Search Publications

Understanding the 8 µm versus Paα Relationship on Subarcsecond Scales in Luminous Infrared Galaxies
DOI: 10.1086/588276 Bibcode: 2008ApJ...685..211D

Colina, Luis; Alonso-Herrero, Almudena; Díaz-Santos, Tanio +3 more

This work explores in detail the relation between the 8 µm and the Paα emissions for 122 H II regions identified in a sample of 10 low-z LIRGs with nearly constant metallicity [12 + log (O/H) ~ 8.8]. We use Gemini T-ReCS high spatial resolution (lesssim0.4''~120 pc for the average distance of 60 Mpc of our sample) mid-infrared imaging (at 8.…

2008 The Astrophysical Journal
eHST 62
Solar Magnetic Tracking. II. The Apparent Unipolar Origin of Quiet-Sun Flux
DOI: 10.1086/524372 Bibcode: 2008ApJ...674..520L

Lamb, D. A.; DeForest, C. E.; Hagenaar, H. J. +2 more

We investigate the origin of small-scale flux concentrations in the quiet Sun. In apparent violation of the physical requirement for flux balance, 94% of the features containing newly detected flux are unipolar at a resolution of 1.2''. We analyze 2619 of these apparent unipolar emergences in an image sequence from the SOHO MDI magnetograph and co…

2008 The Astrophysical Journal
SOHO 62
Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006-2007 outburst
DOI: 10.1051/0004-6361:20079044 Bibcode: 2008A&A...480..339R

Lee, C. -U.; Lähteenmäki, A.; Umana, G. +58 more

Context: The blazar AO 0235+164 was claimed to show a quasi-periodic behaviour in the radio and optical bands in the past, with the main outbursts repeating every 5-6 years. However, the predicted 2004 outburst did not occur, and further analysis suggested a longer time scale, according to which the next event would have occurre…

2008 Astronomy and Astrophysics
eHST 62
First high-energy observations of narrow-line Seyfert 1s with INTEGRAL/IBIS
DOI: 10.1111/j.1365-2966.2008.13657.x Bibcode: 2008MNRAS.389.1360M

de Rosa, A.; Masetti, N.; Bird, A. J. +8 more

Narrow-line Seyfert 1 (NLS1) galaxies are very interesting objects which display peculiar properties when compared to their broad-line analogues (BLS1). Although well studied in many wavebands, their behaviour at >10 keV is poorly studied and yet important to discriminate between models invoked to explain the complexity observed in the X-ray ba…

2008 Monthly Notices of the Royal Astronomical Society
INTEGRAL 62
Dune-forming winds on Titan and the influence of topography
DOI: 10.1016/j.icarus.2007.10.007 Bibcode: 2008Icar..194..243T

Tokano, Tetsuya

Numerous extended dunes on Saturn's moon Titan detected by the Cassini RADAR constrain the long-term pattern of surface winds. We analyse the statistics of surface wind speed and direction and their spatial and temporal variability predicted by a general circulation model (GCM) in order to constrain surface wind predictions of this GCM by dune obs…

2008 Icarus
Cassini 62
An 84-µG magnetic field in a galaxy at redshift z = 0.692
DOI: 10.1038/nature07264 Bibcode: 2008Natur.455..638W

Jorgenson, Regina A.; Heiles, Carl; Wolfe, Arthur M. +2 more

The magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of stars. The field associated with ionized interstellar gas has been determined through observations of pulsars in our Galaxy. Radio-frequency measuremen…

2008 Nature
eHST 62
Automatic Detection and Classification of Coronal Holes and Filaments Based on EUV and Magnetogram Observations of the Solar Disk
DOI: 10.1007/s11207-007-9075-6 Bibcode: 2008SoPh..248..425S

Habbal, Shadia Rifai; Scholl, Isabelle F.

A new method for the automated detection of coronal holes and filaments on the solar disk is presented. The starting point is coronal images taken by the Extreme Ultraviolet Telescope on the Solar and Heliospheric Observatory (SOHO/EIT) in the Fe IX/X 171 Å, Fe XII 195 Å, and He II 304 Å extreme ultraviolet (EUV) lines and the corresponding full-d…

2008 Solar Physics
SOHO 62
GMASS ultradeep spectroscopy of galaxies at z ~ 2 . I. The stellar metallicity
DOI: 10.1051/0004-6361:20078673 Bibcode: 2008A&A...479..417H

Berta, S.; Cimatti, A.; Daddi, E. +12 more

Context: Galaxy metallicities have been measured to redshift z∼2 by gas-phase oxygen abundances of the interstellar medium using the R{23} and N2 methods. Galaxy stellar metallicities provide crucial data for chemical evolution models but have not been assessed reliably much outside the local Universe.
Aims: We determine the iron-abundance, st…

2008 Astronomy and Astrophysics
eHST 62
A Test of Three Optical Flow Techniques—LCT, DAVE, and NAVE
DOI: 10.1086/592761 Bibcode: 2008ApJ...689..593C

Chae, Jongchul; Sakurai, Takashi

A time sequence of high-quality images currently produced by high-resolution observations either from the ground or in space may be utilized to determine the transverse flow field on the plane of the sky with the help of optical flow techniques. We have examined the performance of three different methods—a well-known technique called local correla…

2008 The Astrophysical Journal
Hinode 62
Observational Test of Coronal Magnetic Field Models. I. Comparison with Potential Field Model
DOI: 10.1086/588645 Bibcode: 2008ApJ...680.1496L

Liu, Yu; Lin, Haosheng

Recent advances have made it possible to obtain two-dimensional line-of-sight magnetic field maps of the solar corona from spectropolarimetric observations of the Fe XIII 1075 nm forbidden coronal emission line. Together with the linear polarization measurements that map the azimuthal direction of the coronal magnetic field projected in the plane …

2008 The Astrophysical Journal
SOHO 62