Search Publications
A Pilot Search for Population III Supernova Candidates in the Spitzer/IRAC Dark Field
Krick, Jessica; Surace, Jason; Moustakas, Leonidas A. +1 more
We have undertaken a systematic search for candidate supernovae from high-redshift Population III stars in a field that has been observed with repeated imaging on a cadence of 2-3 weeks over a 2.2 year baseline, the Spitzer/IRAC Dark Field. The individual epochs reach a typical 5σ depth of 1 µJy in IRAC Channel 1 (3.6 µm). Requiring a …
Tidal Stripping of Globular Clusters in the Virgo Cluster
Coenda, Valeria; Muriel, Hernán; Donzelli, Carlos
With the aim of finding evidence of tidal stripping of globular clusters (GCs) we analyzed a sample of 13 elliptical galaxies taken from the ACS Virgo Cluster Survey (VCS). These galaxies belong to the main concentration of the Virgo Cluster (VC) and present absolute magnitudes -18.5 < Mz < -22.5. We used the public GC catalog of …
The Flux of Open and Toroidal Interplanetary Magnetic Field as a Function of Heliolatitude and Solar Cycle
Schwadron, Nathan A.; Smith, Charles W.; Connick, David E.
We examine 45 years of near-Earth interplanetary observations as recorded in the National Space Science Data Center OMNI data set and 18 years of observations by the Ulysses spacecraft. We find that recent claims for a 50+ year low in interplanetary magnetic field intensity are substantiated, that the low flux levels can be attributed to open magn…
On the Anticorrelation Between Galaxy Light Concentration and X-ray-to-Optical Flux Ratio
Cepa, J.; Bongiovanni, A.; Pérez García, A. M. +6 more
Active galactic nuclei (AGNs) play an important role in many aspects of modern cosmology, and of particular interest is the issue of the interplay between AGNs and their host galaxy. Using X-ray and optical data sets, we have explored the properties of a large sample of AGNs in the Subaru/XMM-Newton Deep Survey field, and studied their evolution i…
A Galaxy Merger Scenario for the NGC 1550 Galaxy from Metal Distributions in the X-Ray Emitting Plasma
Fukazawa, Yasushi; Makishima, Kazuo; Nakazawa, Kazuhiro +4 more
The elliptical galaxy NGC 1550 at a redshift of z = 0.01239, identified with an extended X-ray source RX J0419+0225, was observed with XMM-Newton for 31 ks. From the X-ray data and archival near-IR data of Two Micron All Sky survey, we derive the profiles of components constituting the NGC 1550 system: the gas mass, total mass, metal mass, and gal…
The QSO HE 0450-2958: Scantily Dressed or Heavily Robed? A Normal Quasar as Part of an Unusual ULIRG
Wisotzki, Lutz; Pantin, Eric; Lagage, Pierre-Olivier +5 more
The luminous z = 0.286 quasar HE 0450-2958 is interacting with a companion galaxy at 6.5 kpc distance and the whole system radiates in the infrared (IR) at the level of an ultraluminous infrared galaxy (ULIRG). A so far undetected host galaxy triggered the hypothesis of a mostly "naked" black hole (BH) ejected from the companion by three-body inte…
Short-Term Variability and Power Spectral Density Analysis of the Radio-Loud Active Galactic Nucleus 3C 390.3
Eracleous, Michael; Reeves, James N.; Gliozzi, Mario +4 more
We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray…
Mass Composition in Pre-eruption Quiet Sun Filaments
Alexander, David; Kilper, Gary; Gilbert, Holly
Filament eruptions are extremely important phenomena due to their association with coronal mass ejections and their effects on space weather. Little is known about the filament mass and composition in the eruption process, since most of the related research has concentrated on the evolution and disruption of the magnetic field. Following up on our…
Observational Evidence for Coronal Twisted Flux Rope
Raouafi, N. -E.
Multi-instrument data sets of NOAA AR10938 on 2007 January 16 (e.g., Hinode, STEREO, GOES, MLSO, and ISOON Hα) are utilized to study the fine structure and evolution of a magnetic loop system exhibiting multiple crossing threads, whose arrangement and individual shapes are very suggestive of individual field lines in a flux rope. The footpoints of…
A Measurement of the Adiabatic Cooling Index for Interstellar Helium Pickup Ions in the Inner Heliosphere
Wurz, Peter; Kallenbach, Reinald; Saul, Lukas
Interstellar neutral gas enters the inner heliosphere where it is ionized and becomes the pickup ion population of the solar wind. It is often assumed that this population will subsequently cool adiabatically, like an expanding ideal gas due, to the divergent flow of the solar wind. Here, we report the first independent measure of the effective ad…