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GOALS: The Great Observatories All-Sky LIRG Survey
Sturm, E.; Veilleux, S.; Sanders, D. B. +31 more
The Great Observatories All-Sky LIRG Survey (GOALS20 ) combines data from NASA’s Spitzer Space Telescope, Chandra X-Ray Observatory, Hubble Space Telescope (HST), and Galaxy Evolution Explorer (GALEX) observatories, together with ground-based data, into a comprehensive imaging and spectroscopic survey of over 200 low-redshift (z < 0.088), Lumin…
12 New Galactic Wolf-Rayet Stars Identified via 2MASS + Spitzer/GLIMPSE
Van Dyk, Schuyler D.; Mauerhan, Jon C.; Morris, Pat W.
We report new results from our effort to identify obscured Wolf-Rayet stars in the Galaxy. Candidates were selected by their near-infrared (Two Micron All Sky Survey; 2MASS) and mid-infrared (Spitzer/GLIMPSE) color excesses, which are consistent with free-free emission from ionized stellar winds and thermal excess from hot dust. We have confirmed …
The Unevolved Main Sequence of Nearby Field Stars and the Open Cluster Distance Scale
Twarog, Bruce A.; Anthony-Twarog, Barbara J.; Edgington-Giordano, Frederika
The slope and zero point of the unevolved main sequence as a function of metallicity are investigated using a homogeneous catalog of nearby field stars with absolute magnitudes defined with revised Hipparcos parallaxes, Tycho-2 photometry, and precise metallicities from high-dispersion spectroscopy. (B - V) -temperature relations are derived from …
Hubble Space Telescope STIS Spectroscopy of the Peculiar Nova-Like Variables BK Lyn, V751 Cygni, and V380 Oph
Sion, Edward M.; Godon, Patrick; Gänsicke, Boris T. +4 more
We obtained Hubble STIS spectra of three nova-like variables: V751 Cygni, V380 Oph, and—the only confirmed nova-like variable known to be below the period gap—BK Lyn. In all three systems, the spectra were taken during high optical brightness state, and a luminous accretion disk dominates their far-ultraviolet (FUV) light. We assessed a lower limi…
Studying the Imaging Characteristics of Ultra Violet Imaging Telescope (UVIT) through Numerical Simulations
Srivastava, Mudit K.; Prabhudesai, Swapnil M.; Tandon, Shyam N.
Ultra Violet Imaging Telescope (UVIT) is one of the five payloads aboard the Indian Space Research Organization (ISRO)’s ASTROSAT space mission, with broad science objectives extending from individual hot stars and star-forming regions to active galactic nuclei. The imaging performance of UVIT would depend on several factors in addition to the opt…
Lacerta OB1 Revisited
Kaltcheva, Nadia
This investigation utilizes precise uvbyβ photometry and the recently recalculated Hipparcos data to provide an improved homogeneous distance scale for the apparent groups of young stars in Lacerta. All existing uvbyβ photometry for stars earlier than A0-type in a 20° × 20° field centered at l = 100°, b = -15° is collated and the individual stella…
High-Accuracy Near-infrared Imaging Polarimetry with NICMOS
Batcheldor, D.; Sparks, W.; Axon, D. J. +5 more
The findings of a nine-orbit calibration plan carried out during HST Cycle 15, to fully determine the NICMOS camera 2 (2.0 µm) polarization calibration to high accuracy, are reported. Recently Ueta et al. and Batcheldor et al. have suggested that NICMOS possesses a residual instrumental polarization at a level of 1.2%-1.5%. This would comple…
Application of Photoconductor Physical Transient Model to Fourier Transform Spectrometer Data of AKARI/Far-Infrared Surveyor (FIS)
Coulais, A.; Takahashi, H.; Okada, Y. +8 more
AKARI carries on board the Fourier transform spectrometer (FTS) with the gallium-doped germanium (Ge:Ga) photoconductor arrays of the far-infrared surveyor (FIS). Ge:Ga photoconductors are the most sensitive detectors for far-infrared satellite instruments. However, the performance of these detectors is known to be severely influenced by undesirab…
Accurate Analytical and Statistical Approaches to Reduce O-C Discrepancies in the Precessional Parameters
Marco, F. J.; Martínez, M. J.; López, J. A.
The Hipparcos catalog provides a reference frame at optical wavelengths for the new International Celestial Reference System (ICRS). This new reference system was adopted following the resolution agreed at the 23rd IAU General Assembly held in Kyoto in 1997. Differences in the Hipparcos system of proper motions and the previous materialization of …
The Variable 6307 Å Emission Line in the Spectrum of Eta Carinae: Blueshifted [S III] λ6313 from the Interacting Winds
Gull, T. R.
The 6307 Å emission line in the spectrum of η Car, found by Martin et al., is blue-shifted [S iii] λ6313 emission originating from the outer wind structures of the massive binary system. We realized the identification while analyzing multiple forbidden emission lines not normally seen in the spectra of massive stars. The high spatial and moderate …