Search Publications
Automated supervised classification of variable stars in the CoRoT programme. Method and application to the first four exoplanet fields
Auvergne, M.; Deleuil, M.; Jorda, L. +27 more
Context:
Aims: In this work, we describe the pipeline for the fast supervised classification of light curves observed by the CoRoT exoplanet CCDs. We present the classification results obtained for the first four measured fields, which represent a one-year in-orbit operation.
Methods: The basis of the adopted supervised classification meth…
Heliospheric Asymmetries and 2-3 kHz Radio Emission Under Strong Interstellar Magnetic Field Conditions
Zank, Gary P.; Cairns, Iver H.; Pogorelov, Nikolai V. +2 more
We discuss the asymmetry of the major heliospheric discontinuities obtained from the analysis of three-dimensional modeling of the solar wind interaction with the local interstellar medium (LISM). The flow of charged particles is governed by the ideal MHD equations and the transport of neutral particles is described by the Boltzmann equation. The …
The XMM Cluster Survey: Galaxy Morphologies and the Color-Magnitude Relation in XMMXCS J2215.9 - 1738 at z = 1.46
Hilton, Matt; Stott, John P.; West, Michael J. +22 more
We present a study of the morphological fractions and color-magnitude relation (CMR) in the most distant X-ray selected galaxy cluster currently known, XMMXCS J2215.9 - 1738 at z = 1.46, using a combination of optical imaging data obtained with the Hubble Space Telescope Advanced Camera for Surveys, and infrared data from the Multi-Object Infrared…
Turbulent Magnetic Fields in the Quiet Sun: Implications of Hinode Observations and Small-Scale Dynamo Simulations
Danilovic, Sanja; Pietarila Graham, Jonathan; Schüssler, Manfred
Using turbulent MHD simulations (magnetic Reynolds numbers up to ≈8000) and Hinode observations, we study effects of turbulence on measuring the solar magnetic field outside active regions. First, from synthetic Stokes V profiles for the Fe I lines at 6301 and 6302 Å, we show that a peaked probability distribution function (PDF) for observationall…
A New Distance to M33 Using Blue Supergiants and the FGLR Method
Bresolin, Fabio; Kudritzki, Rolf-Peter; Urbaneja, Miguel A. +3 more
The quantitative spectral analysis of medium resolution optical spectra of A and B supergiants obtained with DEIMOS and ESI at the Keck Telescopes is used to determine a distance modulus of 24.93 ± 0.11 mag (968 ± 50 kpc) for the Triangulum Galaxy M33. The analysis yields stellar effective temperatures, gravities, interstellar reddening, and extin…
What is the Relationship Between Photospheric Flow Fields and Solar Flares?
Welsch, Brian T.; Schuck, Peter W.; Li, Yan +1 more
We estimated photospheric velocities by separately applying the Fourier Local Correlation Tracking and Differential Affine Velocity Estimator methods to 2708 co-registered pairs of SOHO/MDI magnetograms, with nominal 96 minute cadence and ~2'' pixels, from 46 active regions (ARs) from 1996 to 1998 over the time interval τ45 when each AR…
Emergence of a Broad Absorption Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007
Hamann, Fred; Leighly, Karen M.; Grupe, Dirk +1 more
We report results from a 2003 Far Ultraviolet Spectroscopic Explorer (FUSE) observation and reanalysis of a 1996 Hubble Space Telescope (HST) observation of the unusual X-ray transient Narrow-line Seyfert 1 galaxy WPVS 007. The HST Faint Object Spectrograph (FOS) spectrum revealed mini-BALs (broad absorption lines) with V max ~ 900 km s…
Speckle Suppression Through Dual Imaging Polarimetry, and a Ground-based Image of the HR 4796A Circumstellar Disk
Hinkley, Sasha; Perrin, Marshall D.; Graham, James R. +7 more
We demonstrate the versatility of a dual imaging polarimeter working in tandem with a Lyot coronagraph and adaptive optics to suppress the highly static speckle noise pattern—the greatest hindrance to ground-based direct imaging of planets and disks around nearby stars. Using a double difference technique with the polarimetric data, we quantify th…
Quantifying the fast outflow in the luminous Seyfert galaxy PG1211+143
Reeves, J. N.; Pounds, K. A.
We report two new XMM-Newton observations of PG1211+143 in 2007 December, again finding evidence for the fast outflow of highly ionized gas first detected in 2001. Stacking the new spectra with those from two earlier XMM-Newton observations reveals strong and broad emission lines of FeXXV and OVIII, indicating the fast outflow to be persistent and…
Evidence of photospheric vortex flows at supergranular junctions observed by FG/SOT (Hinode)
Innes, D. E.; Potts, H. E.; Attie, R.
Context: Twisting motions of different sorts are observed in several layers of the solar atmosphere. Chromospheric sunspot whorls and rotation of sunspots or even higher up in the lower corona sigmoids are examples of the large-scale twisted topology of many solar features. Nevertheless, their occurrence on a large scale in the quiet photosphere h…