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Improved Ti II Log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-Poor Star HD 84937
Sneden, C.; Wood, M. P.; Lawler, J. E. +1 more
Atomic transition probability measurements for 364 lines of Ti II in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform spectrometer (FTS) and a new echelle spectrometer are combined with published radiative lifetimes to determine these transition probabilities. The new results are in generally go…
Young Stellar Objects in Lynds 1641: Disks, Accretion, and Star Formation History
Fang, Min; Henning, Thomas; van Boekel, Roy +3 more
We investigate the young stellar objects (YSOs) in the Lynds 1641 (L1641) cloud using multi-wavelength data including Spitzer, WISE, the Two Micron All Sky Survey, and XMM covering ~1390 YSOs across a range of evolutionary stages. In addition, we targeted a sub-sample of YSOs for optical spectroscopy with the MMT/Hectospec and the MMT/Hectochelle.…
Optical Counterparts of the Nearest Ultraluminous X-Ray Sources
Roberts, Timothy P.; Heinke, Craig O.; Gladstone, Jeanette C. +4 more
We present a photometric survey of the optical counterparts of ultraluminous X-ray sources (ULXs) observed with the Hubble Space Telescope (HST) in nearby (lsim5 Mpc) galaxies. Of the 33 ULXs with HST and Chandra data, 9 have no visible counterpart, placing limits on their MV of ~ -4 to -9, enabling us to rule out O-type companions in 4…
The Spitzer Mid-infrared Active Galactic Nucleus Survey. I. Optical and Near-infrared Spectroscopy of Obscured Candidates and Normal Active Galactic Nuclei Selected in the Mid-infrared
Seymour, N.; Gates, E. L.; Sajina, A. +8 more
We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate active galactic nuclei (AGNs) selected in the mid-infrared. This survey selects both normal and obscured AGNs closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L bol ~ 1010 …
Hot Gas Lines in T Tauri Stars
Edwards, Suzan; Herczeg, Gregory J.; Valenti, Jeff A. +20 more
For Classical T Tauri Stars (CTTSs), the resonance doublets of N V, Si IV, and C IV, as well as the He II 1640 Å line, trace hot gas flows and act as diagnostics of the accretion process. In this paper we assemble a large high-resolution, high-sensitivity data set of these lines in CTTSs and Weak T Tauri Stars (WTTSs). The sample comprises 35 star…
An Interferometric Spectral Line and Imaging Survey of VY Canis Majoris in the 345 GHz Band
Menten, K. M.; Patel, N. A.; Kamiński, T. +2 more
A spectral line survey of the oxygen-rich red supergiant VY Canis Majoris was made between 279 and 355 GHz with the Submillimeter Array (SMA). Two hundred twenty-three spectral features from 19 molecules (not counting isotopic species of some of them) were observed, including the rotational spectra of TiO, TiO2, and AlCl for the first t…
The Interplanetary Network Supplement to the Fermi GBM Catalog of Cosmic Gamma-Ray Bursts
Zhang, X.; Cline, T.; Hurley, K. +37 more
We present Interplanetary Network (IPN) data for the gamma-ray bursts in the first Fermi Gamma-Ray Burst Monitor (GBM) catalog. Of the 491 bursts in that catalog, covering 2008 July 12 to 2010 July 11, 427 were observed by at least one other instrument in the nine-spacecraft IPN. Of the 427, the localizations of 149 could be improved by arrival ti…
The Hubble Space Telescope Treasury Program on the Orion Nebula Cluster
Panagia, N.; Robberto, M.; Scandariato, G. +27 more
The Hubble Space Telescope (HST) Treasury Program on the Orion Nebula Cluster (ONC) has used 104 orbits of HST time to image the Great Orion Nebula region with the Advanced Camera for Surveys (ACS), the Wide-Field/Planetary Camera 2 (WFPC2), and the Near-Infrared Camera and Multi-Object Spectrograph (NICMOS) instrument in 11 filters ranging from t…
Hectospec and Hydra Spectra of Infrared Luminous Sources in the AKARI North Ecliptic Pole Survey Field
Kim, Seong Jin; Papovich, Casey; Weiner, Benjamin J. +7 more
We present spectra of 1796 sources selected in the AKARI North Ecliptic Pole Wide Survey field, obtained with MMT/Hectospec and WIYN/Hydra, for which we measure 1645 redshifts. We complemented the generic flux-limited spectroscopic surveys at 11 µm and 15 µm, with additional sources selected based on the MIR and optical colors. In MMT/…
A Chandra Snapshot Survey for 3C Radio Galaxies with Redshifts between 0.3 and 0.5
Liuzzo, E.; Bonafede, A.; Massaro, F. +3 more
This paper contains an analysis of short Chandra observations of 19 3C sources with redshifts between 0.3 and 0.5 not previously observed in the X-rays. This sample is part of a project to obtain Chandra data for all of the extragalactic sources in the 3C catalog. Nuclear X-ray intensities as well as any X-ray emission associated with radio jet kn…