G. E. Gull

PHARO: A Near‐Infrared Camera for the Palomar Adaptive Optics System

We describe Cornells near-infrared camera system PHARO (Palomar High Angular Resolution Observer) built for use with the JPL Palomar Adaptive Optics System on the 5 m Hale telescope. PHARO uses a HgCdTe HAWAII detector for observations between 1 and 2.5 mm wavelength. An all-reflecting 1024 # 1024

The infrared spectrograph on the Spitzer Space Telescope

The Infrared Spectrograph (IRS) is one of three science instruments on the Spitzer Space Telescope. The IRS comprises four separate spectrograph modules covering the wavelength range from 5.3 to 38 μm with spectral resolutions, R~90 and 650, and it was optimized to take full advantage of the very low background in the space environment. The IRS is performing at or better than the pre-launch predictions. An autonomous target acquisition capability enables the IRS to locate the mid-infrared centroid of a source, providing the information so that the spacecraft can accurately offset that centroid to a selected slit. This feature is particularly useful when taking spectra of sources with poorly known coordinates. An automated data reduction pipeline has been developed at the Spitzer Science Center.

FIRST SCIENCE OBSERVATIONS WITH SOFIA/FORCAST: THE FORCAST MID-INFRARED CAMERA

The Stratospheric Observatory For Infrared Astronomy (SOFIA) completed its first light flight in May of 2010 using the facility mid-infrared instrument FORCAST. Since then, FORCAST has successfully completed 13 science flights on SOFIA. In this Letter, we describe the design, operation, and performance of FORCAST as it relates to the initial three Short Science flights. FORCAST was able to achieve near-diffraction-limited images for λ > 30 μm allowing unique science results from the start with SOFIA. We also describe ongoing and future modifications that will improve overall capabilities and performance of FORCAST.

The performance of TripleSpec at Palomar

We report the performance of Triplespec from commissioning observations on the 200-inch Hale Telescope at Palomar Observatory. Triplespec is one of a set of three near-infrared, cross-dispersed spectrographs covering wavelengths from 1 - 2.4 microns simultaneously at a resolution of ~2700. At Palomar, Triplespec uses a 1×30 arcsecond slit. Triplespec will be used for a variety of scientific observations, including moderate to high redshift galaxies, star formation, and low mass stars and brown dwarfs. When used in conjunction with an externally dispersed interferometer, Triplespec will also detect and characterize extrasolar planets.

Detection of the 157 micron (1910 GHz) (C II) emission line from the interstellar gas complexes NGC 2024 and M42

We present the first detection of the (C II) fine-structure emission line at a wavelength of 157 ..mu..m. The (C II) line strengths are 7.1 x 10/sup -16/ and 1.0 x 10/sup -15/W cm/sup -2/, respectively, in NGC 2024 and M42. The line-to-continuum ratio is higher in NGC 2024 where the continuum is 7.0 x 10/sup -16/ W cm/sup -2/ ..mu..m/sup -1/, in contrast to M42 where it assumes a value of 2.6 x 10/sup -15/W cm/sup -2/ ..mu..m/sup -1/. The respective luminosities in the line are approx.50 and 80 L/sub sun/. The observations were obtained with a stressed Ge:Ga photoconductor.

Resolving the Buried Starburst in Arp 299

We present new 37.7 ?m far-infrared imaging of the infrared luminous (LIR ~ 5.16 ? 1011 L?) interacting galaxy Arp 299 (= IC 694 + NGC 3690). We show that the 38 ?m flux, like the 60 and 100 ?m emission, traces the luminosity of star forming galaxies but at considerably higher spatial resolution. Our data establish that the major star formation activity of the galaxy originates from a point source in its eastern component, IC 694, which is inconspicuous in the optical, becoming visible only at the near- and mid-infrared. We find that IC 694 is 2 times more luminous than NGC 3690, contributing to more than 46% of the total energy output of the system at this wavelength. The spectral energy distribution of the different components of the system clearly shows that IC 694 has 6 times the infrared luminosity of M82, and it is the primary source responsible for the bolometric luminosity of Arp 299.

SpectroCam-10: a 10-μm spectrograph/camera for the Hale Telescope

SpectroCam-10 is a 10 micrometers spectrograph and camera built at Cornell University as a facility instrument for the 200 inch Hale telescope. The instrument is optimized for operation from (lambda) equals 8 to 13 micrometers in three modes: a medium-resolution spectrography (R equals (lambda) /(Delta) (lambda) approximately equals 2000), a low-resolution spectrography (R approximately equals 100), and a camera with diffraction limited (0.5 arcsec) spatial resolution. An optical flat and two reflection gratings mounted on a cryogenic rotating mechanism allow rapid switching between modes. The detector is a Rockwell 128 X 128 Si:As Back Illuminated Blocked Impurity Band array. We discuss the design and operation of the instrument, and present some scientific results from our early observing runs at Palomar.

The Infrared spectrograph on the Spitzer Space Telescope

The Infrared Spectrograph (IRS) is one of three science instruments on the Spitzer Space Telescope .T he IRS comprises four separate spectrograph modules covering the wavelength range from 5.3 to 38 � m with spectral resolutions, R ¼ k=� k � 90 and 600, and it was optimized to take full advantage of the very low background in the space environment. The IRS is performing at or better than the prelaunch predictions. An autonomous target acquisition capability enables the IRS to locate the mid-infrared centroid of a source, providing the information so that the spacecraft can accurately offset that centroid to a selected slit. This feature is particularly useful when taking spectra of sources with poorly known coordinates. An automated data-reduction pipeline has been developed at the Spitzer Science Center. Subject headingg infrared: general — instrumentation: spectrographs — space vehicles: instruments

Detection of the O III 88.16-micron forbidden line in M17

This paper reports the detection of the fine-structure forbidden line of O III at 88.16 microns in emission from M 17 (the Omega Nebula), which is an optically bright galactic H II region and a strong thermal radio source. The observations were made using an airborne 30-cm telescope and a liquid helium-cooled grating spectrometer with Ge:Ga photoconductive detectors. The line intensity is found to be 2.2 (+1.0, -0.7) by 10 to the -15th power W/sq cm. The results are compared with those of a search for the present line in M 42 as well as with theoretical predictions of the line intensity.

The electron density in M82 from the S III mid-infrared line ratio

Strong detections have been made of both the 18.7 microns and 33.4 microns lines of S III in the irregular galaxy M82. This represents the first detection of the 33.4 microns line in an extragalactic object. These measurements sample the ionized gas component which dominates the observed infrared forbidden line and infrared hydrogen recombination line emission. From the ratio of the line fluxes an electron density of 120 (+ 280, - 120) per cu cm is deduced. This result is in agreement with previous estimates of the density derived from high-frequency radio continuum measurements and an assumed emitting volume. They impose further constraints on possible starburst models.