Search Publications
The Evolutionary History of Galactic Bulges: Photometric and Spectroscopic Studies of Distant Spheroids in the GOODS Fields
Treu, Tommaso; Ellis, Richard S.; MacArthur, Lauren A. +3 more
We report on the first results of a new study aimed at understanding the diversity and evolutionary history of distant galactic bulges in the context of now well-established trends for pure spheroidal galaxies. To this end, bulges have been isolated for a sample of 137 spiral galaxies within the redshift range 0.1 < z < 1.2 in the GOODS fiel…
A 1.3 cm wavelength radio flare from a deeply embedded source in the Orion BN/KL region
Menten, K. M.; Reid, M. J.; Forbrich, J.
Aims:Our aim was to measure and characterize the short-wavelength radio emission from young stellar objects (YSOs) in the Orion Nebula Cluster and the BN/KL star-forming region.
Methods: We used the NRAO Very Large Array at a wavelength of λ=1.3 cm and we studied archival X-ray, infrared, and radio data.
Results: During our observation, a …
Wide-Band Spectroscopy of the Compton Thick Seyfert2 Galaxy Markarian 3 with Suzaku
Isobe, Naoki; Kunieda, Hideyo; Okajima, Takashi +15 more
We obtained a wide-band spectrum of the Compton-thick Seyfert2 galaxy Mkn3 with Suzaku. The observed spectrum was clearly resolved into weak, soft power-law emission, a heavily absorbed power-law component, cold reflection, and many emission lines. The heavily absorbed component, absorbed by gas with a column density of 1.1 × 1024 cm
Observations of molecular oxygen ions in Saturn's inner magnetosphere
Johnson, Robert E.; Smith, H. Todd; Martens, Hilary R. +2 more
We present an analysis of molecular oxygen ion (O2 +) abundance in Saturn's inner magnetosphere based on observations made with the Cassini Plasma Spectrometer (CAPS). Using data summed over 23 orbits, we resolve and isolate O2 + counts from the tail of the water group ion mass distribution (W+
Observed tail current systems associated with bursty bulk flows and auroral streamers during a period of multiple substorms
Dandouras, I.; Lucek, E.; Fazakerley, A. N. +10 more
We present a multi-instrument study of a substorm bursty bulk flow (BBF) and auroral streamer. During a substorm on 25 August 2003, which was one of a series of substorms that occurred between 00:00 and 05:00 UT, the Cluster spacecraft encountered a BBF event travelling Earthwards and duskwards with a velocity of ~500 km s-1 some nine m…
The X-ray luminosity of solar-mass stars in the intermediate age open cluster NGC 752
Micela, G.; Favata, F.; Giardino, G. +1 more
Aims: While observational evidence shows that most of the decline in a star's X-ray activity occurs between the age of the Hyades (~ 8 × 108 yr) and that of the Sun, very little is known about the evolution of stellar activity between these ages. To gain information on the typical level of coronal activity at a star's intermediate age, …
Emerging Active Regions Studied with Ring-Diagram Analysis
Howe, R.; Komm, R.; Hill, F. +1 more
We study the temporal variation of subsurface flows associated with emerging active regions, focusing on four regions in detail. Two of them, AR 10314 and AR 10488, emerge near disk center and the other two, AR 10365 and AR 10375, are older regions where new flux emerges during their disk passage. We measure the horizontal subsurface flows from hi…
Triggered or Self-Regulated Star Formation within Intermediate Redshift Luminous Infrared Galaxies. I. Morphologies and Spectral Energy Distributions
Koo, D. C.; Larkin, J. E.; Wright, S. A. +6 more
As part of the Center for Adaptive Optics (AO) Treasury Survey (CATS) we imaged a set of 15 intermediate redshift (z ~ 0.8) luminous infrared (IR) galaxies (LIRGs) with the Keck Laser Guide Star (LGS) AO facility. These galaxies were selected from the Great Observatories Origins Deep Survey (GOODS) southern field, allowing us to combine the high s…
Chandra X-Ray Observatory Observations of the Globular Cluster M71
Ransom, Scott M.; Weisskopf, Martin C.; Bogdanov, Slavko +12 more
We observe the nearby, low-density globular cluster M71 (NGC 6838) with the Chandra X-Ray Observatory to study its faint X-ray populations. Five X-ray sources are found inside the cluster core radius, including the known eclipsing binary millisecond pulsar (MSP) PSR J1953+1846A. The X-ray light curve of the source coincident with this MSP shows ma…
Magnetic clouds seen at different locations in the heliosphere
Zhukov, A. N.; Rodriguez, L.; Mandrini, C. H. +9 more
We analyze two magnetic clouds (MCs) observed in different points of the heliosphere. The main aim of the present study is to provide a link between the different aspects of this phenomenon, starting with information on the origins of the MCs at the Sun and following by the analysis of in-situ observations at 1 AU and at Ulysses. The candidate sou…