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Taeduk Radio Astronomy Observatory (TRAO)

TRAO Main

Call for Proposal (2019-2020 term)

Taeduk Radio Astronomy Observatory (TRAO) would like to call for new proposals using 14m radio telescope from October 2019 to May 2020. Submission deadline of proposals is the end of August 2019 (to traoprop@kasi.re.kr). Submitted proposals will be evaluated, the result will be notified by the end of September. There are generally plenty of telescope time slots available between LST 10 and 15 hours, thus, proposals requesting these time slots are more encouraged. We have remote observation mode available, however, only experienced observers can use it. If you are the first time users of TRAO system, we encourage to find experienced users in KASI as collaborators. Cover page of proposal is provided in TRAO home page. Please write in Words or PDF form up to 4 pages (LP and GP) or 6 pages (KSP) with font size 10, including science justification, technical justification, figures and tables, etc.

Key Science Programs (KSPs): KSP is a multi-year observing program, which could finalize a series of wonderful scientific results, and demonstrating characteristics and advantage of TRAO system. Telescope allocation time would be 400 hours per year for next three years.
General Programs (GPs): GP is a short program, which needs a small amount of telescope time up to 100 hours within a single observing season (October 2019 ~ May 2020), with which fast scientific results could be expected in relatively short period of time.
Large Programs (LPs): LP is a program, which needs a substantial amount of telescope time up to 300 hours within a single observing season (October 2019 ~ May 2020), with which invaluable scientific results could be expected within a year or two.

TRAO’s multi-beam receiver system(SEQUOIA-TRAO), is a cryogenic focal plane array equipped with 16 high performing InP MMIC amplifiers. This receiver system has been operating quite smoothly for last three years. The receiver temperature is ranging from 60 ~ 80 K for 86 to 110 GHz, and 80 ~ 110 K for 115 GHz, and system temperature is ranging from about 200 K for 86 to 110 GHz, and 400 K for 115 GHz.

Two molecular lines could be simultaneously observed as it has two 2nd LO within 15 GHz band range. Backend system is a high performing correlator, providing a bandwidth of 60 MHz with a 15 kHz resolution (0.045 km/s at 100GHz).

OTF (On-The-Fly) mapping mode is the main observing mode, and simple position switching mode is also available. Test observation shows that it takes 27 min for mapping 6’x6’ region, and 37 min for 10’x10’. You may decide a regrid size and convolution parameter after completion of your observation. Pointing accuracy of the telescope is about 5 arcsec.

The backend system (FFT spectrometer) provides the 4096x2 channels with a fine velocity resolution of better than 0.05 km/s (15 kHz) per channel. Its effective spectra bandwidth is 60 MHz.

Please refer the TRAO homepage for system information. Two bedrooms and kitchen are available for outside observers. Taeduk Radio Astronomy Observatory (TRAO) is a part of Korea Astronomy and Space Science Institute (KASI).

Here we provide some instruction for the format of proposal
(please follow the format very strictly)

About 100 hours of telescope time per proposal. (There will be some flexibility of telescope time allocation depending on the weather and system status, and number of proposals)
Proposal Format (please submit your proposals in pdf form)
- We recommend to use MSWord, or alternatively, you may use any other word processing tools
- Strictly 4 pages maximum except coversheet (including figures, tables etc. – no appendix) in English
- Coversheet (MSword & PDF) is provided
- fontsize 9, line space-regular (1pt)
- Science Justification and/or Science Goal
- Observing Strategy (Technical Justification)
- Publication Plan (optional)
- References
Please submit the proposal to the following e-mail address: traoprop(at)kasi.re.kr

Beam parameters

Frequency ~ (GHz)	Θ_B('')	η_A ~ (%)	η_B ~ (%)
86.243	60	39 ± 2	46 ± 2
98.000	53	44 ± 1	52 ± 1
110.201	47	46 ± 1	54 ± 1
115.271	45	43 ± 2	51 ± 2

These parameters will be updated in Dec. 2016, further observations will be made in order to find details for new TRAO receiver systems. Beam sizes are calibrated with 86 GHz Rleo and Orion continuum data. Aperture and Beam efficiencies are measured from Venus and Jupiter continuum data observed at March 2016.

OTF time estimation

Equation of RMS temperature

$T_{rms}=\frac{T_{sys}}{\eta_{spec}\times\sqrt{\Delta\nu\times (t_{\textrm{on}} + t_{\textrm{ref}})}}\times \Biggl[1+\frac{1}{\sqrt{N}}\Biggr]$

where,

$T_{sys}:~500~\textrm{K}~at~115~\textrm{GHz},~300~\textrm{K}~at~110~\textrm{GHz},~200~\textrm{K}~at~86~\textrm{GHz}$
$\eta_{spec}:~\sim 0.5~for~16~\textrm{beams}$
$\Delta\nu:~15.3\times10^3~\textrm{(Hz)} \ ( \ \approx 62.5 \ MHz/4096 \ chs; \ fixed \ )$
$t_{\textrm{on}}~=~X_{\textrm{length}}/\textrm{HPBW} \times t_{\textrm{samp}} \times X_{\textrm{step}} \times 16$ ( exposure time for source position )
$t_{\textrm{ref}}~=~\sqrt{X_{\textrm{length}}\times N_{\textrm{ScanPerCal}}/\textrm{HPBW}}~ \times t_{\textrm{samp}}/2$ ( minimum required integration time on refence position )
$X_{\textrm{ramp}}~=~\frac{X_{\textrm{step}}}{t_{\textrm{samp}}} \times 3$ ( 3 sec are required in order to get proper scan velocity )
$N~=~X_{\textrm{length}}/\textrm{HPBW}$
$T_{rms,final}~=~T_{rms}/\sqrt{\alpha}$ ( α: Scan iteration number in the same area )

Example 1:

HPBW = 44", t_samp = 0.2 sec, t_ref = 2.0 sec
X_step = 0.25 HPBW, Y_step = 0.25 HPBW
X_ramp = 3 HPBW, Y_ramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
T_sys = 500 K, Cell size = 30"

map size	time estimation	raw data size (LO1+LO2)	commant
6' × 6'	> 30 min	~ 0.9 GB	minimum size for OTF
10' × 10'	> 47 min	~ 1.7 GB	T_rms ~ 0.7 K
12' × 12'	> 57 min	~ 2.2 GB
15' × 15'	> 73 min	~ 3.0 GB

Note. Overhead time will be varied upon your reference position. Cell size means the regridded pixel size of output data using OTFtools for CLASS and FITS files.

Example 2:

HPBW = 44", t_samp = 0.2 sec, t_ref = 2.0 sec
X_step = 0.25 HPBW, Y_step = 0.75 HPBW
X_ramp = 3 HPBW, Y_ramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
T_sys = 500 K, Cell size = 30"

map size	time estimation	raw data size (LO1+LO2)	commant
6' × 6'	> 10 min	~ 0.3 GB	minimum size for OTF
10' × 10'	> 16 min	~ 0.6 GB	T_rms ~ 1.2 K
12' × 12'	> 19 min	~ 0.8 GB
15' × 15'	> 25 min	~ 1.0 GB

Example 3:

HPBW = 22", t_samp = 0.2 sec, t_ref = 2.0 sec
X_step = 0.25 HPBW, Y_step = 0.25 HPBW
X_ramp = 3 HPBW, Y_ramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
T_sys = 500 K, Cell size = 30"

map size	time estimation	raw data size (LO1+LO2)	commant
6' × 6'	> 57 min	~ 2.2 GB	minimum size for OTF
10' × 10'	> 105 min	~ 4.8 GB	T_rms ~ 0.35 K
12' × 12'	> 132 min	~ 6.3 GB

Example 4:

HPBW = 22", t_samp = 0.2 sec, t_ref = 2.0 sec
X_step = 0.25 HPBW, Y_step = 0.75 HPBW
X_ramp = 3 HPBW, Y_ramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
T_sys = 500 K, Cell size = 30"

map size	time estimation	raw data size (LO1+LO2)	commant
6' × 6'	> 19 min	~ 0.8 GB	minimum size for OTF
10' × 10'	> 36 min	~ 1.6 GB	T_rms ~ 0.6 K
12' × 12'	> 45 min	~ 2.2 GB
15' × 15'	> 61 min	~ 3.2 GB

Taeduk Radio Astronomy Observatory