Chapter 13
MIRI Coronagraphic Imaging
In this chapter…
13.1 Introduction
The MIRI Coronagraph Imaging template/mode is to be used for all observations using the
coronagraphic imaging mode of MIRI. There are two different types of masks available, each
supporting its own unique science. The phase masks may be useful to investigate regions very
close to stars such as the inner regions of debris disks, and exoplanets orbiting close to the star.
The Lyot mask is useful for investigating the outer regions of debris disks, host galaxies of AGN
and the inner regions of QSOs. The parameters described in this section are used to specify the
Observations for MIRI Coronagraphic Imaging. More complete descriptions of the detector
readout parameters, filters/dispersers, detector characteristics, etc. are available in the MIRI
Instrument Handbook.
The following fields are defined in Chapter 5: Observation Number (5.1), Observation Label
(5.2), Observation Comments (5.3), Target Name (5.4), Observation-Level Special Requirements
(5.5), and On Hold Comments (5.6), and will not be discussed in this Chapter.
The MIRI Coronagraphic Imaging template [MIR0106] consists of the following parameters:
Field
Target Acquisition Filter
[MIR0299]
Science Obs. Coron.
Mask/Filter [MIR0300]
Readout Pattern
[MIR0301]
Number of Groups
[MIR0298]
Details
select filter name
Number of Integrations
[MIR0111]
specify number of
integrations
select mask/filter name
select readout pattern
specify number of groups
Values
choose from list
[MIR0108]
choose from list
[MIR0109]
choose from list
[MIR0110]
number
[MIR0107]
Number
[MIR0112]
1
Notes
see Table 13-1
see Table 13-2
Note that ALL parameters listed below are required as part of your
Phase I submission.
.
13.2 MIRI Coronagraphic Imaging
The following parameters are used to define MIRI Coronagraphic Imaging observations.
13.2.1 Target Acquisition
The following parameter is used to define MIRI Target Acquisition observations. Note that for
Coronagraphic Imaging, the science target is used for the acquisition (unlike NIRCam
Coronagraphy, where an offset target may be used).
Note: The ACQUISITION TARGET FLUX (TACQ FLUX) [MIR0302] value will be
populated by APT based on the science target [MIR0303] (the flux value is part of the target
definition).
13.2.1.1Target Acquisition Filter
Select the name of the TARGET ACQUISITION FILTER [TACQ FILTER] (see Table 13-1)
you wish to use for target acquisition.
Table 13-1 Filters Available for MIRI Target Acquisition
Filter Bandpass (m)
Comment
F560W
Center Wavelength 0
(m)
5.6
1.2
broad band
F1000W
F1500W
10
15
2
3
Silicate, broad band
broad band
FND
13
10
for coronagraphic
acquisitions
Acq. Filter
[MIR0115]
[MIR0116]
[MIR0117]
[MIR0118]
13.2.2 Science Observations
13.2.2.1 Science Observation Coronagraphic Mask/Filter
Select the coronagraphic mask [CORON] and filter [FILTER] you wish to use (see Table 13-2).
2
Table 13-2 Masks/Filters Available for MIRI Coronagraphic Imaging
Mask/Filter
Center
Wavelength
0 (m)
4QPM/F1065C 10.65
4QPM/F1140C 11.4
Filter
Bandpass
(m)
0.53
0.57
4QPM/F1550C 15.5
LYOT/F2300C 23.0
0.78
4.60
Comment
NH3, silicate
continuum or
PAH feature
continuum
Peak of debris
disk
Subarray
[MIR0119] MASK1065
[MIR0120] MASK1140
[MIR0338]
[MIR0339]
[MIR0121] MASK1550
[MIR0122] MASKLYOT
[MIR0340]
[MIR0341]
For developers: for now, only 1 mask/filter can be selected for an observation. However, in the
future, it may be possible to use all 4 [MIR0320]. Also, APT will need to break the selection
into their component values for the scripts [MIR0321]. Also note that only 1 exposure time per
Mask/Filter will be supported. [MIR0344]
13.2.2.2 Readout Pattern
READOUT PATTERN [READOUT PATTERN] = FAST [MIR0450],
SLOW [MIR0451], FASTGRPAVG [MIR0452], FASTINTAVG [MIR0453]
This field specifies the readout pattern to be used to obtain the data. FAST is used for bright
targets and long wavelength imaging, SLOW is used for faint targets, deep imaging, and MRS
spectroscopy, FASTGRPAVG and FASTINTAVG are used for bright targets and to decrease
the data rate.
13.2.2.3 Number of Groups
NUMBER OF GROUPS [NGROUPS] specifies the number of groups in an integration
[MIR0454]. If READOUT PATTERN = FASTGRPAVG, then the number of groups should
be greater than 16 [MIR0123] and a multiple of 4 [MIR0124]. If READOUT PATTERN =
FASTINTAVG, then the number of groups should be 1 [MIR0125].
13.2.2.4 Number of Integrations
NUMBER OF INTEGRATIONS [NINTS] field specifies the number of times the integration
is repeated [MIR0455]. If READOUT PATTERN = FASTINTAVG, then the number of
integrations should be a multiple of 4 [MIR0126].
3