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Vertical shears in Saturn's eastward jets at cloud level
Hueso, R.; Rojas, J. F.; Pérez-Hoyos, S. +2 more
We have measured the vertical shear of the zonal winds in the cloud-haze upper layer of Saturn using Cassini ISS images obtained in the filters MT2 (753 nm methane absorption band, sensitive to the upper haze) and CB2 (adjacent continuum, sensitive to the lower cloud). Our radiative transfer models indicate that at the eastward jet peaks these fil…
Classification of extremely red objects in the Hubble Ultra Deep Field
Kong, Xu; Wang, Min; Fang, Guan-Wen
We present a quantitative study of the classification of Extremely Red Objects (EROs). The analysis is based on the multi-band spatial- and ground-based observations (HST/ACS-BViz, HST/NICMOS- JH, VLT-JHK) in the Hubble Ultra Deep Field (UDF). Overatotal sky area of 5.50 arcmin2 in the UDF, we select 24 EROs with the color criterion (i …
Multi-Epoch Multi-Wavelength Study of an Ultraluminous X-ray Source in M101: The Nature of the Secondary
Liu, Jifeng
Ultraluminous X-ray sources are non-nuclear point sources in external galaxies with LX = 2 × 1039-1041 erg s-1, and thus are possibly stellar black holes with special radiation mechanisms or intermediate mass black holes of 100-105 M sun. To measure their dynamical mass, one needs t…
The ACS Nearby Galaxy Survey Treasury. III. Cepheids in the Outer Disk of M81
Dolphin, Andrew E.; Williams, Benjamin F.; Yoachim, Peter +3 more
The ACS Nearby Galaxy Survey Treasury (ANGST) has acquired deep ACS imaging of a field in the outer disk of the large spiral galaxy M81. These data were obtained over a total of 20 Hubble Space Telescope orbits, providing a baseline long enough to reliably identify Cepheid variable stars in the field. Fundamental mode and first overtone types have…
Broad-Band Temporal and Spectral Variation of 36 Active Galactic Nuclei Observed with Suzaku
Kunieda, Hideyo; Haba, Yoshito; Miyazawa, Takuya
36 AGN data observed by Suzaku were compiled to examine the temporal variability in different energy bands covered by soft X-ray imaging systems (XRT + XIS: 0.5-10 keV) and Hard X-ray Detector (HXD: 15-50 keV) aboard Suzaku. Three band light curves were obtained in L (0.5-2 keV), M (2-10 keV), and H (15-50 keV) with a time binning of 5760 s. The L…
The multi-band non-thermal emission from the supernova remnant RX J1713.7-3946
Zhang, L.; Fang, J.; Zhang, J. F. +2 more
Non-thermal X-rays and very high energy (VHE) γ-rays have been detected from the supernova remnant (SNR) RX J1713.7-3946, and the recent observations with the Suzaku satellite clearly reveal a spectral cut-off in the X-ray spectrum, which directly relates to the cut-off of the energy spectrum of the parent electrons. However, whether the origin of…
The Infrared Array Camera Dark Field: Far-Infrared to X-ray Data
Frayer, D. T.; Surace, J. A.; Egami, E. +7 more
We present 20 band photometry from the far-IR to X-ray in the Spitzer Infrared Array Camera (IRAC) dark field. The bias for the near-IR camera on Spitzer is calibrated by observing a ~20' diameter "dark" field near the north ecliptic pole roughly every two-to-three weeks throughout the mission duration of Spitzer. The field is unique for its extre…
The Extragalactic Distance Scale Without Cepheids. II. Surface Brightness Fluctuations
Sakai, Shoko; Mould, Jeremy
Distances of galaxies in the Hubble Space Telescope (HST) Key Project are based on the Cepheid period-luminosity relation. An alternative basis is the tip of the red giant branch (TRGB). Using archival HST data, we calibrate surface brightness fluctuations using 16 galaxies with TRGB branch measurements. The TRGB and Cepheid distance scales are sh…
Hybrid simulations of the O + ion escape from Venus: Influence of the solar wind density and the IMF x component
Kallio, E.; Janhunen, P.; Lammer, H. +6 more
As an initial effort to study the evolution of the Venus atmosphere, the influence of the solar wind density and the interplanetary magnetic field (IMF) x component (the x-axis points from Venus towards the Sun) on the O + ion escape rate from Venus is investigated using a three-dimensional quasi-neutral hybrid (HYB-Venus) model. The HY…
Quantitative forecasting of near-term solar activity and upper atmospheric density
Lean, J. L.; Picone, J. M.; Emmert, J. T.
Autoregressive algorithms are developed to forecast solar activity on timescales of 1 to 10 days and utilized to forecast upper atmospheric densities using the NRLMSIS density specification model. Quantitative assessment of solar activity observations and forecasts made over 27 years (from 1980 to 2006) indicates that the chromospheric Mg index is…