Top/Summary


#author("2021-03-05T08:11:38+00:00","default:anir","anir")
#author("2021-04-05T04:44:08+00:00","default:anir","anir")
* Brief Introduction to SWIMS [#x02094bd]

''S''imultaneous-color ''W''ide-field ''I''nfrared ''M''ulti-object ''S''pectrograph, or ''&COLOR(#0070c0){SW};'''I'''&COLOR(#f33838){MS};'', is capable of
- simultaneous imaging/spectroscopy of 0.9-1.4 and 1.4-2.5 μm wavelength ranges
- imaging of maximum φ9.6 arcmin FoV (6.6 × 3.3 arcmin^2 on Subaru)
- having a unique set of 8 medium-band and 6+4 narrow-band filters (e.g. SWIMS-18 survey)
- multi-object (max ∼ 40 objects) slit spectroscopy with R ∼ 1000
- integral-field spectroscopy with FoV of 18 × 14 arcsec^2

and
- on [[TAO 6.5m telescope>http://www.ioa.s.u-tokyo.ac.jp/TAO/en/]], large amount of observing time with excellent atmospheric window is available.


|&ref(./material/_1090603s.jpg,,40%);|&ref(./material/swims_optical_components.png,,25%);|
|SWIMS|Component Assembly|f


** Instrument Papers [#q8f44dbc]

*** Overview [#m36b65e3]
- Konishi, M., et al. ''The University of Tokyo Atacama Observatory 6.5m telescope: On-sky performance of the near-infrared instrument SWIMS on the Subaru telescope'', [[Proceedings of the SPIE 11447, 114475H (2020)>https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11447/114475H/The-University-of-Tokyo-Atacama-Observatory-65m-telescope--On/10.1117/12.2560422.full]], &ref(./material/114475H.pdf);
- Konishi, M., et al., ''Development status of the simultaneous two-color near-infrared multi-object spectrograph SWIMS for the TAO 6.5m telescope'', [[Proceedings of the SPIE 10702, 1070226 (2018)>https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10702/2310060/Development-status-of-the-simultaneous-two-color-near-infrared-multi/10.1117/12.2310060.full]]
- Motohara, K., et al., ''NIR camera and spectrograph SWIMS for TAO 6.5m telescope: overview and development status'', [[Proceedings of the SPIE 9908, 99083U (2016)>https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9908/1/NIR-camera-and-spectrograph-SWIMS-for-TAO-65m-telescope/10.1117/12.2231386.full]]
- Motohara, K., et al., ''Development of a simultaneous two-color near-infrared multi-object spectrograph SWIMS for the TAO 6.5-m telescope'', [[Proceedings of the SPIE 9147, 91476K (2014)>http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1888307]]

*** Detector Control [#i1a4cf91]
- Terao, Y., et al., ''NIR camera and spectrograph SWIMS for TAO 6.5m telescope: array control system and its performance'', [[Proceedings of the SPIE 9915, 99151W (2016)>https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9915/99151W/NIR-camera-and-spectrograph-SWIMS-for-TAO-65m-telescope/10.1117/12.2232014.full]]
-  Todo, S., et al., ''Optimization and performance of H2RG detectors and SIDECAR ASICs for SWIMS'', [[Proceedings of the SPIE 9154, 91541L (2014)>http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1891389]]

*** Multi-Object Spectroscopy Unit (MOSU) [#h36eedf5]
- Takahashi, H., et al., ''Development of multi-object spectroscopy unit for simultaneous-color wide-field infrared multi-object spectrograph'', [[Proceedings of the SPIE 9147, 91476N (2014)>http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1888310]]

*** Integral Field Spectroscopy Unit (IFU) [#ffd08990]
- Kushibiki, K., et al. ''Fabrication of mirror arrays with an ultra-precision cutting technique for a near-infrared integral field unit SWIMS-IFU'', [[Proceedings of the SPIE 11451, 114512Y (2020)>https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11451/2560431/Fabrication-of-mirror-arrays-with-an-ultra-precision-cutting-technique/10.1117/12.2560431.full?SSO=1]], &ref(./material/114512Y.pdf);
- Kono, Y., et al. ''Design of an integral field unit for SWIMS and its milling process fabrication with an ultra-high precision machine tool'', [[Proceedings of the SPIE 10706, 107063F (2018)>https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10706/107063F/Design-of-an-integral-field-unit-for-SWIMS-and-its/10.1117/12.2312351.full]]
- Kitagawa, Y,. et al., ''Fabrication of a wide-field NIR integral field unit for SWIMS using ultra-precision cutting'', [[Proceedings of the SPIE 9912, 991225 (2016)>http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2538372]]
//- Kitagawa, Y., et al., ''Concept and optical design of the near-infrared integral field unit for SWIMS'', [[Proceedings of the SPIE 9151, 91514P (2014)>http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1890968&resultClick=1]]


** Field of Views [#q1d7a80a]
Field of view (FoV) of the telescope is covered with multiple HAWAII-2RG arrays (λ_{cut}=2.5 μm, ∼ 0.2-mm or ∼ 10-pixel gap between arrays).
||TAO|Subaru|h
|''Imag. FoV''|φ9.6' (∼ 8.6' × 8.6')|6.6' × 3.3'|
|''Spec. FoV''|3.7' × 8.6'|2.8' × 3.3'|
|''# of arrays per arm''|4&br;(4096 × 4096 pixles)|2&br;(4096 × 2048 pixels)|
|''Pixel scale (arcsec/pix)''|0.126|0.095|
|''Array configuration''|&ref(./material/fov_blue_tao.png,,37%);&br;&ref(./material/fov_red_tao.png,,37%);|&ref(./material/fov_blue_subaru.png,,37%);&br;&ref(./material/fov_red_subaru.png,,37%);|
'''Light-shaded''' regions show the FoV for the imaging mode while '''dark-shaded''' regions for the spectroscopy mode (for full range of spectra).

'''Black dots''' represent positions of source in the imaging mode which are also equivalent to the spectral positions of undeviated wavelength (λ ∼ 1.027 μm for '''blue''', ∼ 1.734 μm for '''red''').

Each stripe indicates the full range of the spectrum obtained (from shorter on the left to longer wavelength on the right). Note that any optical aberrations are '''not''' considered which would make the spectrum slightly broaden.


** Available filters/grisms [#a9a40b8c]

||Blue (0.9-1.4 μm)|Red (1.4-2.5 μm)|h
|''Broad-band''|'''Y''' (λc=1.027, Δλ=0.096 : &ref(swims-y.jpg,noimg,plot);), '''J''' (1.251, 0.167 : &ref(swims-j.jpg,noimg,plot);)|'''H''' (1.644, 0.291 : &ref(swims-h.jpg,noimg,plot);), '''Ks''' (2.139, 0.313 : &ref(swims-ks.jpg,noimg,plot);)|
|''Medium-band''|'''J1''' (1.174, 0.118 : &ref(swims-j1.jpg,noimg,plot);), '''J2''' (1.294, 0.123 : &ref(swims-j2.jpg,noimg,plot);)|'''H1''' (1.502, 0.121 : &ref(swims-h1.jpg,noimg,plot);), '''H2''' (1.617, 0.116 : &ref(swims-h2.jpg,noimg,plot);), '''H3''' (1.735, 0.117 : &ref(swims-h3.jpg,noimg,plot);), '''K1''' (2.023, 0.138 : &ref(swims-k1.jpg,noimg,plot);), '''K2''' (2.170, 0.140 : &ref(swims-k2.jpg,noimg,plot);), '''K3''' (2.314, 0.128 : &ref(swims-k3.jpg,noimg,plot);)|
|''Narrow-band''|'''NB1244'''# (1.244, 0.015 : &ref(swims-nb1244.jpg,noimg,plot);), '''NB1261'''# (1.261, 0.016 : &ref(swims-nb1261.jpg,noimg,plot);), '''Paβ''' (1.294, 0.038 : &ref(swims-nb1292.jpg,noimg,plot);), '''Paβ-off''' (1.329, 0.033 : &ref(swims-nb1326.jpg,noimg,plot);)|'''NB1630'''# (1.630, 0.017 : &ref(swims-nb1630.jpg,noimg,plot);), '''NB1653'''# (1.652, 0.016 : &ref(swims-nb1653.jpg,noimg,plot);), '''Paα''' (1.876, 0.022 : &ref(swims-nb1875.jpg,noimg,plot);), '''Paα-off''' (1.948, 0.036 : &ref(swims-nb1945.jpg,noimg,plot);), '''NB2137'''# (2.133, 0.021 : &ref(swims-nb2137.jpg,noimg,plot);), '''NB2167'''# (2.164, 0.022 : &ref(swims-nb2167.jpg,noimg,plot);)|
|''Grism''|'''zJ''' (2.40 Å/pix, R ∼ 700-1200 w/ 0.5" slit)|'''HKs''' (4.57 Å/pix, R ∼ 600-1000 w/ 0.5" slit)|

Filters followed by "#" are those for SWIMS-18 survey.
//We will kindly consider to use them for any other 
Requests for use for any other purpose will be also welcomed. 
~

|&ref(./material/filter_transmission.png,,50%);|
|Transmission curves|f

ASCII data for each filter transmittance : &ref(swims-filter-data.zip);

** Integral Field Spectroscopy Unit [#y5bfdb7d]
A compact & lightweight image-slicer IFU will be installed into the MOSU cryogenic storage.

Note that the following parameters may be subject to be changed.

||TAO|Subaru|h
|''λ (μm)''|>|0.9-1.4 ('''blue''') & 1.4-2.5 ('''red''')|
|''R (=λ/Δλ)''|>|900-1400 ('''blue'''), 700-1200 ('''red''')|
|''FoV''|18.4" × 13.7"|14.0" × 5.2"|
|''# of slice''|26|13|
|''Slice width''|0.5"|0.4"|


** Multi-object Spectroscopy Unit [#gdb6be15]
The cryogenic storage called the carousel have 23 slots for night observations.
Of them, several kinds of engineering-use masks and long-slit masks (one slot each), and one IFU module (occupying two slots) will be exclusively assigned.
Other (∼ 15) slots can be used for users' MOS masks.

The time required to exchange from one mask to another is about 2.5 minutes (and additional 5 seconds/slot to rotate the carousel).
The time for target acquisition will be measured on the telescope during engineering nights.


** Detector Performance [#k38efd61]
We utilize an ASIC, called SIDECAR, and its interface board, JADE-2, which control all of readout functions, to efficiently operate Teledyne HAWAII-2RG 2048 × 2048 HgCdTe infrared array.

Under cryogenic condition (∼ 77K), the detector performance has been assessed, as listed below.

|''Minimum Exposure Time''|1.48 sec|
|''Dark Current''|< 0.05 e-/sec/pix|
|''Readout Noise''|∼ 20--25 e- (CDS)&br;∼ 3--5 e- (32 Fowler)|

Integrated performance (e.g., simulateneous control of multiple arrays, influences of other peripherals on readout noise, etc.) is currently being investigated.


** Sensitivity [#g1bff609]
Total throughput including the telescope is estimated to be ∼ 0.4 for imaging and ∼ 0.3 for spectroscopy.

Expected sensitivities (AB mag) on the Subaru telescope are calculated with assumptions of seeing size=0.5 arcsec (photometry aperture radius=0.5 arcsec for point source or spatial extent=5.0 arcsec for extended source), exposure time=1 hr, and S/N=5.

Sensitivities on the TAO 6.5-m telescope are supposed to be ∼ 0.3 mag shallower due to smaller light-collecting area.

Note that these values may change according to the background conditions of OH airglow and thermal emission.

- Imaging
|LEFT:BGCOLOR(#d0d8e0):|||c
|''Point source'' [mag]|'''Y'''=25.2, '''J'''=24.9, '''H'''=24.2, '''Ks'''=24.4 |'''J1-2'''~25.0, '''H1-3'''~23.7, '''K1-3'''~24.0|
|''Extended source'' [mag/arcsec^2]|TBW|TBW|
//|''Extended source'' [mag/arcsec^2]|'''Y'''=27.6, '''J'''=27.2, '''H'''=26.9, '''Ks'''=26.9|

- Spectroscopy (slit width=0.5" assumed, no binning applied along wavelength direction)
|''Point source (mag)''|'''J'''=21.1, '''H'''=20.7, '''Ks'''=20.9|
|''Extended source (mag/arcsec2)''|TBW|
//|''Extended source (mag/arcsec2)''|'''J'''=21.1, '''H'''=20.4, '''Ks'''=20.3|


** Current Status [#z1122656]
Coming soon.


** Development Timeline [#w2017765]
Coming soon.


**LogSheets [#icbc05f7]
-A4 : &ref(swimslognote_20180606.xls);
-Letter : &ref(swimslognote_20201002.xls);


トップ   編集 差分 履歴 添付 複製 名前変更 リロード   新規 一覧 検索 最終更新   ヘルプ   最終更新のRSS