Search Publications
Imaging the Environment of a z = 6.3 Submillimeter Galaxy with SCUBA-2
Pérez-Fournon, I.; Ivison, R. J.; Omont, A. +24 more
We describe a search for submillimeter emission in the vicinity of one of the most distant, luminous galaxies known, HerMES FLS3, at z = 6.34, exploiting it as a signpost to a potentially biased region of the early universe, as might be expected in hierarchical structure formation models. Imaging to the confusion limit with the innovative, wide-fi…
A Tale of a Rich Cluster at z ~ 0.8 as Seen by the Star Formation Histories of its Early-type Galaxies
Vazdekis, Alexandre; Sánchez-Blázquez, Patricia; Ferré-Mateu, Anna +1 more
We present a detailed stellar population analysis for a sample of 24 early-type galaxies (ETGs) belonging to the rich cluster RX J0152.7-1357 at z = 0.83. We have derived the age, metallicity, abundance pattern, and star formation history (SFH) for each galaxy individually to further characterize this intermediate-z reference cluster. We then stud…
INTEGRAL SPI Observations of Cygnus X-1 in the Soft State: What about the Jet Contribution in Hard X-Rays?
Jourdain, E.; Roques, J. P.; Chauvin, M.
During the first 7 yr of the INTEGRAL mission (2003-2009), Cyg X-1 has essentially been detected in its hard state (HS), with some incursions in intermediate HSs. This long, spectrally stable period allowed in particular the measurement of the polarization of the high-energy component that has long been observed above 200 keV in this peculiar obje…
Scaling Relations and X-Ray Properties of Moderate-luminosity Galaxy Clusters from 0.3 < z < 0.6 with XMM-Newton
Donahue, Megan; Conselice, Christopher J.; Hoekstra, Henk +4 more
We present new X-ray temperatures and improved X-ray luminosity estimates for 15 new and archival XMM-Newton observations of galaxy clusters at intermediate redshift with mass and luminosities near the galaxy group/cluster division ({M}2500 < 2.4 × 1014 h70-1 {M}_⊙, L < 2 × 1044 erg s
Steadily Increasing Star Formation Rates in Galaxies Observed at 3 <~ z <~ 5 in the CANDELS/GOODS-S Field
Ferguson, Henry C.; Giavalisco, Mauro; Somerville, Rachel S. +3 more
We investigate the star formation histories (SFHs) of high redshift (3 <~ z <~ 5) star-forming galaxies selected based on their rest-frame ultraviolet (UV) colors in the CANDELS/GOODS-S field. By comparing the results from the spectral-energy-distribution-fitting analysis with two different assumptions about the SFHs—i.e., exponentially decl…
Fifty M31 Black Hole Candidates Identified by Chandra and XMM-Newton
Murray, S. S.; Garcia, M. R.; Barnard, R. +1 more
Over approximately the last five years, we have identified ~35 black hole candidates (BHCs) in M31 from their X-ray spectra. Our BHCs exhibited 0.3-10 keV spectra consistent with the X-ray binary (XB) hard state at luminosities that are above the upper limit for neutron star (NS) XBs. When our BHC spectra were modeled with a disk blackbody + black…
Oblique Alfvén Instabilities Driven by Compensated Currents
De Keyser, J.; Malovichko, P.; Voitenko, Y.
Compensated-current systems created by energetic ion beams are widespread in space and astrophysical plasmas. The well-known examples are foreshock regions in the solar wind and around supernova remnants. We found a new oblique Alfvénic instability driven by compensated currents flowing along the background magnetic field. Because of the vastly di…
Heating and Dynamics of Two Flare Loop Systems Observed by AIA and EIS
Ding, M. D.; Li, Y.; Qiu, J.
We investigate heating and evolution of flare loops in a C4.7 two-ribbon flare on 2011 February 13. From Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) imaging observations, we can identify two sets of loops. Hinode/EUV Imaging Spectrometer (EIS) spectroscopic observations reveal blueshifts at the feet of both sets of loops. The evo…
An Upper Bound from Helioseismology on the Stochastic Background of Gravitational Waves
Roth, Markus; Siegel, Daniel M.
The universe is expected to be permeated by a stochastic background of gravitational radiation of astrophysical and cosmological origin. This background is capable of exciting oscillations in solar-like stars. Here we show that solar-like oscillators can be employed as giant hydrodynamical detectors for such a background in the µHz to mHz fr…
Spectral Analysis in Orbital/Superorbital Phase Space and Hints of Superorbital Variability in the Hard X-Rays of LS I +61°303
Torres, Diego F.; Li, Jian; Zhang, Shu
We present an INTEGRAL spectral analysis in the orbital/superorbital phase space of LS I +61°303. A hard X-ray spectrum with no cutoff is observed at all orbital/superorbital phases. The hard X-ray index is found to be uncorrelated with the radio index (non-simultaneously) measured at the same orbital and superorbital phases. In particular, the ab…