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Proper Motions of the HH 47 Jet Observed with the Hubble Space Telescope
Hartigan, Patrick; Bally, John; Reipurth, Bo +2 more
We present a proper-motion study of the shock waves within the classic stellar jet HH 47 based on Hubble Space Telescope (HST) Hα and [S II] images of the region taken over two epochs. Individual knots within the jet and in the bow shock/Mach disk working surface of HH 47A move significantly in the 5 yr that separate the images, and the excellent …
Large-Scale Activity in the Bastille Day 2000 Solar Event
Grechnev, V. V.; Chertok, I. M.
We have analyzed dimmings, i.e., regions of temporarily reduced brightness, and manifestations of a coronal wave in the famous event of 14 July 2000 using images produced with the EUV telescope SOHO/EIT. Our analysis was inspired by a paper by Andrews (2001, Solar Phys. 204, 181 (Paper I)), in which this event was studied using running-difference …
The Optical Counterpart of M101 ULX-1
Chu, You-Hua; Kuntz, K. D.; Gruendl, Robert A. +4 more
We have identified the optical counterpart of the ultraluminous X-ray source M101 ULX-1 (CXOKM101 J140332.37+542102), by comparing Hubble Space Telescope Advanced Camera for Surveys images with Chandra ACIS-S images. The optical counterpart has V=23.75 and colors consistent with those for a mid-B supergiant. Archival Wide Field Planetary Camera 2 …
Detection of a Hot Binary Companion of η Carinae
Hillier, D. John; Gull, Theodore R.; Sonneborn, George +2 more
We report the detection of a hot companion of η Carinae using high-resolution spectra (905-1180 Å) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations were obtained at two epochs of the 2024 day orbit: 2003 June, during ingress to the 2003.5 X-ray eclipse, and 2004 April, several months after egress. These data …
Identification of the optical counterparts of high-mass X-ray binaries through optical photometry and spectroscopy
Reig, P.; Negueruela, I.; Manousakis, A. +2 more
We present the results of our search for optical counterparts to high-mass X-ray transient sources discovered by various X-ray missions. We obtained CCD images of the X-ray fields through BVR and Hα filters to identify early-type stars in the R-Hα versus B-V colour-colour diagram. We also obtained medium-resolution spectroscopy of the candidates i…
Anomalous resistivity due to nonlinear lower-hybrid drift waves
Vaivads, A.; Büchner, J.; Silin, I.
The generation of anomalous collision rate and resistivity by lower-hybrid drift waves is investigated. A general expression involving particle density and current perturbations and electromagnetic field fluctuations is used to estimate the effective collision frequency. Results of Vlasov-code simulations and Cluster spacecraft measurements sugges…
XMM-Newton timing mode observations of Mrk 421
Haberl, F.; Papadakis, I. E.; Brinkmann, W. +2 more
We present the results of a detailed temporal analysis of the bright BL Lac object Mrk 421 using the three available long timing mode observations by the EPIC PN camera. This detector mode is characterized by its long life time and is largely free of photon pile-up problems. The source was found in different intensity and variability states differ…
X-Ray Cluster Associated with the z = 1.063 CSS Quasar 3C 186: The Jet is Not Frustrated
Elvis, Martin; Cheung, C. C.; Bechtold, Jill +5 more
We report the Chandra discovery of an X-ray cluster at redshift z=1.063 associated with the compact steep spectrum (CSS) radio-loud quasar 3C 186 (Q0740+380). Diffuse X-ray emission is detected out to ~120 kpc from the quasar and contains 741+/-40 net counts. The X-ray spectrum of the extended emission shows strong Fe-line emission (EW=412 eV) at …
Panoramic Views of Cluster-Scale Assemblies Explored by Subaru Wide-Field Imaging
Shimasaku, Kazuhiro; Ohashi, Takaya; Kodama, Tadayuki +21 more
We have started PISCES project; a panoramic imaging and spectroscopic survey of distant clusters on Subaru. It exploits the unique wide-field imaging capability of Suprime-Cam, which provides a 34' × 27' field of view corresponding to a physical area of 16 × 13 Mpc2 at z ∼ 1. We plan to target 15 clusters at 0.4 ≲ z ≲ 1.3. We report on …
The Complex Star Formation History of NGC 1569
Leitherer, Claus; Greggio, L.; Tosi, M. +3 more
We present new results on the star formation history of the dwarf irregular galaxy NGC 1569. The data were obtained with the Hubble Space Telescope NICMOS/NIC2 in the F110W (J) and F160W (H) near-infrared (NIR) filters and interpreted with the synthetic color-magnitude diagram method. The galaxy has experienced complex star formation (SF) activity…