Search Publications
Cold Water Vapor in the Barnard 5 Molecular Cloud
Persson, C. M.; Charnley, S. B.; Takakuwa, S. +3 more
After more than 30 yr of investigations, the nature of gas-grain interactions at low temperatures remains an unresolved issue in astrochemistry. Water ice is the dominant ice found in cold molecular clouds; however, there is only one region where cold (~10 K) water vapor has been detected—L1544. This study aims to shed light on ice desorption mech…
Selection and Mid-infrared Spectroscopy of Ultraluminous Star-forming Galaxies at z ~ 2
Fang, Guanwen; Kong, Xu; Willner, S. P. +4 more
Starting from a sample of 24 µm sources in the Extended Groth Strip, we use 3.6-8 µm color criteria to select ultraluminous infrared galaxies (ULIRGs) at z ~ 2. Spectroscopy from 20-38 µm of 14 objects verifies their nature and gives their redshifts. Multi-wavelength data for these objects imply stellar masses >1011…
Identification Campaign of Supernova Remnant Candidates in the Milky Way. II. X-Ray Studies of G38.7-1.4
Kong, A. K. H.; Hui, C. Y.; Wu, J. H. K. +3 more
We report on XMM-Newton and Chandra observations of the Galactic supernova remnant candidate G38.7-1.4, together with complementary radio, infrared, and γ-ray data. An approximately elliptical X-ray structure is found to be well correlated with a radio shell as seen by the Very Large Array. The X-ray spectrum of G38.7-1.4 can be well described by …
The Impact of a Filament Eruption on Nearby High-lying Cool Loops
Long, D. M.; De Pontieu, B.; Doschek, G. A. +2 more
The first spectroscopic observations of cool Mg II loops above the solar limb observed by NASA's Interface Region Imaging Spectrograph (IRIS) are presented. During the observation period, IRIS is pointed off-limb, allowing the observation of high-lying loops, which reach over 70 Mm in height. Low-lying cool loops were observed by the IRIS slit-jaw…
Searching for Debris Disks around Seven Radio Pulsars
Kaplan, David L.; Li, Aigen; Wang, Zhongxiang +2 more
We report on our searches for debris disks around seven relatively nearby radio pulsars, which are isolated sources that were carefully selected as targets on the basis of our deep Ks -band imaging survey. The Ks images obtained with the 6.5 m Baade Magellan Telescope at Las Campanas Observatory are analyzed together with the…
3C 220.3: A Radio Galaxy Lensing a Submillimeter Galaxy
Wilkes, Belinda J.; Clements, David L.; Lagattuta, David J. +17 more
Herschel Space Observatory photometry and extensive multiwavelength follow-up have revealed that the powerful radio galaxy (PRG) 3C 220.3 at z = 0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z = 2.221. At an observed wavelength of 1 mm, the SMG is lensed into three distinct images. In the observed near infrared,…
Understanding the Nature of the Blazar CGRaBS J0211+1051
Ganesh, S.; Foschini, L.; Chandra, Sunil +1 more
The source CGRaBS J0211+1051 (MG1 J021114+1051, z = 0.20) flared up on 2011 January 23 in high-energy γ-rays as reported by the Large Area Telescope (LAT) on board Fermi. This event was followed by increased activity at the UV, optical, and radio frequencies as detected by the observing facilities worldwide. The source also showed a high and varia…
AKARI Observations of Brown Dwarfs. IV. Effect of Elemental Abundances on Near-infrared Spectra between 1.0 and 5.0 µm
Yamamura, I.; Sorahana, S.
The detection of the CO2 absorption band at 4.2 µm in brown dwarf spectra by AKARI has made it possible to discuss CO2 molecular abundance in brown dwarf atmospheres. In our previous studies, we found an excess in the 4.2 µm CO2 absorption band of three brown dwarf spectra, and suggested that these devi…
Intensity Enhancement of O VI Ultraviolet Emission Lines in Solar Spectra due to Opacity
Doyle, J. G.; Madjarska, M. S.; Mathioudakis, M. +5 more
Opacity is a property of many plasmas. It is normally expected that if an emission line in a plasma becomes optically thick, then its intensity ratio to that of another transition that remains optically thin should decrease. However, radiative transfer calculations undertaken both by ourselves and others predict that under certain conditions the i…
Spatial Nonlocality of the Small-scale Solar Dynamo
Lamb, D. A.; DeForest, C. E.; Howard, T. A.
We explore the nature of the small-scale solar dynamo by tracking magnetic features. We investigate two previously explored categories of the small-scale solar dynamo: shallow and deep. Recent modeling work on the shallow dynamo has produced a number of scenarios for how a strong network concentration can influence the formation and polarity of ne…