Search Publications
EF Chamaeleontis: Warm Dust Orbiting a Nearby 10 Myr Old Star
Zuckerman, B.; Song, Inseok; Rhee, Joseph H.
Most Vega-like stars have far-infrared excess (60 µm or longward in IRAS, ISO, or Spitzer MIPS bands) and contain cold dust (<~150 K) analogous to the Sun's Kuiper Belt region. However, dust in a region more akin to our asteroid belt and thus relevant to the terrestrial planet building process is warm and produces excess emission in mid-i…
Detection of CO Hot Spots Associated with Young Clusters in the Southern Starburst Galaxy NGC 1365
Ho, Paul T. P.; Mao, Rui-Qing; Matsushita, Satoki +2 more
We have used the Submillimeter Array for the first interferometric CO imaging toward the starburst-Seyfert nucleus of the southern barred spiral galaxy NGC 1365, which is one of the four galaxies within 30 Mpc that have L8-1000µm>=1011 Lsolar. Our mosaic maps of 12CO, 13CO, and C…
A Check for Consistency between Different Magnetic Helicity Measurements Based on the Helicity Conservation Principle
Moon, Yong-Jae; Chae, Jongchul; Lim, Eun-Kyung +1 more
Magnetic helicity is a useful quantity in characterizing the magnetic systems of solar active regions. The purpose of the present work is to check for consistency between the local correlation tracking (LCT) method used to measure helicity injection through the photosphere, and the linear force-free field (LFFF) method used to determine helicity i…
Clustered Star Formation in the Small Magellanic Cloud. A Spitzer/IRAC View of the Star-Forming Region NGC 602/N 90
Henning, Thomas; Gouliermis, Dimitrios A.; Quanz, Sascha P.
We present Spitzer/IRAC photometry on the star-forming H II region N 90, related to the young stellar association NGC 602 in the Small Magellanic Cloud. Our photometry revealed bright mid-infrared sources, which we classify with the use of a scheme based on templates and models of red sources in the Milky Way, and criteria recently developed from …
Gemini Spectroscopic Survey of Young Star Clusters in Merging/Interacting Galaxies. I. NGC 3256 Tidal Tail Clusters
Schweizer, François; Miller, Bryan W.; Trancho, Gelys +1 more
We present Gemini optical spectroscopy of three young star clusters in the western tidal tail of NGC 3256. Compact star clusters (as opposed to dwarf galaxy candidates) in tidal tails are rare, and these three clusters are the first for which detailed quantitative spectroscopy has ever been obtained. We find that two of these clusters appear to be…
Radius-dependent Luminosity Evolution of Blue Galaxies in GOODS-N
Faber, S. M.; Koo, D. C.; Melbourne, J. +3 more
We examine the radius-luminosity (R-L) relation for blue galaxies in the Team Keck Redshift Survey (TKRS) of GOODS-N. We compare with a volume-limited, Sloan Digital Sky Survey sample and find that the R-L relation has evolved to lower surface brightness since z=1. Based on the detection limits of GOODS, this cannot be explained by incompleteness …
Lost and Found: A New Position and Infrared Counterpart for the X-Ray Binary Scutum X-1
Erb, Dawn K.; Chakrabarty, Deepto; Moon, Dae-Sik +5 more
Using archival X-ray data, we find that the catalog location of the X-ray binary Scutum X-1 (Sct X-1) is incorrect and that the correct location is that of the X-ray source AX J183528-0737, which is 15' to the west. Our identification is made on the basis of the 112 s pulse period for this object detected in an XMM-Newton observation, as well as s…
Emission Line Variability of the Accreting Young Brown Dwarf 2MASSW J1207334-393254: From Hours to Years
Stelzer, Beate; Jayawardhana, Ray; Scholz, Alexander
We have obtained a series of high-resolution optical spectra for 2MASSW J1207334-393254 (2M 1207). Two consecutive observing nights at the ESO Very Large Telescope with the Ultraviolet and Visual Echelle Spectrograph yielded a time series with a resolution of ~12 minutes. Additional high-resolution optical spectra were obtained months apart at the…
Lyα Absorption from Heliosheath Neutrals
Wood, Brian E.; Linsky, Jeffrey L.; Izmodenov, Vladislav V. +1 more
We assess the information that HST observations of stellar Lyα lines can provide on the heliosheath, the region of the heliosphere between the termination shock and heliopause. To search for evidence of heliosheath absorption, we conduct a systematic inspection of stellar Lyα lines reconstructed after correcting for ISM absorption (and heliospheri…
Ultracompact Dwarf Candidates in the Hydra Cluster
Harris, William E.; Wehner, Elizabeth M. H.
NGC 3311, the giant cD galaxy in the Hydra Cluster (A1060), has one of the largest globular cluster systems known. We describe new Gemini GMOS (g', i') photometry of the NGC 3311 field which reveals that the red, metal-rich side of its globular cluster population extends smoothly upward into the mass range associated with the…