Far infrared and submillimeter astronomy with the Gerald P. Kuiper airborne Observatory

As the first steps in building a submillimeter polarimeter, a rail system was built to help install the instrument at the focal plane, and a high-quality spectral filter was developed

A sensitive far infrared detection system

An infrared field optics system was designed which achieves the maximum flux concentration allowed by the Abbe sine inequality and provides efficient coupling to bolometer-type detectors

The determination of cloud masses and dust characteristics from submillimetre thermal emission

The principles by which the dust and masses and total masses of interstellar clouds and certain characteristics of interstellar dust grains can be derived from observations of far infrared and submillimeter thermal emission are reviewed. To the extent possible, the discussion will be independent of particular grain models

Observation of the Cosmic Ray Electron- Positron Ratio from 100 Mev to 3 Bev in 1964

Balloon flight data on cosmic ray electron- positron ratio from 100 MeV to 3 Be

Detection of submillimeter polarization in the Orion Nebula

Linear polarization of the submillimeter (270 micron) continuum radiation from two regions of Orion was observed: one centered on the Kleinmann-Low Nebula and one centered on the 400 micron peak 1.5' south of the nebula. The polarizations measured for these regions are P = (1.7 +/-0.4)% at phi = 23 deg +/-7 deg and P=(1.7 +/- 0.5)% at phi = 27 deg +/- 7 deg respectively. A 2(sigma) upper limit, P or = 1.6%, was found for the nebular W3(OH). The position angle at KL is orthogonal to that measured at 11 microns by Dyck and Beichman and at 11 and 20 microns by Knacke and Capps. The far-IR values for KL reported by Gull et. al. (approx 2%) and by Cudlip et al. (1 to 2% level) are consistent with the submillimeter results

High-spatial-resolution CN and CS observation of two regions of massive star formation

Molecular line CN, CS and mm continuum observations of two intermediate- to high-mass star-forming regions - IRAS20293+3952 and IRAS19410+2336 - obtained with the Plateau de Bure Interferometer at high spatial resolution reveal interesting characteristics of the gas and dust emission. In spite of the expectation that the CN and CS morphology might closely follow the dense gas traced by the dust continuum, both molecules avoid the most central cores. Comparing the relative line strengths of various CN hyperfine components, this appears not to be an opacity effect but to be due to chemical and physical effects. The CN data also indicate enhanced emission toward the different molecular outflows in the region. Regarding CS, avoiding the central cores can be due to high optical depth, but the data also show that the CS emission is nearly always associated with the outflows of the region. Therefore, neither CS nor CN appear well suited for dense gas and disk studies in these two sources, and we recommend the use of different molecules for future massive disk studies. An analysis of the 1 and 3mm continuum fluxes toward IRAS20293+3952 reveals that the dust opacity index beta is lower than the canonical value of 2. Tentatively, we identify a decreasing gradient of beta from the edge of the core to the core center. This could be due to increasing optical depth toward the core center and/or grain growth within the densest cores and potential central disks. We detect 3mm continuum emission toward the collimated outflow emanating from IRAS20293+3952. The spectral index of alpha ~ 0.8 in this region is consistent with standard models for collimated ionized winds.Comment: 5 pages, 2 tables, 9 figures, accepted for Ap

Far-Infrared Spectral Energy Distributions and Photometric Redshifts of Dusty Galaxies

We infer the large-scale source parameters of dusty galaxies from their observed spectral energy distributions (SEDs) using the analytic radiative transfer methodology presented in Chakrabarti & McKee (2005). For local ultra-luminous infrared galaxies (ULIRGs), we show that the millimeter to far-infrared (FIR) SEDs can be well fit using the standard dust opacity index of 2 when self-consistent radiative transfer solutions are employed, indicating that the cold dust in local ULIRGs can be described by a single grain model. We develop a method for determining photometric redshifts of ULIRGs and sub-mm galaxies from the millimeter-FIR SED; the resulting value of $1+z$ is typically accurate to about 10%. As such, it is comparable to the accuracy of near-IR photometric redshifts and provides a complementary means of deriving redshifts from far-IR data, such as that from the upcoming $\it{Herschel Space Observatory}$. Since our analytic radiative transfer solution is developed for homogeneous, spherically symmetric, centrally heated, dusty sources, it is relevant for infrared bright galaxies that are primarily powered by compact sources of luminosity that are embedded in a dusty envelope. We discuss how deviations from spherical symmetry may affect the applicability of our solution, and we contrast our self-consistent analytic solution with standard approximations to demonstrate the main differences.Comment: 37 pages, 14 Figures, 3 Tables, submitted to ApJ. submitted to Ap

Evaluating the Magnetic Field Strength in Molecular Clouds

We discuss an extension to the Chandrasekhar-Fermi method for the evaluation of the mean magnetic field strength in molecular clouds to cases where the spatial orientation of the field is known. We apply the results to M17, using previously published data.Comment: 10 pages, 1 figure, accepted for publication in the ApJ Letter

Extended dust emission and atomic hydrogen, a reservoir of diffuse H_2 in NGC 1068

We report on sensitive sub-mm imaging observations of the prototype Seyfert~2/starburst galaxy NGC 1068 at 850 $\mu$m and 450 $\mu$m using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). We find clear evidence of dust emission associated with the extended HI component which together with the very faint $^{12}$CO J=1--0 emission give a gas-to-dust ratio of $\rm M_{\rm gas}/M_{\rm dust} \sim 70-150$. This contrasts with the larger ratio $\rm M_{\rm gas}/M_{\rm dust}\sim 330$ estimated within a galactocentric radius of $r\leq 1.36$ kpc, where the gas is mostly molecular and starburst activity occurs. The large gas-to-dust ratio found for the starburst region is attributed to a systematic overestimate of the molecular gas mass in starburst environments when the luminosity of the $^{12}$CO J=1--0 line and a standard galactic conversion factor is used. On the other hand sub-mm imaging proves to be a more powerful tool than conventional CO imaging for revealing the properties of the diffuse $\rm H_2$ that coexists with HI. This molecular gas phase is characterized by low densities ($\rm n(H_2)<10^3$ cm$^{-3}$), very faint emission from sub-thermally excited CO, and contains more mass than HI, namely $\rm M(H_2)/M(HI)\sim 5$.Comment: Accepted for publication in the Astrophysical Journal Letter

Cold Dust in Kepler's Supernova Remnant

The timescales to replenish dust from the cool, dense winds of Asymptotic Giant Branch stars are believed to be greater than the timescales for dust destruction. In high redshift galaxies, this problem is further compounded as the stars take longer than the age of the Universe to evolve into the dust production stages. To explain these discrepancies, dust formation in supernovae (SNe) is required to be an important process but until very recently dust in supernova remnants has only been detected in very small quantities. We present the first submillimeter observations of cold dust in Kepler's supernova remnant (SNR) using SCUBA. A two component dust temperature model is required to fit the Spectral Energy Distribution (SED) with $T_{warm} \sim 102$K and $T_{cold} \sim 17$K. The total mass of dust implied for Kepler is $\sim 1M_{\odot}$ - 1000 times greater than previous estimates. Thus SNe, or their progenitors may be important dust formation sites.Comment: 12 pages, 2 figures, accepted to ApJL, corrected proof