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Fazio, G.

Publications and source records attributed to Fazio, G..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

First Solar System Results of the Spitzer Space Telescope

The Spitzer Space Telescope, formerly known as SIRTF, is now operational and delivers unprecedented sensitivity for the observation of Solar System targets. Spitzer's capabilities and first general results were presented at the January 2004 AAS meeting. In this poster, we focus on Spitzer's performance for moving targets, and the first Solar System results. Spitzer has three instruments, IRAC, IRS, and MIPS. IRAC (InfraRed Array Camera) provides simultaneous images at wavelengths of 3.6, 4.5, 5.8, and 8.0 microns. IRS (InfraRed Spectrograph) has 4 modules providing low-resolution (R=60-120) spectra from 5.3 to 40 microns, high-resolution (R=600) spectra from 10 to 37 m, and an autonomous target acquisition system (PeakUp) which includes small-field imaging at 15 m. MIPS (Multiband Imaging Photometer for SIRTF) does imaging photometry at 24, 70, and 160 m and low-resolution (R=15-25) spectroscopy (SED) between 55 and 96 microns. Guaranteed Time Observer (GTO) programs include the moons of the outer Solar System, Pluto, Centaurs, Kuiper Belt Objects, and comets

VanCleve, J.↗
NASA NTRS2004

Star Formation as Seen by the Infrared Array Camera on Spitzer

The Infrared Array Camera (IRAC) onboard Spitzer has imaged regions of star formation (SF) in its four IR bands with spatial resolutions of approximately 2"/pixel. IRAC is sensitive enough to detect very faint, embedded young stars at levels of tens of Jy, and IRAC photometry can categorize their stages of development: from young protostars with infalling envelopes (Class 0/1) to stars whose infrared excesses derive from accreting circumstellar disks (Class 11) to evolved stars dominated by photospheric emission. The IRAC images also clearly reveal and help diagnose associated regions of shocked and/or PDR emission in the clouds; we find existing models provide a good start at explaining the continuum of the SF regions IRAC observes.

Smith, Howard A.↗
NASA NTRS1992

Galactic structure from the Spacelab infrared telescope. I - 2.4 micron map

The Infrared Telescope, flown aboard the Space Shuttle as part of the Spacelab-2 mission, scanned a large fraction of the sky at 2.4 microns with a resolution of approximately 1 deg. A calibrated map of the Galactic plane in the region -20-120 deg l and -30-30 deg b. The photometry is accurate to a surface brightness of mu K = 20.0 mag/arcsec. Aside from uncertainties in the magnitude zero-point, the data agree quite well with previous maps derived from balloon experiments, except that some systematic differences at high Galactic longitudes are evident. These data will permit more extensive modeling of the 2.4-micron emissivity in the Milky Way than has been possible previously.

Kent, S. M.↗
NASA NTRS1991

Galactic structure from the Spacelab infrared telescope. II - Luminosity models of the Milky Way

A 2.4-micron map of the northern Galactic plan is used to determine the 3D luminosity distribution of the Milky Way. The radial surface brightness profile of the disk is found to have an exponential scale length of 3.0 kpc. In the solar neighborhood, the scale height is about 247 pc, which is in agreement with star counts perpendicular to the Galactic plane. The scale height is not constant with the radius but decreases to about 165 pc. To the first order, the bulge can be represented by an oblate spheroid with an axis ratio of 0.61. The 2.2-micron/12-micron flux ratio for the bulge is typical of other dust-free spheroidal systems. Luminosity fluctuations along the Galactic plane are found to be caused chiefly by variations in the line-of-sight extinction.

Kent, S. M.↗
NASA NTRS1989

Space Infrared Telescope Facility (SIRTF) science instruments

Concepts of scientific instruments designed to perform infrared astronomical tasks such as imaging, photometry, and spectroscopy are discussed as part of the Space Infrared Telescope Facility (SIRTF) project under definition study at NASA/Ames Research Center. The instruments are: the multiband imaging photometer, the infrared array camera, and the infrared spectograph. SIRTF, a cryogenically cooled infrared telescope in the 1-meter range and wavelengths as short as 2.5 microns carrying multiple instruments with high sensitivity and low background performance, provides the capability to carry out basic astronomical investigations such as deep search for very distant protogalaxies, quasi-stellar objects, and missing mass; infrared emission from galaxies; star formation and the interstellar medium; and the composition and structure of the atmospheres of the outer planets in the solar sytem.

Ramos, R.↗
NASA NTRS1986

Far-infrared and radio observations of DR 6, DR 7, and DR 22

Far-infrared maps are presented for three young H II regions in the Cygnus X region. DR 6 and 7 were mapped in the wavelength band from 40 to 250 microns at 1 arcmin resolution, while DR 22 was mapped in the same band and also at 100-250 microns, providing dust temperature and optical depth information. New VLA maps of these sources are also presented. It is concluded that DR 6 and 7 are powered by clusters of late O or early B type stars, with ages 100,000 yr or less, while DR 22 appears to be produced by a single O6 ZAMS star. Existing (C-12)O maps suggest that the formation of these objects occurred near the edges of molecular clouds.

Odenwald, S.↗
NASA NTRS1984

Astronomical applications of the new Goddard Si:Bi 16 x 16 array camera system

An improved 4-18 micron array camera system has been developed at NASA Goddard Space Flight Center for astronomical protometry, using 16 x 16 Si:Bi (bismuth dope silicon) accumulation mode charge injection device (AMCID) with 256 active pixels. An astronomical observing program using this device has been carried out. The 16 x 16 device had sufficiently good sensitivity, uniformity and noise characteristics to be used for successful observations at the Steward Observatory Mt. Lemmon 60 and 61-inch telescopes in May 1983, and at the NASA Infrared Telescope Facility (IRTF) at Mauna Kea in August 1983. Initial results indicate that this detector has sensitivity and noise characteristics comparable to other devices from the same generation of Aerojet arrays.

Lamb, G.↗
NASA NTRS1981

Definition phase effort of the Spacelab-2 Infrared Telescope Experiment (IRT)

Activities associated with a proposal for the reflight of the small helium cooled infrared telescope scheduled to make its maiden voyage on Spacelab-2 are reported. The experiments requirements document was revised and updated and an investigation development plan was prepared for the refurbishment and reflight of the telescope. The summary of a briefing held to discuss Spacelab interfaces for the proposal is included.

Fazio, G.↗