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Taeduk Radio Astronomy Observatory (TRAO)

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Call for Proposal (2018-2019 term)

For internal users;
We would like to encourage internal users to submit pilot programs (short telescope time of 20hrs or so) as long as telescope time is availble. Please submit one page scientific justification with a coversheet at any time.

We would like to call for proposals using TRAO (Taeduk Radio Astronomy Observatory) 14-m telescope for the term of 2018 autumn - 2019 spring. Recently we successfully installed a multi-beam receiver system, SEQUOIA-TRAO, and renovated most part of the telescope system.

The new receiver system is now equipped with high-performing 16-pixel MMIC preamplifiers in a 4 x 4 array, operating within 85-115.6 GHz frequency range. System temperature ranges from 170 K (86~110 GHz) to 400 K (115 GHz; ¹²CO). The 2^nd IF modules with the narrow band and the 8 channels with 4 FFT spectrometers allow to observe 2 frequencies simultaneously within the 85~100 or 100~115 GHz bands for all 16 pixels of the receiver. OTF (On-The-Fly) mapping mode is the main observing mode, and a simple position switching mode is also available.

OTF test observation shows that it takes 27 minutes for 6’ x 6’ region, and 37 minutes for 10’ x 10’. You may decide the regrid size and convolution parameter after completion of your observation. Pointing accuracy is about 6 acrsec. The backend system (FFT spectrometer) provide the 4096 x 2 channels with a fine velocity resolution of better than 0.05 km/s (15 kHz) per channel. Its effective spectra bandwidth is 60 MHz.

There are three Key Science Programs (KSP) running for three years, abstracts of which are accessible at the TRAO home page. Proposals which are not overlapped with KSPs are encouraged. Please refer the TRAO homepage for KSPs and other information. There are lots of telescope time available between LST 10 and 15 hrs, thus proposals using this time slots would have more privilege. The upper limit of telescope time per proposal is suggested as 100 hours.

Scientists who did not have an observing experience at TRAO, are encouraged to have an internal collaborator(s) of KASI (Korea Astronomy and Space Science). Two bedrooms and kitchen are available for outside observers.

Deadline for proposal submission is August 31^st 2018 (KST 23:59; UT+9).

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