# Call for Proposal (2017-2018 term)

We would like to call for proposals using TRAO (Taeduk Radio Astronomy Observatory) 14-m telescope for the term of 2017 autumn - 2018 spring. Recently we successfully installed a multi-beam receiver system, SEQUOIA-TRAO, and renovated some part of the telescope system.

The new receiver system is equipped with high-performing 16-pixel MMIC preamplifiers in a 4x4 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 2nd 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 (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 min for 6’x6’ region, and 37 min for 10’x10’. You may decide the regrid size and convolution parameter after observation. Pointing accuracy is about 6 acrsec. The backend system (FFT spectrometer) provide the 4096x2 channel with fine velocity resolution of better than 0.05 km/s (15 kHz) per channel, and its effective spectra bandwidth is 60 MHz.

It is strongly encouraged to have an internal collaborator(s) of KASI (Korea Astronomy and Space Science) for scientists who did not have an observing experience at TRAO. The upper limit of telescope time is suggested as 100 hours per proposal.

We TRAO are equipped with two bedrooms for outside observers and kitchen facilities for cooking. Deadline for proposal submission is August 31th 2017 (KST 23:59; UT+9). There are three Key Science Programs (KSP) running for three years, abstracts of which are all 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.

Please find the attached temporary manual (kor & eng) for observation. English version will be provided sooner or later.

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

1. 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
2. Please submit the proposal to the following e-mail address: traoprop@kasi.re.kr

### Beam parameters

Frequency ~ (GHz) ΘB('') ηA ~ (%) ηB ~ (%)
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

$\dpi{100}\bg_white T_{rms}=\frac{T_{sys}}{\eta_{spec}\times\sqrt{\Delta\nu\times (t_{\textrm{on}} + t_{\textrm{ref}})}}\times \Biggl[1+\frac{1}{\sqrt{N}}\Biggr]$

where,

• $\dpi{100}\bg_white T_{sys}:~500~\textrm{K}~at~115~\textrm{GHz},~300~\textrm{K}~at~110~\textrm{GHz},~200~\textrm{K}~at~86~\textrm{GHz}$
• $\dpi{100}\bg_white \eta_{spec}:~\sim 0.5~for~16~\textrm{beams}$
• $\dpi{100}\bg_white \Delta\nu:~15.3\times10^3~\textrm{(Hz)} \ ( \ \approx 62.5 \ MHz/4096 \ chs; \ fixed \ )$
• $\dpi{100}\bg_white t_{\textrm{on}}~=~X_{\textrm{length}}/\textrm{HPBW} \times t_{\textrm{samp}} \times X_{\textrm{step}} \times 16$   ( exposure time for source position )
• $\dpi{100}\bg_white t_{\textrm{ref}}~=~\sqrt{X_{\textrm{length}}\times N_{\textrm{ScanPerCal}}/\textrm{HPBW}}~ \times t_{\textrm{samp}}/2$   ( minimum required integration time on refence position )
• $\dpi{100}\bg_white X_{\textrm{ramp}}~=~\frac{X_{\textrm{step}}}{t_{\textrm{samp}}} \times 3$   ( 3 sec are required in order to get proper scan velocity )
• $\dpi{100}\bg_white N~=~X_{\textrm{length}}/\textrm{HPBW}$
• $\dpi{100}\bg_white T_{rms,final}~=~T_{rms}/\sqrt{\alpha}$   ( α: Scan iteration number in the same area )

### Example 1:

HPBW = 44", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.25 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 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 Trms ~ 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", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.75 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 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 Trms ~ 1.2 K
12' × 12' > 19 min ~ 0.8 GB
15' × 15' > 25 min ~ 1.0 GB

### Example 3:

HPBW = 22", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.25 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 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 Trms ~ 0.35 K
12' × 12' > 132 min ~ 6.3 GB

### Example 4:

HPBW = 22", tsamp = 0.2 sec, tref = 2.0 sec
Xstep = 0.25 HPBW, Ystep = 0.75 HPBW
Xramp = 3 HPBW, Yramp = 3 HPBW
Rows per Scan = 2, Scans per Cal = 4
Tsys = 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 Trms ~ 0.6 K
12' × 12' > 45 min ~ 2.2 GB
15' × 15' > 61 min ~ 3.2 GB

Taeduk Radio Astronomy Observatory