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First Orbit and Mass Determinations for Nine Visual Binaries
Ling, J. F.
This paper presents the first published orbits and masses for nine visual double stars: WDS 00149-3209 (B 1024), WDS 01006+4719 (MAD 1), WDS 03130+4417 (STT 51), WDS 04357+3944 (HU 1084), WDS 19083+2706 (HO 98 AB), WDS 19222-0735 (A 102 AB), WDS 20524+2008 (HO 144), WDS 21051+0757 (HDS 3004 AB), and WDS 22202+2931 (BU 1216). Masses were calculated…
Chandra Observations of the Nuclear Star Cluster and Ultraluminous X-Ray Sources in NGC 2139
Böker, Torsten; Ho, Luis C.; Shields, Joseph C. +3 more
We report Chandra observations of the Scd galaxy NGC 2139, which is known to host a recently formed (107.6 yr) nuclear star cluster. The star cluster is undetected in X-rays, with an upper bound on 0.5-7 keV luminosity of L X < 7.1 × 1037 erg s-1. This bound implies a bolometric accretion luminosity &…
On the Nature of Hard X-Ray Extragalactic Sources Observed with XMM-Newton
Schartel, N.; Santos-Lleó, M.; Jiménez-Bailón, E. +3 more
Over the last decade, X-ray surveys have provided outstanding new results due to the lack of the common selection effects present at other wavelengths. Here, we have selected a sample of unidentified sources from the XMM-Newton Slew Survey Catalog, likely to be extragalactic. Five of them were observed with the XMM-Newton observatory. In this work…
The Nature of a Galaxy along the Sight Line to PKS 0454+039
Kulkarni, Varsha P.; Gharanfoli, Soheila; Takamiya, Marianne +1 more
We report on the properties of a faint blue galaxy (G1) along the line of sight to the QSO PKS 0454+039 from spectroscopic and imaging data. We measured emission lines of Hα, [S II] λλ6716, 6732, and [N II] λ6584 in the spectrum of G1 obtained with the Gemini/GMOS instrument. The spectroscopic redshift of G1 is z = 0.0715 ± 0.0002. From the extinc…