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Multiple and Precessing Collimated Outflows in the Planetary Nebula IC 4634

Guerrero, Martín A.; Chu, You-Hua; Miranda, Luis F. +6 more

With its remarkable double-S shape, IC 4634 is an archetype of point-symmetric planetary nebulae (PNe). In this paper, we present a detailed study of this PN using archival HST WFPC2 and ground-based narrowband images to investigate its morphology, and long-slit spectroscopic observations to determine its kinematics and to derive its physical cond…

AKARI/FIS Mapping of the ISM-Wind Bow Shock around α Orionis

Yamamura, Issei; Matsunaga, Noriyuki; Mito, Hiroyuki +7 more

We present 10' × 50'scan maps around an M supergiant αOri at 65, 90, 140, and 160µm obtained with the AKARI Infrared Astronomy Satellite. Higher spatial resolution data with the exact analytic solution permit us to fit the de-projected shape of the stellar-wind bow shock around αOri to have a stand-off distance of 4'.8, position angle of 55°…

L-Dwarf Binaries in the 20-Parsec Sample

Burgasser, Adam J.; Reid, I. Neill; Liu, Michael C. +1 more

We have used the NICMOS NIC1 camera on the Hubble Space Telescope to obtain high-resolution near-infrared images of 27 nearby ultracool dwarfs with formal distance estimates less than 20 parsecs. One target, 2MASS J22551861-5713056, is resolved as a binary system, with a 4:1 flux ratio in the F110W passband. The primary has spectral type L6, and t…

Albedo, Size, and Surface Characteristics of Hayabusa-2 Sample-Return Target 162173 1999 JU3 from AKARI and Subaru Observations

Müller, T. G.; Wada, T.; Ita, Y. +7 more

Searching for mid-IR obscured AGN in the Chandra deep field North

Georgakakis, A.; Georgantopoulos, I.; Rovilos, E. +1 more

The efficiency of mid-infrared selection methods for finding obscured AGN is investigated using data in the Chandra Deep Field North. It is shown that samples of AGN candidates compiled on the basis of mid-infrared colours only suffer substantial contamination from normal galaxies. X-ray stacking analysis reveals a soft mean X-ray spectrum for the…

Suzaku Observation of the Ophiuchus Galaxy Cluster: One of the Hottest Cool Core Clusters

Sarazin, Craig L.; Reiprich, Thomas H.; Hayashida, Kiyoshi +6 more

We present the analysis of a Suzaku observation of the Ophiuchus galaxy cluster. We confirmed that the cluster has a cool core. While the temperature of the intracluster medium (ICM) decreases toward the center, the metal abundance increases. Except for the core (r lesssim 50kpc), the cluster is hot (∼9-10keV) and is almost isothermal for r lesssi…

Angular Diameters of the G Subdwarf µ Cassiopeiae A and the K Dwarfs σ Draconis and HR 511 from Interferometric Measurements with the CHARA Array

Gies, Douglas R.; Henry, Todd; Jao, Wei-Chun +13 more

Using the longest baselines of the CHARA Array, we have measured the angular diameter of the G5 V subdwarf µ Cas A, the first such determination for a halo population star. We compare this result to new diameters for the higher metallicity K0 V stars, σ Dra and HR 511, and find that the metal-poor star, µ Cas A, has an effective temper…

Star formation histories of early-type galaxies at z = 1.2 in cluster and field environments

Demarco, R.; Rosati, P.; Nonino, M. +3 more

We derive the star formation histories of early-type galaxies at z≃1.2 in both low and high density environments. To this purpose, we compare the co-added spectroscopic and 8-9 band photometric data of 43 mass selected early-type galaxies in the massive cluster RDCS J1252.9-2927 and the GOODS/CDF-S field with a large grid of composite stellar popu…

Sequestration of Ethane in the Cryovolcanic Subsurface of Titan

Mousis, Olivier; Schmitt, Bernard

Saturn's largest satellite, Titan, has a thick atmosphere dominated by nitrogen and methane. The dense orange-brown smog hiding the satellite's surface is produced by photochemical reactions of methane, nitrogen, and their dissociation products with solar ultraviolet, which lead primarily to the formation of ethane and heavier hydrocarbons. In the…

Auroral current systems in Saturn's magnetosphere: comparison of theoretical models with Cassini and HST observations

Coates, A. J.; Dougherty, M. K.; Nichols, J. D. +7 more

The first simultaneous observations of fields and plasmas in Saturn's high-latitude magnetosphere and UV images of the conjugate auroral oval were obtained by the Cassini spacecraft and the Hubble Space Telescope (HST) in January 2007. These data have shown that the southern auroral oval near noon maps to the dayside cusp boundary between open and…