Application of HAWAII-2 FPAs for an astronomical wide-field imager and multi-object spectrograph

Application of HAWAI I-2 FPAs for an Astronomical WideField Imager and Multi-Ob ject Sp ectrographYuka Katsunoa,Takashi Ichikaw, Daigo Matsumoto, Ken'ichiro Asai,Ryuji Suzukia, Chihiro Tokoku, Kenshi Yanagisawaband Tetsuo NishimuracaTohoku University, Sendai, Miyagi, Japan 980-8578bOkayama Astronomical Observatory,National Astronomical Observatory of Japan, Japan 719-0232cSubaru Telescope, National Astronomical Observatory of Japan, Hilo, Hawaii 96720ABSTRACTWe use the HAAII-2 (20482048 HgCdTe) FPAs in MOIRCS (Multi-Ob ject Infra-Red Camera and Sp ec-trograph) for the astronomical use on the Subaru telescop e. MOIRCS, which is currently b eing constructedbyTohoku University and the National Astronomical Observatory of Japan, is one of the second generationinstruments for Subaru.It will provide the wide- eld imaging mo de (47 arcmin2) and the multi-ob jectspectroscopy mo de with the wavelength range of 0.8 to 2.5m.To achieve the large eld of view with the high spatial resolution, we use two large-format near-infraredarrays, HAWAII-2. Wehave developed an infrared array control system sp ecially designed for exible controland ecient data acquisition of the HAWAII-2 arrays.The array control system, TUFPAC, consists of apersonal computer op erated by LINUX OS and commercially available DSP b oards. By using TUFPACandthe cryostat for array tests, we have made tests of the HAWAII-2 array. In this pap er, we rep ort on our arraycontrol system and the results of various p erformance tests for the HAWAII-2 array.Keywords:Infrared Astronomy,HAWAII-2, Infrared FPA, Performance, Data Acquisition System, Wide- eldCamera, Multi-Ob ject Sp ectrograph1. INTRODUCTIONWith the recentadvent of large telescop es and large format FPAs, astronomers are exploring deep er and widerinto the universe. The sup erb image quality of the 8.2m Subaru telescop e of National Astronomical Observatoryof Japan and excellent atmospheric condition at Mauna Kea in Hawaii enable us to observe ner structures ofmore distant ob jects. To enjoy the advantages of the Subaru telescop e and the development of large formatarrays in near-infrared, we are constructing a new facility instrument, Multi-Ob ject InfraRed Camera andSpectrograph (MOIRCS) (Fig. 1 left). One of the notable features of MOIRCS is the large eld of view of 47arcmin2with the high spatial resolution of 0.12 arcsec pixel1pro jected on the sky in the wide wavelengthrange of 0.8 to 2.5m. Since the widest eld of view of the present Subaru instruments in near-infrared is 22arcmin2, MOIRCS expands the wide- eld imaging capabilities of Subaru. Another feature is the capability ofmulti-ob ject sp ectroscopy at the near-infrared wavelengths, esp ecially inK-band (e =2:2m), with multi-slitmasks co oled to 150 K (Tokoku et al. 2002, in preparation). We have developed the slit-mask exchanger, whichcan select one of 24 slit-masks housed in a vacuum carrousel at cryo-temp erature and places the mask at theproper p osition at the Caseggrain fo cus.We fo cus our scienti c targets of MOIRCS on the evolution of galaxies and the large scale structure in thehigh redshift universe. MOIRCS has two observation mo des of the wide- eld imaging and the multi-ob jectspectroscopy. The wide- eld imaging in near-infrared will reveal the hierarchical evolution of galaxy clusteringFurther principal author information:E-mail: katsuno@astr.tohoku.ac.jp, Telephone: +81-22-217-6500, Fax: +81-22-217-6513WWW: http://www.astr.tohoku.ac.jp/~tokoku/moircs/indexe.html