PROJECTSOLAR OBSERVATIONS WITH ALMADESCRIPTIONS FOR “CALL FOR PROPOSAL" OF CYCLE4

DATE

2016-03-29@ NAOJAUTHOR

MASUMI SHIMOJO (NAOJ)

Today’s topics
Brief Introduction of Atacama Large mm/sub-mm Array(ALMA)
Advantage & disadvantage of an interferometer observation
What we can get, and what we cannot get?

Observing parameters for solar observations in Cycle 4
What kinds of observing modes are available in Cycle 4?

Dress-Rehearsal of solar observations in Cycle 4
Preliminary Results of ALMA solar development campaign 2015.

2

Atacama Large Millimeter/sub-millimeter Array(ALMA)
12m antenna (J)7m antenna (J)12m antenna (Europe)

12m antenna (US)Me (J)
Near the array center when the array is most compact (2014/12/13)

ALMA is the largest millimeter/sub-millimeter array in the world, constructed from54 12m-antennas and 12 7m-antennas.
Observing Frequency: 84 GHz ~ 950 GHz (Wavelength: 0.3 ~ 3.6 mm)
Longest Baseline: 150 m ~ 16 km (The array configuration is changing at all times.)3

in Figure 4.4. The Cold Cartridge Assembly (CCA) contains the cold optics, OMT, SIS mixers and the low-noise
HEMT first IF amplifiers. At room temperature, the Warm Cartridge Assembly (WCA) includes further IF
amplification and the Local Oscillator covering 92–108 GHz.

Receivers of ALMA
The antenna of ALMA has 7 observing bands (receivers).
Band 3: 84 – 116 GHz* 3.75 – 2.59 mm

Band 4: 125 – 163 GHz * 2.40 – 1.83 mm
Band 6: 211 – 275 GHz * 1.42 – 1.09 mm
Band 7: 274 – 373 GHz * 1.09 – 0.80 mm
Band 8: 385 – 500 GHz * 0.78 – 0.60 mm
Band 9: 602 – 720 GHz

0.50 – 0.43 mm

Band 10: 787 – 950 GHz

0.38 – 0.32 mm

Band3 receiver

Figure 4.4: Block diagram of the Band 3 receiver (left) including CCA (upper) and WCA (lower). Right image
shows a Band 3 CCA. Note the single feedhorn which feeds the OMT, splitting the two polarization signals forthe 2SB mixers. The Band 3 cartridges were constructed in Canada at NRC-HIA, Victoria.

Asterisks indicate that the receiver (band) can observe 4 frequency ranges in the band (Width of eachrange is 2 GHz ) simultaneously. Band 9 /10 can observe
2 frequency
rangessimultaneously.
The specification
for the Band 3 receivernoise performance(T ) is <41 K at LO=104 GHz, and <45 K forrx

any other valid LO setting.The atmospheric transmission over most of Band 3 is very high, even with a large
PWV (Figure 4.5) which means observations in Band 3 can, in principle, take place with 10 mm or more of
PWV. The resulting system temperature (Tsys ) shows the expected rise at the higher end, due to an atmospheric
oxygen line (Figure 4.6).

Each band has the function of measuring two linear polarizations (X, Y)

The full stokes information can be derived from the correlations (XX, YY, XY, YX) with all bands,
ideally.
Although the observing band can be changed within a few minutes if we neglect the changing of
focus and pointing, the change of the band is not permitted in one observation (one Scheduling
Block: SB).
4• For the lower sideband (LSB): (FLO1 - IFlo ) to (FLO1 - IFhi )Setting of observing frequencies forstandard observations (for non-solar)• For the upper sideband (USB): (FLO1 + IFlo ) to (FLO1 + IFhi )where IFlo and IFhi are the lower and upper IF ranges in the “IF Range” column of Table 4.1, and the IF
bandwidth (per sideband) is IFhi –IFlo . This is illustrated in Figure 4.2. Note that the maximum IF bandwidthin Table 4.1 may be a few percent less than the IF range in Table 4.1 (see Section 6.5.1).

Figure4.2:within
IF ranges
for the two
sidebands
in a heterodyne receiver.
LO1 can be changed
freelythe frequency
rangeof the receivers.
In each sideband (Bandwidth of one sideband is 4 GHz@Band3 / 5 GHz@Band6), PI can select two spectrum
windows (for LSB, SPW#1 and SPW#2 / for USB, SPW#3 and SPW#4).

4.2

The Cycle 3 Receivers

PI can select the frequency range of each spectrum window and number of channels from the provided
options. (Most high spectral resolution is 15.3 kHz / 3840 ch in 58.6 MHz bandwidth).
The Band 3, 4, 6, 7, and 8 receivers are dual sideband (2SB) receivers, where both the upper and lower sidebands
are provided
separately
simultaneously.
There
are 4 outputs
from
each
the receivers,
comprising
upper
The continue
mode andis calledTime Domain
Mode(TDM).
In thecase,theofbandwidth,andnumber ofthechannelsare 2 GHz and 128 ch for each polarization and each BB (15.6 MHz = 45km/s@Band3, 20km/s@Band6).
5

ALMA’s Field of View
60”

The FoV of an interferometer is limited by the size of dish, basically.
The size of FoV < HalfPowerBeamWidth(HPBW) = 1.02 x [Wavelength] / [Dish size]< 60”@Band3 (100GHz) / < 25”@Band6 (230GHz)
MOSAIC (scanning) observations is for large FoV.
6

Today’s topics
Brief Introduction of Atacama Large mm/sub-mm Array (ALMA)
Advantage & disadvantage of an interferometer observation
What we can get, and what we cannot get?

Observing parameters for solar observations in Cycle 4
What kinds of observing modes are available in Cycle 4?

Dress-Rehearsal of solar observations in Cycle 4
Preliminary Results of ALMA solar development campaign 2015.

Before the call for proposal of Cycle 4….
Scientific Verification (SV) data is useful for your studies.

One strategy for the call for proposal of Cycle 4

7

An radio interferometer measures thecoefficient of the Fourier series thatindicates the brightness distribution of sky.
One pair of two antennas (baseline) measure one Fourier (complex)
coeﬃcient (visibility).
Since a visibility is a complex value, it has amplitude and phase using
Euler’s formula. (Amplitude & Phase Calibration….)
When there is N antennas, the number of the coeﬃcient obtained from theantennas is N(N-1)/2.
Above sentence is correct when the antennas are located randomly.
Since the antennas of Nobeyama Radioheliograph are distributed
linearly, the number of the obtained coeﬃcient is not N(N-1)/2.
The Fourier coeﬃcients are derived from the cross-correlation coeﬃcients
between the signals from two antennas.
When the auto-correlation coeﬃcients are derived from the signals, we
can obtain the spectrum of the radio sources too.
Purple words indicate the jargons in the community of radio astronomy.
8Advantage & disadvantage
of an radio interferometer
Advantages
Obtain radio images with ultra-high spatial resolution without ahuge antenna (mirror).
Obtain radio spectrum data simultaneously.
Disadvantages
PSF (synthesized beam) has many ripples.
Absolute flux cannot be derived from interferometric data
fundamentally.
When the spatial frequency of a brightness variation
corresponds with the Fourier coeﬃcient that is not in data, thevariation does not appear in a synthesized image (resolve-out).
9

0
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50 100 150 200 250 300
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mapઢΛ࢖༻͍ͯ͠Δ෼ɼ
beam ͕ԣ௕ʹͳ͍ͬͯΔ͜ͱ͕෼͔Δɽ֤഑ྻͷ beam(a) Dirty map(c) Model map

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mJy/pixel

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Y (arcsecs)

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Y (arcsecs)

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Jy/pixel
Jy/pixel(Investigated by Miyawaki-san [Ibaraki-U])

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v (klambda)

v (klambda)

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Model
CLEAN
map
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Jy/pixel

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X (arcsecs)-100-200 map(b)
CLEAN(d)(e)
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Y (arcsecs)
Y (arcsecs)
Y (arcsecs)

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arcsec)
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105How do we recover the disadvantages?
All disadvantages are caused by the lack of Fourier coeﬃcients.
Fundamental solution: Increasing the number of antennas! ➜❌
Ripples of PSF
CLEAN process (Deconvolution Process)
Earth-Rotation Synthesis Mapping
Resolve-out
Observe the target with multiple antenna configurations
Combine the data of the interferometric and single-dish observations.

11

Example of CLEAN process(A flare observed by SSRT)
SSRT Synthesized beam

Before CLEAN

After CLEAN

Kochanov et al. 201312

Issue of CLEAN process(Clark 1982)
When CLEAN process is applied to a large structure, the artificial
pattern appears as in above image.
Solutions
Steer-CLEAN (“koshix” synthesizing program of NoRH)
Multi-Scale CLEAN (“msclean" option of the CLEAN task of CASA)
13

90

Earth-rotation Synthesis
mapping (Super-Synthesis)

CHAPTER 7. IMAGING WITH ALMA

1 min observations

1 hour observations

Figure 7.10: uv-plane sampling distributions of a model ALMA observation with 1-minute integration (left) and1-hour integration (right), using the C36-4 configuration to observe a source at a declination of 23 .
14

Earth-rotation Synthesis
mapping (Super-Synthesis)

Figure 7.10: uv-plane sampling distributions of a model ALMA observation with 1-minute integration (left) and1-hour integration (right), using the C36-4 configuration to observe a source at a declination of 23 .
90

CHAPTER 7. IMAGING WITH ALMA

1 min observations

1 hour observations

Figure 7.10: uv-plane sampling distributions of a model ALMA observation with 1-minute integration (left) and1-hour integration (right), using the C36-4 configuration to observe a source at a declination of 23 .
14

Solution of “resolve-out”:1
CHAPTER 2. ARRAY COMPONENTS
14

CHAPTER 2. ARRAY COMPOThe ACA Correlator is normally used for the ACA, and can work with two sub-arrays. It is an FX c(Fourier transform first, then cross-correlate) with 3-bit input and 4 bits in the correlation. The cgenerates 120 cross-correlations and 16 auto-correlations for each baseband. These are passed to a
purpose) data processing computer at up to ⇠0.6 GB/s per baseband.

Observe the target withmultipleantennaconfigurations
cuments-and-tools/.

No baseline coverage from even the most compact configuration of the 12-m Array is obtained forsmaller than 15 m. The array configuration of the 7-m Array are designed to fill missing spacings in fro
9 m to ⇠30 m (Chapter 7).

2.3.2

The TP Array

The TP Array can fill in baseline coverage from 0 m to about 12 m, complementing the 7-m and 12-mbaseline coverage. It consists of four 12-m diameter antennas built by East Asia (See Appendix
specifications of the TP antennas are almost identical to the 12-m Array elements. The TP ante
located on stations surrounding the 7-m Array. The TP antennas will eventually be fitted with asubreflector (also known as wobbler or chopper) in full operations. The ALMA nutator is a single axi
used to alternatively point the primary beam of the antenna between two defined sky positions by ti
subreflector along the azimuth direction, at constant elevation. A modulation of the observed signal
known frequency is introduced by rapidly switching between the celestial source and a nearby reference
A synchronous demodulation technique is then used to extract the flux of the source. This method can
improve the quality of single dish observations by suppressing atmospheric and noise components at fre
lower than the nutator frequency.

ALMA prepared the 7m-array of the Atacama Compact
Array (a.k.a. Morita-array) for short baselines.

The TP Array is usually connected to the ACA Correlator, but its antennas can also be connected t
input Correlator and used for cross-correlation. The call materials describe the observing mode and cap
oﬀered for the TP Array for each cycle.

Figure 2.2: The Morita Array - In Remembrance of Professor Koh-Ichiro Morita. Koh-ichiro Morita, a p
at the NAOJ Chile Observatory, was one of the world’s renowned scientists in the field of aperture s
He made a great contribution to designing the configuration of 16 antennas composing the Atacam
pact Array (ACA) manufactured by Japan, as well as to realizing high-resolution and high-qualityim
15

Solution of “resolve-out”:1
96

CHAPTER 7. IMAGING WITH ALMA

Observe the target withmultiple antenna configurations 2“C36-compact” and “C36-extended” (i.e., one of the more compact and one of the more extended 12-m
Array configurations). Here C36-extended provides the required angular resolution, and C36-compact
provides the sensitivity to intermediate angular scales needed to smoothly match up with the 7-m
Array data. Which specific 12-m Array configurations are used for C36-compact and C36-extended
depend on the range of {✓res ,✓LAS }; allowed combinations are shown in Table 7.4.

4. Finally, if ✓LAS is larger than the ✓M RS of the 7-m Array, the Total Power Array will also be included.

84

Array configuration of ALMA is changing in everyday.

It is important that you provide an accurate estimate of ✓LAS for your target, as the quality of the
final image will depend very much on the observation with the proper set of array configurations.

CHAPTER 7. IMAGING WITH ALMA

Combination of Array Configurations for Band3✓res (arcsec)
0.075
0.075
0.1
0.1
0.3
0.3
0.3
0.3
0.5
0.5
0.5
0.5
0.7
0.7
0.7
0.7
1.2
1.2
1.2
1.8
1.8
1.8
3.4
3.4
3.4

✓LAS (arcsec)
< 1.1
> 1.1
< 1.5
> 1.5
< 4.8
4.8-25.2
25.2-42.8> 42.8< 7.8
7.8-25.2
25.2-42.8> 42.8< 9.6
9.6-25.3
25.3-42.8> 42.8< 25.225.2-42.8> 42.8< 25.225.2-42.8> 42.8< 25.325.3-42.8> 42.8Array combination
C36-8
C36-7
C36-6
C36-6 + C36-3
C36-6 + C36-3 + 7-m
C36-6 + C36-3 + 7-m + TP
C36-5
C36-5 + C36-2
C36-5 + C36-2 + 7-m
C36-5 + C36-2 + 7-m + TP
C36-4
C36-4 + C36-1
C36-4 + C36-1 + 7-m
C36-4 + C36-1 + 7-m + TP
C36-3
C36-3 + 7-m
C36-3 + 7-m + TP
C36-2
C36-2 + 7-m
C36-2 + 7-m + TP
C36-1
C36-1 + 7-m
C36-1 + 7-m + TP

Time ratios
1
1
1
1 : 0.5
1 : 0.5 : 2
1 : 0.5 : 2 : 4
1
1 : 0.5
1 : 0.5 : 2
1 : 0.5 : 2 : 4
1
1 : 0.5
1 : 0.5 : 2
1 : 0.5 : 2 : 4
1
1: 2
1: 2: 41
1: 2
1: 2: 41
1: 2
1: 2: 4

Total Time
1.0 ⇥ extended
1.0 ⇥ extended
1.0 ⇥ extended
1.5 ⇥ extended
3.5 ⇥ extended
5.5 ⇥ extended
1.0 ⇥ extended
1.5 ⇥ extended
3.5 ⇥ extended
5.5 ⇥ extended
1.0 ⇥ extended
1.5 ⇥ extended
3.5 ⇥ extended
5.5 ⇥ extended
1.0 ⇥ extended
3.0 ⇥ extended
5.0 ⇥ extended
1.0 ⇥ extended
3.0 ⇥ extended
5.0 ⇥ extended
1.0 ⇥ extended
3.0 ⇥ extended
5.0 ⇥ extended

Table 7.4: Array combination with the corresponding {✓res , ✓LAS } conditions for an observation at 100 GHz. As
16

Figure 7.2: Representative 12-m Array configurations for Cycle 3. Note that the scale changes for the final two
panels.

Solution of “resolve-out”:1
96

CHAPTER 7. IMAGING WITH ALMA

Observe the target withmultiple antenna configurations 2“C36-compact” and “C36-extended” (i.e., one of the more compact and one of the more extended 12-m
Array configurations). Here C36-extended provides the required angular resolution, and C36-compact
provides the sensitivity to intermediate angular scales needed to smoothly match up with the 7-m
Array data. Which specific 12-m Array configurations are used for C36-compact and C36-extended
depend on the range of {✓res ,✓LAS }; allowed combinations are shown in Table 7.4.

4. Finally, if ✓LAS is larger than the ✓M RS of the 7-m Array, the Total Power Array will also be included.

84

Array configuration of ALMA is changing in everyday.

It is important that you provide an accurate estimate of ✓LAS for your target, as the quality of the
final image will depend very much on the observation with the proper set of array configurations.

CHAPTER 7. IMAGING WITH ALMA

Combination of Array Configurations for Band3✓res (arcsec)
0.075
0.075
0.1
0.1
0.3
0.3
0.3
0.3
0.5
0.5
0.5
0.5
0.7
0.7
0.7
0.7
1.2
1.2
1.2
1.8
1.8
1.8
3.4
3.4
3.4

✓LAS (arcsec)
< 1.1
> 1.1
< 1.5
> 1.5
< 4.8
4.8-25.2
25.2-42.8> 42.8< 7.8
7.8-25.2
25.2-42.8> 42.8< 9.6
9.6-25.3
25.3-42.8> 42.8< 25.225.2-42.8> 42.8< 25.225.2-42.8> 42.8< 25.325.3-42.8> 42.8Array combination
C36-8
C36-7
C36-6
C36-6 + C36-3
C36-6 + C36-3 + 7-m
C36-6 + C36-3 + 7-m + TP
C36-5
C36-5 + C36-2
C36-5 + C36-2 + 7-m
C36-5 + C36-2 + 7-m + TP
C36-4
C36-4 + C36-1
C36-4 + C36-1 + 7-m
C36-4 + C36-1 + 7-m + TP
C36-3
C36-3 + 7-m
C36-3 + 7-m + TP
C36-2
C36-2 + 7-m
C36-2 + 7-m + TP
C36-1
C36-1 + 7-m
C36-1 + 7-m + TP

Time ratios
1
1
1
1 : 0.5
1 : 0.5 : 2
1 : 0.5 : 2 : 4
1
1 : 0.5
1 : 0.5 : 2
1 : 0.5 : 2 : 4
1
1 : 0.5
1 : 0.5 : 2
1 : 0.5 : 2 : 4
1
1: 2
1: 2: 41
1: 2
1: 2: 41
1: 2
1: 2: 4

Total Time
1.0 ⇥ extended
1.0 ⇥ extended
1.0 ⇥ extended
1.5 ⇥ extended
3.5 ⇥ extended
5.5 ⇥ extended
1.0 ⇥ extended
1.5 ⇥ extended
3.5 ⇥ extended
5.5 ⇥ extended
1.0 ⇥ extended
1.5 ⇥ extended
3.5 ⇥ extended
5.5 ⇥ extended
1.0 ⇥ extended
3.0 ⇥ extended
5.0 ⇥ extended
1.0 ⇥ extended
3.0 ⇥ extended
5.0 ⇥ extended
1.0 ⇥ extended
3.0 ⇥ extended
5.0 ⇥ extended

Table 7.4: Array combination with the corresponding {✓res , ✓LAS } conditions for an observation at 100 GHz. As
16

Figure 7.2: Representative 12-m Array configurations for Cycle 3. Note that the scale changes for the final two
panels.

How do we recover the disadvantages?
All disadvantages are caused by the lack of Fourier coeﬃcients.
Fundamental solution: Increasing the number of antennas! ➜❌
Ripples of PSF
CLEAN process (Deconvolution Process)For Solar: Multi-Scale CLEAN is essential.
Earth-Rotation Synthesis Mapping➜❌
Resolve-out
Observe the target with multiple antenna configurations
For Solar: Simultaneous observation is essential. The observation with multiple
antenna configurations is impossible except 7m-array.
Combine the data of the interferometric and single-dish observations.
For Solar: Simultaneous observation is essential.
17

Today’s topics
Brief Introduction of Atacama Large mm/sub-mm Array(ALMA)
Advantage & disadvantage of an interferometer observation
What we can get, and what we cannot get?

Observing parameters for solar observations in Cycle 4
What kinds of observing modes are available in Cycle 4?

Dress-Rehearsal of solar observations in Cycle 4
Preliminary Results of ALMA solar development campaign 2015.

18

Items of the observing setup
Receiver setup
Observing frequencies, Spatial resolution
Correlator setup
Spectrum resolution, Time cadence of visibility (integration time), Polarization
Array Configuration
Spatial resolution, Dynamic range, Season of the observations
Observing Sequence
On-source time, Frequency and duration of the suspension for phase & amplitude calibrations.
Single-Point or MOSAIC (How many pointings for one image?)
Field of View, Time cadence of images
The setup of Single-Dish (TP-array) observations
Observing Season in a year and Observing Period of a day
Joint observations with the other telescopes
19

For the upper sideband (USB): (FLO1 + IFlo ) to (FLO1 + IFhi )Receiver & Correlator Setup
for solar observations in Cycle4

where IFlo and IFhi are the lower and upper IF ranges in the “IF Range” column of Table 4.1, and the I
dwidth (per sideband) is IFhi –IFlo . This is illustrated in Figure 4.2. Note that the maximum IF bandwid
able 4.1 may be a few percent less than the IF range in Table 4.1 (see Section 6.5.1).

Band3

SPW#1
Cen. 93 GHz

92 GHz

SPW#3
SPW#4
Cen. 105 GHz Cen. 107GHz

SPW#2
Cen. 95GHz

96 GHz

100 GHz104 GHz108 GHzFor solar observations in Cycle4, observations with Band3 and Band6 receivers are oﬀered.

Figure 4.2: IF ranges for the two sidebands in a heterodyne receiver.

LO1 is fixed to 100 GHz for Band3, 239 GHz for Band6.
Polarization is Stokes-I or XX only
The correlator mode is TDM only.

The Cycle
3 isReceivers# of ch128 ch/spw (Stokes-I), 256ch/spw (XX only)

Spectrum resolution: 15.6 MHz (Stokes-I) / 7.8 MHz (XX only)
time is 2areseconds.
➜ Shortest
time receivers,
cadence ofwhereimagesbothis 2 seconds.
Band 3, 4, 6, Integration
7, and 8 receivers
dual sideband(2SB)
the upper and lower sideban

provided separately and simultaneously. There are 4 outputs from each of the receivers, comprising the upp
20

For the upper sideband (USB): (FLO1 + IFlo ) to (FLO1 + IFhi )Receiver & Correlator Setup
for solar observations in Cycle4

where IFlo and IFhi are the lower and upper IF ranges in the “IF Range” column of Table 4.1, and the I
dwidth (per sideband) is IFhi –IFlo . This is illustrated in Figure 4.2. Note that the maximum IF bandwid
able 4.1 may be a few percent less than the IF range in Table 4.1 (see Section 6.5.1).

Band6

SPW#1
Cen. 230GHz

229 GHz

SPW#3
Cen. 246GHz

SPW#2
Cen. 232GHz

233 GHz239GHz245 GHz

SPW#4
Cen. 248GHz

249GHzFor solar observations in Cycle4, observations with Band3 and Band6 receivers are oﬀered.

Figure 4.2: IF ranges for the two sidebands in a heterodyne receiver.

LO1 is fixed to 100 GHz for Band3, 239 GHz for Band6.
Polarization is Stokes-I or XX only
The correlator mode is TDM only.

The Cycle
3 isReceivers# of ch128 ch/spw (Stokes-I), 256ch/spw (XX only)

Spectrum resolution: 15.6 MHz (Stokes-I) / 7.8 MHz (XX only)
time is 2areseconds.
➜ Shortest
time receivers,
cadence ofwhereimagesbothis 2 seconds.
Band 3, 4, 6, Integration
7, and 8 receivers
dual sideband(2SB)
the upper and lower sideban

provided separately and simultaneously. There are 4 outputs from each of the receivers, comprising the upp
21

Array configuration
for solar observation in Cycle 4ઢΛ࢖༻͍ͯ͠Δ෼ɼbeam ͕ԣ௕ʹͳ͍ͬͯΔ͜ͱ͕෼͔Δɽ֤഑ྻͷ beam ͷ൒஋શ෯ (FWHM) Λ·ͱΊͨͷ͕ද 2 Ͱɼ͓͓Αͦͷۭؒ෼ղೳΛද͍ͯ͠ΔɽX, Y ࣠ํ޲ͦΕͧΕͰ FWHM ͕‫ํ͍ڱ‬Λ Bmaj ɼ޿͍ํΛ Bmin ͱ͍ͯ͠Δɽ࠷΋഑ྻ͕ίϯύΫτͳ C4-1 Ͱ͸ FWHM ͕໿ 3–4 ඵ֯ɼC4-2 Ͱ͸ 2–3 ඵ֯ɼC4-3 Ͱ͸ 1–2 ඵ֯ͱͳͬͯ
͍Δɽ

C40-2+7m
C40-3+7m

1.5”

1.8”
1.2”

0.8”
0.5”

100

Y (m)

100

Y (m)

100

0

0

-100

-100

-200

-200

-200

-300
-300 -200 -100 0 100 200 300
X (m)

-300
-300 -200 -100 0 100 200 300
X (m)

-300
-300 -200 -100 0 100 200 300
X (m)(d) C4-1 UV coverage(e) C4-2 UV coverage(f) C4-3 UV coverage
150

100

100

100

50
0
-50

v (klambda)

150

v (klambda)

150

50
0
-50

50
0
-50

-100

-100

-100

-150

-150

-150

-150-100 -50 0 50 100 150
u (klambda)-150-100 -50 0 50 100 150
u (klambda)-150-100 -50 0 50 100 150
u (klambda)(g) C4-1 Synthesized beam(h) C4-2 Synthesized beam(i) C4-3 Synthesized beam

10

10

10

5

5

5

Y (arcsecs)

3.4”

200

Y (arcsecs)

C40-1+7m

Band6

200

-100

Typical spatial resolution [TBC]
Band3

200

0

v (klambda)

The array configurations of 12m-arrayfor solar observations are C40-1,
C40-2, C40-3 [TBC].

(c) C4-3 Antenna position
300

0
-5
-10
-10

ਤ4

Y (arcsecs)

All antennas is connected to the 64input correlator (BL correlator).

(b) C4-2 Antenna position
300

Y (m)

The heterogeneous array is constructedfrom 40 12-m antennas and 10 7mantennas only for solar observation.

(a) C4-1 Antenna position
300

0
-5

-5

0
5
X (arcsecs)

10

-10
-10

0
-5

-5

0
5
X (arcsecs)

10

-10
-10

-5

0
5
X (arcsecs)

10(a, b, c), (d, e, f), (g, h, i) ͦΕͧΕɼC4-1, C4-2, C4-3 ʹ͓͚ΔΞϯςφҐ
ஔɼUV coverageɼSynthesized beamɽ
22

Observing sequence of
solar observations in Cycle4
The observing sequence of one solar observation (Scheduling Block: SB)
1. Calibration of the Zero level of the SQLD detector
2. Pointing Calibration for Bandpass Calibrator
3. Sideband-ratio Calibration
4. Atmospheric Calibration for Bandpass Calibrator
5. Bandpass Calibration
6. Pointing Calibration for Flux/Phase Calibration and Target(Sun)7. Atmospheric Calibration for Flux Calibrator
8. Flux Calibration
9. Phase Calibration
10. Atmospheric Calibration for Phase Calibrator and Target
11. Scientific Observations (On & OFF-source: Duration: ~10min)
12. Phase Calibration
13. Atmospheric Calibration for Phase Calibrator and Target
Repeat from 11 to 13 until the total observation time exceeds the PI’s requirement.

• The initial calibration (1~10) takes about 25 mins.
• The duration of calibration between scientific observations (12 & 13) is less than 3 mins.
The band changing in one SB and a simultaneous observation with two bands are not oﬀered.
One target (one ephemeris file) is for one SB; multiple targets for one SB is not permitted.
The limit of total observing time for one SB is 2 hours.
23

FoV & Time-cadence of images
Single-pointing vs. MOSAIC Obs. in Cycle4
Single-pointing observation
Band3: < 60”𝛷 / Band6: < 25”𝛷Minimum time cadence of images: 2 seconds
It is limited by the integration time in the correlator.
MOSAIC observation
Maximum number for pointing one map: 150 pts.

FoV of 149pts-MOSAIC@Band6“150 pts" corresponds with 350” x 350”@Band3, 150”x150”@Band6.
FoV is not need to be a square. A rectangular FoV is OK too.
Integration time for one pointing (included overhead): ~7.6 seconds
Time cadence of MOSAIC images[< a few x 10 pts] 7.6 sec x # of points [[Ex. 8-pts MOSAIC (90” x 90”@Band3) 1 image/min]][> a few x 10 pts] 7.6 sec x # of points + 3mins <Calibration between scientific observations>
The pointing accuracy of ALMA is very good. You can believe the coordinate (RADEC) in the FITS header.
24

Setup for Single-Dish (Total Power:TP)
observations in Cycle4
Total-power single-dish observations are oﬀered as
supporting for interferometric observations; proposals
requesting purely single-dish observations will not be
accepted in Cycle 4.
Observing Frequencies are the same as that for theinterferometric observation.
# of channel in one spectrum window is ONE.
Polarization setup is also the same as the interferometric one.
The FoV is fixed to the Full Sun.
2400”-diameter circle FoV centered on solar disk center.
Spatial resolution: ~60”@Band3 / ~25”@Band6
Nyquist Smapling
Time-cadence of TP images: 7mins@Band3 / 10mins@Band6
Simultaneous observation with the interferometricobservation.

230GHz Single-Dish Obs. (2015.12.18)

25

Solar Observing Season &Observing Period in a day
Solar observing season
Solar observations are carried out using C40-1, 2, and 3 [TBC]. The configurations might beformed between December, 2016 and May 2017, considering the configuration schedule of
Cycle3.
Solar observations are done by ‘campaign mode’.
ALMA observatory will determine the week (or days) for solar observations in above
season, based on the result of the proposal review.
ALMA observatory will inform the schedule of solar observing week to PIs [TBD] months
before the week. In the week, PI has to prepare the ephemeris file for own target using
ALMA solar ephemeris generator, and provide to the observatory in the week.
Solar observing period in a day
To avoid shadowing of 7m antennas, observations will be carried out between 13:00 UT and
20:00 UT.
Although PI can inform the demand of his/her observing date & time to the observatory, it is
not guaranteed that his/her observation is executed along the demand.
The observatory informs the time table of the observations of a day to the community [TBD].
26

The total observing time of a solar projectis NOT determined based on the sensitivity.
•

The limitations of ALMA observations
1. The longest duration of one scheduling block (SB) is 2 hours.

2. Every SB includes a calibration session before starting scientiﬁcobservation. The duration of the session is 25~30 minutes. Therefore,
the maximum of on-source (solar observation) in a SB is about 1.5hours.

3. Solar proposals are considered ʻRegular Proposalʼ and total observing
time is therefore less than 50 hours. When you determine the total
observing time for your project•

The total observing time of a solar project must be determined fromthe scientiﬁc point of view. For example, if your target phenomenon ispresent always in the Sun, the total observing time might be based on the
lifetime of the target phenomenon. On the other hand, if your target

phenomenon is not always present, the total observing time might bedetermined based on the occurrence frequency of your target phenomenon.
1127

Items of the observing setup
Receiver setup
Observing frequencies, Spatial resolution
Correlator setup
Spectrum resolution, Time cadence of visibility (integration time), Polarization
Array Configuration
Spatial resolution, Dynamic Range, Season of the observations
Observing Sequence
On-source time, Frequency and duration of the suspension for phase & amplitude calibrations.
Single-Point or MOSAIC (How many pointings for one image?)
Field of View, Time cadence of images
The setup of Single-Dish (TP-array) observations
Solar Observing Season / Observing Period in a day
Joint observations with the other telescopes
28

Today’s topics
Brief Introduction of Atacama Large mm/sub-mm Array(ALMA)
Advantage & disadvantage of an interferometer observation
What we can get, and what we cannot get?

Observing parameters for solar observations in Cycle 4
What kinds of observing modes are available in Cycle 4?

Dress-Rehearsal of solar observations in Cycle 4
Preliminary Results of ALMA solar development campaign 2015.

29

Solar Development Campaign 2015
2015/12/14 - 2015/12/21
We could not carry out observations in afternoon 19-21 Dec, because the wind in the antennasite is too strong mainly (>20m/s : threshold of suspending operations).
# of antennas: 20~23 12-m + 7~8 7-m antennas. Total: 27~31 antennas…

(Cycle4: 50 antennas)

Lead of The Campaign: Tim Bastian (NRAO)
Lead of the interferometric obs. : Masumi Shimojo (NAOJ)
Lead of the single-dish obs.: Stephen White (AFRL)
Supporters from Joint ALMA Observatory: Antonio Hales,
Goals: Dress-Rehearsal of Cycle4 / New function of Cycle5• EastAsia (EA)
• Masumi Shimojo (NAOJ)• Kazumasa Iwai (NICT)• Sujin Kim (KASI)• Europe (EU)• Ivica Skokie (Ondřejov Observatory)• NorthAmerica (NA)• Tim Bastian (NRAO)• Stephen White (AFRL)• China (as participants of NA development team)• Yihua Yang, Sijie Yu, Donghao Liu (NAOC)
30

In solar atmosphere,
where mm/sub-mm waves come from?
✤ When flares don’t occur,✤ Thermal emission fromlower chromosphere.
✤ from optically thick layer

ALMA Band3
ALMA Band6(𝜏=1 layer), basically✤ Tbrightness = Tphysical✤ When a flare occurs,✤ Gyro-synchrotron emission

from non-thermal electrons
accelerated by the flare
Hinode-9 @ Queen’s University, Belfast 2015/09/15

Vernazza, Avrett & Loeser, 1981
31

ALMA Cycle4の日程
2016年3月22日：プロポーザル受付開始
同日：プロポーザル投稿用ツール(Observing Tool)の公開。
2016年4月21日 15:00UT (2016年4月22日00:00JST)：プロポーザル受付〆切
2016年8月：プロポーザル採択結果を応募者に発送。
2016年10月：Cycle4の観測が開始
2016年12月~2017年5月：太陽観測シーズン
2月は装置保守月間のため観測は中断(ボリビア・ウィンター）プロポーザルのレビュー結果により、太陽観測の総時間やキャンペーン日程が決定2017年9月：Cycle4の観測が終了
32

プロポーザルのタイプ：１
Regular Proposal
太陽観測のプロポーザルはこのタイプ。
総観測時間が50時間以下
Target of Opportunity (ToO) Proposal
PIからの連絡後、48時間以内に行うことを要求する観測提案
Large Proposal
総観測時間が50時間以上150~300時間以下の観測提案
mm-VLBI Proposal
Director Discretionary Time (DDT) Proposal
33プロポーザルのタイプ：２Standard Proposal
該当する観測モードがこなれていて、観測所で行うキャリブレーションがパイプライン処理で行われる観測提案
Non-standard Proposal
試験的な観測モードで、キャリブレーションが人力で行われる観測提案•

Bands 8, 9 & 10 observations•

Band 7 observations with maximum baselines > 5.3 km•

All polarization observations•

Spectral Scans•

Bandwidth switching projects•

Solar Observations•

VLBI observations•

User-defined calibrations
34

Cycle4 レビューパネルのカテゴリー
レビューパネルのカテゴリー
同じカテゴリーのプロポーザルが、最初に同じレビューパネルで評価される。
最終的には全プロポーザル(のうち上位)に順番をつけ、受諾の可否を決定する。
カテゴリー
1. Cosmology and the high redshift universe
2. Galaxies and galactic nuclei
3. Interstellar medium, star formation and astrochemistry
4. Circumstellar disks, exoplanets and the solar system
5. Stellar evolution and the Sun
a.The Sunb.Main sequence stars
c. Asymptotic Giant Branch (AGB) stars
d.Post-AGB starse. Hypergiants
f. Evolved stars: Shaping/physical structure
g. Evolved stars: Chemistryh. Cataclysmic stars

i. Luminous Blue Variables (LBV)

j. White dwarfs
k. Brown dwarfs
l. Supernovae (SN) ejecta
m .Pulsars and neutron stars
n. Black holeso. Transients35

Cycle4での太陽観測のプロポーザルは、
Regular Proposal
総観測時間：< 50 hours
Non-Standard Proposal
観測所でのキャリブレーションが人力
Category 5: Stellar evolution and the Sun
最初の競争相手は、AGB/Supernovae/Black Hole/Brown Dwarf/
White Dwarf/Pulsar/Neutron Star…
最終的には全分野で順位付けされる。

36

受諾プロポーザルの種別
Grade A: 最優先で観測される。Cycle4で観測できなかった場合は、Cycle５に持ち越しされる。
Grade B: 優先的に観測される。Cycle4で観測できなかった場合、Cycle5への持ち越しはなし。
Grade C: Grade AやBが観測が終了または、LSTやAntenna Configuration、天候状況により観測できな
い場合に観測が行われる。

37

総観測時間への制限
Cycle4で提供される総観測時間12-m array: 3000 hrs / Morita-array: 2000[TBC] hrs
観測対象毎に保障される観測時間はない。
最悪、Cycle4で太陽観測がない場合もありえる。
保障されているのは、各領域に対する観測時間の割り当て。
EU: Europe (ESO参加国): 33.75%
NA: North America(アメリカ/カナダ/台湾) 33.75%
EA: East Asia(日本/台湾/大韓民国) 22.5% (675 hrs for 12-m array)
Chile: 10%PIの所属する研究所の国籍により、受諾観測提案の総観測時間が上記の領域別に積算される。領域別の総観測時間が上記の割合を超える場合、受諾観測提案に調整が
行われる。
38

各領域での倍率 (in Cycle3)
Figure 3. Regional share of ACA time for all submitted proposals, and for the proposals recommended forscheduling with Grade A, Grades A and B, and Grade C.

(ALMA Early Science Cycle 3: Outcome of the Proposal Review Process より)

受付総数：1578 (EU: 657/NA: 465.5 /EA: 295.5 /Chile: 115/Other: 45)

39

ALMA Science Portal (EA)
https://almascience.nao.ac.jp

40

プロポーザル投稿に関する注意
PIだけでなくCo-Iも、ALMA観測所のアカウントを取得する必要がある。

41