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Measurements of starlight polarized by aligned interstellar dust grains are used to probe the relation between the orientation of the ambient interstellar magnetic field (ISMF) and the ISMF traced by the ribbons of energetic neutral atoms discovered by the Interstellar Boundary Explorer spacecraft. We utilize polarization data, many acquired specifically for this study, to trace the configuration of the ISMF within 40 pc. A statistical analysis yields a best-fit ISMF orientation, B magpol, aligned with Galactic coordinates ℓ = 42°, b = 49°. Further analysis shows the ISMF is more orderly for “downfield” stars located over 90° from B magpol. The data subset of downfield stars yields an orientation for the nearby ISMF at ecliptic coordinates λ, β ≈ 219° ± 15°, 43° ± 9° (Galactic coordinates l, b ≈ 40°, 56°, ±17°). This best-fit ISMF orientation from polarization data is close to the field direction obtained from ribbon models. This agreement suggests that the ISMF shaping the heliosphere belongs to an extended ordered magnetic field. Extended filamentary structures are found throughout the sky. A previously discovered filament traversing the heliosphere nose region, “Filament A,” extends over 300° of the sky, and crosses the upwind direction of interstellar dust flowing into the heliosphere. Filament A overlaps the locations of the Voyager kilohertz emissions, three quasar intraday variables, cosmic microwave background (CMB) components, and the inflow direction of interstellar grains sampled by Ulysses and Galileo. These features are likely located in the upstream outer heliosheath where ISMF drapes over the heliosphere, suggesting Filament A coincides with a dusty magnetized plasma. A filament 55° long is aligned with a possible shock interface between local interstellar clouds. A dark spot in the CMB is seen within 5° of the filament and within 10° of the downfield ISMF direction. Two large magnetic arcs are centered on the directions of the heliotail. The overlap between CMB components and the aligned dust grains forming Filament A indicates the configuration of dust entrained in the ISMF interacting with the heliosphere provides a measurable foreground to the CMB.

We describe the 1- to 2-GHz radio telescope built by undergraduates with faculty guidance at the University of California at Berkeley. The telescope is optimized to observe the 1420-MHz (21-cm) emission line of neutral atomic hydrogen and is used in the recently created advanced undergraduate radio astronomy laboratory course, as well as in part of a graduate course on astronomical observation. We discuss the design of the telescope and the structure of the course and also present astronomical observations made with the telescope.

Starlight linearly polarized by aligned interstellar dust grains provides the necessary data for tracing the structure of the very local interstellar magnetic field (ISMF). Two methods have been developed to recover the ISMF direction from polarized starlight, using data from an ongoing polarization survey. Both methods rely on the probability distribution function for polarized light. Method 1 calculates the ISMF direction from polarization position angles regardless of the data accuracy, while Method 2 relies on high-probability data points. The ISMF direction Bibex recovered by Method 1 corresponds to the closest ISMF to the heliosphere, traced by the center of the IBEX Ribbon arc. Method 2 reveals a new direction for the more distant ISMF, B new, toward l=41.1° ± 4.1° and b= 25.8° ± 3.0°, which differs by 30.4° ± 5.6° from the IBEX ISMF direction. Polarizations of filament stars that are located within 25° of a pole of Bnew, where background polarizations would be minimal, show the highest statistical probabilities of tracing the filament ISMF. The IBEX ISMF direction orders the kinematics of interstellar clouds within 15 pc, and B new must therefore dominate beyond 15 pc. These new data are consistent with the location of the Sun in the rim of an expanding superbubble shell associated with the evolved Loop I superbubble.

Very sensitive, wideband CO J = 1-0 and HCO + J = 1-0 line spectra axe obtained using the 12 m telescope at Kitt Peak for several young stellar objects: GL 490, HH7-11 (see also Lizano et al. 1987), S140, and MWC 1080. Very weak and "extremely high-velocity" (EHV) CO wings are found in all objects. Velocity widths of the EHV wings are substantially larger than those of the associated classical high-velocity outflows (e.g., Bally and Lada 1983). Broad wings are also found in HCO + spectra, but they are not as broad as CO wings in most cases. The observed parameters of the spectra are summarized in Table 1 and the spectra axe shown in Figure 1. The maximum velocity width AVm~x in Table 1 is measured at 2 mK level. All CO spectra are flat at least at one extreme velocity, i.e., either at maximum blueshifted velocity or at maximum redshifted velocity, and increase slowly at intermediate velocities before they finally increase steeply at low velocities. The line profiles suggest that some of the EHV CO emission is emitted from the neutral stellar wind (Lizano et al. 1987) which has not experienced much interaction with the surrounding medium, and some from both a decelerating neutral stellar wind and an ambient material entrained by a stellar wind. This interpretation is consistent with HCO + observations which show enhancement of HCO + emission compared to CO emission at high velocities.

Radio observations of gas in the Milky Way and Local Group are vital for understanding how galaxies function as systems. The unique sensitivity of Arecibo's 305m dish, coupled with the 7-beam Arecibo L-Band Feed Array (ALFA), provides an unparalleled tool for investigating the full range of interstellar phenomena traced by the HI 21cm line. The GALFA (Galactic ALFA) HI Survey is mapping the entire Arecibo sky over a velocity range of -700 to +700 km/s with 0.2 km/s velocity channels and an angular resolution of 3.4 arcminutes. We present highlights from the TOGS (Turn on GALFA Survey) portion of GALFA-HI, which is covering thousands of square degrees in commensal drift scan observations with the ALFALFA and AGES extragalactic ALFA surveys. This work is supported in part by the National Astronomy and Ionosphere Center, operated by Cornell University under cooperative agreement with the National Science Foundation., 3 pages, including 2 figure pages; figure image quality significantly reduced; for full resolution version, please see http://www.naic.edu/~gibson/cv/ao08_writeup.pdf ; to be published in AIP conference proceedings for ``The Evolution of Galaxies through the Neutral Hydrogen Window'', eds. R. Minchin & E. Momjian

We review observations of the physical properties of the diffuse ISM HI components, namely the Cold and Warm Neutral Media (CNM and WNM). There is somewhat more WNM than CNM, and at least half of the WNM is not thermally stable. The CNM has typical turbulent Mach number 3. Magnetic energy densities in the CNM considerably exceed thermal energy densities, and are comparable to turbulent energy densities. Magnetic fields in the CNM are comparable to those in the Warm Ionized Medium and the volume-average field strength from synchrotron emissivity.

We report the detection of molecular clouds associated with three giant galactic H I shells.

We review the distribution of diffuse gas, both neutral and ionized, in the Galaxy and the galactic halo.

On presente une compilation des donnees d'observation concernant les relations entre l'intensite du champ magnetique interstellaire et la densite du gaz

On donne les estimations du rougissement basees sur la methode de Burstein et Heiles (densite de colonne HI, comptages de galaxies) pour environ 13000 galaxies du Catalogue General d'Uppsala, compile par Nilson et pour pres de 4350 galaxies du Second Catalogue de Reference, compile par de Vaucouleurs, de Vaucouleurs et Corwin, 1976, avec |b|≥9,7°

H I, when viewed in narrow velocity ranges, is concentrated in arcs with typical diameters of tens of degrees. In some cases the diameters change with velocity in the manner expected for expanding shells. The clearest example appears to be consistent with a model involving an old supernova explosion. Much of the interstellar volume is probably contained with H I shells. (AIP)

HI column densities for the LSR velocity ranges -50 to +50kms-1 and -100 to + 100 km S -1 are given in tabular and photographic forms for ~ .,. - 30� and I b I ~ 10�

On a detecte un dedoublement Zeeman des raies d'absorption OH en direction de Ori B, W22 et Cas A. On en deduit les caracteristiques des champs magnetiques

We consider the pervasiveness of the ''not strongly absorbing'' (NSA) H I gas, which is the intercloud medium in steady state theories of the interstellar medium. We study the question by analyzing wide emission components in nearby gas, and the absence of absorption components in distant gas. We conclude that the NSA material is deficient in the immediately local solar vicinity. In nearby regions it contains 38% of the interstellar H I; it is generally pervasive and often has internal motions which greatly increase its velocity dispersion above the 5 km s/sup -1/ minimum value. It contains large holes, perhaps ranging up to 400 pc diameter, which probably occupy 10--20% of the volume. In distant regions the NSA material seems to be pervasive outside 8 kpc galactic radius. For galactic radii between 8 and 10 kpc its thickness agrees with previous determinations of 370 pc for nearby regions. Outside 10 kpc the thickness increases dramatically. Inside 8 kpc there are no data.

Highly accurate H/sub 2/CO 6-cm line profiles were observed in 14 positions located in dark dust clouds. Analyses of the relative strengths of the hyperfine components showed no anomalies. Therefore, excitation temperatures were derived for 10 positions which exhibited measurable saturation due to optical-depth effects. Nine of these positions have nearly the same excitation temperature, about 1.6M. The other position definitely has a higher excitation temperature, about 2.2 deg K; this position is located in a cloud whose kinetic temperature is 18 deg K, substantially hotter and also probably denser than the usual'' dark dust cloud. (auth)