Adaptive Optics Imaging at 1–5 Microns on Large Telescopes: The COMIC Camera for ADONIS

Abstract

A new 1-5 mm high-resolution camera dedicated to the ESO adaptive optics system ADONIS has been developed as a collaborative project of Observatoire de Paris-Meudon and Observatoire de Grenoble, under ESO contract. Since this camera has been designed to correctly sample the diffraction, two focal plate scales are available: 36 mas pixel Ϫ1 for the 1-2.5 mm range and 100 mas pixel Ϫ1 for the 3-5 mm range, yielding fields of view of and , respectively. Several broadband and narrowband filters are available 4Љ .5 # 4Љ .512Љ .8 # 12Љ .8 as well as two circular variable filters, allowing low spectral resolution ( -120) imagery between 1.2 and R ∼ 60 4.8 mm. This camera is equipped with a HgCdTe/CCD array detector built by the CEA-LETI-LIR 128 # 128 (Grenoble, France). Among its main characteristics, this detector offers a remarkably high storage capacity (more than 10 6 electrons) with a total system readout noise of ≈1000 electrons rms, making it particularly well suited for long integration time imagery in the 3-5 mm range of the near-infrared domain. The measured dark current is 2000 electrons s Ϫ1 pixel Ϫ1 at the regular operating temperature of 77 K, allowing long exposure times at short wavelengths ( mm), where the performances are readout-noise limited. At longer wavelengths ( mm), l ! 3 l 1 3 the performances are background-noise limited. We have estimated the ADONIS ϩ COMIC imaging performances using a method specially dedicated to high angular resolution cameras.

VLT 3–5 micron spectroscopy and imaging of NGC 1068: Does the AGN hide nuclear starburst activity?

“…The dust/molecular torus surrounding the AGN has been tentatively observed using adaptive-optic systems (Lacombe et al 1998) in the nearinfrared by Marco & Alloin (2000) and Rouan et al (1998). Both sets of results show disk-like structures extending eastwest (a few tens of parsecs) from the central peak of infrared emission.…”

Adaptive optics $\vec{L}$-band observations of the Galactic Center region

“…Using a Shack-Hartman wave-front sensor, it usually analyzes the light at visible wavelengths, but during this observing run, we used RASOIR, a prototype of the infrared wave-front sensor of NAOS, the future adaptive optics system of the VLT (see Appendix A). The science camera was COMIC, optimized for Land M -band observations (Lacombe et al 1998). The plate scale was 0.1 arcsec/pixel and the field of view 12.8 × 12.8 .…”

Circumstellar medium around close southern PMS binaries

“…1−2.5 µm observations were performed using the SHARP camera (Hofmann et al 1995) during two nights (1996, May 1 and 2). The new COMIC camera (Lacombe et al 1998) was used during the last night of the run (1996, May 5) and allowed observations in L and M bands. These were the first scientific observations performed with the COMIC instrument (Monin & Geoffray 1997).…”