-Transparency Radome (85-90%)– Diameter: 13.7 m– Pointing Accuracy: < 10” over the whole sky– Beamwidth (HPBW): ~60” – Aperture Efficiency: 39%– Main Beam Efficiency: 77%– Surface Accuracy: ~0.1 mm

Telescope Description Telescope Description ---- Current Status (2)Current Status (2)

Receiver– 85 to 115 GHz SIS Receiver– TSYS : typically ranging from 180 to 250K (DSB @EL=60°)

Backends– Continuum backends (Bandwidth 800MHz)

Total Power (TP) Chopping Modulation (SP)

– Spectrum Backends AOS1: Center 70MHz / BW 43MHz / 1024 chs AOS2: Center 70MHz / BW 43MHz / 1024 chs AOS3: Center 225MHz / BW 145MHz / 1024 chs

Observation Mode– Position-Switch, spectral mapping– 12CO (J=1-0), 13CO (J=1-0), C18O (J=1-0) observation simultaneously– Fast beam switching (chopper-wheel modulating), continuum mapping

Upgrade Activities Upgrade Activities (1)(1)-- Multi-Line System -- Multi-Line System (2002)(2002)

Observing 12CO, 13CO, C18O (J=1-0) lines simultaneously,

Because of the DSB Receiver

LO

Frequency

C18O 13CO

12CO 109.78 GHz

⇓AOS1

110.20 GHz

⇓AOS2

115.27 GHz

⇓AOS3

Set to112.6 GHz

Upgrade Activities Upgrade Activities (1)(1)-- Multi-Line System-- Multi-Line System

An example of simultaneously observations of CO(J=1-0) and its isotopes, toward NGC 2264. The on-source integration time is 60 seconds and Tsys=248K.

Upgrade Activities Upgrade Activities (2)(2) -- SIS Mixer Stability Improvement Below 100 GHz -- SIS Mixer Stability Improvement Below 100 GHz (2004)(2004)

The SIS mixer is designed to operate in the range of 90-115 GHz, but …

Below 100 GHz, the pumped quantum steps are too flat to stably bias (very large dynamic resistance at the step)

DC bias is very sensitive to noise and interference Solution: putting a shunt resistance in the DC bias

circuit of the mixer, parallel to the SIS junction. Reducing the dynamic resistance

Pumped I-V curve @90GHz,Without any shunt resistance in the DC bias circuit

Pumped I-V curve @90GHz,with a 36 resistance paralleled to the SIS junction


After putting a shunt resistance, the stability improved significantly,in the range of 85-115 GHz (fLO). See the red points. The black points indicate the case before (without any shunt resistance).


Five-point mapping toward an SiO(J=2-1) maser source at 86.243GHz, to verify telescope pointing on the northern sky

Source: R-CAS Line:SiO (=1, J=2-1)

It is possible to take five-point mapping observations toward SiO maser sources at 86.243GHz to verify the telescope pointing on the northern hemisphere

Upgrade Activities Upgrade Activities (3)(3) -- Near Field Receiver Beam Measurement System -- Near Field Receiver Beam Measurement System (2004)(2004)

Measuring the receiver (including all the optical components) beam pattern to determine– Whether all the optical components are well aligned or not– Receiver beam axis (other than the mechanical axis)– Antenna illumination, edge taper


A probe source is mounted on an x-y motion stage Probe scanning area: 500×500 mm The scanning measurement should be taken at (at least) two different

distances from the receiver to determine the beam axis. Then using a laser beam memorizes the axis for further aligning the receiver with the sub-reflector.

Scalar measurement, only measured the power, the phase information may included in the future


x scan @2m

y scan @2m

The red circle indicates the sub-reflector edge. The edge taper is about –10dB

Map @1.5m

Upgrade Activities Upgrade Activities (4)(4) -- Subreflector Real-Time Control -- Subreflector Real-Time Control (2004)(2004)

The subreflector is relatively large (1.08m) and heavy It will tilt and drop down a bit with EL getting low due to gr

avity, affecting the alignment (between subref. and Rx, and between subref. and main dish)

This can be corrected by re-positioning the subref.– Re-position Z1 axis and Y axis simultaneously while EL changes

Upgrade Activities Upgrade Activities (4)(4) -- Subreflector Real-Time Control -- Subreflector Real-Time Control (2004)(2004)

Measured 2-D beam pattern

EL=71° Saturn map EL=35° Jupiter map

Future PlansFuture Plans

Antenna servo system updatingDigital Spectrometer with 500MHz BWJoining east-Asia mm-wave VLBI

network

Science ActivitiesScience Activities Physical structure study of Galactic molecular clouds High-velocity outflows from young stellar objects Interstellar chemistry Molecular gas distributions in the Galactic star form reg

ions Galactic dynamics Star evolution and molecular gas of late stars Large-scale molecular line survey for cold IRAS sources

in the Galaxy ……

Recent Selected Publication (I)Recent Selected Publication (I)

-- -- Molecular Clouds & Star form RegionsMolecular Clouds & Star form RegionsAo, Yiping; Yang, Ji; Sunada, Kazuyoshi, 13CO, C18O, and CS Observations toward

Massive Dense Cores, AJ, 128...1716A, 2004

Qin S.L., Wu Y.F., et al, Star Formation in Molecular Cloud Associated with IRAS 07028-1100， 2004， Chinese Physics Letter， Vol.21 No.8, 1677

J. Sun, et al., A study of molecular clouds with compact HII regions in GalacticScience in China (A), 2001

Y. Xu, D. Jiang, X. Zheng, M. Gu, Z. Yu, C. PeiHigh-Velocity H2O Maser Associated Massive Star Formation RegionsChin. Phys. Lett., 18(12), 1663-1665(2001)

J. Sun, Y. C. Sun, New detected CO(J=1-0) emission from planetary nebulaeScience in China (Series A), 43(2), 217, (2001)

Y. Wu, J. WU, and J. Wang, A search for massive dense cores with 13CO J=1-0 line A&A, 2001, December 12

Recent Selected Publication (II)Recent Selected Publication (II)

-- Molecular Outflow-- Molecular OutflowXu Y., Yang J., Zheng X.W., et al, Discovery of Multiple outflows in IRAS06056+213

1,2004， Chin. Phys. Lett., Vol.21, No.10, 2071-2072

SUN K.F., WU Y.F.,A New High-velocity Molecular Outflow of IRADS 19282+1814，2003， Chinese Astronomy and Astrophysics， 27, 73-78

Y. Xu, D. R. Jiang, C. Y. Yang et al., High-velocity gas associated ultra-compact HII regions.Science in China(A), 32, 177-184, 2002

S. Qin, Y. WuNew high-velocity bipolar outflows in S39 and IRAS 06306+0232Science in China (Series A), 2001

Y. Wu, C. Yang, Y. Li, et al.High-velocity molecular outflows near massive young stellar objectsScience in China (Series A), 42(7), 732, (1999)

Recent Selected Publication (III)Recent Selected Publication (III)

-- -- Survey of Molecular Lines from IRAS SourcesSurvey of Molecular Lines from IRAS Sources

J. Yang, Z. Jiang, M. Wang, B. Ju, & H. Wang A Large-Scale Molecular Line Survey for Cold IRAS Sources in the Galaxy:

I. The CO (J=1-0) Data ApJS, v141,157, (2002).

J. Yang, Z. Jiang, M. Wang, H. Wang, R. Mao, B. Ju, &Y. AoMolecular Line Studies of Galactic Young Stellar ObjectsAPRM2002_OHP (invited talk)， Japan, 2002

Ji YangGalactic Star Forming Regions: Local and Distantin Proceedings of 3rd OCPA3(invited talk)， 2000

Recent Selected Publications (IV)Recent Selected Publications (IV) – Other Topics– Other Topics

Wu Y.F.，Wang J.Z.，Wu J.W., A Search for Extremely Young Stellar Objects， 2003， Chin. Phys. Lett.， Vol.20, No.8, 1409

Y. Xu, X. Zheng, D. Jiang, et al, An H2O flare in GGD25, Chinese Science Bulletin, 46(1), 35-38(2001)

J.J. Zhou and X.W. Zheng, Short Time Variability of the Water Masers in W51M, Astrophysics and Space Science, 275, 431-439(2001)

Y. Xu, X. W. Zheng , et al, Rapid time variation of water maser emission in W3(OH) and NGC6334C, Astronomy and Astrophysics, 364（ 2000）， 232.

Y. Wu, Wang, Wu, Yan, Lei, Sun, Wang, A 13CO mapping study for massive molecular cloud cores, Science in China (A), 44(4), 536-544(2001)

C. C. Pei, R. Q. Mao, Q. Zeng, Molecular lines and continuum from W51A, Science in China (A), 44(9), 1209-1215(2001)

Y. Wu， H. Yan， J. Wu， Y. Zhao, A mapping study for massive dense cores, Imaging at radio through sub-millimeter wavelengths, ASP Conference Series, 217(2000),96.

Sample Spectral LinesSample Spectral LinesObtained from the 13.7-m TelescopeObtained from the 13.7-m Telescope

Besides CO, 13CO and C18O, the telescope can be used to

observe many other molecular lines in the 3mm band, such

as HCO+, N2H+, CN, CS, CH3CN, SO, HC3N, CH3OH,

OCS, SiO, HCN, CH13CN, …, from molecular clouds and

circumstellar envelope.

Following are some examples of molecular transition

spectra obtained from our telescope.

HCHC33N Line Toward IRC+10216N Line Toward IRC+10216

109155 109160 109165 109170 109175 109180 109185 109190 109195-0.4

-0.2

0.0

0.2

0.4

0.6

0.8 Source:IRC+10216Formula:HC

3N

Freq:109174.212MHzQuatum number: 12-11

T

(K)

Frequency(MHz)

CHCH33OH Line Toward OrionOH Line Toward Orion

108880 108885 108890 108895 108900 108905 108910

- 0. 4

- 0. 2

0. 0

0. 2

0. 4

0. 6

0. 8

SOURCE: ORI ONA

For mul a: CH3OH

Fr eq: 108894. 663MHz

Q. n: 0( 0) - 1( - 1) E

T (K)

Fr equency ( MHz)

CN Hyperfine TransitionsCN Hyperfine Transitions Toward OrionToward Orion

113470 113480 113490 113500 113510 113520

- 0. 5

0. 0

0. 5

1. 0

1. 5

2. 0

2. 5

3. 0

a: Fr eq: 113488. 618MHz Quant um number : 1- 0 J =3/ 2- 1/ 2 F=3/ 2- 1/ 2

b: Fr eq: 113491. 467MHz Quant um number : 1- 0 J =3/ 2- 1/ 2 F=5/ 2- 3/ 2

c: Fr eq: 113500. 137MHz Quant um number : 1- 0 J =3/ 2- 1/ 2 F=1/ 2- 1/ 2

d: Fr eq: 113509. 456MHz Quant um number : 1- 0 J =3/ 2- 1/ 2 F=3/ 2- 3/ 2

dc

b

a

SOURCE: ORI ONA

For mul a: CN

T(K)

Fr equency ( MHz)

N2H+ Lines Toward L134NN2H+ Lines Toward L134N

HCO+(1-0) Line Toward S140HCO+(1-0) Line Toward S140

H13CN (1-0) Line Toward OrionAH13CN (1-0) Line Toward OrionA

Welcome to DelinghaWelcome to Delingha

http://www.pmodlh.ac.cnhttp://www.pmodlh.ac.cn

Open Time: September 1 – May 31Open Time: September 1 – May 31

Proposal submission (all over the year)Proposal submission (all over the year)[email protected]@pmodlh.ac.cn

Delingha 13.7-m mm-Wave Telescope

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