Search Publications
A High Angular Resolution Survey of Massive Stars in Cygnus OB2: Results from the Hubble Space Telescope Fine Guidance Sensors
Herrero, A.; Gies, D. R.; Moffat, A. F. J. +8 more
We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the fine guidance sensor 1R (FGS1r) on the Hubble Space Telescope. FGS1r is able to resolve binary systems with a magnitude difference ΔV < 4 down to separations as small as 0.''01. The sample includes 58 of the bright…
SiO and H2O Maser Survey toward Post-asymptotic Giant Branch and Asymptotic Giant Branch Stars
Kim, Jaeheon; Cho, Se-Hyung; Yoon, Dong-Hwan +2 more
We performed simultaneous observations of SiO v = 1, 2, 29SiO v = 0, J = 1-0 and H2O 616-523 maser lines toward 143 AGB and 164 post-asymptotic giant branch (AGB) stars in order to investigate how evolutionary characteristics from AGB to post-AGB stars appear in both SiO and H2O maser emission…
The Blue Straggler Star Population in NGC 1261: Evidence for a Post-core-collapse Bounce State
Sills, Alison; Puzia, Thomas H.; Simunovic, Mirko
We present a multi-passband photometric study of the Blue Straggler Star (BSS) population in the Galactic globular cluster (GC) NGC 1261, using available space- and ground-based survey data. The inner BSS population is found to have two distinct sequences in the color-magnitude diagram (CMD), similar to double BSS sequences detected in other GCs. …
Cross-calibration of the XMM-Newton EPIC pn and MOS on-axis effective areas using 2XMM sources
Read, A. M.; Guainazzi, M.; Sembay, S.
Aims: We aim to examine the relative cross-calibration accuracy of the on-axis effective areas of the XMM-Newton EPIC pn and MOS instruments.
Methods: Spectra from a sample of 46 bright, high-count, non-piled-up, isolated on-axis point sources are stacked together, and model residuals are examined to characterize the EPIC MOS-to-pn inter…
The debris disc of solar analogue τ Ceti: Herschel observations and dynamical simulations of the proposed multiplanet system
Heras, A. M.; Fridlund, M.; Blommaert, J. A. D. L. +16 more
τ Ceti is a nearby, mature G-type star very similar to our Sun, with a massive Kuiper Belt analogue and possible multiplanet system that has been compared to our Solar system. We present Herschel Space Observatory images of the debris disc, finding the disc is resolved at 70 µm and 160 µm, and marginally resolved at 250 µm. The H…
Herschel HIFI Observations of O2 toward Orion: Special Conditions for Shock Enhanced Emission
Caselli, Paola; Viti, Serena; Encrenaz, Pierre +18 more
We report observations of molecular oxygen (O2) rotational transitions at 487 GHz, 774 GHz, and 1121 GHz toward Orion Peak A. The O2 lines at 487 GHz and 774 GHz are detected at velocities of 10-12 km s-1 with line widths ~3 km s-1 however, the transition at 1121 GHz is not detected. The observed line ch…
Jupiter's equatorward auroral features: Possible signatures of magnetospheric injections
Bonfond, B.; Gérard, J. -C.; Grodent, D. +2 more
The present study investigates the characteristics of ultraviolet auroral features located equatorward of the main emission appearing in Hubble Space Telescope images of the northern and southern Jovian hemispheres obtained in 2000-2007. On average, one feature is observed every day, but several auroral structures are occasionally seen over a wide…
Ultraluminous Infrared Galaxies in the AKARI All-sky Survey
Goto, T.; Doi, Y.; Kilerci Eser, E.
We present a new catalog of 118 ultraluminous infrared galaxies (ULIRGs) and one hyperluminous infrared galaxy (HLIRG) by cross-matching the AKARI all-sky survey with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the final data release of the Two-Degree Field Galaxy Redshift Survey. Forty of the ULIRGs and one HLIRG are new identifi…
Physical and dynamical properties of the main belt triple Asteroid (87) Sylvia
Berthier, J.; Carry, B.; Marchis, F. +2 more
We present the analysis of high angular resolution observations of the triple Asteroid (87) Sylvia collected with three 8-10 m class telescopes (Keck, VLT, Gemini North) and the Hubble Space Telescope. The moons’ mutual orbits were derived individually using a purely Keplerian model. We computed the position of Romulus, the outer moon of the syste…
Revealing the Location and Structure of the Accretion Disk Wind in PDS 456
Turner, T. J.; Reeves, J. N.; Braito, V. +7 more
We present evidence for the rapid variability of the high-velocity iron K-shell absorption in the nearby (z = 0.184) quasar PDS 456. From a recent long Suzaku observation in 2013 (~1 Ms effective duration), we find that the equivalent width of iron K absorption increases by a factor of ~5 during the observation, increasing from <105 eV within t…