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Simultaneous multi-wavelength observations of GRS 1915+105
Goldoni, P.; Chaty, S.; Rodriguez, J. +11 more
We present the result of multi-wavelength observations of the microquasar GRS 1915+105 in a plateau state with a luminosity of ~ 7.5*E38 erg s-1 ( ~ 40% L_Edd), conducted simultaneously with the INTEGRAL and RXTE satellites, the ESO/NTT, the Ryle Telescope, the NRAO VLA and VLBA, in 2003 April 2-3. For the first time were obs…
The Low-Mass X-Ray Binary-Globular Cluster Connection. II. NGC 4472 X-Ray Source Properties and Source Catalogs
Kundu, Arunav; Zepf, Stephen E.; Maccarone, Thomas J.
We present the results of a Chandra/Hubble Space Telescope (HST) study of the point sources of the Virgo Cluster giant elliptical galaxy NGC 4472. We identify 144 X-ray point sources outside the nuclear region, 72 of which are located within the HST fields. The optical data show 1102 sources, of which 829 have colors consistent with being globular…
The properties of the absorbing and line-emitting material in IGR J16318 - 4848
Guainazzi, Matteo; Matt, Giorgio
We have performed a detailed analysis of the XMM-Newton observation of IGR J16318-4848, to study the properties of the matter responsible for the obscuration and for the emission of Fe and Ni lines. Even if the line-of-sight material has a column density of about 2 × 1024 cm-2, from the Fe Kα line EW and Compton Shoulder we a…
A Keplerian disk around the Herbig Ae star HD 34282
Kahane, C.; Dutrey, A.; Piétu, V.
We report new millimeter observations of the circumstellar material surrounding the Herbig Ae A0.5 star HD 34282 performed with the IRAM array in CO ~ and in continuum at 1.3 mm. These observations have revealed the existence of a large Keplerian disk around the star. We have analysed simultaneously the line and continuum emissions to derive the p…
Month-Timescale Optical Variability in the M87 Jet
Perlman, Eric S.; Sparks, William B.; Macchetto, F. Duccio +2 more
A previously inconspicuous knot in the M87 jet has undergone a dramatic outburst and now exceeds the nucleus in optical and X-ray luminosity. Monitoring of M87 with the Hubble Space Telescope and Chandra X-Ray Observatory during 2002-2003, has found month-timescale optical variability in both the nucleus and HST-1, a knot in the jet 0.82" from the…
An absorption event in the X-ray light curve of NGC 3227
Uttley, P.; McHardy, I. M.; Lamer, G.
We have monitored the Seyfert galaxy NGC 3227 with the Rossi X-ray Timing Explorer (RXTE) since 1999 January. During late 2000 and early 2001 we observed an unusual hardening of the 2-10 keV X-ray spectrum which lasted several months. The spectral hardening was not accompanied by any correlated variation in flux above 8 keV. We therefore interpret…
The [Fe II] 1.644 Micron Emission in M82 and NGC 253: Is It a Measure of the Supernova Rate?
Rieke, George H.; Alonso-Herrero, Almudena; Rieke, Marcia J. +1 more
We present Hubble Space Telescope NICMOS [Fe II] 1.644 µm, Paα (1.87 µm), and continuum images of the starburst galaxies M82 and NGC 253 at an unprecedented spatial resolution. In both galaxies we detect [Fe II] compact sources superposed on a diffuse background in the disk of the galaxies, together with a component above and below the…
The DA+dMe eclipsing binary EC13471-1258: its cup runneth over ... just
Koester, D.; Stobie, R. S.; O'Donoghue, D. +5 more
The optical spectrum and light curve of EC13471-1258 show that it is an eclipsing binary with an orbital period of 3h 37m comprising a DA white dwarf and a dMe dwarf. Total eclipses of the white dwarf are observed lasting 14 min, with the partial phases lasting 54 s. On one occasion, two pre-eclipse dips were seen. Timings of…
An X-Ray Jet Discovered by Chandra in the z=4.3 Radio-selected Quasar GB 1508+5714
Schwartz, D. A.; Smith, Randall K.; Siemiginowska, Aneta +3 more
We report the Chandra discovery of an X-ray jet associated with the z=4.3 radio-loud quasar GB 1508+5714. The jet X-ray emission peaks ~2" to the southwest of the quasar core. We present archival Hubble Space Telescope Wide Field Planetary Camera 2 data of the quasar field that show no optical emission at the location of the X-ray jet. We discuss …
Cluster electric current density measurements within a magnetic flux rope in the plasma sheet
Balogh, A.; Owen, C. J.; Reme, H. +11 more
On August 22, 2001 all 4 Cluster spacecraft nearly simultaneously penetrated a magnetic flux rope in the tail. The flux rope encounter took place in the central plasma sheet, βi ~ 1-2, near the leading edge of a bursty bulk flow. The ``time-of-flight'' of the flux rope across the 4 spacecraft yielded Vx ~ 700 km/s and a diame…