Economic benefits from instream flow in a Colorado mountain stream

Submitted to Office of Water Research and Technology, U.S. Department of Interior.Bibliography: pages [131]-135.OWRT project no. A-035-COLO and OWRT project no. A-040-COLO

Absorption-Line Probes of Gas and Dust in Galactic Superwinds

We discuss moderate resolution spectra of the NaD absorption-line in a sample of 32 far-IR-bright starburst galaxies. In 18 cases, the line is produced primarily by interstellar gas, and in 12 of these it is blueshifted by over 100 km/s relative to the galaxy systemic velocity. The absorption-line profiles in these outflow sources span the range from near the galaxy systemic velocity to a maximum blueshift of 400 to 600 km/s. The outflows occur in galaxies systematically viewed more nearly face-on than the others. We therefore argue that the absorbing material consists of ambient interstellar gas accelerated along the minor axis of the galaxy by a hot starburst-driven superwind. The NaD lines are optically-thick, but indirect arguments imply total Hydrogen column densities of N_H = few X 10^{21} cm^{-2}. This implies that the superwind is expelling matter at a rate comparable to the star-formation rate. This outflowing material is very dusty: we find a strong correlation between the depth of the NaD profile and the line-of-sight reddening (E(B-V) = 0.3 to 1 over regions several-to-ten kpc in size). The estimated terminal velocities of superwinds inferred from these data and extant X-ray data are typically 400 to 800 km/s, are independent of the galaxy rotation speed, and are comparable to (substantially exceed) the escape velocities for $L_*$ (dwarf) galaxies. The resulting loss of metals can establish the mass-metallicity relation in spheroids, produce the observed metallicity in the ICM, and enrich a general IGM to 10$^{-1}$ solar metallicity. If the outflowing dust grains survive their journey into the IGM, their effect on observations of cosmologically-distant objects is significant.Comment: 65 pages, including 16 figures. ApJ, in pres

Estimates with an Effective Chiral Lagrangian for Heavy Mesons

On the basis of an effective lagrangian incorporating approximate chiral symmetry and heavy-quark spin and flavor symmetries, and by use of information on leptonic decays, we estimate the effective $D^\star D\pi$ coupling.Comment: UGVA-DPT 1992/07-779, BARI-TH/92-117 Revised version, September 1992, LaTeX (style article), 7 page

Formation of a Massive Black Hole at the Center of the Superbubble in M82

We performed 12CO(1-0), 13CO(1-0), and HCN(1-0) interferometric observations of the central region (about 450 pc in radius) of M82 with the Nobeyama Millimeter Array, and have successfully imaged a molecular superbubble and spurs. The center of the superbubble is clearly shifted from the nucleus by 140 pc. This position is close to that of the massive black hole (BH) of >460 Mo and the 2.2 micron secondary peak (a luminous supergiant dominated cluster), which strongly suggests that these objects may be related to the formation of the superbubble. Consideration of star formation in the cluster based on the infrared data indicates that (1) energy release from supernovae can account for the kinetic energy of the superbubble, (2) the total mass of stellar-mass BHs available for building-up the massive BH may be much higher than 460 Mo, and (3) it is possible to form the middle-mass BH of 100-1000 Mo within the timescale of the superbubble. We suggest that the massive BH was produced and is growing in the intense starburst region.Comment: 9 pages, 3 figures, to appear in ApJ Lette

Nuclear starburst-driven evolution of the central region in NGC 6764

We study the CO and the radiocontinuum emission in an active galaxy to analyze the interplay between the central activity and the molecular gas. We present new high-resolution observations of the CO(1-0) and CO(2-1) emission lines, and 3.5 cm and 20 cm radio continuum emission in the central region of the LINER/starburst galaxy NGC 6764. The galaxy has an outflow morphology in radio continuum, spatially coincident with the CO and H$\alpha$ emission, and centered slightly off the radio continuum peak at the LINER nucleus. The total molecular gas mass in the center is about 7x10^8 \msun, using a CO luminosity to total molecular gas conversion factor that is three times lower than the standard one. CO(1-0) emission is found near the boundaries of the radio continuum emission cone. The outflow has a projected expansion velocity of 25 km/s relative to the systemic velocity of NGC6764. About 4x 10^6 \msun of molecular gas is detected in the outflow. The approximate location (~1 kpc) of the dynamical inner Lindblad resonance has been derived from the rotation curve. The peak of the CO emission is slightly (< 200 pc) offset from the peak of the radio continuum. The molecular gas has most likely been ejected by the stellar winds from the recent starburst, but the CO line ratios show indication of an interaction with the AGN. The energy released by the nuclear starburst is sufficient to explain the observed outflow, even if the data cannot exclude the AGN from being the major energy source. Comparison of the outflow with hydrodynamical simulations suggests that the nuclear starburst is 3--7 Myr old and the bubble-like outflow is still confined and not freely expanding.Comment: Accepted for publication in A&

Family and school social capital, school burnout and academic achievement : a multilevel longitudinal analysis among Finnish pupils

Research on the associations between family and school social capital, school burnout and academic achievement in adolescence is scarce and the results are inconclusive. We examined if family and school social capital at the age of 13 predicts lower school burnout and better academic achievement when graduating at the age of 16. Using data from 4467 Finnish adolescents from 117 schools and 444 classes a three-level multilevel analysis was executed. School social capital, the positive and supportive relationships between students and teachers, predicted lower school burnout and better academic achievement among students. Classmates' family social capital had also significance for students' academic achievement. Our results suggest that building school social capital is an important aspect of school health and education policies and practices.Peer reviewe

GALEX Observations of the Ultraviolet Halos of NGC 253 and M82

We present Galaxy Evolution Explorer (GALEX) images of the prototypical edge-on starburst galaxies M82 and NGC253. Our initial analysis is restricted to the complex of ultraviolet (UV) filaments in the starburst-driven outflows in the galaxy halos. The UV luminosities in the halo are too high to be provided by shock-heated or photoionized gas except perhaps in the brightest filaments in M82, suggesting that most of the UV light is the stellar continuum of the starburst scattered into our line of sight by dust in the outflow. This interpretation agrees with previous results from optical imaging polarimetry in M82. The morphology of the UV filaments in both galaxies shows a high degree of spatial correlation with H-alpha and X-ray emission. This indicates that these outflows contain cold gas and dust, some of which may be vented into the intergalactic medium (IGM). UV light is seen in the ``H-alpha cap'' 11 kpc North of M82. If this cap is a result of the wind fluid running into a pre-existing gas cloud, the gas cloud contains dust and is not primordial in nature but was probably stripped from M82 or M81. If starburst winds efficiently expel dust into the IGM, this could have significant consequences for the observation of cosmologically distant objects.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issue. Links to the full set of papers will be available at http://www.galex.caltech.edu/PUBLICATIONS/ after November 22, 200

Molecular Gas and the Modest Star Formation Efficiency in the ``Antennae'' Galaxies: Arp~244=NGC 4038/39

(abridged) We report here a factor of 5.7 higher total CO flux in Arp~244 (the ``Antennae'' galaxies) than that previously accepted in the literature (thus a total molecular gas mass of 1.5x10$^{10}$ Msun), based on our fully sampled CO(1-0) observations at the NRAO 12m telescope. Our observations show that the molecular gas peaks predominately in the disk-disk overlap region between the nuclei, similar to the far-infrared (FIR) and mid-infrared (MIR) emission. The bulk of the molecular gas is forming into stars with a normal star formation efficiency (SFE) L_{IR}/M(H_2) \approx 4.2 Lsun/Msun, same as that of giant molecular clouds in the Galactic disk. Additional supportive evidence is the extremely low fraction of the dense molecular gas in Arp~244, revealed by our detections of the HCN(1-0) emission. We estimate the local SFE indicated by the ratio map of the radio continuum to CO(1-0) emission. Remarkably, the local SFE stays roughly same over the bulk of the molecular gas distribution. Only some localized regions show the highest radio-to-CO ratios that we have identified as the sites of the most intense starbursts with SFE >~ 20 Lsun/Msun. These starburst regions are confined exclusively in the dusty patches seen in the HST images near the CO and FIR peaks where presumably the violent starbursts are heavily obscured. Nevertheless, recent large-scale star formation is going on throughout the system, yet the measured level is more suggestive of a moderate starburst (SFE >~ 10 Lsun/Msun) or a weak to normal star formation (SFE ~ 4 Lsun/Msun). The overall starburst from the bulk of the molecular gas is yet to be initiated as most of the gas further condenses into kpc scale in the final coalescence.Comment: 31 pages including 3 postscript & 10 gif figures, final version to appear in ApJ, 2001 Feb. 10. A single .ps.gz file can be down-loaded from: http://spider.ipac.caltech.edu/staff/gao/Papers

Educating a syndrome? Seeking a balance between identifying a learning profile and delivering inclusive education

This article summarizes research related to pedagogical approaches to special education, and characteristics of teacher's attitudes and beliefs that supports effective inclusion practices. Additionally, the author summarizes factors that may both enable and disable children with DS's progress, and notes speech and language characteristics from research to date