Search Publications
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…
Interferometric Detections of GOODS 850-5 at 1 mm and 1.4 GHz
Morrison, G.; Walter, F.; Dannerbauer, H.
We have obtained a position (at subarcsecond accuracy) of the submillimeter bright source GOODS 850-5 (also known as GN 10) in the GOODS-North field using the IRAM Plateau de Bure interferometer at 1.25 mm wavelengths (MM J123633+6214.1; flux density: S1.25 mm = 5.0 +/- 1.0 mJy). This source has no optical counterpart in deep ACS imagin…
The Accuracy of Morphological Decomposition of Active Galactic Nucleus Host Galaxies
Urry, C. M.; Simmons, B. D.
In order to assess the accuracy with which we can determine the morphologies of AGN host galaxies, we have simulated more than 50,000 ACS images of galaxies with z < 1.25, using image and noise properties appropriate for the GOODS survey. We test the effect of central point-source brightness on host galaxy parameter recovery with a set of simul…
Frequent Occurrence of High-Speed Local Mass Downflows on the Solar Surface
Kubo, M.; Lites, B. W.; Ichimoto, K. +7 more
We report on new spectropolarimetric measurements with simultaneous filter imaging observation, revealing the frequent appearance of polarization signals indicating high-speed, probably supersonic, downflows that are associated with at least three different configurations of magnetic fields in the solar photosphere. The observations were carried o…
Chandra Observation of PSR B1823-13 and Its Pulsar Wind Nebula
Pavlov, G. G.; Kargaltsev, O.; Brisken, W. F.
An observation of the Vela-like pulsar B1823-13 and its synchrotron nebula with the Chandra X-Ray Observatory allowed us to resolve the pulsar and the fine structure of the nebula. The pulsar's spectrum fits a power-law model with a photon index ΓPSR ≈ 2.4 for the plausible hydrogen column density nH = 1 × 1022 cm<…
Gemini Imaging of Mid-Infrared Emission from the Nuclear Region of Centaurus A
Levenson, N. A.; Perlman, Eric; De Buizer, James M. +7 more
We present high spatial resolution mid-IR images of the nuclear region of NGC 5128 (Centaurus A). Images were obtained at 8.8 µm, N band (10.4 µm), and 18.3 µm using the mid-IR imager/spectrometer T-ReCS on Gemini South. These images show a bright unresolved core surrounded by low-level extended emission. We place an upper limit …
A New Approach to the Study of Stellar Populations in Early-Type Galaxies: K-Band Spectral Indices and an Application to the Fornax Cluster
Kuntschner, Harald; Lyubenova, Mariya; Silva, David R.
The strong spectral features near 2.2 µm in early-type galaxies remain relatively unexplored. Yet, they open a tightly focused window on the coolest giant stars in these galaxies—a window that can be used to explore both age and metallicity effects. Here, new measurements of K-band spectral features are presented for 11 early-type galaxies i…
The Globular Cluster System of M60 (NGC 4649). II. Kinematics of the Globular Cluster System
Rey, Soo-Chang; Lee, Myung Gyoon; Hwang, Ho Seong +7 more
We present a kinematic analysis of the globular cluster (GC) system in the giant elliptical galaxy (gE) M60 in the Virgo Cluster, using a photometric and spectroscopic database of 121 GCs (83 blue and 38 red GCs). We have found that the M60 GC system shows a significant overall rotation. The rotation amplitude of the blue GCs is slightly smaller t…
The Variation of Relative Magnetic Helicity around Major Flares
Yang, Guo; Jing, Ju; Wang, Haimin +5 more
We have investigated the variation of magnetic helicity over a span of several days around the times of 11 X-class flares which occurred in seven active regions (NOAA 9672, 10030, 10314, 10486, 10564, 10696, and 10720) using the magnetograms taken by the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO). As a ma…
2 Years of INTEGRAL Monitoring of GRS 1915+105. I. Multiwavelength Coverage with INTEGRAL, RXTE, and the Ryle Radio Telescope
Belloni, T.; Rodriguez, J.; Cadolle Bel, M. +13 more
We report the results of simultaneous monitoring observations of the Galactic microquasar GRS 1915+105 with INTEGRAL and RXTE from 3 up to ~300 keV, and the Ryle Telescope at 15 GHz. We first identify the classes of variability in which GRS 1915+105 is found, and report some direct transitions between them. The accretion ejection connections are s…