Concert recording 2015-04-24

[Track 01]. Adagio et rondo / Etienne Ozi ; arranged by John C. Worley -- [Track 02]. With tranquility from Sonata op. 19 / Paul Creston -- [Track 03]. Five lyric pieces. Allegro scherzando ; [Track 04]. Erotic ; [Track 05]. French serenade ; [Track 06]. Notturno ; [Track 07]. Scherzo-impromptu / Edvard Grieg ; arranged by Lee Patrick -- [Track 08]. Partita. Prelude - allemande ; [Track 09]. Canzone ; [Track 10]. Courante ; [Track 11]. Pavane ; [Track 12]. Gigue / Erwin Dressel -- [Track 13]. Sonata IV. Adagio ; [Track 14]. Allemanda ; [Track 15]. Corrente ; [Track 16]. Moderato / Johann Ernst Galliard ; arranged by Sigurd Rascher -- [Track 17]. Dialogue for two saxophones. With freedom ; [Track 18]. Playfully / Fisher Tull

Measuring the Magnetic Field on the Classical T Tauri Star TW Hydrae

We present infrared (IR) and optical echelle spectra of the Classical T Tauri star TW Hydrae. Using the optical data, we perform detailed spectrum synthesis to fit atomic and molecular absorption lines and determine key stellar parameters: Teff = 4126 \pm 24 K, log g = 4.84 \pm 0.16, [M/H] = -0.10 \pm 0.12, vsini = 5.8 \pm 0.6 km/s. The IR spectrum is used to look for Zeeman broadening of photospheric absorption lines. We fit four Zeeman sensitive Ti I lines near 2.2 microns and find the average value of the magnetic field over the entire surface is 2.61 \pm 0.23 kG. In addition, several nearby magnetically insensitive CO lines show no excess broadening above that produced by stellar rotation and instrumental broadening, reinforcing the magnetic interpretation for the width of the Ti I lines. We carry out extensive tests to quantify systematic errors in our analysis technique which may result from inaccurate knowledge of the effective temperature or gravity, finding that reasonable errors in these quantities produce a 10% uncertainty in the mean field measurement.Comment: The tar file includes one Tex file and four .eps figures. The paper is accepted and tentatively scheduled for the ApJ 1 December 2005, v634, 2 issue. ApJ manuscript submission # 6310

Concert recording 2015-02-17

[Track 01]. Sonatine sportive. Lutte / Alexandre Tcherepnine -- [Track 02]. Second prelude in C# minor / George Gershwin -- [Track 03]. Prelude-allemande from Partita / Erwin Dressel -- [Track 04]. Sonata op. 29. Andante maestoso ; Allegro energico / Robert Muczynski -- [Track 05]. Soanta. Allegro moderato ; Molto vivace ; Lento / Walter Hartley -- [Track 06]. Hot-sonate. I ; II ; IV / Erwin Schulhoff

Effective Temperatures of Low-Mass Stars from High-Resolution H-band Spectroscopy

High-resolution, near-infrared spectra will be the primary tool for finding and characterizing Earth-like planets around low-mass stars. Yet, the properties of exoplanets can not be precisely determined without accurate and precise measurements of the host star. Spectra obtained with the Immersion GRating INfrared Spectrometer (IGRINS) simultaneously provide diagnostics for most stellar parameters, but the first step in any analysis is the determination of the effective temperature. Here we report the calibration of high-resolution H-band spectra to accurately determine effective temperature for stars between 4000-3000 K ($\sim$K8--M5) using absorption line depths of Fe I, OH, and Al I. The field star sample used here contains 254 K and M stars with temperatures derived using BT-Settl synthetic spectra. We use 106 stars with precise temperatures in the literature to calibrate our method with typical errors of about 140 K, and systematic uncertainties less than $\sim$120 K. For the broadest applicability, we present T$_{\rm eff}$--line-depth-ratio relationships, which we test on 12 members of the TW Hydrae Association and at spectral resolving powers between $\sim$10,000--120,000. These ratios offer a simple but accurate measure of effective temperature in cool stars that is distance and reddening independent.Comment: 19 pages, 11 figures and 3 tables. Accepted in Ap

The FUV spectrum of TW Hya. I. Observations of H2_2 Fluorescence

We observed the classical T Tauri star TW Hya with \textit{HST}/STIS using the E140M grating, from 1150--1700 \AA, with the E230M grating, from 2200--2900 \AA, and with \FUSE from 900--1180 \AA. Emission in 143 Lyman-band H$_2$ lines representing 19 progressions dominates the spectral region from 1250--1650 \AA. The total H$_2$ emission line flux is $1.94 \times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$, which corresponds to $1.90\times10^{-4}$ $L_\odot$ at TW Hya's distance of 56 pc. A broad stellar \Lya line photoexcites the H$_2$ from excited rovibrational levels of the ground electronic state to excited electronic states. The \ion{C}{2} 1335 \AA doublet, \ion{C}{3} 1175 \AA\ multiplet, and \ion{C}{4} 1550 \AA doublet also electronically excite H$_2$. The velocity shift of the H$_2$ lines is consistent with the photospheric radial velocity of TW Hya, and the emission is not spatially extended beyond the 0\farcs05 resolution of \textit{HST}. The H$_2$ lines have an intrinsic FWHM of $11.91\pm0.16$ \kms. One H$_2$ line is significantly weaker than predicted by this model because of \ion{C}{2} wind absorption. We also do not observe any H$_2$ absorption against the stellar \Lya profile. From these results, we conclude that the H$_2$ emission is more consistent with an origin in a disk rather than in an outflow or circumstellar shell. We also analyze the hot accretion-region lines (e.g., \ion{C}{4}, \ion{Si}{4}, \ion{O}{6}) of TW Hya, which are formed at the accretion shock, and discuss some reasons why Si lines appear significantly weaker than other TR region lines.Comment: accepted by ApJ, 42 pages -- 20 text, 11 figure

Cocaine Disrupts Pup-Induced Maternal Behavior in Juvenile and Adult Rats

Impaired onset of maternal behavior in first generation rat dams was previously correlated with rearing by cocaine-treated dams and prenatal cocaine exposure. Pup-induced maternal behavior in non-lactating rats has not been examined with regard to cocaine exposure and rearing conditions. First generation male and female juveniles and young adult males reared by cocaine-treated or control dams and prenatally exposed to either cocaine or control conditions were tested for pup-induced maternal behavior at postnatal days 28 and 60. We now report disruptions in pup-induced maternal behavior in both 28 and 60 day old first generation offspring attributable to rearing condition and prenatal cocaine exposure. Originally published Neurotoxicology and Teratology, Vol. 29, No. 6, Nov 200

The mutual interplay between calcification and coccolithovirus infection

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Johns, C. T., Grubb, A. R., Nissimov, J. I., Natale, F., Knapp, V., Mui, A., Fredricks, H. F., Van Mooy, B. A. S., & Bidle, K. D. The mutual interplay between calcification and coccolithovirus infection. Environmental Microbiology, 21(6), (2019): 1896-1915, doi:10.1111/1462-2920.14362.Two prominent characteristics of marine coccolithophores are their secretion of coccoliths and their susceptibility to infection by coccolithoviruses (EhVs), both of which display variation among cells in culture and in natural populations. We examined the impact of calcification on infection by challenging a variety of Emiliania huxleyi strains at different calcification states with EhVs of different virulence. Reduced cellular calcification was associated with increased infection and EhV production, even though calcified cells and associated coccoliths had significantly higher adsorption coefficients than non‐calcified (naked) cells. Sialic acid glycosphingolipids, molecules thought to mediate EhV infection, were generally more abundant in calcified cells and enriched in purified, sorted coccoliths, suggesting a biochemical link between calcification and adsorption rates. In turn, viable EhVs impacted cellular calcification absent of lysis by inducing dramatic shifts in optical side scatter signals and a massive release of detached coccoliths in a subpopulation of cells, which could be triggered by resuspension of healthy, calcified host cells in an EhV‐free, ‘induced media’. Our findings show that calcification is a key component of the E. huxleyi‐EhV arms race and an aspect that is critical both to the modelling of these host–virus interactions in the ocean and interpreting their impact on the global carbon cycle.We thank Liti Haramaty for her guidance and assistance in culturing and infection experiments. This research was funded by the Gordon and Betty Moore Foundation (GBMF3301 to BVM and KDB and GBMF3789 to KDB) and the National Science Foundation (OCE‐1537951 and OCE‐1559179 to KDB)

Observations of T-Tauri Stars using HST-GHRS: I. Far Ultraviolet Emission Lines

We have analyzed GHRS data of eight CTTS and one WTTS. The GHRS data consists of spectral ranges 40 A wide centered on 1345, 1400, 1497, 1550, and 1900 A. These UV spectra show strong SiIV, and CIV emission, and large quantities of sharp (~40 km/s) H2 lines. All the H2 lines belong to the Lyman band and all the observed lines are single peaked and optically thin. The averages of all the H2 lines centroids for each star are negative which may indicate that they come from an outflow. We interpret the emission in H2 as being due to fluorescence, mostly by Ly_alpha, and identify seven excitation routes within 4 A of that line. We obtain column densities (10^12 to 10^15 cm^-2) and optical depths (~1 or less) for each exciting transition. We conclude that the populations are far from being in thermal equilibrium. We do not observe any lines excited from the far blue wing of Ly_alpha, which implies that the molecular features are excited by an absorbed profile. SiIV and CIV (corrected for H2 emission) have widths of ~200 km/s, and an array of centroids (blueshifted lines, centered, redshifted). These characteristics are difficult to understand in the context of current models of the accretion shock. For DR Tau we observe transient strong blueshifted emission, perhaps the a result of reconnection events in the magnetosphere. We also see evidence of multiple emission regions for the hot lines. While CIV is optically thin in most stars in our sample, SiIV is not. However, CIV is a good predictor of SiIV and H2 emission. We conclude that most of the flux in the hot lines may be due to accretion processes, but the line profiles can have multiple and variable components.Comment: 67 pages, 19 figures, Accepted in Ap

Structure and variability of the Antilles current at 26.5°N

Observations from five different systems provide a robust picture of the structure and variability of the Antilles Current, an important contributor to the oceanic flux budget, at 26.5°N during 2005–2015. The analysis includes three direct measurement technologies (current meters, shipboard acoustic Doppler current profilers, and lowered acoustic Doppler current profilers) and two geostrophy‐based measurement technologies (conductivity‐temperature‐depth profilers and pressure‐equipped inverted echo sounders). The direct systems are shown to produce weaker, and less variable, Antilles Current transport estimates than the geostrophy‐based systems. The record‐length‐mean geostrophic estimate for the Antilles Current is 4.7 Sverdrups (Sv; 1 Sv = 106 m3/s), and the daily temporal standard deviation is 7.5 Sv. The variations of the Antilles Current transport exceed those of the entire basin‐wide meridional overturning circulation, illustrating the impact of this unusual current. Seasonal variability shows a maximum northward transport in August–September; however, the seasonal component of the variability is weak, and aliasing of higher frequencies is still a problem even with 10.5 years of data. The dominant time scales of variability in the spectra are at 70 and 180 days, and there is indication of westward propagation of Rossby Wave‐like features into the region at a speed of 9 cm/s. There is no significant correlation between the Antilles Current transport variations and those of the Florida Current at 27°N, in phase or at lags/leads of up to 5 years, likely reflecting the varying coastal wave/wall jet time scales for information to pass from the basin interior through the Bahamas Islands