Search Publications
No Evidence of Morning or Large-Scale Drizzle on Titan
Geballe, Thomas R.; Kim, Sang J.; Trafton, Laurence M.
Widespread methane precipitation on Titan has been predicted by several authors since methane saturation in the upper troposphere was measured by the Huygens probe over its landing site. Recently, observational evidence of widespread morning drizzle has been suggested based on detection of a dark morning site in surface-subtracted 2 µm spect…
An Analysis of the Dust Halo and Extinction toward X Persei
Smith, Randall K.; Valencic, Lynne A.
Interstellar dust grain models are not sufficiently constrained by UV extinction curves to allow researchers to distinguish between them. By testing grain models in the X-ray regime and applying elemental abundance constraints, we show to what extent the models can reproduce the observables in these regimes and whether they are capable of doing so…
IRAS 04325+2402C: A Very Low Mass Object with an Edge-On Disk
Wood, Kenneth; Doyon, René; Lafrenière, David +3 more
IRAS 04325+2402C is a low-luminosity object located near a protostar in Taurus. We present new spatially resolved millimeter observations, near-infrared spectroscopy, and Spitzer photometry that improve the constraints on the nature of this source. The object is clearly detected in our 1.3 mm interferometry map, allowing us to estimate the mass in…
XMM-Newton Detection of a Compton-thick AGN in the 1 Jy ULIRG/LINER F04103-2838
Veilleux, S.; Sanders, D. B.; Young, A. J. +3 more
We report on the detection of Fe Kα emission in F04103-2838, an ultraluminous infrared galaxy [ULIRG; log (LIR/L⊙) >= 12] optically classified as a LINER. Previous Chandra observations suggested the presence of both a starburst and an active galactic nucleus (AGN) in this source. A deeper (~20 ks) XMM-Newton spectrum revea…
The Source Region of Coronal Mass Ejections
Lara, Alejandro
We use the large database of coronal mass ejections (CMEs) observed by SOHO LASCO during solar cycle 23 to statistically obtain information about the source regions of CMEs. By determining the functional form of the position angle (P.A.) distribution, we are able to construct a random set of CME direction vectors (DVCME) under the follo…
Evidence for a Photoevaporated Circumbinary Disk in Orion
Robberto, M.; Da Rio, N.; Ricci, L. +1 more
We have found a photoevaporated disk in the Orion Nebula that includes a wide binary. HST ACS observations of the proplyd 124-132 show two pointlike sources separated by 0.15'', or about 60 AU at the distance of Orion. The two sources have nearly identical I and z magnitudes. We analyze the brightest component, source N, comparing the observed mag…
The Radio Signature of Magnetic Reconnection for the M-Class Flare of 2004 November 1
Ji, Haisheng; Huang, Guangli; Wu, Guiping
In this Letter, we present radio diagnostics for the magnetic field and the density distribution of nonthermal electrons in the microwave source of the M1.1 flare of 2004 November 1. We calculate the nonthermal gyrosynchrotron radiation using observations made at the Nobeyama Radio Observatory to get the longitudinal magnetic field and the magnitu…
On the Formation of Perseus OB1 at High Galactic Latitudes
Lim, Jeremy; Lee, Hsu-Tai
The Per OB1 association, which contains the remarkable double cluster h and χ Per, is unusual in not having a giant molecular cloud in its vicinity. We show from Hipparcos data that the luminous members of this association exhibit a bulk motion away from the Galactic plane, such that their average velocity increases with height above the Galactic …
Comparison of High-Resolution TRACE Data to Spectroscopic CDS Data for Temperature Determination
Walsh, R. W.; Noglik, J. B.; Cirtain, J.
In this paper we aim to measure the temperature along a specific coronal loop feature which is located in an active region on the western solar limb. The data are taken from Joint Observing Program 146 and consist of high-cadence TRACE triple-filter images coinciding with sparse raster Coronal Diagnostic Spectrometer (CDS) spectroscopic data. The …
HST NICMOS Observations of Fast Infrared Flickering in the Microquasar GRS 1915+105
Patel, Shannon G.; Remillard, Ronald; Pooley, Guy G. +3 more
We report infrared observations of the microquasar GRS 1915+105 using the NICMOS instrument of the Hubble Space Telescope during nine visits in 2003 April-June. During epochs of high X-ray/radio activity near the beginning and end of this period, we find that the 1.87 µm infrared flux is generally low (~2 mJy) and relatively steady. However,…